Design of Floating Production Storage Offloading Vessel for the Gulf of Mexico

OCEN 407 Design of Ocean Engineering Facilities

Team Members:

Chris Chipuk McAlan Clark

Caroline Hoffman James Peavy Ramez Sabet Baron Wilson

Ocean Engineering Program Civil Engineering Department

Texas A&M University College Station, Texas 77843-3136

June 19, 2003

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Table of Contents ABSTRACT ................................................................................................................................................ VI EXECUTIVE SUMMARY ...................................................................................................................... VII ACKNOWLEDGEMENT ...................................................................................................................... XIV INTRODUCTION ................................................................................................................................... XIV FIELD TRIP ............................................................................................................................................ XIV SITE............................................................................................................................................................... 1 WIND, WAVE AND CURRENT LOADING ............................................................................................ 1 CODES AND REGULATIONS .................................................................................................................. 4

FACILITY LAYOUT....................................................................................................................................... 4 VESSEL CONDITIONS................................................................................................................................... 4 STABILITY ................................................................................................................................................... 4 LIFESAVING REQUIREMENTS....................................................................................................................... 4 FIRE FIGHTING SYSTEMS............................................................................................................................. 5

GENERAL ARRANGEMENTS AND OVERALL HULL/SYSTEM DESIGN..................................... 5 CREW QUARTERS ........................................................................................................................................ 5 DECK PRODUCTION SYSTEMS ..................................................................................................................... 5 LIFEBOATS .................................................................................................................................................. 6 OIL TANKS .................................................................................................................................................. 6 BALLAST TANKS ......................................................................................................................................... 7 OTHER BELOW DECK COMPONENTS ........................................................................................................... 7 CRANES....................................................................................................................................................... 8 HULL........................................................................................................................................................... 8

WEIGHT, BUOYANCY AND STABILITY.............................................................................................. 9 STABCAD................................................................................................................................................. 10

Design Process ..................................................................................................................................... 10 RESULTS.................................................................................................................................................... 11

Intact and Damage Stability Results for Calculated KG...................................................................... 12 ABS MODU Intact and Damage Stability Results based on Allowable KG ......................................... 13

HYDRODYNAMICS OF MOTIONS AND LOADING......................................................................... 15 MOORING/STATION KEEPING ........................................................................................................... 17

TURRET DESIGN ........................................................................................................................................ 17 MOORING ANALYSIS ................................................................................................................................. 21

Synthetic Mooring Lines....................................................................................................................... 22 Rules and Regulations .......................................................................................................................... 22 Catenary, Taut, and Semi-taut Mooring............................................................................................... 23

MIMOSA.................................................................................................................................................. 23 Design Process ..................................................................................................................................... 23 Catenary System ................................................................................................................................... 24

MOORING RESULTS................................................................................................................................... 24 8 Line Polyester-Chain......................................................................................................................... 24 12 Line Wire-Chain .............................................................................................................................. 25 16 Line Wire-Chain .............................................................................................................................. 25 Mooring Line Cost Analysis ................................................................................................................. 26 Comparison of Results.......................................................................................................................... 26

MOORING RECOMMENDATION .................................................................................................................. 28 OFFLOADING........................................................................................................................................... 28

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GAS PROCESSING ...................................................................................................................................... 29 WATER INJECTION..................................................................................................................................... 29 WATER PRODUCTION HANDLING AND DISPOSAL...................................................................................... 29 SHUTTLE TANKERS.................................................................................................................................... 30 PUMPS AND HOSES.................................................................................................................................... 30 PUMP LAYOUT .......................................................................................................................................... 30 POWER GENERATOR.................................................................................................................................. 31

COST ESTIMATE ..................................................................................................................................... 31 SUMMARY AND CONCLUSIONS......................................................................................................... 33 REFERENCES ........................................................................................................................................... 34 APPENDIX I: ENVIRONMENTAL LOADS........................................................................................... 1 APPENDIX II: STABILITY AND STABCAD......................................................................................... 5

PRESTAB GRAPHICS INPUT AND BETA FILE SETUP PROCESS FOR STABCAD ANALYSIS ............................. 5 INTACT STABILITY PLOTS FOR CALCULATED KG ....................................................................................... 6 DAMAGED STABILITY PLOTS FOR CALCULATED KG .................................................................................. 8 ABS MODU INTACT STABILITY PLOTS FOR ALLOWABLE KG ................................................................... 9 ABS MODU DAMAGED STABILITY PLOTS FOR ALLOWABLE KG ............................................................ 11 EXAMPLE STABCAD INPUT FILE .............................................................................................................. 12 EXAMPLE STABCAD OUTPUT FILE........................................................................................................... 26

APPENDIX III: MOORING/MIMOSA & COST ANALYSIS............................................................. 35 INPUT PROCEDURE FOR MIMOSA............................................................................................................... 35 MIMOSA MASS, WIND, AND CURRENT COEFFICIENTS INPUT .................................................................... 36 ENVIRONMENTAL DATA MACRO FILE....................................................................................................... 37 VESSEL DYNAMIC WAVE ANALYSIS (G12.SIF) ........................................................................................ 38 EXAMPLE 8 LINE SYNTHETIC INPUT.......................................................................................................... 39 EXAMPLE 16 LINE CHAIN-WIRE-CHAIN INPUT ......................................................................................... 42 EXAMPLE 8 LINE SYNTHETIC OUTPUT ...................................................................................................... 46 EXAMPLE 16 LINE CHAIN-WIRE-CHAIN OUTPUT...................................................................................... 50 COST ANALYSIS ........................................................................................................................................ 56

APPENDIX IV: HYDRODYNAMICS OF MOTION AND LOADING.............................................. 57

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List of Figures Figure 1: Western Gulf of Mexico with Voss Prospect Site.......................................................................... 1 Figure 2: Divided Areas above the Waterline Used for Evaluating the Environmental Loads ..................... 1 Figure 3: Side and Front Views of Crew Quarters (Dimensions in Meters).................................................. 5 Figure 4: Top, Front, and Right side Views of the Production Systems (Dimensions in Meters) ................. 6 Figure 5: Top, Front, and Right Side Views of Oil Tanks (Dimensions in Meters) ...................................... 6 Figure 6: Top, Front, and Right Side Views of Side and Bottom Ballast Tanks (Dimensions in Meters) .... 7 Figure 7: Vessel Ballast Tanks ...................................................................................................................... 7 Figure 8: Beam View of Vessel Showing Turret and Mooring System Connection ..................................... 8 Figure 9: Crane Design (Dimensions in Meters) ........................................................................................... 8 Figure 10: Top, Front, and Right side Views of the FPSO Hull (Dimensions in Meters) ............................. 9 Figure 11: ABS MODU Intact Stability (Bauer 2003) ................................................................................ 10 Figure 12: ABS MODU Damage Stability (Bauer 2003)............................................................................ 11 Figure 13: Displacement Versus Draft ........................................................................................................ 12 Figure 14: Intact Stability (Maximum Oil Capacity w/o Ballast)................................................................ 12 Figure 15: StabCAD Model Showing Damaged Starboard Ballast Tanks .................................................. 13 Figure 16: Damage Stability (Maximum Oil Capacity w/o Ballast) ........................................................... 13 Figure 17: Allowable KG versus Wind Heading for Various Vessel Cargo Conditions............................. 14 Figure 18: ABS MODU Intact Stability (Maximum Oil Capacity w/o Ballast).......................................... 14 Figure 19: Damage Stability (Maximum Oil Capacity w/o Ballast) ........................................................... 15 Figure 20: JONSWAP Spectrum................................................................................................................. 16 Figure 21: Comparison of Heave RAO and JONSWAP Spectrum............................................................. 16 Figure 22: Different Vessel Motions ........................................................................................................... 17 Figure 23: Example of External Turret on the Buffalo Venture FPSO (BHP) ............................................ 18 Figure 24: Example of Internal Turret on the Amoco Liuhua FPSO (BHP) ............................................... 18 Figure 25: Typical Turret and Swivel Stack Layout (SBM Offshore Systems) .......................................... 20 Figure 26: Example of Swivel Stack (RDM Technology, 2001)................................................................. 20 Figure 27: Turret Design (Dimensions in Meters)....................................................................................... 21 Figure 28: Comparison of Offsets ............................................................................................................... 27 Figure 29: Comparison of Tension Factors of Safety.................................................................................. 27 Figure 30: Water Treatment Facility on Board............................................................................................ 29 Figure 31: Two Pumps in Parallel. .............................................................................................................. 31

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List of Appendix Figures

Appendix Figure 1: Intact Stability (Light Ship w/o Ballast).................................................................... A-6 Appendix Figure 2: Intact Stability (Zero Oil with Full Ballast)............................................................... A-6 Appendix Figure 3: Intact Stability (1/3 Oil w/o Ballast).......................................................................... A-7 Appendix Figure 4: Intact Stability (½ Oil w/o Ballast)............................................................................ A-7 Appendix Figure 5: Intact Stability (Maximum Oil Capacity w/o Ballast) ............................................... A-7 Appendix Figure 6: Damaged Stability (1/3 Oil w/o Ballast) ................................................................... A-8 Appendix Figure 7: Damaged Stability (½ Oil w/o Ballast) ..................................................................... A-8 Appendix Figure 8: Damaged Stability (Maximum Oil Capacity w/o Ballast)......................................... A-8 Appendix Figure 9: ABS MODU Intact Stability (Light Ship w/o Ballast) .............................................. A-9 Appendix Figure 10: ABS MODU Intact Stability (Zero Oil with Full Ballast)....................................... A-9 Appendix Figure 11: ABS MODU Intact Stability (1/3 Oil w/o Ballast)................................................ A-10 Appendix Figure 12: ABS MODU Intact Stability (½ Oil w/o Ballast).................................................. A-10 Appendix Figure 13: ABS MODU Intact Stability (Maximum Oil Capacity w/o Ballast) ..................... A-10 Appendix Figure 14: ABS MODU Damaged Stability (1/3 Oil w/o Ballast).......................................... A-11 Appendix Figure 15: ABS MODU Damaged Stability (½ Oil w/o Ballast)............................................ A-11 Appendix Figure 16: ABS MODU Damaged Stability (Maximum Oil Capacity w/o Ballast) ............... A-11 Appendix Figure 17: Surge Response Spectrum ..................................................................................... A-57 Appendix Figure 18: Heave Response Spectrum .................................................................................... A-57 Appendix Figure 19: Yaw Response Spectrum....................................................................................... A-57 Appendix Figure 20: Roll Response Spectrum........................................................................................ A-58 Appendix Figure 21: Pitch Response Spectrum ...................................................................................... A-58 Appendix Figure 22: Sway Response Spectrum...................................................................................... A-58

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List of Tables Table 1: Center of Gravity and Drafts for Different Loading Conditions ..................................................... x Table 2: Loading Conditions for StabCAD Input......................................................................................... xi Table 3: Particulars of 8 Line Polyester-Chain Mooring............................................................................. xii Table 4: Environmental Conditions............................................................................................................... 1 Table 5: Dimensions of Topside Structures................................................................................................... 2 Table 6: Wind Forces .................................................................................................................................... 2 Table 7: Current Forces ................................................................................................................................. 3 Table 8: Wave Drift Forces ........................................................................................................................... 3 Table 9: Total Environmental Loads ............................................................................................................. 4 Table 10: FPSO Weight Distribution Results................................................................................................ 9 Table 11: Vessel Centers of Gravity............................................................................................................ 10 Table 12: Loading Conditions for Stabcad Input......................................................................................... 11 Table 13: Allowable KG Values for the Five Vessel Cargo Conditions ..................................................... 14 Table 14: JONSWAP Wave Parameters...................................................................................................... 15 Table 15: Response Movement for All 6 Motions ...................................................................................... 17 Table 16: Passive, Partially Active, and Active Systems ............................................................................ 19 Table 17: Tension Limits and Equivalent Factors of Safety (API RP 2SK 1995)....................................... 22 Table 18: Mooring Constraints for VOSS FPSO......................................................................................... 23 Table 19: Line Particulars of Eight Line Polyester-Chain........................................................................... 24 Table 20: Results of Eight Line System ...................................................................................................... 25 Table 21: Line Particulars for Twelve Line System .................................................................................... 25 Table 22: Results for Twelve Line System.................................................................................................. 25 Table 23: Line Particulars for Sixteen Line Wire–Chain ............................................................................ 26 Table 24: Results for Sixteen Line System.................................................................................................. 26 Table 25: Mooring Line Cost Analysis Results........................................................................................... 26 Table 26: Particulars of Final Design .......................................................................................................... 28 Table 27: Criteria for Shuttle Tanker Connection ....................................................................................... 30 Table 28: Input for Pump Selection............................................................................................................. 30 Table 29: Pump Characteristics ................................................................................................................... 30 Table 30: Cost Estimate for FPSO Design .................................................................................................. 32

List of Appendix Tables Appendix Table 1: 100 Year Tropical Environmental Load (Fully Loaded Condition: Draft=21.5m) ..... A-1 Appendix Table 2: 100 Year Tropical Environmental Load (1/3 Loaded Condition: Draft=10.42m) ...... A-2 Appendix Table 3: 10 Year Tropical Environment Load with Extreme Eddy Current ............................. A-3 Appendix Table 4: 10 Year Tropical Environment Load with Extreme Eddy Current ............................. A-4 Appendix Table 5: 8 Line Polyester Cost Analysis ................................................................................. A-56 Appendix Table 6: 12 Line Wire-Chain Cost Analysis ........................................................................... A-56 Appendix Table 7: 16 line Wire-Chain Cost Analysis ............................................................................ A-56

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Abstract This report describes the design of a Floating Production Storage and Offloading system (FPSO) for the deep waters of the GOM. The reemergence of the GOM as one of the principal offshore oil and gas basins in the world has brought the challenge of integrating new technology into the business of developing the deepwater discoveries thus placing the FPSO at the forefront for its practicality, relatively inexpensive and revolutionary in terms of its on deck storing capacity. The FPSO is located at the Voss Prospect site with a depth of 1865 m (6,120 ft) and is designed to sustain the 100 year hurricane environmental conditions. The DNV and ABS guidelines were closely followed to ensure compliance with the major classification societies. The FPSO is purposely built for the site mentioned and will serve there for its full duration. The Voss prospect site is expected to produce around 308 MMB of oil over a life span of 25 years and a 120 MMB of natural gas annually. The FPSO has a large oil capacity of 2.0MMBL to decrease the occurrence of the offloading procedure. Power generation will be accomplished on deck through a dual fuel power generator that operates on natural gas and diesel fuel in case of emergencies. The mooring system is designed with a turret at the bow of the vessel. The environmental loads on the FPSO and mooring system were analyzed, and it is concluded as best option for the FPSO to be weathervaned into the environmental conditions to reduce the area of the ship withstanding the loads. The hydrodynamics of the FPSO were evaluated to ensure that the FPSO is hydro-dynamically stable. The Voss FPSO has a total cost of $492 million dollars.

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Executive Summary

During the 2003 Spring Semester, a team of six senior Ocean Engineering

students completed the preliminary design of a Floating Production Storage Offloading

system (FPSO) for the deep waters of the Gulf of Mexico under the mentorship of

ConocoPhillips. The eight competency areas addressed were general arrangement,

stability, global loading, cost, risk and regulations, hydrodynamic motions, wind wave

and current loading, and mooring. The site is 380 km (236 miles) off the coast of

Galveston, Texas in a water depth of 1865 m (6,120 ft). The rules and regulations from

the American Bureau Shipping (ABS), Det Norske Veritas (DNV), and American

Petroleum Institute (API) were followed to provide a safe working environment. The

ABS regulations were used for the design layout and the stability calculations and DNV

and API codes were used in analyzing the mooring design. In the general arrangement

and overall hull or system design three basic hull designs 1.5 MMBBL, 1.75 MMBBL,

and 2.0 MMBBL oil storage capacity were studied for the design project. The 2.0

MMBBL oil storage capacity was chosen as the final design to minimize the offloading

frequency for shuttle tankers and to accommodate the estimated production.

The 2 MMBBL vessel has a length of 311 m (1020 ft) and breath of 60 m (196.9

ft). The height of the vessel from the keel to the main deck is 33 m (108.3 ft). The

vessel’s hull also has a forecastle that extends 4 m (13.1 ft) high above the main deck to

prevent green water occurrences. The hull of the vessel is built from mild steel with a

minimum design life of twenty-five years, which is the length of the field life. The FPSO

is a double hull design with a 3 m (9.8 ft) space on the sides and a 2 m (6.6 ft) space on

the bottom. The 2 MMBBL FPSO is divided into 15 different crude oil tanks that are

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arranged three across the breadth and five along the length. The use of the double hull

provides the tank with a smooth inner surface making it easier for maintenance. The use

of the double hull also provides ample space for ballast tanks, and reduces the risk of an

oil spill. Ballast tanks are located along the vessel sides and bottom. These tanks are

primarily used for changing and controlling the draft. There are also two bow and two aft

ballast tanks for trimming the vessel during loading and offloading of cargo.

In the wind, wave and current loading analysis, the Magnolia Development

MetOcean data were used to evaluate the environmental loading on the FPSO. The

MetOcean data from the Magnolia Development could be used since it was located close

to the Voss site. The 100-year hurricane and the 10-year return period with a 100-year

eddy loop current were used to analyze the environmental forces in the bow, beam, and

quartering seas. The forces applied to the vessel were analyzed for the 1/3 and fully

loaded conditions to find the maximum forces. In the fully loaded condition there would

be a larger effect from the loop current and less effect from the wind forces and the

opposite was expected for the 1/3 loaded condition. The 100-year hurricane

environmental conditions produced the extreme governing loads on the FPSO for both

1/3 and fully loaded conditions.

The vessel’s turret and riser system were designed for environmental conditions

approaching from all directions, and the vessel was designed to weathervane into the

oncoming environmental forces. This was accomplished with the use of an internal

forward mounted turret. An internal turret was selected over an external turret because of

its safety and easy access for maintenance. The turret is located at the bow to aid in its

ability to weathervane. A partially active design that permits locking the turret for

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offloading and maintenance. The turret does not require the aid of thrusters when

weathervaning. The crew accommodations, which acts as a large sail providing all the

force required to weathervane the vessel, are located at the FPSO stern. The turret is

attached to the mooring line system to handle the harshest environmental loads. A swivel

stack is mounted on the turret and allows the vessel to rotate freely. The swivel stack

accommodates up to 25 flexible risers and 12 different swivels. All of the risers and

swivels are not needed for the initial design, but they are available to provide capabilities

for future expansion. The turret system is 30 m (98.4 ft) above the main deck, and has a

diameter of 20 m (65.6 ft).

The flare tower is only allowed to flare gas during emergencies in the Gulf of

Mexico, and it is located above the swivel stack that it is far away from the crew

accommodations as possible as recommended in ABS (2000). If it is necessary to flare,

the flare tower is high enough that the fumes will not endanger any of the crew. Also, the

crew accommodations are not located above any crude oil tanks as recommended by

ABS (2000). The heli-deck is located above the crew accommodations to allow more

deck space and to provide a safe place for landing. Lifeboats are located on either side of

the FPSO that are capable of holding twice the number of crew (ABS 2000). Two cranes

are located on either side of the FPSO with a radius arm of 30 m (98.4 ft). The production

equipment is located along the main deck in between the crew accommodations and the

turret.

For the weight, buoyancy and stability analysis the vessel was divided into

different blocks so that the distribution of weight could be determined. The reference

plane of the ship was assumed to be at the keel and aft perpendicular. The longitudinal,

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vertical, and transverse centers of gravity were calculated by taking the moment of each

ship component by multiplying its weight by its distance from a reference plane. Then,

the weights and moments of all the components were added, and the total moment was

divided by the total weight. Table 1 shows the draft and KG for the different loading

conditions.

Table 1: Center of Gravity and Drafts for Different Loading Conditions

0 Ballast 1/3 ½ Full KG m (ft) 22.70 (74.5) 18.33 (60.1) 14.20 (46.6) 13.97 (45.8) 17.16 (56.4)

Draft m (ft) 4.95 (16.2) 10.61 (34.8) 10.42 (34.2) 13.23 (43.4) 21.50 (70.5)

It was determined that the vessel did not require any ballast if the oil tanks were

filled greater than one third of their total capacity. The operational draft of the vessel

ranges between 10 m (32.8 ft) to 21.5 m (70.5 ft), and the weight of the oil above one-

third its total capacity places the vessel at its operational draft. This allows the ballast

tanks to only be employed to trim or heel the vessel.

In the stability analysis of the FPSO, the program StabCAD was used to calculate

the vessel’s allowable KG values and intact and damage stability data. StabCAD is used

extensively in the offshore industry for the stability analyses of offshore floating

production systems, and other floating designs. Initially, intact and damage stability plots

were created in StabCAD based on the actual KG values, which are listed along with

corresponding displacement and draft values for the five cargo conditions in Table 2. In

the ABS MODU intact and damage stability analysis the allowable KG had to be

calculated by StabCAD. Finding the allowable KG was necessary to generate intact

stability plots that satisfy the ABS MODU rules. The allowable KG values were then

entered in StabCAD so that the range of stability for the damaged condition could be

computed.

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Table 2: Loading Conditions for StabCAD Input

Vessel Cargo Condition Displacement M. Tons (S. Tons)

Draft m (ft)

KG m (ft)

Empty without ballast 79582 (49,692) 4.95 (16.2) 22.70 (74.5) Empty with ballast 170,415 (106,409) 10.61 (34.8) 18.33 (60.1)

1/3 oil without ballast 167,382 (104,515) 10.42 (34.2) 14.20 (46.6) ½ oil without ballast 212,582 (132,739) 13.23 (43.4) 13.97 (45.8)

Full oil without ballast 345,492 (215,729) 21.50 (70.5) 17.16 (56.4)

Overall the stability analysis showed that the FPSO design met all the ABS

MODU area ratio, range of stability, and damage condition requirements. This meant that

initial design of vessel would be a good platform for the second iteration in the design

process. The intact stability results for each of the five cargo conditions showed that

vessel was overly stable because of the low drafts and the excessive freeboard of the

design, which caused down flooding to only be possible in the fully loaded condition. For

the second iteration of the design process a longer and narrower vessel with less

freeboard but similar draft values as the first design was analyzed. The Recommended

length, breadth, and depth values for the analysis of a final hull design are 350 m (1148

ft), 55 m (180.4 ft), and 25 m (82.02 ft) respectively.

The mooring/station keeping analysis was performed using the DNV software

MIMOSA. The mooring system was designed to withstand the environmental loading of

a 100 yr hurricane and designed according to API RP 2SK (1995) that set the allowable

offsets and tension factors of safety for the mooring system. The recommended offsets

were 10% of water depth for the intact condition and 12% in the damaged condition. The

tension factors of safety are 1.67 and 1.25 for the intact and damaged conditions

respectively.

The selected mooring design is an eight line taut leg system consisting of Marlow

Superline® (2700 m) and K4 chain (200 m), as summarized in Table 3. The mooring

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system that consisted of the synthetic lines was selected because it greatly outperformed

the conventional wire-chain mooring lines. The calculated offsets were 2% of water

depth for the intact condition and 4% in the damaged condition. The tension factors of

safety were 2.37 and 1.55. It was also less expensive at $6.7 million for the line elements.

Suction pile caissons were used to anchor the system due to the large vertical forces

exerted by a taut leg system.

Table 3: Particulars of 8 Line Polyester-Chain Mooring Segment Line Type Diameter Breaking Strength

1 K4 Chain 120.7 mm

4.75 in 13,710 kN 3,082 kips

2 Marlow Superline® 221 mm

8.7 in 13,345 kN 3,00 kips

3 K4 Chain 120.7 mm

4.75 in 13,710 kN 3,082 kips

The hydrodynamic motion behavior and response of the moored FPSO were

obtained using SESAM software. To obtain values for the Response Amplitude Operator

(RAO) for the six different possible motions in different headings, response spectrums

were calculated and plotted using the JONSWAP spectrum for the 100 yr hurricane

conditions in the Gulf of Mexico. The roll, yaw, and heave motions were all analyzed to

make sure that the flexible risers were not overstressed. The rolling motion was also

checked to make sure it was within allowable limits of the topside production equipment.

Finally, the surge and sway were analyzed to make sure there was ample space between

the FPSO and the tanker during offloading.

The FPSO is designed for year round production, and offloads off the stern with a

flexible floating hose. To meet the Jones Act requirements the offloading tanker must be

built in the United States. The shuttle tanker will offload approximately every 6 days

taking approximately 22 hours to complete the total transfer. A large amount of gas is

produced with the oil; therefore gas-processing facilities are located on the FPSO to

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separate it from the oil. The gas is transported through a pipeline system to the coast. A

cost analysis was completed that included the costs for the hull structure, topside,

mooring system, offloading system, transportation and installation, and engineering and

project management costs, and the estimated FPSO design project cost is $492 million

dollars.

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Acknowledgement Team Gulf of Mexico would like to thank the following individuals and companies for their help and support throughout this project.

Dr. Robert Randall, TAMU Matthew Pritchard, ConocoPhillips Peter Noble, ConocoPhillips Chuck Steube, ConocoPhillips J. R. King, ConocoPhillips Tom Bauer, Halliburton-KBR DNV – Sesam Package Zentech - StabCAD

Introduction The progression of field discoveries in Gulf of Mexico to increasingly deeper water depths has initiated a change in regulations by Minerals Management Service to allow the introduction of FPSOs to select Gulf of Mexico regions. Deep-water discoveries in areas, where the costs of tying into existing pipeline infrastructure are prohibitive or impractical, which increased the attractiveness of FPSO utilization in the Gulf of Mexico. Although commonly used throughout the rest of the world FPSOs were forbidden for use in the Gulf of Mexico, and gained approval only in January 2002. The intent of this project is to design a FPSO system for placement in the Gulf of Mexico at water depth of 1865 m (6,120 ft), which reflects the regulatory changes and employs shuttle tanker offloading. Designing and building an FPSO is a huge project where final decisions are made based on a thorough engineering examination of different alternatives and influenced by economic and environmental constraints. The project includes an overall hull design with different alternatives studied for optimal performance. The detailed study addresses the fundamental aspects of design including solutions to technical matters such as ship hydrodynamics of motion and loading, the effects of wind and current loading and a full mooring system analysis. The design approach begins with deciding on several hull designs with different geometries to find which one has the best stability characteristics. Next topside equipment was estimated for weights and location. Then courtesy of Zenntech, the program StabCad was used to test the stability of different hull geometries. Since the environment is not benign a spread mooring system was ruled out. Therefore a turret mooring system was designed and the program Mimosa, donated by DNV, was used to run different mooring configurations. The Gulf of Mexico team members and their design responsibilities are the following: McAlan Clark, general hull layout; Chris Chipuk, turret design and cost analysis; Caroline Hoffman, rules and regulations, and environmental loads; James Peavy, mooring design using Mimosa; Ramez Sabet, offloading procedures; and Baron Wilson, weight, buoyancy, and stability analysis using StabCad. Since, everyone’s responsibilities depend on one another everyone is familiar with each other’s research to avoid redesigning components.

Field Trip The students in the ocean engineering design class completed a tour of the “Continental,” which is a ConocoPhillips oil tanker, on January 24, 2003. The tanker has a capability to carry up to 650,000 barrels of oil. The purpose of the tour was to gather information about the tanker that could be applied to the Gulf of Mexico FPSO design. The tour included the engine room, crew accommodations, and the observation of vessel offloading procedures. The tour provided knowledge of how large oil industry equipment is, which was useful for size estimates and general arrangement of topside equipment in the design of the Gulf of Mexico FPSO.

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Site The FPSO design is to be positioned at ConocoPhillips Voss Prospect site. The Voss Prospect is in the western part of the Gulf of Mexico in the Keathley Canyon block 511. The exact longitude and latitude coordinates of the site are 26 28.6759 N, 92 36.9282 W. The site is in deep water at a depth of 1865 m (6,120 ft). The Voss Prospect Site is approximately 380 km (236 miles) from Galveston.

Figure 1: Western Gulf of Mexico with Voss Prospect Site

Wind, Wave and Current Loading Environmental loads consist of wind forces, wave forces, and mean wave drift forces. The Magnolia Development MetOcean criteria supplied by ConocoPhillips were used to analyze the different environmental conditions. The dominating cases were the 10-year return period with an eddy loop current and the 100-year return period. The environmental conditions used to solve for the environmental forces are shown in Table 3. Table 4: Environmental Conditions

Wind Speed Current Speed Hs Knots (m/s) Knots (m/s) ft (m) 10-yr return period w/ eddy loop current 50.5 (26.0) 3.11 (1.60) 26.2 (8.0) 100 -yr return period 75.8 (39.0) 2.72 (1.40) 40.0 (12.2) To simplify the calculations the FPSO is divided into ten separate areas above the waterline shown in Figure 2 below.

Figure 2: Divided Areas above the Waterline Used for Evaluating the Environmental Loads

The dimensions of the topside structure were kept constant to obtain a better understanding of how the different storm conditions affected the vessel. The dimensions of the topside are shown in Table 5.

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Table 5: Dimensions of Topside Structures Length Width Height ft (m) ft (m) ft (m)

Production Equipment 850.0 (259.1) 180.4 (55.0) 39.4 (12.0)Turret & Super Structure 98.4 (30.0) 98.4 (30.0) 90.0 (27.4)

Crew Quarters 98.4 (30.0) 156.9 (47.8) 65.6 (20.0)Helideck 90.3 (27.5) 90.3 (27.5) 1.6 (0.5)

Flare Tower 9.8 (3.0) 9.8 (3.0) 49.2 (15.0) The environmental forces were analyzed when the FPSO was fully loaded and one-third loaded. The environmental loads on the FPSO increase as the drafts decrease corresponding to the level of the oil tanks. The wind forces were calculated by multiplying the cross-sectional areas by the shape and height coefficients found on Table 3-1 and 3-2 in API RP 2SK (API, 1995). The values were summed to find the total wind forces. The wind force results for the 10-year wind and wave with a 100-year loop current and 100-year hurricane for the fully and one-third loaded cases are shown in Table 6. Table 6: Wind Forces

Bow Seas Beam Seas Quartering Seas Kips (KN) Kips (KN) Kips (KN)

Fully Loaded 10-yr Wind and Wave + 100 yr. Loop Current 400.2 (1780.2) 778.1 (3461.1) 785.6 (3494.5) 100-yr Hurricane 900.5 (4005.6) 1750.7 (7,784.4) 1767.5 (7862.2)

1/3 Fully Loaded 10-yr Wind and Wave + 100 yr. Loop Current 426.6 (1897.6) 915.7 (4073.2) 894.9 (3980.7) 100-yr Hurricane 959.9 (4269.8) 2060.3 (9164.6) 2013.5 (8956.5) The wetted surface area was calculated using Equation 1 based on Taylor’s Theory (Lewis, 1988).

S = C (∆L)0.5 (1)

where, C is the coefficient of 16.5, ∆ is the displacement, and L is the length. The current forces on the vessel were calculated using Equation 2, which was given in section 3.7.2 of API RP 2SK. Fc = 0.5(ρwCdAcuc|uc|) (2) where, ρw is the density of water, Cd is the drag coefficient, Ac is the projected area exposed to the current, and uc is the current velocity. The current force calculations can be found in Appendix Table 5 in Appendix I. The current force results for the 10-year wind and wave including the 100 year eddy loop current and 100-year hurricane for the fully and one third loaded cargo conditions are shown in Table 7 below.

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Table 7: Current Forces

Bow Seas Beam Seas Quartering Seas Kips (KN) Kips (KN) Kips (KN)

Fully Loaded 10-yr Wind and Wave + 100 yr. Loop Current 29.1 (129.4) 727.1 (3234.3) 504.1 (2242.3) 100-yr Hurricane 22.5 (100.0) 556.2 (2474.1) 385.6 (1715.2)

1/3 Fully Loaded 10-yr Wind and Wave + 100 yr. Loop Current 20.4 (90.7) 509.9 (2268.1) 353.6 (1572.9) 100-yr Hurricane 15.6 (69.4) 390.1 (1735.2) 270.4 (12092.8) The mean wave drift forces were calculated by using the curve fitting formulas shown below as Equations 3, 4, 5, and 6 found in section 3.7 of API RP 2SK. Bow Seas

9.63*ln( ) 14y x= − (3)

Beam Seas

5 4 5 3 22*10 5*10 0.14 7.39 8.93y x x x x− −= − − + − (4)

Quartering Seas (Surge)

0.9366 1.2207y x= + (5)

Quartering Seas (Sway)

5 4 3 21*10 0.0003 0.06 4.095 7.27y x x x x−= − − + − (6)

The mean wave drift force calculations are shown in Appendix I. The mean wave drift force results for the 10-year wind and wave with the 100-year eddy loop current and 100-year hurricane for the fully and one third loaded cases are shown in Table 8. Table 8: Wave Drift Forces

Bow Seas Beam Seas Quartering Seas kN (kips) kN (kips) kN (kips)

Fully Loaded 10-yr Wind and Wave + 100 yr. Loop Current 77.8 (17.5) 423.0 (95.1) 256.2 (57.6) 100-yr Hurricane 95.6 (21.5) 470.2 (105.7) 282.0 (63.4)

1/3 Fully Loaded 10-yr Wind and Wave + 100 yr. Loop Current 77.8 (17.5) 423.0 (95.1) 256.2 (57.6) 100-yr Hurricane 95.6 (21.5) 470.2 (105.7) 282.0 (63.4) The total environmental loads for the 10-year wind and wave with a 100-year eddy loop current and 100-year hurricane for the fully and one-third loaded cases are shown in Table 9. The most extreme loads occurred in the 100-year hurricane environmental conditions in the beam and quartering seas. Therefore, the FPSO is to be weathervane in the direction of the environmental conditions to reduce the loads on the vessel. Also, the 100-year hurricane conditions are used as the dominating environmental data in the design of the FPSO.

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Table 9: Total Environmental Loads

Bow Seas Beam Seas Quartering Seas kN (kips) kN (kips) kN (kips)

Fully Loaded 10-yr Wind and Wave + 100 yr. Loop Current 1989 (446.8) 7119 (1600) 5993 (1347) 100-yr Hurricane 4200 (944.3) 10732 (2413) 9859 (2217)

1/3 Fully Loaded 10-yr Wind and Wave + 100 yr. Loop Current 2066 (464.5) 6765 (1521) 5810 (1306) 100-yr Hurricane 4435 (997.0) 11371 (2556) 10441 (2347)

Codes and Regulations Mineral Management Services (MMS) has recently permitted FPSOs to be in specified blocks in the Gulf of Mexico. Currently there are not any FPSOs in the Gulf of Mexico but due to the deeper waters a FPSO would be more economical. The Jones Act requires that all vessels transporting cargo between two U.S. ports be built in the United States, crewed by U.S. mariners, and owned by U.S. The purpose of the Jones Act is to maintain shipbuilding and ship repair industrial base, a trained merchant mariner manning pool, and assets to respond in times of national security emergencies. This act applies to the FPSO located at the Keathley Canyon block. Rules and regulations are important in maintaining a safe environment for the crew and visitors. Agencies such as ABS (American Bureau of Shipping), API (American Petroleum Institute), and DNV (Det Norske Veritas) provided many of these rules and regulations to ensure a safe working environment.

Facility Layout Equipment items that could become fuel sources in the event of a fire are to be separated from potential ignition sources by space separation, firewall or protective walls. Living quarters are to be located outside of hazardous areas and may not be located above or below crude oil storage tanks or process areas. Wellhead areas are to be separated or protected from sources of ignition and mechanical damage. Crude oil storage tanks, slop tanks, and flammable liquid storage tanks are to be separated from machinery spaces, service spaces, and other similar sources of ignition spaces by at least 0.76 m (2.49). (ABS, 2000)

Vessel Conditions The vessel is to have markings that designate the maximum permissible draft that the vessel may be loaded to. The primary structure is to be analyzed using severe storm conditions and normal operating environmental conditions. The ship should be subject to partial filling levels of the tanks. The sloshing analysis is to determine if the filling levels in the tanks are close to the vessels natural pitch and roll motion periods. It is recommended that the natural periods of the fluid motion in the tanks are 20% greater than or less than that of the relevant vessel’s motion. (ABS, 2000)

Stability All vessels are to have a positive meta-centric height in calm water equilibrium position for all floating conditions, including temporary positions during fabrications, installation, ballasting, and deballasting. All vessels are to have sufficient stability at intact as well as damage conditions. (ABS, 2000)

Lifesaving Requirements All materials that comprise the lifeboat embarkation platform are to be of steel or equivalent material. The lifeboats are to be able to hold a capacity of twice the total number of people onboard the vessel. They are to be installed on at least two sides of the installation, in safe areas in which there will be accommodation for 100%, in case one of the stations becomes inoperable. Inflatable life rafts are to be provided onboard such that their total capacity is sufficient to accommodate the total number of people expected to be onboard the facility. At least four life buoys are to be provided with floating water lights. Also there should be at least one life jacket for each person on the vessel. Each facility is to have means of embarkation to allow personnel to leave the facility in an emergency. All materials that comprise the

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escape routes are to be of steel material. The perimeter of all open deck areas, walkways and accommodation spaces, catwalks and openings, are to be protected with guardrails. (ABS, 2000)

Fire Fighting Systems Water fire fighting systems are to be capable of maintaining a continuous supply in the event of damage to water piping. Piping is to be arranged so that the supply of water could be from two different sources. There are to be at least two independently driven and self-priming fire pumps. The primary and standby fire pumps are each to be capable of supplying the maximum probable water demand for the facility. There are to be fire detectors, gas detectors, smoke detectors and a general alarm system on the vessel. Also two sets of fire-fighting outfits and equipment are to be provided and stowed in a suitable container. A minimum of two self-contained breathing apparatus should be provided and stowed with the fireman’s outfits. (ABS, 2000)

General Arrangements and Overall Hull/System Design

Crew Quarters The crew quarters are located at the stern of the vessel. It can accommodate up to 150 persons spread throughout 6 floors. The dimensions of the crew quarters are 46 m (150.9 ft) across the length, 30 m (98.4 ft) across the breadth, and 20 m (65.6 ft) high off the vessel’s deck. The crew quarters are positioned at the stern to act as a sail to help weathervane the vessel into the environment. The crew quarters has an expanded bridge with solid glass windows encompassing for a broad range of sight from the bridge. Located on top of the crew quarters is an antennae tower for communication purposes. Also located on the roof of the crew quarters is the heli-deck. It is in the shape of an octagon and has a diameter of 16 m (52.5 ft) to provide for a maximum landing surface. The heli-deck was placed on top of the crew quarters to allow for more space on the main deck. To ensure maximum safety the crew quarters are coated with Pitt-Char XP Fire Protective Coating., which is a 2 component epoxy based coating that produces a flexible and tough epoxy barrier that insulates and provides thermal protection of the crew quarters even under hydrocarbon and jet fire conditions. Pitt-Char XP Coating also protects the crew quarters from corrosion and retains its fire protection properties under aggressive chemical environments. Figure 3 shows the side and front views of the crew quarters.

Figure 3: Side and Front Views of Crew Quarters (Dimensions in Meters)

Deck Production Systems The deck production systems are located on the main deck directly above the oil tanks. There is a 4 m (13.1 ft) space between the top of the oil storage tanks and the main deck. The production systems are placed to the turret to minimize piping costs and for the safety of the crew. The production systems deck has 6 major components as seen in Figure 4 below. Closest to the crew quarters is the water injection part of the production systems. Just forward of the water injection system is the gas compression portion of the production systems. Then we placed the processed water system. Next the gas separation part of the production systems, followed by the power generation system and electrical room, which is centrally located between all the production systems, the turret, and the crew quarters. Finally the emergency flare tower is located on top of the turret.

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Figure 4: Top, Front, and Right side Views of the Production Systems (Dimensions in Meters)

Lifeboats In the Lifesaving Appliances and Equipment section of the ABS guide for Building and Classing Facilities on Offshore Installations it is stated that motorized lifeboats capable of carrying twice the maximum number of persons aboard are required. To meet the requirements three Sotra JY80K open lifeboats are located on the starboard and port sides of the vessel. The JY80K is an easily accessible and detachable diesel powered lifeboat capable of carrying 50 persons. It requires a 7 m (23.0 ft) hook length for expulsion from the vessel, and its length, breadth, and depth are 8 m (26.2 ft), 2.6 m (8.53 ft), and 1.1 m (3.61 ft) respectively. Two lifeboats are placed on each side of the crew quarters and the other two are located on each side of the bow close to the turret. The lifeboats are placed in locations at both ends of the vessel so that all personnel can evacuate the vessel quickly. The lifeboats carry all safety necessities including regulated lifejackets, and flares. The JY80K is a cost efficient, sturdy lifeboat that meets all safety requirements and can help prevent major loss of life if ever needed.

Oil Tanks The oil storage tanks are arranged with 3 oil tanks across the breadth and 5 oil tanks along the length of the vessel for a total of 15 tanks. Each individual tank is capable of storing approximately 133,000 barrels of oil. The length, width, and height of each individual tank are 44.1 m (144.7 ft), 18 m (59.1 ft), and 27 m (88.6 ft) respectively. The overall dimensions of all tanks combined will be 220.5 x 54 x 27 m (723.4 x 177.2 x 88.6 ft) (L x W x H). All oil tanks are designed with steel at a thickness of approximately 20 mm to 30 mm (0.79 in to 1.18 in). The tanks are centrally located between the bow and stern, and the main deck and keel. The majority of the vessel’s weight will be held by the oil tanks during operation, to evenly distribute the loads from the internal turret is located at the bow and the crew quarters located at the stern. ABS regulations state that the crew quarters cannot reside over any part or portion of the oil tanks. Of which the vessel is designed for and complies with all regulations. The tanks will also have an efficient pumping system capable of unloading maximum oil capacity in 24 hours. Offloading procedures will be discussed more in later sections of the report. Three views of oil storage tanks are shown in Figure 5.

Figure 5: Top, Front, and Right Side Views of Oil Tanks (Dimensions in Meters)

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Ballast Tanks The vessel’s side and bottom ballast tanks are located around the oil storage tanks in which they surround them completely except for the topside. There are 10 main ballast tanks in the order of 5 along the length and 2 across the breadth of the vessel. The individual and overall dimensions of the main ballast tanks are shown in Figure 6.

Figure 6: Top, Front, and Right Side Views of Side and Bottom Ballast Tanks (Dimensions in Meters) Four additional ballast tanks are located in pairs at the bow and stern of the vessel. Altogether there are 14 ballast tanks to provide stability adjustments for the vessel. The location of the bow and stern ballast tanks are shown in Figure 7.

Figure 7: Vessel Ballast Tanks

Other Below Deck Components Below the main deck the vessel has features acquainted with almost all floating, production, storage, and offloading units. A potable water tank is located at the stern of the vessel. The tank provides all the fresh water for crew aboard the FPSO. It has a maximum capacity of 125,000 gal (473,200 L) of water and provides water even when power is down on the vessel. A processed water tank capable of holding 75,000 gal (283,900 L) of water is also included in the below deck components. The processed water tank, which is located at the stern, can treat waste water generated from the cleaning of machinery and equipment by separating free oil and dirt from the water, which makes it suitable for sewer discharge. The processes used include aeration, gravity separation, solids separation, oil coalescence separation, ozone disinfection, and oxidation. It has the potential to process 50 gal/min (189.3 L/min), and has freeze prevention valves and lines. Finally there are two separate oil lube tanks located below deck at the stern. These tanks have two different grades of oil lube enclosed. The oil lube in each tank is for specific parts on the water and oil

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tanks pumping systems. The lube tanks help maintain consistent flow rates and also prolong the lives of the pumping systems.

Figure 8: Beam View of Vessel Showing Turret and Mooring System Connection

Cranes The two cranes aboard the vessel are Kenz cranes capable of lifting a maximum load of 50 m tons (31.2 s tons) at a 12 m (39.4 ft) radius. Each crane has a 30 m (98.4 ft) main boom length and can reach all accessible loads on the production system decks. It rises 24 m (78.7 ft) off the main deck’s surface and it has a base diameter of approximately 2 m (6.6 ft). The cranes are located in relation to one another on both the port and starboard sides of the vessel. One crane is located along the starboard side towards the bow of the vessel around one-third of the way along the length of the production systems deck. The other crane is positioned on the port side of the ship towards the stern of the vessel over two-thirds of the way along the length of the production systems deck. One crane is placed further down the deck so that when anything is added to the existing main deck components the crane will be able to reach it, and provide the needed lift. The Kenz cranes are not only a safe and reliable product, but are also cost and weight efficient.

Figure 9: Crane Design (Dimensions in Meters)

Hull The hull is the basis for the general arrangement and design of everything on the vessel. Several different shape and size designs of the hull were considered before choosing the one shown in Figure 10. The three different sizes that considered were those of a 1.5, 1.75, and 2 MMBBL capacity vessels. Each vessel proved to be capable but for cost efficiency and the possibility that the Voss Prospect site could bring in more wells the 2 MMBBL vessel was chosen. The two different shapes considered by Team Gulf of Mexico were that of a vessel with a bow bulb and one without. Bow bulbs reduce a vessels form drag by a small amount, which adds up to substantial savings on fuel over decades. The design not including the bow bulb was chosen since fuel savings provided by it are not applicable to a moored FPSO without an engine, and the amount that it reduces the drag force is negligible. The hull length, breadth, and depth are 311 m (1020.3 ft), 60 m (196.9 ft), and 33 m (108.3 ft) respectively. A forecastle that extends 4 m (13.1 ft) high above the main deck is also included in the hull design to protect from green water occurrences. The vessel has a double hull to meet OPA 90 regulations (EPA, 2003).

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Figure 10: Top, Front, and Right side Views of the FPSO Hull (Dimensions in Meters)

Weight, Buoyancy and Stability When computing stability calculations the ship was divided into different blocks so that the distribution of weight could be determined. The reference plane of the ship was assumed to be at the keel and aft perpendicular. The longitudinal, vertical, and transverse centers of gravity were calculated by taking the moment of each ship component and multiplying its weight by its distance from a reference plane. The weights and moments of all the components were then added, and the total moment was divided by the total weight. The result was the distance of the center of gravity from the reference plane. The location of the center of gravity is determined when the distance from each of the three reference planes is known. The stability is influenced a great deal by the interaction of the forces of weight and buoyancy. Therefore, it is important to determine the ships center of gravity and buoyancy. It was determined that the vessel would not require any ballast if the oil tanks were filled greater than one third of their total capacity. The operational draft of the vessel ranges between 10 m (32.8 ft) to 21.5 m (70.5 ft) and the weight of the oil above one third its total capacity places the vessel in its operational draft. This allows the ballast tanks to only be employed to trim or heel the vessel, lowering the possibility of extensive corrosion in the tank from sea water. Table 10 below shows the results for the calculated weight distributions. Table 10: FPSO Weight Distribution Results

Vessel Cargo Condition 0 Ballast 1/3 1/2 Full

Light Ship m. tons (s. tons) 79,582 (49,692)

79,582 (49,692)

79,582 (49,692)

79,582 (49,692)

79,582 (49,692)

Oil m. tons (s. tons) 0 0 87,800 (54,823)

133,000 (83,047)

265,910 (166,038)

Ballast m. tons (s. tons) 0 90,833 (56,717) 0 0 0

Total m. tons. (s. tons) 79,582 (49,692)

170,415 (106,409)

167,382 (104,515)

212,582 (132,739)

345,492 (215,730)

KG m (ft) 22.7 (74.5) 18.3 (60.0) 14.2 (46.6) 14.0 (45.9) 17.2 (56.4) KB m (ft) 2.7 (12) 5.9 (8.9) 5.8 (19.0) 7.3 (24.0) 11.9 (39.0)

Draft m (ft) 5.0 (12) 10.6 (34.8) 10.4 (34.1) 13.2 (43.3) 21.5 (70.5) If the ship is heeled to a small angle, φ the center of buoyancy will move off of the ship centerline. Therefore, a distance, GZ the righting arm, will separate the lines along the results of the weight and buoyancy. A vertical line through the new center of buoyancy to the original vertical through the center of buoyancy will intersect at a point, M called the transverse metacenter. The location of this value will vary at different trim angles. The distance from the center of gravity to the metacenter is GM. The righting arms for small angles of heel can be calculated by the Equation 7 shown below:

GZ=GMsin(φ) (7)

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From the information listed in Table 9 the ship centers of gravity were calculated and are shown in Table 11 below. The centers of gravity were measured from a coordinate system in which the origin was located at the stern of the vessel centered at the keel. Table 11: Vessel Centers of Gravity

VCG m (ft) 17.2 (56.4) LCG m (ft) 154.1 (505.6) TCG m (ft) 30.0 (98.4)

StabCAD StabCAD is a program that is extensively used in the offshore and shipping industries for the stability analyses of offshore floating production systems, ships, or any other floating designs. The program uses a 3D graphic interface for creating and modifying the vessel model. The StabCAD beta file, which is setup in a text editor format, allows the user to input the various StabCAD cards for any stability parameters desired. The StabCAD cards also determine what will be listed in the StabCAD output files after the program runs its analysis. Some examples of the general StabCAD cards are listed below.

• STBOPT (stability options) • KGPAR (parameters of allowable KG calculation) • CFORM (specification for hydrostatic analysis) • INTACT (specification for heel angles for intact stability) • DRAFT (specification for stability analysis VCG) • GRPDES (group identification description)

A more detailed description of the process for the setup of the Gulf of Mexico FPSO beta file is given in Appendix II.

Design Process StabCAD was used in the stability analysis of the FPSO for calculating the following:

• Vessel allowable KG • Intact and Damage Stability Plots for actual KG values • ABS MODU Intact and Damage Stability Plots based on allowable KG values

StabCAD was used to calculate the allowable KG values for the five cargo conditions ranging empty to fully loaded. The StabCAD KGCYCLE card was set to solve for the allowable KG necessary for a 1.4 or greater area ratio required by ABS MODU. The KGCYCLE card iterates KG values until it converges on the 1.4 area ratio. Figure 11 shows how the area ratio is defined by ABS MODU.

Figure 11: ABS MODU Intact Stability (Bauer 2003)

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The ABS MODU intact and damage stability requirements are listed below. The intact and damage wind speeds were inputed in the StabCAD KGPAR card.

• Intact Condition: Wind = 100 knots - Sufficient residual dynamic stability (measured from righting and heeling curves)

• Damage Condition: Wind = 50 knots - Final waterline should not submerge any non-watertight openings

• Damage Residual: Wind = 50 knots - 2nd Intercept must be 7 degrees past 1st intercept - Within extent of weathertight integrity, righting moment reaches a value 2x healing moment (both

measured at the same angle).

The ABS MODU damage stability requirements can be better understood by analyzing Figure 12 shown below.

Figure 12: ABS MODU Damage Stability (Bauer 2003)

The allowable KG data calculated by StabCAD was also useful for creating a plot of allowable KG versus wind heading for the various cargo conditions. The wind heading corresponding to the lowest KG value determined the limiting stability criteria.

Results The StabCAD output consisted of two sections: the intact and damage stability results for calculated KG values, and the ABS MODU intact and damage stability results based on allowable KG values. The StabCAD analyses were completed on each of the five cargo conditions based on the calculated centers of gravity. The empty ship or light ship condition KG was calculated as 22.7 m (74.5 ft), and the light ship with full ballast had a KG of 18.3 m (60.0 ft). The 1/3 oil, 1/2 oil, and fully loaded conditions KG values were 14.2 m (46.6 ft), 14.0 m (45.9 ft), and 17.2 m (56.4 ft) respectively all with empty ballast tanks. The displacement, draft, and KG values for the different vessel loading conditions are shown in Table 12. Table 12: Loading Conditions for Stabcad Input

Vessel Cargo Condition Displacement m. tons (s. tons)

Draft m (ft)

KG m (ft)

Empty without ballast 79582 (49,692) 4.95 (16.2) 22.70 (74.5) Empty with ballast 170,415 (106,409) 10.61 (34.8) 18.33 (60.1)

1/3 oil without ballast 167,382 (104,515) 10.42 (34.2) 14.20 (46.6) ½ oil without ballast 212,582 (132,739) 13.23 (43.4) 13.97 (45.8)

Full oil without ballast 345,492 (215,729) 21.50 (70.5) 17.2 (56.4)

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Drafts for the various cargo conditions range from empty ship’s 4.95 m (16.2 ft) to the fully loaded 21.5 m (70.5 ft). Figure 13 shows the vessels displacement for drafts up to 27 m (88.6 ft).

0

50000

100000

150000

200000

250000

300000

350000

400000

450000

500000

0 5 10 15 20 25 30

Draft (M)

Dis

plac

emen

t (M

. Ton

s)

Figure 13: Displacement Versus Draft

Intact and Damage Stability Results for Calculated KG The intact stability results for the fully loaded case had a range of stability of 26.17°. The input KG was 17.6 m (57.7 ft), which resulted in an area ratio of 18.96, and the first and second intercepts were 0.46° and 81.76° respectively. The intact stability plot for the fully loaded condition is shown in Figure 14. The intact stability plots for the other cargo conditions are shown in Appendix Figures 1 thru 5 in Appendix II.

Figure 14: Intact Stability (Maximum Oil Capacity w/o Ballast)

In the damaged stability analysis each of the starboard ballasts tanks were damaged separately so that the one causing the lowest range of stability could be determined. Interestingly the starboard ballast tanks corresponding to the lowest range of stability did change for the various cargo conditions. For example, in

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the ABS MODU, which will be discussed later, the damage stability results for the fully loaded condition the ballast tank closest to the stern had the lowest range of stability, while the one closest to the bow had the lowest range of stability for the one-third loaded condition as seen in Figure 15.

Figure 15: StabCAD Model Showing Damaged Starboard Ballast Tanks

The range of stability decreased to 24.24° in the results for damage stability for the fully loaded condition. The input KG was kept at 17.6 m (57.7 ft) and the first and second intercepts were 1.60° and 82.00° respectively. The damage stability plot for the fully loaded condition is shown in Figure 16. The damage stability plots for the other oil cargo conditions are shown in Appendix Figures 6 thru 8 in Appendix II.

Figure 16: Damage Stability (Maximum Oil Capacity w/o Ballast)

ABS MODU Intact and Damage Stability Results based on Allowable KG The second part of the StabCAD analysis involved the use of the KGCYCLE card for calculating the allowable KG values for the various cargo conditions. The KGCYCLE card uses the input KG value as a starting point. It then runs the calculations, finds an allowable KG, and iterates the new value back in and runs the calculations over again. The process continues until the program converges on a more accurate allowable KG value that will satisfy the ABS MODU 1.4 area ratio requirement. Multiple DRAFT cards were also included in the Beta files for the second portion of the StabCAD analyses, which allowed multiple wind headings to be indicated. Enough DRAFT cards were included to investigate wind headings 360˚ around the vessel so that the worst heading could be determined. An allowable KG is generated for each wind heading and the lowest KG value corresponds to the worst wind heading/trim axis. The lowest allowable KG, and corresponding wind heading is the deciding stability requirement. The trim axis is always 90° to the wind heading. Plots of allowable KG versus the wind heading are shown Figure 17, which shows the variation in KG values as the wind moves around the vessel.

14

0

10

20

30

40

50

60

70

0 50 100 150 200 250 300 350 400

Wind Heading (Degrees)

Allo

wab

le K

G (m

)

Empty

Empty With Ballast

One third Oil

Half Oil

Full Oil

Figure 17: Allowable KG versus Wind Heading for Various Vessel Cargo Conditions

The limiting stability criteria occurred in fully loaded condition since it KG was the lowest. The lowest allowable KG values for each of the cargo conditions are listed in Table 13. Table 13: Allowable KG Values for the Five Vessel Cargo Conditions

Vessel Cargo Condition Allowable KG m (ft)

Empty without ballast 55.15 (180.9) Empty with ballast 32.71 (123.7)

1/3 oil without ballast 33.03 (108.4) ½ oil without ballast 28.87 (94.7)

Full oil without ballast 24.43 (80.2) The ABS MODU intact stability for the fully loaded condition had a range of stability of 26.17°. The input KG was 17.6 m (57.7 ft) and StabCAD calculated an allowable 24.43 m (80.2 ft) corresponding to an acceptable area ratio of 1.76. The results for the one-third oil condition were a range of stability was 32.13°, with an 18.33 m (60.1 ft) input KG and StabCAD calculated and allowable KG of 33.03 m (108.4 ft) for a perfect 1.4 area ratio. The intact stability plot for the empty ship is shown in Figure 18. The ABS MODU intact stability plots for the other cargo conditions are shown in Appendix Figures 9 thru 13 in Appendix II.

Figure 18: ABS MODU Intact Stability (Maximum Oil Capacity w/o Ballast)

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In the ABS MODU damaged stability analyses method was the same as the method used for damage analysis for the calculated KG values except the input KG values were the allowable KG values that were calculated in the ABS MODU intact analysis. For instance, an input KG of 24 m (78.7 ft) was used for the damage calculations based on the results from intact stability for allowable KG ran earlier for the fully loaded case. ABS MODU requires a 7° range of stability for one flooded compartment, therefore the 11.53° range of stability calculated for the fully loaded condition was acceptable. The range of Stability for the 1/3 third oil condition increased to 20.56° which was also acceptable. The ABS MODU damage stability plot is shown in Figure 19, and once again the ABS MODU damage stability plots for the other oil cargo conditions are shown in Appendix Figures 14 thru 16 in Appendix II.

Figure 19: Damage Stability (Maximum Oil Capacity w/o Ballast)

Hydrodynamics of Motions and Loading An FPSO can be exposed to a Hurricane, in which the wind direction is continuously changing and waves and loop currents are not collinear. For the safety of the FPSO in such a survival condition, it is very important to predict accurately the extreme response and the maximum mooring tension during the storm. The correct estimation of the motion natural periods is an important step in the design process. If the structures are excited with oscillation periods in the vicinity of the peak period of the wave spectrum, large motions are likely to occur. For a typical moored structure the natural periods in surge, sway and yaw are of the order of magnitude of minutes and will therefore be long relative to the wave periods occurring in the sea. The first task is calculating the JONSWAP wave spectrum for the environmental conditions. The parameters used for the spectrum are Table 14: JONSWAP Wave Parameters

Hs 12.2M Tp 14.3S Alpha 0.01264 Beta 1.25 Gamma 2.834 Where Hs is the significant wave height and Tp is the peak period based on the Metocean data. Figure 20 below depicts the results.

16

JONSWAP

02468

1012141618

0 0.1 0.2 0.3 0.4 0.5 0.6

Figure 20: JONSWAP Spectrum

The next step was to calculate the Response Amplitude Operator (RAO) in each motion behavior. The RAO of the ship was computed with the assumption there is no additional stiffness from mooring or risers since a flexible riser system is in operation. RAO is a linear transfer function from force to displacement with the force being the wave force represented by the wave spectral density. This task was accomplished using the SESAM, which is part of the DNV software. The program calculated the RAO in different headings using the Wadam file created for the GOM group by Halliburton. Since the FPSO is weathervaned, the primary concern was the data for the 0° heading. The spectral density of displacement of the ship was calculated using Equation 8.

)()()( 2 ωω SRAOSRij = (8) After computing the spectral density of the displacement, the significant amplitude of displacement was computed using Equation 9 2ij oR m= (9) where 0m is the area under the graph and was calculated using Simpson’s rule. Figure 21 below shows the JONSWAP spectrum compared to the heave response spectrum

JONSWAP vs Heave response spectrum

0

2

4

6

8

10

0 0.2 0.4 0.6

Frequency (rad/s)

HeaveJonswap

Figure 21: Comparison of Heave RAO and JONSWAP Spectrum

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Calculations for the pitch, roll, yaw, heave, surge and sway response are tabulated and graphed in Appendix IV. Table 15 below shows the peak in each case. Each response spectrum was then calculated for each degree of motion, then after plotting them, the peak response was observed and multiplied by the significant wave height of a 100 year storm to obtain the motion distance. Results are tabulated in Table 15, and the plots of each motion’s response spectrum are included in Appendix IV in Appendix Figures 17 thru 22. All spectrums have been multiplied by Hs = 12.2 m (40.0 ft) to include the motion distance traveled. Table 15 lists data calculated for each motion and the frequency it corresponds to. Table 15: Response Movement for All 6 Motions

Pitch (m) Roll (rad) Yaw (rad) Heave (m) Surge (m) Sway (rad) 0.0562 Small Small 9.49 8.29 Small The data obtained for the pitch, roll, yaw and sway motions was very small and will not affect the FPSO design. The heave and surge are also in a safe range and will not overstress the flexible risers. Figure 22 below is an illustration of the different motions.

Figure 22: Different Vessel Motions

Mooring/Station Keeping

Turret Design Environmental conditions are variable at every site. At any time the location of the wind and waves can rotate in any direction. For this reason the FPSO must be able to position itself in the direction of the oncoming wind and wave forces in order to minimize the forces acting on the hull. If the FPSO does not face the oncoming wind and waves, the forces would be applied to a larger area and put more pressure on the mooring system. The area represented by the port or starboard side of the FPSO is extremely large. This large area would allow extremely large forces to act on the hull. The forces could become so large that the FPSO could capsize or brake away from its mooring system. The use of a turret solves the problem of positioning the FPSO with only minor complications to either a new or existing design. A turret is a device, which allows a vessel to be moored, and with the vessel connected to the turret it has the ability to swivel 360 degrees. There are two main types of turrets, internal and external designs.

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An example of an external turret design is shown below in Figure 23. The external design can be mounted on the bow or the stern of the FPSO depending on the design setup. The external turret is a proven design that can handle moderate environments. The external design turret can be used on either a newly built or converted vessel. External turrets are typically far less expensive than the internal turret designs. One of the main flaws in the external design however is scheduled maintenance and repairs. The maintenance and repairs have to be done on the dangerous and small working area over the sea.

Figure 23: Example of External Turret on the Buffalo Venture FPSO (BHP)

The internal turret, on the other hand, is located inside the hull and goes through the bottom of the hull to connect to the mooring system. An internal turret can be designed for converted vessels, but tends to be expensive and difficult to construct. The internal turret is used mostly in newly built vessels that need to withstand heavy environmental conditions. An example of an internal turret is shown in Figure 24.

Figure 24: Example of Internal Turret on the Amoco Liuhua FPSO (BHP)

A vessel may decide to disconnect from its mooring system in order to avoid a large storm or an iceberg. A turret can be designed to disconnect from its mooring system in case of such an emergency. This process usually takes several hours to disconnect both the flow line and the mooring system. This procedure is used only in case of an emergency because of both the large cost to reconnect and loss of production time. All turrets are designed to rotate 360 degrees but some do so in different ways. There are three main types

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of rotation systems, passive, partially active, and active. The passive system cannot be used to lock the position of the vessel. The partially active system has the ability to either lock the turret or use thrusters to position the vessel in any direction, but does not require the use of these functions to operate. The active system relies solely on the thrusters to weathervane the vessel in the correct position. Table 16 is a list of advantages and disadvantages of each of the rotation systems. Table 16: Passive, Partially Active, and Active Systems

Type of System Advantages Disadvantages

Passive

• Smooth operation in calm weather

• Lower cost

• No ability to lock turret for maintenance

• Vessel may fish-tail in certain environmental conditions

• Extra movement may be uncomfortable for passengers

Partially Active

• Hold or position vessel for off loading

• Ability to lock turret for maintenance

Extra Cost

Active

• Hold or position vessel for off loading

• Ability to lock turret for maintenance

• Maintain position in mooring failure

• High Cost • Extra maintenance of

thrusters • Possibility of human

error • Possibility of loss of

weather veining

The FPSO design for the Voss Prospect site utilizes an internal turret design because of its capability to withstand the environmental conditions at the site. The design is for a newly built vessel so that the cost and installation are not large drawbacks. Safety is a large concern in the vessel design and the internal design offers a safe environment for scheduled maintenance and repairs. The design does not call for the use of a disconnectable type because the vessel will be designed to withstand the harshest storm conditions. The placement of the turret in a FPSO is a critical design decision. The further forward the turret is placed, the more the weather veining characteristics improves. There is a limitation to the location of the turret, however, because both the size and area of turret require space to operate properly. The turret is located twenty meters off the bow for the Voss design to maximize it weather-veining properties. With this turret placement, the vessel will not require any assistance in weather veining from thrusters. The turret must be designed to meet all the codes for a required area. A brief summary of the requirements required by the ABS code are listed below. The loads acting on an internal turret system include those basic loads induced by the mooring lines, riser, gravity, buoyancy, inertia, and hydrostatic pressure. Other loads, such as wave slam and loads resulting from misalignment and tolerance that may have an effect on the turret should also be considered in the design. In establishing the controlling turret design loads, various combinations of vessel loading condition ranging from the full to minimum storage load condition, wave directions and both collinear and non-collinear environments are to be considered.

A structural analysis using finite element method is required to verify the sufficient strength of the turret structure. The allowable vonMises stress of the turret structure is to be 0.6 of the yield strength for the operational intact mooring design conditions as specified in 3-3/1.3. A one-third increase in the allowable stress is allowed for the design storm intact mooring design conditions and for the design storm one line broken mooring condition to verify the turret structure mooring attachment locations and supporting structure

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The buckling strength check for the turret structures is to be performed using the criteria in Part 5 of the steel vessel rules, API RP 2U, 2V, or other proven approaches is needed to determine the fatigue lives for the turret components. Fatigue life of the turret should not be less than 3 times the design life for inspectable areas and 10- times for uninspectable areas.

With the vessel rotating freely to align with the weather a device is needed to transfer the fluid from the sea floor to the rotating vessel. Mounted on top of the turret is a swivel stack, which serves as the interface between the subsea production system and the topsides processing, and storage system. This component enables the vessel to freely weathervane, while transferring oil, water and gas streams (as well as electric power, utilities, chemicals and optical signals) without interruption. The swivel stack has multi product swivel modules stacked on top of each other. This modular concept offers complete flexibility for any project requirement and can be adapted to suit the required number of "flowpaths" and "volumes of flow". Below in Figures 25 and 26 are a typical lay-up and a true swivel stack.

Figure 25: Typical Turret and Swivel Stack Layout (SBM Offshore Systems)

Figure 26: Example of Swivel Stack (RDM Technology, 2001)

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The Voss FPSO design is to have a production of one hundred thousand barrels of oil a day. The turret will be designed to accommodate up to 20 flexible risers and electrical and other cables need for production. Swivel capabilities for the design swivel stack are listed below.

• One 12in water injection flow line • One 14in oil production flow line • One 10in fire water flow line • One 8in production test flow line • Two 6in gas lift/export flow lines • Two electric (power and control) flow lines

The turret has a 17 m (55.8 ft) diameter and a height of 30 m (98.4 ft) with a total weight of 1,000 m tons (624.4 s tons).

Figure 27: Turret Design (Dimensions in Meters)

Mooring Analysis Mooring systems are crucial elements in the design of any floating offshore facility. A vessel station keeping, or its ability to maintain position in a location, is directly related to the mooring systems strength. The two main types of mooring systems are either a spread mooring or a single point mooring. Spread mooring systems are most commonly used in unidirectional environments or on production systems that are insensitive to the direction of environmental loads, such as a semi-submersible or spar design. As the environmental conditions in the Gulf of Mexico are multidirectional, especially in the case of the 100 yr. design criterion, which corresponds to a hurricane causes this type of mooring system to not be ideal for an FPSO. Single point moorings are generally used on ship type vessels. In this mooring system the anchor legs connect to a single point. This can be an internal or external turret, a large buoy in CALM (Catenary Anchor Leg Mooring), or a SALM (Single Anchor Leg Mooring). These systems allow for the moored vessel to weathervane into environmental conditions. On a ship shaped vessel this corresponds to the bow sea loading condition, which is significantly smaller than its beam sea loading. The final type of system used for station keeping is the DPS or Dynamically Positioning Systems. A DPS uses thrusters to maintain a vessel station keeping. Dynamic positioning can be used as the only station keeping system of a vessel or can be combined with a mooring system to provide assistance.

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An internal turret design was chosen as the best mooring option for a new build FPSO in the Gulf of Mexico. It was chosen on its ability to weathervane into the environment. The internal turret also offered advantages over external equivalents as it increases accessibility for maintenance and modification. Also, the vessel provides added security and protection from the elements and possible damage due to accidental collisions.

Synthetic Mooring Lines Following industry trends a synthetic mooring system was designed alongside a conventional chain-wire system for comparison. The use of synthetic mooring lines for the permanent mooring of floating production systems is a relatively new innovation to the offshore industry. These synthetics primarily in the form of polyester and high modulus polyester (HMPE) offer advantages over conventional mooring systems which primarily consist of chain and wire. The advantages of these systems are that synthetics are much lighter than conventional chain and wire, which are made of steel. In fact the synthetics are nearly neutrally buoyant in seawater. Synthetics also have a greater strength to weight ratio than that of steel. The weight savings is particularly of value in deepwater applications where the great length of the mooring lines results in an extremely heavy mooring system if conventional lines are used. This is vital in floating productions systems such as semi-submersibles and spars which have limited buoyancy available which would be better used for supporting topside equipment rather than the mooring system. Though synthetic mooring systems have been used fairly extensively in drilling applications which are short duration, their use in permanent systems is relatively limited. There is a lot of research that is ongoing to determine the long term performance of synthetics in permanent mooring applications. One of the most important areas under study is creep. Creep is the elongation over time of a synthetic line under tension (DNV OS E301 2001). Potentially failure could occur in a line under constant tension called creep rupture. In permanent moorings the combination of creep and fatigue is also important. The most recent industry guideline for the use of synthetic mooring systems is API RP 2SM (API 2001). API RP 2SM primarily focuses on the construction and fatigue of synthetic lines. Currently, HMPE is not recommended for use in permanent moorings as it is more prone to secondary creep, which results in a permanent elongation of the lines increasing the chance for creep rupture. Furthermore, synthetic lines are more expensive than equivalent conventional mooring lines and require special handling as they are not as abrasion resistant as steel mooring lines. For a given line breaking strength synthetics also have a larger diameter. In practice this can require the use of special line laying vessels equipped to handle the larger diameter of the line.

Rules and Regulations The rules and regulations for the Voss FPSO mooring system can be obtained in API RP 2SK. These rules and regulations focus on two aspects of a mooring systems performance, these are tension limits and the maximum allowable offset. Table 17 outlines the tension limits alongside its respective factor of safety for damaged and intact conditions. A dynamic analysis for the intact and damaged conditions was performed for the Voss FPSO. The mooring also had to survive the 100 yr extreme environmental loading, which corresponds to a 100 yr hurricane at the Voss location. Table 17: Tension Limits and Equivalent Factors of Safety (API RP 2SK 1995)

Condition Analysis Method Tension Limit (percent

breaking strength) Equivalent Factor of

Safety Intact Dynamic 60 1.67 Damaged Dynamic 80 1.25 The maximum offset limits as recommended by API is 8% of the water depth for rigid risers and 10% of the water depth for flexible risers, this corresponds to a maximum offset limits for the Voss site at 1865 m (6118.8 ft) is 186.5 m (611.9 ft). The design constraints are summarized in Table 18. In the damaged condition the offset allowance is 12% to 15% of water depth.

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Table 18: Mooring Constraints for VOSS FPSO

Condition Allowable Offset Tension Factors of Safety Intact 187m (612ft) 1.67 Damaged 224m (734ft) 1.25

Catenary, Taut, and Semi-taut Mooring Three types of mooring systems were investigated for the mooring system. They are catenary, taut, and semi-taut moorings. A catenary mooring system utilizes the weight of the legs to provide a restoring force to the system. Catenary refers to the shape that a free hanging line assumes under the sole influence of gravity. In a catenary system, anchor chain lies on the seafloor and as the moored vessel moves under environmental loading it attempts to lift these lines. In a catenary mooring, the lines must terminate completely horizontal. This requires that the legs be relatively long compared to the water depth especially in deep water. Another drawback of a catenary system in deepwater is that the weight of the legs increases rapidly with the water depth. The defining characteristic of a taut mooring system is that the legs are pre-tensioned until they are taut. Another principal difference between catenary mooring and taut mooring is that the in taut mooring the anchoring device must support vertical loads. This requires the use of suction pile caissons or vertical load anchors (VLA), which have been specifically developed to resist vertical loads. A semi-taut system is a combination of the taut and catenary mooring systems, wherein some of the elements are taut and others catenary. In general, taut and semi-taut systems are better suited for deepwater applications as they require less of a seafloor spread than a catenary system. This results in an overall lighter and less costly design. A taut-leg mooring design was chosen as the best solution for the deepwater Voss site, as it would require a smaller spread and would reduce the total weight of the system.

MIMOSA MIMOSA is a mooring analysis program from MARINTEK. It is part of the DNV software suite SESAM. MIMOSA calculates the vessel’s motion and mooring line tensions due to environmental forces (MARINTEK 2002). MIMOSA version 5.6 was used to calculate the vessel’s offsets and line tension factors of safety through a frequency domain dynamic analysis. A description of the input files used can be found in Appendix III.

Design Process After choosing a taut-leg mooring system, the mooring design process started with two general design goals to design a wire-chain system and polyester Superline® and chain system which met the allowable offsets and tension factors of safety. Each initial system consisted of 8 lines equally spaced. A maximum 30% of breaking strength was allowed for pretension of the system. The number lines of were incremented in groups of 4 for a maximum number of sixteen. The first step was to choose an initial line diameter based upon the breaking strength. The initial line length was estimated using Equation 10. This corresponded to an initial approximate line length of 3000 m (10,000 ft). (Bauer 2003)

WaterDepth*6.1 (10)

The initial pretension was set at 15% of the line breaking strength. Mimosa was then used to analyze the system in the intact condition. The tension factors of safety and offsets obtained were then checked to see if they met the allowable limits. If the allowable limits were met the system was then analyzed in the broken state wherein the most critical line was broken and the results checked. If the system succeeded it was then optimized by adjusting the pretension, and line length until it approached the design limits as nearly as possible. There were three basic failure cases. The first case was that neither limit was met, most often this was due to lines that were simply too weak for the applied loads and thus required an increased line breaking strength and repeating the design process. The other two cases involved one of the limits being satisfied at

24

the expense of the other. In these cases the pretensions and line lengths were adjusted until the system satisfied both conditions, or it became apparent that changing the breaking strength of the line was necessary. If having reached the maximum line breaking strength available at which no adequate solution could be found then the total number of lines were increased, as was the case for an 8 line wire-chain system. The final phase involved checking that slackening did not occur on the leeward lines which would result in the non-chain sections of the line lying on the bottom in either of the intact or damaged conditions. As the FPSO weathervanes about the fixed mooring system it was also necessary to analyze different orientations of the FPSO with respect to the mooring system. This was accomplished by offsetting the line headings until the maximum loading case was obtained.

Catenary System For thoroughness a catenary design was also attempted using conventional chain-wire. No adequate solution was found. The weight loading on the mooring lines required that significant pretensions be set that would be larger than 30% breaking strength of the lines. At such a high pretension the fatigue life of the line is reduced. At these higher pretensions the systems analyzed also failed to meet the tension factors of safety. A possible solution might have been achieved by reducing the self weight through the use of synthetic lines and chain.

Mooring Results After extensive trial and error two mooring solutions were found, an 8 line polyester-chain, a 12 line wire-chain system, and a 16 line wire-chain system. As discussed in the design process section in order to optimize each design the breaking strength and pretension of the mooring lines were varied until the 100 yr hurricane, offset and tension limits were met. The analysis covered both intact and damaged conditions. All of the systems were similar in that the mooring lines of each system were arrayed such that all were equidistantly spaced. This was necessary in order to take into account the omni-directional loading conditions of a weathervaning FPSO.

8 Line Polyester-Chain The 8 line polyester system consisted 2700 m (8858 ft) of 221 mm (8.70 in) diameter Marlow Superline® and 200 m (656.2 ft) of 120.7 mm (4.75 in) K4 chain. The chain was divided into 50 m (164.0 ft) of fairlead and 150 m (492.1 ft) of anchor chain. The breaking strength of the polyester line was 13,345.2 kN (3000.12 kips) and that of the K4 chain was 13,710 kN (3082.13 kips). The eight mooring lines were spread at 45° intervals. Table 19: Line Particulars of Eight Line Polyester-Chain

Segment Line Type Diameter Breaking Strength

1 K4 Chain 120.7 mm

4.75 in 13,710 kN 3,082 kips

2 Marlow

Superline® 221 mm

8.7 in 13,345 kN 3,00 kips

3 K4 Chain 120.7 mm

4.75 in 13,710 kN 3,082 kips

The intact offset and safety factor for the line was 2% of water depth and 2.37. For the damaged condition an offset of 4% water depth and equivalent safety factor of 1.55 were calculated. The results are tabulated in Table 20.

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Table 20: Results of Eight Line System

Condition Offset F.S.

Intact 2.0 % WD

36.8 m(120 ft)<186.5 m 2.37>1.67

Damaged 11.2% WD

208.7 m(684 ft)<223.8 m 1.55>1.25

12 Line Wire-Chain This system utilized 2000 m (6562 ft) of 154.2 mm (6.07 in) jacketed spiral strand wire and 450 m (1476 ft) of 149.2 mm (5.87 in) K4 anchor chain divided into 50 m (164.0 ft) of fairlead and 1000 m (3280 ft) of anchor chain. The breaking strength of the wire was 16,906 kN (3800 kips). The fairlead K4 chain has a breaking strength of 19,577 kN (4400 kips) and the anchor chain has a breaking strength of 13,094 kN (2943 kips). The breaking strength of the anchor chain was reduced in order to reflect the lower tension on the bottom segments of the line. The decreased self weight that these lower segments results in the lowered tension. The mooring lines were spread at 45° intervals. Table 21: Line Particulars for Twelve Line System

Segment Line Type Diameter (mm/in)

Breaking Strength (kN)

1 K4 Chain 117.5 mm

4.63 in 13,094 kN 2,943 kips

2 Wire 142.9 mm

5.63 in 16,906 kN 3,800 kips

3 K4 Chain 149.2 mm

5.87 in 19,577 kN 4,400 kips

The calculated factors of safety for the intact and damaged condition are 2.28 and 1.40. The corresponding offsets were 10.0% water depth and 13.0% water depth. The results can be found in Table 22.

Table 22: Results for Twelve Line System

Condition Offset F.S.

Intact 10.0% WD

185.7 m (609 ft)<186.5 m 2.28>1.67

Damaged 13.0% WD

242.8 m (797 ft)>223.8 m 1.40>1.25

16 Line Wire-Chain The 16 line wire system consisted of 2800 m (9186 ft) of 142.9 mm (5.63 in) jacketed spiral strand wire and 266.5 m (874.3 ft) of 136.5 mm (5.37 in) K4 chain. The chain was divided into a 66.5 m (218.2 ft) of fairlead and 200 m (656.2 ft) of anchor chain. The breaking strength of the wire was 16,906 kN (3800 kips) and that of the K4 chain was 16,607 kN (3733 kips). The lines were spread at 22.5° intervals. The line particulars are summarized in Table 23.

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Table 23: Line Particulars for Sixteen Line Wire–Chain

Segment Line Type Diameter (mm/in)

Breaking Strength (kN)

1 K4 Chain 142.9mm

5.62in 14334/ 3,224

2 Wire 123.8m 4.87in 14339/ 3,224

3 K4 Chain 142.9mm

5.62in 14334/ 3,224 The calculated factors of safety for the intact and damaged condition are 2.05 and 1.34. The corresponding offsets were 9.9% water depth and 11.2% water depth. The results can be found in Table 24. Table 24: Results for Sixteen Line System

Condition Offset F.S.

Intact 9.9% WD

184.6(605ft)<186.5m 2.05>1.67

Damaged 11.2% WD

208.7m(684ft)<223.8m 1.34>1.25

Mooring Line Cost Analysis The cost of the mooring systems was calculated using cost information from Deepsea Engineering. The cost estimate of each mooring line element is based upon the material used, and is in the form of dollars per breaking strength and line length (Deepsea Engineering, 2002). In the cost analysis only the cost of the line elements were calculated. Hardware costs were included in the total project cost estimate. Table 25 shown below summarizes the cost analysis results. As seen in the table, which is based on line material costs the 8 line polyester system was the least expensive at $6.7 million dollars. The primary cause for the lessened cost of the synthetic system was a result of fewer lines being necessary along with having shorter element lengths. A more detailed cost breakdown of the mooring system can be found in Appendix III. Table 25: Mooring Line Cost Analysis Results

Mooring 8 Line Polyester 12 Line Wire 16 Line Wire Element Material

Unit cost ($/kN-m)

Cost ($)

Cost ($)

Cost ($)

Fairlead Chain 0.034 $23,307 $33,281 $38,224 Anchor Chain 0.034 $93,228 $445,196 $114,961

Wire 0.02 - $676,240 $929,992 Polyester 0.02 $720,630 - -

Cost per

Line $837,165 $1,154,717 $1,083,177 Total $6,697,320 $13,856,603 $17,330,836

Comparison of Results The offset and tension factor of safety results are compared in Figures 28 and 29. The 8 line polyester Superline® system outperformed the other systems for both conditions. The great performance difference is due to the unique properties of the synthetic material. These properties include the greatly reduced weight and elastic properties of the material, which results in a greater portion of the loads versus the self weight being exerted on the lines. This is very critical in deepwater as the line lengths required are significant. The chain wire systems proved very difficult to optimize as they required high pretensions to offset their

27

high self weight and maintain a reasonable offset, which reduced the tension factors of safety. The wire-chain systems were very stiff and the responded sharply to changes in the line characteristics.

0.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

14.0%

% WD 2.0% 4.0% 10.0% 13.0% 9.9% 11.2%

8 Line Polyester

Intact

8 Line Polyester Damaged

12 Line Wire Intact

12 Line Wire Damaged

16 Line Wire Intact

16 Line Wire Damaged

Damaged Offset Limit

Intact Offset Limit

Figure 28: Comparison of Offsets

0

0.5

1

1.5

2

2.5

Tesi

on F

acto

r of S

afet

y

F.S. 2.37 1.55 2.28 1.4 2.05 1.34

8 Line Polyester

Intact

8 Line Polyester Damaged

12 Line Wire Intact

12 Line Wire

Damaged

16 Line Wire Intact

16 Line Wire

Damaged

Intact F.S.

Damaged F.S.

Figure 29: Comparison of Tension Factors of Safety

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Mooring Recommendation The mooring analysis showed that it was possible to moor the Voss FPSO using a variety of different systems. Conventional mooring systems were analyzed alongside synthetic designs. The synthetic system significantly outperformed the conventional system. However, these results must be weighed against the unknown long term performance of synthetics in permanent moorings. Some of these issues include creep rupture and the overall durability of the materials. The best overall mooring system design is the 8 line polyester system. First this system has the best offsets (2% - 4% WD) and tension factors of safety (2.37 & 1.55) in both the intact and damaged conditions. Secondly, it requires only 8 lines versus 12 lines for the nearest alternative. The reduction in the number of lines and therefore hardware results in a lower mooring system cost of $6.7 million dollars. The particulars of the final design can be seen in Table 26. In order to account for wear and tear overtime a damage allowance of 8 mm (0.315 in) would be added to the design line diameter (API 2001). Table 26: Particulars of Final Design

Segment Line Type Diameter Breaking Strength

Fairlead 50m K4 Chain

120.7mm+8mm 4.75in

13,710kN 3,082kips

Main Section 2700m

Marlow Superline®

221mm +8mm 8.7in

13,345kN 3,00kips

Anchor 150m K4 Chain

120.7mm+8mm 4.75in

13,710kN 3,082kips

Offloading For the Gulf of Mexico Keathley Canyon area, the use of shuttle tankers to export crude oil from the FPSO is the most feasible option for a number of reasons:

1) The field is in very deep water of more than 1865 m (6,120 ft) and no pipeline infrastructure exists there.

2) The use of pipelines is not the most efficient method of production. 3) Shuttle tankers operate at a very low capex since they are usually leased on a long term daily rate

or, in the case of ConocoPhillips, owned by the oil company and available to serve the designed FPSO.

4) Although the opex of shuttle tanker use is higher than it is for a pipeline system, the benefit lies in its proportionality to the FPSO production. When the field production falls well below its peak period, oil tanker offloading can be made less frequently thus saving money on the opex.

The main disadvantage in shuttle offloading is its vulnerability to weather conditions, hurricanes, storms and environmental conditions that generate high significant wave heights disrupting the offloading process. This disruption is balanced by the FPSO’s ability to store oil in its tanks; this is also one of the main reasons why more and more companies have selected to use FPSO over other production platforms like TLPs and semi-submersibles. Two main options for offloading have been considered. The first option is tandem offloading, which means that shuttle tankers and the FPSO are positioned behind each other. Discharge can be accomplished either at the bow or the stern, using either a BLS (bow loading system) or a SDS (stern discharge system). The second option is offloading side by side, in which the tanker is positioned at the side of the FPSO. After an extensive study of the weather conditions at the Gulf of Mexico, side by side offloading was deemed unfeasible because it needs a more benign environment. The last option is offloading through a buoy, which is located at distance from the FPSO.

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Since the GOM FPSO is designed for an all year round production that is it can function under severe weather conditions, offloading systems need to be reliable to ensure that production never shuts down. Offloading rates depend on the kind of pump used and the hose diameter. Pump options are as follows:

1) Diesel direct drives centerline located at the machinery space. 2) Diesel caisson pumps located at the main decks. 3) Diesel/hydraulic drive caisson pumps with deck mounted pumps and remote drivers.

Different factors go into the pump selection process, these factors include the oil viscosity, such as its API gravity and other properties. For the Keathley canyon field, it is expected to produce sweet-light crude oil with API gravity ranging from 27 to 40 degrees containing 0.5 to 2% Asphaltene and 2 to 6% Paraffin. Rules and regulations concerning driver requirement, batteries, hydraulic starting, aspiration air, exhausts, oil storage can all be found in the following regulation codes

• ABS, chapter 3, section 8, subsection 5. • DNV, chapter 2.

Gas Processing A large amount of gas is pumped with the oil; therefore gas-processing facilities are located on the FPSO to separate the gas. The size of these processing facilities depends mainly on the gas to oil ratio. Gas pipelines are relatively cheap to install and operate. A gas pipeline system is to be installed and ready for gas export to the southern United States. In the Gulf of Mexico gas flaring is not allowed unless there is an emergency situation. To meet American Bureau of Shipping (ABS) regulations, flares and vents for hydrocarbon gas disposal are located at the opposite end of the crew quarters and in the direction of the prevailing winds to limit the exposure of personnel to the toxic flare exhaust. The sizing of relief devices and the flare system are implemented according to the API codes of practice, API RP 520 sizing, selection and installation of pressure relieving devices in refineries and API RP 521 guide for pressure relieving and depressing systems.

Water Injection The injection of high-pressure water provides the reservoir with the pressure support needed. Water injected may be seawater provided that it is filtered and the oxygen is removed from it. The tower for the treatment of water is designed using either vacuum deaeration or nitrogen stripping. The injection of water into the well is accomplished using a single high-powered centrifugal pump.

Water Production Handling and Disposal Water produced from the well may be reinjected for reservoir support without being treated. It can also be mixed with treated seawater on the condition that both fluids are compatible. If for any reason the injection pump ceases to work for extended period of time, water can be stored on board for a short period or discharged over board providing that its oil content specification does not exceed 48 ppm oil in water according to legislation enacted by Congress. A flow diagram for the water treatment facility is shown in Figure 30.

Figure 30: Water Treatment Facility on Board

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Shuttle tankers Shuttle tanker offloading is designed to maximize production time by preventing it from shutting down due to full tanks or harsh weather. Most shuttle tankers will be dynamically positioned with around 98% reliability even in harsh conditions. According to a recent study for the offshore industry, shuttle tankers have been observed to be able to remain connected under the following conditions outlined in Table 27. Table 27: Criteria for Shuttle Tanker Connection

Criteria

Connection

Disconnection

Significant wave height (m)

4.5

5.5-6

Maximum wave height (m)

8 9.5

Maximum wave period (s)

15 15

Wind speed (knots) 35-40 35-40

Visibility (m) 500-800

Pumps and Hoses According to API standard 610, eighth edition, pumps must be designed for a service life of 20 years of which it should function for at least a 3 years uninterrupted period. Several factors were considered for the pump selection processes, which were the oil specific gravity, viscosity, head, temperature and flow rate needed. To achieve the flow rates needed, 2 main pumps working full time and one emergency pump are installed. The design requires a pump that can produce a flow rate of 3000 m3/hr. For the pump selection process, pump flow software with catalogs of all available pumps were used. Input for the software is tabulated in Table 28 below. Table 28: Input for Pump Selection

API Gravity 40 degrees Specific Gravity 0.825

Viscosity 2.5 cP Flow rate needed 3000 m3/hr.

Head 27 m The software returned a list of pumps that meet the design criteria, and all of them were the horizontally split case (HSC) pumps. HSC pumps are centrifugal double suction pumps that are designed for a high flow rate. From the available list, the best pump had to meet the minimum design criteria and the comparison at the end was based on whichever one had the lowest Net Positive Suction Head required (NPSHr) . The selection yielded that the 340_HSC-XHD 20*24-27 X-HD pump would be the best for the design goals. The pump has the following characteristics listed in Table 29.

Pump Layout Table 29: Pump Characteristics

Type 34-_HSC Speed 900 RPM Efficiency 74 % Electricity consumption 210 kw NPSHr 3 m Diameter 21.5 in

Reducing the time required for offloading crude oil from the FPSO is an economic trade off between an increase in capex and loading efficiency. The faster the transfer rate is, the less the shuttle tanker would be required to be in close proximity of the FPSO, which reduces risk and increases production. On the other

31

hand, an increase in the transfer rate requires bigger pumps that are more expensive. The most desirable transfer time is in the range of 15 to 20 hours. Two alternatives exist for the pump layout, they can either be installed in a series or parallel. Running 2 different models have yielded that two pumps in parallel are the most efficient way to produce the desired flow rates. Figure 31 below is a graph for the pump with the desired flow rates.

Figure 31: Two Pumps in Parallel.

Options for the hose system was limited to two alternatives, a reel system where the hose is stored in a hydraulic reel and a chute system where the hose is stored in a long cradle alongside of the deck. Due to the large diameter of the hose and its relatively long length, the chute system is the most economical despite the high wear and tear rate associated with it.

Power Generator Power generation is accomplished through a GE generator that provides around 48 MW of electricity. It is a dual fuel system that runs on Natural gas extracted from the field and diesel fuel in case of emergencies. The gas consumption of the generator is around 8% of the total gas output from the field.

Cost Estimate The cost estimate was calculated using unit cost for different parts and procedure required to complete and install the design. The unit cost of different components and procedure were provided by ConocoPhillips and multiplied by different weights, units, and days that were calculated for the design. In the Table 30 below is a complete breakdown of all the unit cost required to complete the building and installation of the Voss FPSO. The cost of the hull is large compared to a past project conducted by ConocoPhillips. Mr. Noble advised the GOM team that the cost of the hull should be about one third of the topside cost, but the over all cost estimation is in the right area for a primary design. The mooring line cost estimation was defined by its braking strength and line length. The transport times were calculated for the hull being built in Korea and the mooring lines being built in the United States. The total cost of the project is $492 million dollars. The cost of the FPSO is a large estimate that includes many over estimations.

32

Table 30: Cost Estimate for FPSO Design

Hull Unit Cost Total Hull Steel Weight 54000 mt $2,500 $135,000,000

Hull Outfitting Weight 13% steel $17,550,000 Accommodation Weight 800 mt $18,500 $14,800,000

Corrosion Protection 3% steel $4,050,000 Painting, Insulation, Fireproofing 8% Top Side $18,606,640 Land out, commission, yard cost 1250000 fixed $1,250,000 $191,256,640

Topside Weight Generator 1 1600 mt $9,000 $14,400,000

Electric and Electronic weight 700 mt $4,000 $2,800,000 Other 160 mt $3,500 $560,000

Hydraulic Power Unit 1500 mt $8,000 $12,000,000 Water Injection 1 1200 mt $20,000 $24,000,000 Electrical Room 850 mt $5,000 $4,250,000

Generator 2 985 mt $9,000 $8,865,000 Process Water 1350 mt $17,000 $22,950,000

Separation 1700 mt $16,000 $27,200,000 Separation 1700 mt $16,000 $27,200,000

Gas Compression 3546 mt $23,000 $81,558,000 Crane 1 125 mt $3,200 $400,000 Crane 2 125 mt $3,200 $400,000

Installation 30 days $100,000 $3,000,000 Hook-up and Commissioning 30 days $100,000 $3,000,000 $232,583,000

Turret and Swivel Stack 6000 mt $5,500 $33,000,000 Risers 45 $17,000 $765,000 $33,765,000

Mooring Line 8 lines $837,165 $6,697,320

Connectors 8 unit $12,000 $96,000 Anchors 8 unit $225,000 $1,800,000 $8,593,320

Off Loading Hoses 25 mt $8,000 $200,000

Hawser 20 mt $4,500 $90,000 Chute 21 mt $4,500 $94,500 $384,500

Transport Hull 60 days $150,000 $9,000,000

Mooring 5 days $110,000 $550,000 $9,550,000Installation

Hull 15 days $500,000 $7,500,000 Derrick barge to pre-install mooring 25 days 400000 $10,000,000

Base port for Derrick Barge fixed 900000 $900,000 Transport Mooring components 10 days 110000 $1,100,000

AHTS to hook up moorings fixed 900000 $900,000 Base port for AHTS fixed 200000 $200,000

AHTS Mooring hookup 8 unit 90000 $720,000 $21,320,000Engineer Management 10 % $44,731,495

Total $492,046,440

33

Summary and Conclusions In summary the Gulf of Mexico team consisting of Chris Chipuk, McAlan Clark, Caroline Hoffman, James Peavy, Ramez Sabet, and Baron Wilson designed an FPSO for the Gulf of Mexico with the help of ConnocoPhilips and other engineering firms. The design calls for the use of a 2 MMBBL barrel capacity double hull vessel. The double hull satisfies the requirements of the Oil Pollution Act of 1990. The vessel is designed with extra capacity and deck space for possible future expansion. The use of an internal turret was chosen because the FPSO must be weathervaned into the direction of the varying weather conditions. It was found that the vessel maximum is applied by the 100 year hurricane storm in the Gulf of Mexico causing a maximum bow load of 988 kips (4395 KN). With the maximum load and turret design, a number of different mooring options were analyzed to find the one with the best safety factor and the minimum cost. The best overall mooring system design is the 8 line polyester system. The system has the best offsets (2% - 4% WD) and tension factors of safety (2.37 & 1.55) in both the intact and damaged conditions. The system also only requires only 8 lines versus 12 lines for the nearest alternative. The reduction in the number of lines and therefore hardware results in a lower mooring system cost of $6.7 million dollars. The vessel design was analyzed through many different simulations in StabCAD to find its range of stability. It was found the lowest stability was when the vessel was at its fully loaded condition with a draft of 21.5 m (70.5 ft) and had an intact stability of 26.17˚ with allowable KG of 24.43m (80.15 ft) and Damaged stability of 11.53˚ with a KG of 24.0 m (78.7 ft). The vessel meets all ABS and MODU rules and regulations. The offloading system selected is a floatable hose off the stern of the vessel. The hose is stored in a shoot that will run the length of the deck so that it can be easily examined for flaws or damages. The design proved to be the simplest and safest, and most cost effective process. The Jones Act requires that the shuttle tankers be built in America. The overall cost of the building and transportation and installation of the vessel and its mooring will cost approximately $492 million dollars with should return a profit on the project and lead to future expansion in the Gulf of Mexico.

34

References American Bureau of Shipping (ABS), Inc. Guide for Building and Classing Facilities on Offshore

Installations. Houston, 2000. American Bureau of Shipping (ABS), Inc. Guide for Building and Classing Floating Production, Storage,

and Offloading Systems. New York, 1996. American Bureau of Shipping (ABS), Inc. Guidance Notes on Risk Assessment Applications for the

Marine and Offshore Oil and Gas Industries. Houston, June 2000. American Petroleum Institute (API). Recommended Practice for Design and Analysis of Stationkeeping

Systems for Floating Structures, API Recommended Practice 2SK Second Edition. Washington, December 1996.

Bauer, T. Personal Communication. Halliburton: Houston, 2003. Deepsea Engineering & Management Ltd. Fibre Reinforced Plastic Mooring Lines Joint

IndustryProposal, Appendix to the JIP Participation Agreement. November 11, 2001. Det Norske Veritas. Position Mooring, Offshore Standard DNV-OS-E301. June 2001. Environmental Protection Agency. http://www.epa.gov/region09/waste/sfund/oilpp/opa.htm. Oil Pollution

Act of 1990. 2003. King, J. R. Personal Communication. ConocoPhillips: Houston, 2003. Lewis E. V. Principles of Naval Architecture, Second Edition. Jersey City, 1988. Maari, R. Single Point Moorings. Monaco, 1985. RDM Technology. http://rdmt.nl./mechanicalengineering/index2.htm?swivelstack.htm. 2003. SBM Offshore Systems. http://info.ogp.org.uk/metocean/FloatingSystems/presentations/Pollock.pdf.

2003. Steube, C. Personal Communication. ConocoPhillips: Houston, 2003. UKOOA. UKOOA FPSO Design Guidance Notes for UKCS Service. Glasgow, 2002. Vinnem, J. E. R&D into Operational Safety Aspects of FPSO/Shuttle Tanker Collision Hazard. SINTEF,

1999. Zentech Inc. StabCAD User’s Manual. Houston, 1999.

Appendix I: Environmental Loads Appendix Table 1: 100 Year Tropical Environmental Load (Fully Loaded Condition: Draft=21.5m)

Wind Force

Wind Speed Vw(knots) 75.810 alpha 1.180 Projected Areas ft2 (Above Water Line)

Bow Seas Beam Seas Cs Ch A(Bow) AChCs Cs Ch A(Beam) AChCs

A1 1.0 1.0 2202.8 2202.8 1.0 1.0 11491.0 11491.0

A2 1.0 1.0 3726.85 3726.9 1.0 1.0 2337.7 2337.7

A3 1.0 1.2 6568.6712 8079.5 1.0 1.2 4120.3 5067.9

A4 1.5 1.4 148.2 311.1 1.5 1.4 148.2 311.1 A5 1.0 1.0 7103.9 7103.9 1.0 1.0 33464.5 33464.5

A6 1.0 1.0 2337.7 2337.7 1.0 1.0 2337.7 2337.7

A7 1.0 1.2 4921.5 6053.4 1.0 1.2 4921.5 6053.4

A8 1.0 1.4 1599.5 2239.3 1.0 1.4 1599.5 2239.3

A9 1.5 1.2 172.1 317.6 1.5 1.2 172.1 317.6

A10 1.5 1.0 484.1 726.2 1.5 1.0 484.1 726.2

Sum(CsChA) 33098.3 Sum(CsChA) 64346.5

Force(Kips) Fwx 900.5 Fwy 1750.7

Quartering Seas

Theta 45.0

Force(Kips) Fwq 1767.5

Current Force

Current Speed Vc(knot) 2.720 Bow Seas Beam Seas Oblique Environment

Cs(Bow Sea) 0.016 SVc2 4145994.203 SVc2 4145994.203 Theta 45.000

Csy(Beam Sea) 0.400 Fc(kips) 66.336 Fc(kips) 1658.398 Fc(kips) 1149.822

Weted Area 560390.652

Mean Wave Drift Force

Curve Fitting Formulae [x=Hs(ft), y=Force (kips)]

Bow Seas y=9.63ln(x)-14

Beam Seas y=2E-5X^4-5E-5X^3-0.1433X^2+7.3983*X-8.9346

Quartering Seas (Surge) y=0.9366x+1.2207

Quartering Seas (Sway) y=1E-5x^4-0.0003x^3-0.0638x^2+4.0954x-7.2682

Significant Wave Height 40.030 Bow Seas Beam Seas Quartering Seas

Force(Kips) 21.5 105.7 63.4

Total Environmental Forces

Force(Kips) Bow Seas Beam Seas Quartering Seas

Wind 900.5 1750.7 1767.5

Current 66.3 1658.4 1149.8

Mean Wave Drift Force 21.5 105.7 63.4

Total Force(Kips) 988.4 3514.9 2980.7

A-2

Appendix Table 2: 100 Year Tropical Environmental Load (1/3 Loaded Condition: Draft=10.42m)

Wind Force

Wind Speed Vw(knots) 75.810 alpha 1.180 Projected Areas ft2 (Above Water Line)

Bow Seas Beam Seas Cs Ch A(Bow) AChCs Cs Ch A(Beam) AChCs

A1 1.0 1.0 4383.8 4383.8 1.0 1.0 22869.1 22869.1

A2 1.0 1.0 3726.85 3726.9 1.0 1.0 2337.7 2337.7

A3 1.0 1.2 6568.6712 8079.5 1.0 1.2 4120.3 5067.9

A4 1.5 1.4 148.2 311.1 1.5 1.4 148.2 311.1 A5 1.0 1.0 7103.9 7103.9 1.0 1.0 33464.5 33464.5

A6 1.0 1.0 2337.7 2337.7 1.0 1.0 2337.7 2337.7

A7 1.0 1.2 4921.5 6053.4 1.0 1.2 4921.5 6053.4

A8 1.0 1.4 1599.5 2239.3 1.0 1.4 1599.5 2239.3

A9 1.5 1.2 172.1 317.6 1.5 1.2 172.1 317.6

A10 1.5 1.0 484.1 726.2 1.5 1.0 484.1 726.2

Sum(CsChA) 35279.4 Sum(CsChA) 75724.6

Force(Kips) Fwx 959.9 Fwy 2060.3

Quartering Seas

Theta 45.0

Force(Kips) Fwq 2013.5

Current Force

Current Speed Vc(knot) 2.720 Bow Seas Beam Seas Oblique Environment

Cs(Bow Sea) 0.016 SVc2 2908042.295 SVc2 2908042.295 Theta 45.000

Csy(Beam Sea) 0.400 Fc(kips) 46.529 Fc(kips) 1163.217 Fc(kips) 806.497

Weted Area 393063.675

Mean Wave Drift Force

Curve Fitting Formulae [x=Hs(ft), y=Force (kips)]

Bow Seas y=9.63ln(x)-14

Beam Seas y=2E-5X^4-5E-5X^3-0.1433X^2+7.3983*X-8.9346

Quartering Seas (Surge) y=0.9366x+1.2207

Quartering Seas (Sway) y=1E-5x^4-0.0003x^3-0.0638x^2+4.0954x-7.2682

Significant Wave Height 40.030 Bow Seas Beam Seas Quartering Seas

Force(Kips) 21.5 105.7 63.4

Total Environmental Forces

Force(Kips) Bow Seas Beam Seas Quartering Seas

Wind 959.9 2060.3 2013.5

Current 46.5 1163.2 806.5

Mean Wave Drift Force 21.5 105.7 63.4

Total Force(Kips) 1027.9 3329.3 2883.3

A-3

Appendix Table 3: 10 Year Tropical Environment Load with Extreme Eddy Current

(Fully Loaded Condition: Draft=21.5m)

Wind Force

Wind Speed Vw(knots) 50.540 alpha 1.180 Projected Areas ft2 (Above Water Line)

Bow Seas Beam Seas

Cs Ch A(Bow) AChCs Cs Ch A(Beam) AChCs

A1 1.0 1.0 2202.8 2202.8 1.0 1.0 11491.0 11491.0

A2 1.0 1.0 3726.85 3726.9 1.0 1.0 2337.7 2337.7

A3 1.0 1.2 6568.6712 8079.5 1.0 1.2 4120.3 5067.9

A4 1.5 1.4 148.2 311.1 1.5 1.4 148.2 311.1

A5 1.0 1.0 7103.9 7103.9 1.0 1.0 33464.5 33464.5

A6 1.0 1.0 2337.7 2337.7 1.0 1.0 2337.7 2337.7

A7 1.0 1.2 4921.5 6053.4 1.0 1.2 4921.5 6053.4

A8 1.0 1.4 1599.5 2239.3 1.0 1.4 1599.5 2239.3

A9 1.5 1.2 172.1 317.6 1.5 1.2 172.1 317.6

A10 1.5 1.0 484.1 726.2 1.5 1.0 484.1 726.2

Sum(CsChA) 33098.3 Sum(CsChA) 64346.5

Force(Kips) Fwx 400.2 Fwy 778.1

Quartering Seas

Theta 45.0

Force(Kips) Fwq 785.6

Current Force

Current Speed Vc(knot) 3.110 Bow Seas Beam Seas Oblique Environment

Cs(Bow Sea) 0.016 SVc2 5420154.430 SVc2 5420154.430 Theta 45.000

Csy(Beam Sea) 0.400 Fc(kips) 86.722 Fc(kips) 2168.062 Fc(kips) 1503.189

Weted Area 560390.652

Mean Wave Drift Force

Curve Fitting Formulae [x=Hs(ft), y=Force (kips)]

Bow Seas Y=9.63ln(x)-14

Beam Seas y=2E-5X^4-5E-5X^3-0.1433X^2+7.3983*X-8.9346

Quartering Seas (Surge) y=0.9366x+1.2207

Quartering Seas (Sway) y=1E-5x^4-0.0003x^3-0.0638x^2+4.0954x-7.2682 Significant Wave Height 26.240 Bow Seas Beam Seas Quartering Seas

Force(Kips) 17.5 95.1 57.6

Total Environmental Forces

Force(Kips) Bow Seas Beam Seas Quartering Seas

Wind 400.2 778.1 785.6

Current 86.7 2168.1 1503.2

Mean Wave Drift Force 17.5 95.1 57.6

Total Force(Kips) 504.4 3041.3 2346.3

A-4

Appendix Table 4: 10 Year Tropical Environment Load with Extreme Eddy Current

(1/3 Loaded Condition: Draft=10.42m)

Wind Force

Wind Speed Vw(knots) 50.540 alpha 1.180 Projected Areas ft2 (Above Water Line)

Bow Seas Beam Seas

Cs Ch A(Bow) AChCs Cs Ch A(Beam) AChCs

A1 1.0 1.0 2202.8 2202.8 1.0 1.0 11491.0 11491.0

A2 1.0 1.0 3726.85 3726.9 1.0 1.0 2337.7 2337.7

A3 1.0 1.2 6568.6712 8079.5 1.0 1.2 4120.3 5067.9

A4 1.5 1.4 148.2 311.1 1.5 1.4 148.2 311.1

A5 1.0 1.0 7103.9 7103.9 1.0 1.0 33464.5 33464.5

A6 1.0 1.0 2337.7 2337.7 1.0 1.0 2337.7 2337.7

A7 1.0 1.2 4921.5 6053.4 1.0 1.2 4921.5 6053.4

A8 1.0 1.4 1599.5 2239.3 1.0 1.4 1599.5 2239.3

A9 1.5 1.2 172.1 317.6 1.5 1.2 172.1 317.6

A10 1.5 1.0 484.1 726.2 1.5 1.0 484.1 726.2

Sum(CsChA) 33098.3 Sum(CsChA) 64346.5

Force(Kips) Fwx 400.2 Fwy 778.1

Quartering Seas

Theta 45.0

Force(Kips) Fwq 785.6

Current Force

Current Speed Vc(knot) 3.110 Bow Seas Beam Seas Oblique Environment

Cs(Bow Sea) 0.016 SVc2 5420154.430 SVc2 5420154.430 Theta 45.000

Csy(Beam Sea) 0.400 Fc(kips) 86.722 Fc(kips) 2168.062 Fc(kips) 1503.189

Weted Area 560390.652

Mean Wave Drift Force

Curve Fitting Formulae [x=Hs(ft), y=Force (kips)]

Bow Seas y=9.63ln(x)-14

Beam Seas y=2E-5X^4-5E-5X^3-0.1433X^2+7.3983*X-8.9346

Quartering Seas (Surge) y=0.9366x+1.2207

Quartering Seas (Sway) y=1E-5x^4-0.0003x^3-0.0638x^2+4.0954x-7.2682 Significant Wave Height 26.240 Bow Seas Beam Seas Quartering Seas

Force(Kips) 17.5 95.1 57.6

Total Environmental Forces

Force(Kips) Bow Seas Beam Seas Quartering Seas

Wind 400.2 778.1 785.6

Current 86.7 2168.1 1503.2

Mean Wave Drift Force 17.5 95.1 57.6

Total Force(Kips) 504.4 3041.3 2346.3

Appendix II: Stability and StabCAD

Prestab Graphics Input and Beta File Setup Process for StabCAD Analysis Preparing to run the StabCAD analysis for the FPSO began with completing the PreStab graphics input. In the PreStab graphics input the ship hull was drawn using joints that were connected with lines to form the ship panels. The first step was to orient the drawing area in the proper plane for setting the starboard panel plane view. Plane views allow the StabCAD operator to separate panels from the rest of the drawing for easier panel creation and modification. After defining the starboard plane view the joints that outlined the starboard panel were placed in the drawing area using the “Shift/Rotate” command from the joint menu. Then using the right hand rule the joints were connected together with lines rotating in a clockwise direction to create the starboard panel. Connecting the joints in a clockwise rotation enables StabCAD to recognize the direction of the water pressure as pushing inward from the outside of the hull. The portside panel was then created using the “Shift/Rotate” command by shifting the starboard panel 60 m in the y-direction. When using “Shift/Rotate” to copy a panel defining the plane view it resides in requires the use of the “Group ID” command under the elements menu. After defining the portside plane view the panels direction according to the right hand rule had to reversed using the “Reverse Direction” command under the elements menu so that the direction of the water pressure would be opposite of the starboard panel. For defining the remaining main and bottom deck, aft and bow end, and rake plane views the “Define by Joints” command from the plane menu was used. To define the plane by joints three of its outlining joints were selected with the mouse in the 3D drawing view then StabCAD automatically switched to the 2D plane view of the panel that was to be added. The appropriate direction for the water pressure was then selected for the remaining panels after which the drawing was completed. After completing the drawing the “Beta: Edit Text File” command selected from the input menu in the Master StabCAD menu driver was used to create the input file for the StabCAD analysis of the FPSO drawing. The Beta spreadsheet editor opened up showing all joint and panel information gathered from the drawing automatically. Some blank lines were then created to make room the cards used to setup the StabCAD data specifications.

STBOPT (stability options) KGPAR (parameters of allowable KG calculation) CFORM (specification for hydrostatic analysis) INTACT (specification for heel angles for intact stability) DRAFT (specification for stability analysis VCG) GRPDES (group identification description)

The STBOPT card was set up so that StabCAD would calculate the trim while heeling the model and generate wind loads and heeling arms for each angle of heel. In the KGPAR card 100 was keyed in under the “WIND INT 1” field for StabCAD to calculate the heeling arms for a wind velocity of 100 knots. Also in the KGPAR card, 1.4 was entered for the “AREA RATIO” field to satisfy the ABS MODU requirements. When setting up the CFORM card 1, 27, and 1 were keyed in for the “DRAFT / START,” “DRAFT / END” and “DRAFT / END” fields respectively for the hydrostatic analysis. The INTACT card was setup similarly by inputting the starting and ending heel angles, and the angle increment necessary for the intact stability heel angles. In the DRAFT card 25 meters was inputted for the ships normal operating draft and the vessels vertical center of gravity was set as 25 meters with zero values for the transverse and longitudinal centers of gravity. Inputting the VCG as 25 meters was a conservative assumption since a good VCG approximation still needs to be determined. The GRPDES cards were filled in with the appropriate panel ID’s, and labels required for StabCAD to organize the output after completing the analysis.

A-6

Intact Stability Plots for Calculated KG

Appendix Figure 1: Intact Stability (Light Ship w/o Ballast)

Appendix Figure 2: Intact Stability (Zero Oil with Full Ballast)

A-7

Appendix Figure 3: Intact Stability (1/3 Oil w/o Ballast)

Appendix Figure 4: Intact Stability (½ Oil w/o Ballast)

Appendix Figure 5: Intact Stability (Maximum Oil Capacity w/o Ballast)

A-8

Damaged Stability Plots for Calculated KG

Appendix Figure 6: Damaged Stability (1/3 Oil w/o Ballast)

Appendix Figure 7: Damaged Stability (½ Oil w/o Ballast)

Appendix Figure 8: Damaged Stability (Maximum Oil Capacity w/o Ballast)

A-9

ABS MODU Intact Stability Plots for Allowable KG

Appendix Figure 9: ABS MODU Intact Stability (Light Ship w/o Ballast)

Appendix Figure 10: ABS MODU Intact Stability (Zero Oil with Full Ballast)

A-10

Appendix Figure 11: ABS MODU Intact Stability (1/3 Oil w/o Ballast)

Appendix Figure 12: ABS MODU Intact Stability (½ Oil w/o Ballast)

Appendix Figure 13: ABS MODU Intact Stability (Maximum Oil Capacity w/o Ballast)

A-11

ABS MODU Damaged Stability Plots for Allowable KG

Appendix Figure 14: ABS MODU Damaged Stability (1/3 Oil w/o Ballast)

Appendix Figure 15: ABS MODU Damaged Stability (½ Oil w/o Ballast)

Appendix Figure 16: ABS MODU Damaged Stability (Maximum Oil Capacity w/o Ballast)

A-12

Example StabCAD Input File ALPID 3D VIEW 0.832 0.555 -0.148 0.222 0.964 1 ALPID GLOBAL XY PL 10.000 10.000 ALPID Global YZ Pl 10.000 10.000 ALPID Global XZ Pl 10.000 10.000 ALPID STBD SIDE -20.00 55.000-20.00 -20.0010.000 ALPID PORT SIDE 33.000 10.00033.000 33.00010.000 ALPID MAIN DECK 33.00010.000 33.000 10.00033.000 ALPID BOTTOM DECK 10.000 10.000 ALPID AFT END 10.000 10.00010.000 ALPID FWD END 60.000-20.00 5.00060.00020.000 5.00060.000-20.0010.000 ALPID RAKE 55.000-20.00 55.00020.000 60.000-20.00 5.000 ALPID STARBOARD -33.00 10.000-33.00 -33.0010.000 ALPID CREW BOW 45.000-23.0033.00045.00023.00033.00045.00023.00053.000 ALPID CREW STAR 15.000-23.0033.00045.000-23.0033.00045.000-23.0053.000 ALPID CREW AFT 15.000-23.0033.00015.00023.00033.00015.00023.00053.000 ALPID CREW PORT 15.00023.00033.00045.00023.00033.00045.00023.00053.000 ALPID CREW TOP 15.000-23.0053.00045.000-23.0053.00045.00023.00053.000 ALPID BOW END 310.00 310.0010.000 310.0010.00010.000 ALPID PORT 3D1 -0.718 0.696 -0.051-0.053 0.997 1 ALPID BOW 3D1 -0.032 0.999 0.032 0.001 0.999 1 ALPID PORT BOW 3D -0.707 0.707 -0.424-0.424 0.800 1 ALPID AFT 3D1 0.088-0.996 0.034 0.003 0.999 1 ALPID BOW PORT 3D2 -0.094 0.996 -0.132-0.012 0.991 1 ALPID BOW PORT3D3 -0.604 0.797 -0.127-0.096 0.987 1 ALPREF 3D View 0.0 0.0 1 GULF OF MEXICO FPSO -- INTACT STABILITY ANALYSIS STBOPT CALC ME ME KGPAR 51.4 1.4 INTACT 0. 85. 1. CFORM 1. 27. 1. DRAFT 21.5 17.6 USER USER DWNFLD HATCH 139 DWNFLD HATCH 137 DWNFLD HATCH 223 DWNFLD HATCH 221 DWNFLD W VENT 273 DWNFLD W VENT 274 DWNFLD W VENT 275 DWNFLD W VENT 276 DWNFLD W VENT 277 DWNFLD W VENT 278 DWNFLD W VENT 279 DWNFLD W VENT 280 DWNFLD W VENT 281 DWNFLD W VENT 282 GRPDES STB STARBOARD PRT PORT GRPDES TOP MAIN DECK BOT BOTTOM DECK GRPDES STE AFT END BOW BOW END GRPDES CRE CREW QUARTERS OIL OIL CARGO GRPDES BBL BOW BALLAST TANKS ABL AFT BALLAST TANKS GRPDES SID SIDE BALLAST TANKS BTL BOTTOM BALLAST JOINT 1 0.000 16.000 33.000 JOINT 2 1.000 21.200 33.000 JOINT 3 2.000 23.210 33.000

A-13

JOINT 4 3.000 24.660 33.000 JOINT 5 4.000 25.800 33.000 JOINT 6 5.000 26.720 33.000 JOINT 7 6.000 27.490 33.000 JOINT 8 7.000 28.120 33.000 JOINT 9 8.000 28.650 33.000 JOINT 10 9.000 29.080 33.000 JOINT 11 10.000 29.420 33.000 JOINT 12 11.000 29.670 33.000 JOINT 13 12.000 29.860 33.000 JOINT 14 13.000 29.960 33.000 JOINT 15 14.000 30.000 33.000 JOINT 16 0.000-16.000 33.000 JOINT 17 1.000-21.200 33.000 JOINT 18 2.000-23.210 33.000 JOINT 19 3.000-24.660 33.000 JOINT 20 4.000-25.800 33.000 JOINT 21 5.000-26.720 33.000 JOINT 22 6.000-27.490 33.000 JOINT 23 7.000-28.120 33.000 JOINT 24 8.000-28.650 33.000 JOINT 25 9.000-29.080 33.000 JOINT 26 10.000-29.420 33.000 JOINT 27 11.000-29.670 33.000 JOINT 28 12.000-29.860 33.000 JOINT 29 13.000-29.960 33.000 JOINT 30 14.000-30.000 33.000 JOINT 31 0.000 16.000 10.000 JOINT 32 1.000 21.200 5.641 JOINT 33 2.000 23.210 4.000 JOINT 34 3.000 24.660 2.859 JOINT 35 4.000 25.800 2.000 JOINT 36 5.000 26.720 1.340 JOINT 37 6.000 27.490 0.835 JOINT 38 7.000 28.120 0.461 JOINT 39 8.000 28.650 0.202 JOINT 40 9.000 29.080 0.050 JOINT 41 10.000 29.420 0.000 JOINT 42 11.000 29.670 0.000 JOINT 43 12.000 29.860 0.000 JOINT 44 13.000 29.960 0.000 JOINT 45 14.000 30.000 0.000 JOINT 46 0.000-16.000 10.000 JOINT 47 1.000-21.200 5.641 JOINT 48 2.000-23.210 4.000 JOINT 49 3.000-24.660 2.859 JOINT 50 4.000-25.800 2.000 JOINT 51 5.000-26.720 1.340 JOINT 52 6.000-27.490 0.835 JOINT 53 7.000-28.120 0.461 JOINT 54 8.000-28.650 0.202 JOINT 55 9.000-29.080 0.050 JOINT 56 10.000-29.420 0.000 JOINT 57 11.000-29.670 0.000 JOINT 58 12.000-29.860 0.000 JOINT 59 13.000-29.960 0.000

A-14

JOINT 60 14.000-30.000 0.000 JOINT 61 283.000 30.000 33.000 JOINT 62 285.000 29.930 33.000 JOINT 63 287.000 29.730 33.000 JOINT 64 289.000 29.390 33.000 JOINT 65 291.000 28.910 33.000 JOINT 66 293.000 28.280 33.000 JOINT 67 295.000 27.500 33.000 JOINT 68 297.000 26.530 33.000 JOINT 69 299.000 25.380 33.000 JOINT 70 301.000 24.000 33.000 JOINT 71 303.000 22.360 33.000 JOINT 72 305.000 20.400 33.000 JOINT 73 307.000 18.000 33.000 JOINT 74 309.000 14.970 33.000 JOINT 75 310.000 13.080 33.000 JOINT 76 311.000 10.770 33.000 JOINT 77 312.000 7.680 33.000 JOINT 78 313.000 0.000 33.000 JOINT 79 283.000-30.000 33.000 JOINT 80 285.000-29.930 33.000 JOINT 81 287.000-29.730 33.000 JOINT 82 289.000-29.390 33.000 JOINT 83 291.000-28.910 33.000 JOINT 84 293.000-28.280 33.000 JOINT 85 295.000-27.500 33.000 JOINT 86 297.000-26.530 33.000 JOINT 87 299.000-25.380 33.000 JOINT 88 301.000-24.000 33.000 JOINT 89 303.000-22.360 33.000 JOINT 90 305.000-20.400 33.000 JOINT 91 307.000-18.000 33.000 JOINT 92 309.000-14.970 33.000 JOINT 93 310.000-13.080 33.000 JOINT 94 311.000-10.770 33.000 JOINT 95 312.000 -7.680 33.000 JOINT 96 313.000 0.000 33.000 JOINT 97 283.000 30.000 0.000 JOINT 98 285.000 29.930 0.000 JOINT 99 287.000 29.730 0.000 JOINT 100 289.000 29.390 0.000 JOINT 101 291.000 28.910 0.000 JOINT 102 293.000 28.280 0.000 JOINT 103 295.000 27.500 0.000 JOINT 104 297.000 26.530 0.000 JOINT 105 299.000 25.380 0.000 JOINT 106 301.000 24.000 0.000 JOINT 107 303.000 22.360 0.036 JOINT 108 305.000 20.400 0.325 JOINT 109 307.000 18.000 0.923 JOINT 110 309.000 14.970 1.876 JOINT 111 310.000 13.080 3.276 JOINT 112 311.000 10.770 5.340 JOINT 113 312.000 7.680 8.803 JOINT 114 313.000 0.000 14.000 JOINT 115 283.000-30.000 0.000

A-15

JOINT 116 285.000-29.930 0.000 JOINT 117 287.000-29.730 0.000 JOINT 118 289.000-29.390 0.000 JOINT 119 291.000-28.910 0.000 JOINT 120 293.000-28.280 0.000 JOINT 121 295.000-27.500 0.000 JOINT 122 297.000-26.530 0.000 JOINT 123 299.000-25.380 0.000 JOINT 124 301.000-24.000 0.000 JOINT 125 303.000-22.360 0.036 JOINT 126 305.000-20.400 0.325 JOINT 127 307.000-18.000 0.923 JOINT 128 309.000-14.970 1.876 JOINT 129 310.000-13.080 3.276 JOINT 130 311.000-10.770 5.340 JOINT 131 312.000 -7.680 8.803 JOINT 132 313.000 0.000 14.000 JOINT 133 10.000 23.000 33.000 JOINT 134 10.000 23.000 53.000 JOINT 135 10.000-23.000 33.000 JOINT 136 10.000-23.000 53.000 JOINT 137 40.000 23.000 33.000 JOINT 138 40.000 23.000 53.000 JOINT 139 40.000-23.000 33.000 JOINT 140 40.000-23.000 53.000 JOINT 141 52.500-27.000 2.000 JOINT 142 52.500 -9.000 2.000 JOINT 143 52.500 9.000 2.000 JOINT 144 52.500 27.000 2.000 JOINT 145 52.500-27.000 29.000 JOINT 146 52.500 -9.000 29.000 JOINT 147 52.500 9.000 29.000 JOINT 148 52.500 27.000 29.000 JOINT 149 96.600-27.000 2.000 JOINT 150 96.600 -9.000 2.000 JOINT 151 96.600 9.000 2.000 JOINT 152 96.600 27.000 2.000 JOINT 153 96.600-27.000 29.000 JOINT 154 96.600 -9.000 29.000 JOINT 155 96.600 9.000 29.000 JOINT 156 96.600 27.000 29.000 JOINT 157 140.700-27.000 2.000 JOINT 158 140.700 -9.000 2.000 JOINT 159 140.700 9.000 2.000 JOINT 160 140.700 27.000 2.000 JOINT 161 140.700-27.000 29.000 JOINT 162 140.700 -9.000 29.000 JOINT 163 140.700 9.000 29.000 JOINT 164 140.700 27.000 29.000 JOINT 165 184.800-27.000 2.000 JOINT 166 184.800 -9.000 2.000 JOINT 167 184.800 9.000 2.000 JOINT 168 184.800 27.000 2.000 JOINT 169 184.800-27.000 29.000 JOINT 170 184.800 -9.000 29.000 JOINT 171 184.800 9.000 29.000

A-16

JOINT 172 184.800 27.000 29.000 JOINT 173 228.900-27.000 2.000 JOINT 174 228.900 -9.000 2.000 JOINT 175 228.900 9.000 2.000 JOINT 176 228.900 27.000 2.000 JOINT 177 228.900-27.000 29.000 JOINT 178 228.900 -9.000 29.000 JOINT 179 228.900 9.000 29.000 JOINT 180 228.900 27.000 29.000 JOINT 181 273.000-27.000 2.000 JOINT 182 273.000 -9.000 2.000 JOINT 183 273.000 9.000 2.000 JOINT 184 273.000 27.000 2.000 JOINT 185 273.000-27.000 29.000 JOINT 186 273.000 -9.000 29.000 JOINT 187 273.000 9.000 29.000 JOINT 188 273.000 27.000 29.000 JOINT 189 299.000 23.000 2.000 JOINT 190 301.000 20.000 2.000 JOINT 191 299.000-23.000 2.000 JOINT 192 301.000-20.000 2.000 JOINT 193 273.000 20.000 2.000 JOINT 194 273.000-20.000 2.000 JOINT 195 299.000 23.000 29.000 JOINT 196 301.000 20.000 29.000 JOINT 197 299.000-23.000 29.000 JOINT 198 301.000-20.000 29.000 JOINT 199 273.000 20.000 29.000 JOINT 200 273.000-20.000 29.000 JOINT 201 12.000 27.000 2.000 JOINT 202 12.000 17.000 2.000 JOINT 203 12.000 27.000 29.000 JOINT 204 12.000 17.000 29.000 JOINT 205 52.500 27.000 2.000 JOINT 206 52.500 17.000 2.000 JOINT 207 52.500 27.000 29.000 JOINT 208 52.500 17.000 29.000 JOINT 209 12.000-27.000 2.000 JOINT 210 12.000-17.000 2.000 JOINT 211 12.000-27.000 29.000 JOINT 212 12.000-17.000 29.000 JOINT 213 52.500-27.000 2.000 JOINT 214 52.500-17.000 2.000 JOINT 215 52.500-27.000 29.000 JOINT 216 52.500-17.000 29.000 JOINT 217 96.600 15.000 33.000 JOINT 218 96.600 15.000 43.000 JOINT 219 96.600-15.000 33.000 JOINT 220 96.600-15.000 43.000 JOINT 221 273.000 15.000 33.000 JOINT 222 273.000 15.000 43.000 JOINT 223 273.000-15.000 33.000 JOINT 224 273.000-15.000 43.000 JOINT 225 52.500 30.000 2.000 JOINT 226 96.600 30.000 2.000 JOINT 227 140.700 30.000 2.000

A-17

JOINT 228 184.800 30.000 2.000 JOINT 229 228.900 30.000 2.000 JOINT 230 273.000 30.000 2.000 JOINT 231 52.500 30.000 29.000 JOINT 232 96.600 30.000 29.000 JOINT 233 140.700 30.000 29.000 JOINT 234 184.800 30.000 29.000 JOINT 235 228.900 30.000 29.000 JOINT 236 273.000 30.000 29.000 JOINT 237 52.500-30.000 2.000 JOINT 238 96.600-30.000 2.000 JOINT 239 140.700-30.000 2.000 JOINT 240 184.800-30.000 2.000 JOINT 241 228.900-30.000 2.000 JOINT 242 273.000-30.000 2.000 JOINT 243 52.500-30.000 29.000 JOINT 244 96.600-30.000 29.000 JOINT 245 140.700-30.000 29.000 JOINT 246 184.800-30.000 29.000 JOINT 247 228.900-30.000 29.000 JOINT 248 273.000-30.000 29.000 JOINT 249 52.500-27.000 0.000 JOINT 250 52.500 -9.000 0.000 JOINT 251 52.500 9.000 0.000 JOINT 252 52.500 27.000 0.000 JOINT 253 96.600-27.000 0.000 JOINT 254 96.600 -9.000 0.000 JOINT 255 96.600 9.000 0.000 JOINT 256 96.600 27.000 0.000 JOINT 257 140.700-27.000 0.000 JOINT 258 140.700 -9.000 0.000 JOINT 259 140.700 9.000 0.000 JOINT 260 140.700 27.000 0.000 JOINT 261 184.800-27.000 0.000 JOINT 262 184.800 -9.000 0.000 JOINT 263 184.800 9.000 0.000 JOINT 264 184.800 27.000 0.000 JOINT 265 228.900-27.000 0.000 JOINT 266 228.900 -9.000 0.000 JOINT 267 228.900 9.000 0.000 JOINT 268 228.900 27.000 0.000 JOINT 269 273.000-27.000 0.000 JOINT 270 273.000 -9.000 0.000 JOINT 271 273.000 9.000 0.000 JOINT 272 273.000 27.000 0.000 JOINT 273 74.55 -28.5 33. JOINT 274 74.55 28.5 33. JOINT 275 118.65 -28.5 33. JOINT 276 118.65 28.5 33. JOINT 277 162.75 -28.5 33. JOINT 278 162.75 28.5 33. JOINT 279 206.85 -28.5 33. JOINT 280 206.85 28.5 33. JOINT 281 250.95 -28.5 33. JOINT 282 250.95 28.5 33. PANEL TOP 15 61 79 30

A-18

PANEL PRT 61 15 45 97 PANEL W CRE 136 140 139 135 PANEL W CRE 136 134 138 140 PANEL W CRE 140 138 137 139 PANEL W CRE 133 134 136 135 PANEL W CRE 137 138 134 133 PANEL W PRO 220 224 223 219 PANEL W PRO 218 220 219 217 PANEL W PRO 222 218 217 221 PANEL W PRO 224 222 221 223 PANEL W PRO 220 218 222 224 PANEL STB 30 79 115 60 PANEL BOW 79 80 116 115 PANEL BOW 80 81 117 116 PANEL BOW 81 82 118 117 PANEL BOW 82 83 119 118 PANEL BOW 83 84 120 119 PANEL BOW 84 85 121 120 PANEL BOW 85 86 122 121 PANEL BOW 86 87 123 122 PANEL BOW 87 88 124 123 PANEL BOW 88 89 125 124 PANEL BOW 89 90 126 125 PANEL BOW 90 91 127 126 PANEL BOW 91 92 128 127 PANEL BOW 92 93 129 128 PANEL BOW 93 94 130 129 PANEL BOW 94 95 131 130 PANEL BOW 95 96 114 131 PANEL BOW 78 77 113 114 PANEL BOW 77 76 112 113 PANEL BOW 76 75 111 112 PANEL BOW 75 74 110 111 PANEL BOW 74 73 109 110 PANEL BOW 73 72 108 109 PANEL BOW 72 71 107 108 PANEL BOW 71 70 106 107 PANEL BOW 70 69 105 106 PANEL BOW 69 68 104 105 PANEL BOW 68 67 103 104 PANEL BOW 67 66 102 103 PANEL BOW 66 65 101 102 PANEL BOW 65 64 100 101 PANEL BOW 64 63 99 100 PANEL BOW 63 62 98 99 PANEL BOW 62 61 97 98 PANEL BOW 131 114 113 PANEL BOW 130 131 113 112 PANEL BOW 129 130 112 111 PANEL BOW 128 129 111 110 PANEL BOW 127 128 110 109 PANEL BOT 45 60 115 97 PANEL BOT 45 44 59 60 PANEL BOT 44 43 58 59 PANEL BOT 43 42 57 58 PANEL BOT 42 41 56 57

A-19

PANEL BOT 107 106 124 125 PANEL BOT 106 105 123 124 PANEL BOT 105 104 122 123 PANEL BOT 104 103 121 122 PANEL BOT 103 102 120 121 PANEL BOT 102 101 119 120 PANEL BOT 101 100 118 119 PANEL BOT 100 99 117 118 PANEL BOT 99 98 116 117 PANEL BOT 98 97 115 116 PANEL BOW 126 127 109 108 PANEL BOW 125 126 108 107 PANEL STE 40 55 56 41 PANEL STE 40 39 54 55 PANEL STE 39 38 53 54 PANEL STE 37 52 53 38 PANEL STE 37 36 51 52 PANEL STE 36 35 50 51 PANEL STE 35 34 49 50 PANEL STE 34 33 48 49 PANEL STE 32 47 48 33 PANEL STE 31 46 47 32 PANEL STE 1 16 46 31 PANEL STE 15 14 44 45 PANEL STE 14 13 43 44 PANEL STE 13 12 42 43 PANEL STE 12 11 41 42 PANEL STE 11 10 40 41 PANEL STE 10 9 39 40 PANEL STE 9 8 38 39 PANEL STE 8 7 37 38 PANEL STE 7 6 36 37 PANEL STE 6 5 35 36 PANEL STE 5 4 34 35 PANEL STE 4 3 33 34 PANEL STE 3 2 32 33 PANEL STE 2 1 31 32 PANEL STE 29 30 60 59 PANEL STE 28 29 59 58 PANEL STE 27 28 58 57 PANEL STE 26 27 57 56 PANEL STE 25 26 56 55 PANEL STE 24 25 55 54 PANEL STE 23 24 54 53 PANEL STE 22 23 53 52 PANEL STE 21 22 52 51 PANEL STE 20 21 51 50 PANEL STE 19 20 50 49 PANEL STE 18 19 49 48 PANEL STE 17 18 48 47 PANEL STE 16 17 47 46 PANEL TOP 2 3 18 17 PANEL TOP 16 1 2 17 PANEL TOP 14 15 30 29 PANEL TOP 13 14 29 28 PANEL TOP 12 13 28 27

A-20

PANEL TOP 11 12 27 26 PANEL TOP 10 11 26 25 PANEL TOP 9 10 25 24 PANEL TOP 8 9 24 23 PANEL TOP 7 8 23 22 PANEL TOP 6 7 22 21 PANEL TOP 5 6 21 20 PANEL TOP 4 5 20 19 PANEL TOP 3 4 19 18 PANEL TOP 61 62 80 79 PANEL TOP 62 63 81 80 PANEL TOP 63 64 82 81 PANEL TOP 64 65 83 82 PANEL TOP 65 66 84 83 PANEL TOP 66 67 85 84 PANEL TOP 67 68 86 85 PANEL TOP 68 69 87 86 PANEL TOP 69 70 88 87 PANEL TOP 70 71 89 88 PANEL TOP 71 72 90 89 PANEL TOP 72 73 91 90 PANEL TOP 73 74 92 91 PANEL TOP 74 75 93 92 PANEL TOP 75 76 94 93 PANEL TOP 76 77 95 94 PANEL TOP 77 96 95 BODY 1 .8925 .02 100. OIL CARGO 1 PANEL OIL 186 187 183 182 PANEL OIL 178 186 182 174 PANEL OIL 179 178 174 175 PANEL OIL 187 179 175 183 PANEL OIL 175 174 182 183 PANEL OIL 178 179 187 186 PANEL OIL 177 178 174 173 PANEL OIL 179 180 176 175 PANEL OIL 179 171 172 180 PANEL OIL 179 175 167 171 PANEL OIL 172 171 167 168 PANEL OIL 168 167 175 176 PANEL OIL 180 172 168 176 PANEL OIL 173 165 169 177 PANEL OIL 169 170 178 177 PANEL OIL 170 169 165 166 PANEL OIL 166 165 173 174 PANEL OIL 170 166 174 178 PANEL OIL 170 171 167 166 PANEL OIL 170 162 163 171 PANEL OIL 162 170 166 158 PANEL OIL 163 162 158 159 PANEL OIL 167 159 158 166 PANEL OIL 163 159 167 171 PANEL OIL 161 162 158 157 PANEL OIL 163 164 160 159 PANEL OIL 163 155 156 164 PANEL OIL 159 151 155 163 PANEL OIL 157 149 153 161

A-21

PANEL OIL 153 154 162 161 PANEL OIL 154 153 149 150 PANEL OIL 158 150 149 157 PANEL OIL 152 151 159 160 PANEL OIL 156 155 151 152 PANEL OIL 164 156 152 160 PANEL OIL 162 154 150 158 PANEL OIL 154 155 151 150 PANEL OIL 154 146 147 155 PANEL OIL 150 142 146 154 PANEL OIL 142 143 147 146 PANEL OIL 151 155 147 143 PANEL OIL 143 142 150 151 BODY 2 .8925 .02 100. OIL CARGO 2 PANEL OIL 187 179 180 188 PANEL OIL 187 188 184 183 PANEL OIL 179 187 183 175 PANEL OIL 178 179 175 174 PANEL OIL 180 179 175 176 PANEL OIL 180 176 184 188 PANEL OIL 176 175 183 184 PANEL OIL 178 170 171 179 PANEL OIL 170 178 174 166 PANEL OIL 169 170 166 165 PANEL OIL 171 172 168 167 PANEL OIL 169 161 162 170 PANEL OIL 161 169 165 157 PANEL OIL 171 163 164 172 PANEL OIL 167 159 163 171 PANEL OIL 158 162 161 157 PANEL OIL 158 166 170 162 PANEL OIL 158 157 165 166 PANEL OIL 164 163 159 160 PANEL OIL 164 160 168 172 PANEL OIL 160 159 167 168 PANEL OIL 171 170 166 167 PANEL OIL 179 171 167 175 PANEL OIL 167 166 174 175 PANEL OIL 162 163 159 158 PANEL OIL 162 154 155 163 PANEL OIL 154 162 158 150 PANEL OIL 150 151 155 154 PANEL OIL 151 150 158 159 PANEL OIL 155 151 159 163 PANEL OIL 153 154 150 149 PANEL OIL 155 156 152 151 PANEL OIL 153 145 146 154 PANEL OIL 149 141 145 153 PANEL OIL 151 143 147 155 PANEL OIL 155 147 148 156 PANEL OIL 146 145 141 142 PANEL OIL 148 147 143 144 PANEL OIL 142 141 149 150 PANEL OIL 144 143 151 152 PANEL OIL 146 142 150 154 PANEL OIL 148 144 152 156

A-22

PANEL OIL 174 173 181 182 PANEL OIL 178 177 173 174 PANEL OIL 178 174 182 186 PANEL OIL 177 178 186 185 PANEL OIL 185 186 182 181 PANEL OIL 177 185 181 173 BODY 3 .02 100. SIDE BALLAST TANKS 1 PANEL SID 188 236 230 184 PANEL SID 235 236 188 180 PANEL SID 180 188 184 176 PANEL SID 246 169 165 240 PANEL SID 245 161 169 246 PANEL SID 245 246 240 239 PANEL SID 172 234 228 168 PANEL SID 164 233 234 172 PANEL SID 164 172 168 160 PANEL SID 244 153 149 238 PANEL SID 243 145 153 244 PANEL SID 243 244 238 237 PANEL SID 156 232 226 152 PANEL SID 148 231 232 156 PANEL SID 148 156 152 144 PANEL SID 145 243 237 141 PANEL SID 145 141 149 153 PANEL SID 141 237 238 149 PANEL SID 231 148 144 225 PANEL SID 225 144 152 226 PANEL SID 232 231 225 226 PANEL SID 161 245 239 157 PANEL SID 157 239 240 165 PANEL SID 161 157 165 169 PANEL SID 233 164 160 227 PANEL SID 227 160 168 228 PANEL SID 233 227 228 234 PANEL SID 235 180 176 229 PANEL SID 235 229 230 236 PANEL SID 229 176 184 230 PANEL SID 247 177 185 248 PANEL SID 248 185 181 242 PANEL SID 177 173 181 185 PANEL SID 177 247 241 173 PANEL SID 173 241 242 181 PANEL SID 247 248 242 241 BODY 4 .02 100. SIDE BALLAST TANKS 2 PANEL SID 241 247 177 173 PANEL SID 246 169 177 247 PANEL SID 246 247 241 240 PANEL SID 180 235 229 176 PANEL SID 172 234 235 180 PANEL SID 172 180 176 168 PANEL SID 164 233 227 160 PANEL SID 156 232 233 164 PANEL SID 156 164 160 152 PANEL SID 153 161 245 244 PANEL SID 161 157 239 245 PANEL SID 244 245 239 238

A-23

PANEL SID 153 244 238 149 PANEL SID 153 149 157 161 PANEL SID 149 238 239 157 PANEL SID 232 156 152 226 PANEL SID 232 226 227 233 PANEL SID 226 152 160 227 PANEL SID 169 246 240 165 PANEL SID 165 240 241 173 PANEL SID 169 165 173 177 PANEL SID 234 172 168 228 PANEL SID 228 168 176 229 PANEL SID 234 228 229 235 BODY 5 .02 100. BOW BALLAST TANKS PANEL BBL 199 236 195 196 PANEL BBL 190 196 195 189 PANEL BBL 199 196 190 193 PANEL BBL 236 199 193 230 PANEL BBL 236 230 189 195 PANEL BBL 230 193 190 189 PANEL BBL 197 248 200 198 PANEL BBL 197 198 192 191 PANEL BBL 198 200 194 192 PANEL BBL 242 248 197 191 PANEL BBL 200 248 242 194 PANEL BBL 242 191 192 194 BODY 6 .02 100. AFT BALLAST TANKS PANEL ABL 211 209 210 212 PANEL ABL 209 213 214 210 PANEL ABL 216 212 210 214 PANEL ABL 213 215 216 214 PANEL ABL 211 215 213 209 PANEL ABL 215 211 212 216 PANEL ABL 208 204 203 207 PANEL ABL 208 207 205 206 PANEL ABL 207 203 201 205 PANEL ABL 203 204 202 201 PANEL ABL 201 202 206 205 PANEL ABL 204 208 206 202 BODY 7 .02 100. BOTTOM BALLAST TANKS 1 PANEL BTL 182 183 271 270 PANEL BTL 175 183 182 174 PANEL BTL 174 182 270 266 PANEL BTL 175 174 266 267 PANEL BTL 175 267 271 183 PANEL BTL 267 266 270 271 PANEL BTL 173 174 266 265 PANEL BTL 175 176 268 267 PANEL BTL 166 174 173 165 PANEL BTL 165 173 265 261 PANEL BTL 166 165 261 262 PANEL BTL 166 262 266 174 PANEL BTL 262 261 265 266 PANEL BTL 175 167 168 176 PANEL BTL 167 175 267 263 PANEL BTL 168 167 263 264 PANEL BTL 168 264 268 176

A-24

PANEL BTL 264 263 267 268 PANEL BTL 166 167 263 262 PANEL BTL 166 158 159 167 PANEL BTL 158 166 262 258 PANEL BTL 159 158 258 259 PANEL BTL 159 259 263 167 PANEL BTL 259 258 262 263 PANEL BTL 157 158 258 257 PANEL BTL 159 160 260 259 PANEL BTL 160 152 256 260 PANEL BTL 159 151 152 160 PANEL BTL 255 151 159 259 PANEL BTL 151 255 256 152 PANEL BTL 256 255 259 260 PANEL BTL 149 150 158 157 PANEL BTL 149 157 257 253 PANEL BTL 150 149 253 254 PANEL BTL 150 254 258 158 PANEL BTL 254 253 257 258 PANEL BTL 150 151 255 254 PANEL BTL 143 151 150 142 PANEL BTL 142 150 254 250 PANEL BTL 143 142 250 251 PANEL BTL 143 251 255 151 PANEL BTL 251 250 254 255 BODY 8 .02 100. .95 BOTTOM BALLAST TANKS 2 PANEL BTL 181 182 270 269 PANEL BTL 183 184 272 271 PANEL BTL 181 173 174 182 PANEL BTL 173 181 269 265 PANEL BTL 183 175 176 184 PANEL BTL 175 183 271 267 PANEL BTL 174 173 265 266 PANEL BTL 174 266 270 182 PANEL BTL 266 265 269 270 PANEL BTL 176 175 267 268 PANEL BTL 176 268 272 184 PANEL BTL 268 267 271 272 PANEL BTL 174 175 267 266 PANEL BTL 174 166 167 175 PANEL BTL 166 174 266 262 PANEL BTL 167 166 262 263 PANEL BTL 167 263 267 175 PANEL BTL 263 262 266 267 PANEL BTL 167 168 264 263 PANEL BTL 165 166 262 261 PANEL BTL 165 157 158 166 PANEL BTL 157 165 261 257 PANEL BTL 158 157 257 258 PANEL BTL 158 258 262 166 PANEL BTL 258 257 261 262 PANEL BTL 167 159 160 168 PANEL BTL 159 167 263 259 PANEL BTL 160 159 259 260 PANEL BTL 160 260 264 168 PANEL BTL 260 259 263 264

A-25

PANEL BTL 158 159 259 258 PANEL BTL 158 150 151 159 PANEL BTL 150 158 258 254 PANEL BTL 151 150 254 255 PANEL BTL 255 259 159 151 PANEL BTL 255 254 258 259 PANEL BTL 151 152 256 255 PANEL BTL 149 150 254 253 PANEL BTL 151 143 205 152 PANEL BTL 143 151 255 251 PANEL BTL 213 142 150 149 PANEL BTL 213 149 253 249 PANEL BTL 142 213 249 250 PANEL BTL 142 250 254 150 PANEL BTL 250 249 253 254 PANEL BTL 252 251 255 256 PANEL BTL 144 143 251 252 PANEL BTL 252 256 152 205 END

A-26

Example StabCAD Output File StabCAD Ver. 4.20 GULF OF MEXICO FPSO -- INTACT STABILITY ANALYSIS Page 1 The following Nomenclature is used in the computer output: Draft ... Measured from the base line (z=0, or x-y plane) Disp .... Displacemet of the vessel TPI ..... Tons/inch displacement KPI ..... Kips/inch displacement MT/Cm ... Metric Ton/ cm displacement KMT ..... Transverse metacentric height (measured from base line) KML ..... Longitudinal metacentric height (measured from base line) LCB ..... Center of Buoyancy position (Longitudinal) (measured from reference point for LCB & LCF) TCB ..... Center of Buoyancy position (Transverse) (measured from coordinate system origin) VCB ..... Center of Buoyancy position (Vertical) (measured from base line) WPA ..... Water plane Area BMT ..... Transv metacentric ht (from ctr of buoyancy) BML ..... Longit metacentric ht (from ctr of buoyancy) LCF ..... Center of Floatation position (Longitudinal) (measured from reference point for LCB & LCF) TCF ..... Center of Floatation position (Transverse) (measured from coordinate system origin) W.P.Moment of Inertia: Longitudinal About neutral axis of water plane area Transverse About neutral axis of water plane area Volume .. of submerged body Tilt Axis The angle of the tilt axis is measured from the posive x-axis Optimum tilt angle The minimum tilt angle at which the area ratio requirement is satisfied KG that satisfies : Heeling arm = Righting arm at or before the downflooding angle Static angle At which the righting moment is zero Area ratio = 1.0 For damage stability - starting at the static angle RM/HM Ratio KG that satisfies the requirement : Righting Moment/Heeling Moment >or= 2 within 7 deg past static angle Equilibrium position tilt angle When vessel is in equilibrium and not at the upright position, the positive angle indicate that the part of the vessel to the right of the tilt axis is immersed in water

A-27

StabCAD Ver. 4.20 GULF OF MEXICO FPSO -- INTACT STABILITY ANALYSIS Page 2 * * * Hydrostatic Table * * * Draft AFT (X-Coordinate) ....... 0.00 Initial Heel Angle ......... 0.000 Deg Draft FWD (X-Coordinate) ....... 0.00 Initial Trim Angle ......... 0.000 Deg Reference Point for LCB & LCF Density of Water ........... 1.025 MT/Cu.Meter (X-Coordinate) ....... 0.00 /--- Draft ---/ /-- Center of Buoyancy--/ /-Center of Floatation-/ Water plane Submerged AFT FWD Disp TPI LCB TCB VCB LCF TCF Area Volume ( M.) ( M.) (M.Tons) (MT/Cm) ( M.) ( M.) ( M.) ( M.) ( M.) (S.Meter) (M^3) ------- ------- -------- ------- ------- ------- ------- ------- ------- ----------- --------- 1.00 1.00 18190.2 183.45 155.17 0.00 0.50 155.10 0.00 17897.1 17746.5 2.00 2.00 36618.3 185.00 155.08 0.00 1.00 154.89 0.00 18048.4 35725.1 3.00 3.00 55158.0 185.78 154.96 0.00 1.51 154.59 0.00 18125.0 53812.7 4.00 4.00 73765.4 186.36 154.84 0.00 2.01 154.36 0.00 18181.4 71966.2 5.00 5.00 92420.6 186.77 154.73 0.00 2.51 154.23 0.00 18221.0 90166.5 6.00 6.00 111112.5 187.04 154.63 0.00 3.02 154.12 0.00 18247.7 108402.4 7.00 7.00 129823.8 187.20 154.56 0.00 3.52 154.09 0.00 18263.0 126657.4 8.00 8.00 148549.8 187.34 154.50 0.00 4.02 154.06 0.00 18277.4 144926.6 9.00 9.00 167289.4 187.47 154.45 0.00 4.52 154.04 0.00 18289.6 163209.2 10.00 10.00 186040.5 187.56 154.40 0.00 5.02 153.99 0.00 18298.8 181502.9 11.00 11.00 204797.8 187.58 154.37 0.00 5.52 154.00 0.00 18300.3 199802.7 12.00 12.00 223556.8 187.61 154.34 0.00 6.03 154.03 0.00 18303.4 218104.2 13.00 13.00 242317.0 187.59 154.31 0.00 6.53 154.06 0.00 18301.8 236406.8 14.00 14.00 261077.8 187.61 154.29 0.00 7.03 154.02 0.00 18303.4 254710.0 15.00 15.00 279838.6 187.62 154.27 0.00 7.53 153.98 0.00 18304.9 273013.3 16.00 16.00 298599.5 187.66 154.26 0.00 8.03 154.02 0.00 18307.9 291316.6 17.00 17.00 317360.4 187.59 154.24 0.00 8.53 154.04 0.00 18301.8 309619.9 18.00 18.00 336121.2 187.62 154.23 0.00 9.03 154.04 0.00 18304.9 327923.2 19.00 19.00 354882.1 187.59 154.22 0.00 9.53 154.02 0.00 18301.8 346226.5 20.00 20.00 373643.0 187.59 154.21 0.00 10.03 154.03 0.00 18301.8 364529.8 21.00 21.00 392403.9 187.62 154.20 0.00 10.53 154.01 0.00 18304.9 382833.1 22.00 22.00 411164.8 187.59 154.20 0.00 11.03 154.03 0.00 18301.8 401136.3 23.00 23.00 429925.6 187.66 154.19 0.00 11.53 154.01 0.00 18307.9 419439.6 24.00 24.00 448686.5 187.59 154.18 0.00 12.03 154.07 0.00 18301.8 437742.9 25.00 25.00 467447.4 187.59 154.18 0.00 12.53 154.02 0.00 18301.8 456046.2 26.00 26.00 486208.2 187.62 154.17 0.00 13.03 154.01 0.00 18304.9 474349.5 27.00 27.00 504969.1 187.62 154.16 0.00 13.53 154.00 0.00 18304.9 492652.8 StabCAD Ver. 4.20 GULF OF MEXICO FPSO -- INTACT STABILITY ANALYSIS Page 3 * * * Hydrostatic Table * * * Draft AFT (X-Coordinate) ....... 0.00 Initial Heel Angle ......... 0.000 Deg Draft FWD (X-Coordinate) ....... 0.00 Initial Trim Angle ......... 0.000 Deg Reference Point for LCB & LCF Density of Water ........... 1.025 MT/Cu.Meter (X-Coordinate) ....... 0.00 /----- Water Plane -----/ With KG=0 With KG=0 /--- Draft ---/ /---------- Metacenter ---------/ /-- Moment Of Inertia --/ Moment to Heel Moment to Trim AFT FWD Disp KMT KML BMT BML Transverse Longitudinal 0.01 Deg. 0.01 Deg. ( M.) ( M.) (M.Tons) ( M.) ( M.) ( M.) ( M.) ( M^4) ( M^4) (M.Ton-M) (M.Ton-M) ------- ------- -------- ------- ------- ------- ------- ------------ ----------- -------------- -------------- 1.00 1.00 18190.2 298.46 7483.47 297.95 7482.97 5287646. 132796520. 947.5 23758.4 2.00 2.00 36618.3 149.76 3816.46 148.75 3815.45 5314172. 136307584. 957.1 24391.3 3.00 3.00 55158.0 100.51 2568.42 99.00 2566.91 5327456. 138132544. 967.6 24725.9 4.00 4.00 73765.4 76.16 1939.43 74.15 1937.42 5336172. 139428592. 980.5 24969.1 5.00 5.00 92420.6 61.75 1559.31 59.24 1556.80 5341510. 140370912. 996.1 25152.4 6.00 6.00 111112.5 52.32 1304.02 49.31 1301.01 5344842. 141032528. 1014.6 25288.7 7.00 7.00 129823.8 45.73 1119.80 42.21 1116.28 5346152. 141385552. 1036.1 25373.0

A-28

8.00 8.00 148549.8 40.92 981.86 36.90 977.84 5347289. 141715248. 1060.8 25456.5 9.00 9.00 167289.4 37.29 874.74 32.77 870.22 5348582. 142027216. 1088.9 25540.1 10.00 10.00 186040.5 34.49 788.75 29.47 783.72 5348938. 142247888. 1120.0 25610.7 11.00 11.00 204797.8 32.30 717.82 26.77 712.30 5349234. 142319024. 1154.4 25657.8 12.00 12.00 223556.8 30.55 658.67 24.52 652.64 5348974. 142343600. 1192.0 25699.9 13.00 13.00 242317.0 29.15 608.71 22.63 602.19 5348871. 142360704. 1233.0 25743.9 14.00 14.00 261077.8 28.03 566.01 21.00 558.98 5349100. 142379008. 1277.2 25791.3 15.00 15.00 279838.6 27.12 529.04 19.59 521.51 5349186. 142379552. 1324.7 25838.9 16.00 16.00 298599.5 26.39 496.83 18.36 488.80 5349478. 142394704. 1375.5 25892.4 17.00 17.00 317360.4 25.81 468.38 17.28 459.85 5349164. 142379504. 1429.5 25943.7 18.00 18.00 336121.2 25.34 443.26 16.31 434.23 5349465. 142393328. 1486.8 26003.5 19.00 19.00 354882.1 24.98 420.74 15.45 411.21 5349245. 142370400. 1547.4 26059.9 20.00 20.00 373643.0 24.71 400.65 14.68 390.62 5349502. 142393232. 1611.3 26127.9 21.00 21.00 392403.9 24.51 382.49 13.97 371.96 5349464. 142397120. 1678.4 26195.7 22.00 22.00 411164.8 24.37 365.94 13.34 354.91 5349295. 142367360. 1748.7 26260.8 23.00 23.00 429925.6 24.29 351.03 12.75 339.49 5349410. 142397584. 1822.4 26339.8 24.00 24.00 448686.5 24.25 337.31 12.22 325.27 5349358. 142385200. 1899.4 26414.6 25.00 25.00 467447.4 24.26 324.74 11.73 312.20 5349467. 142379024. 1979.6 26493.7 26.00 26.00 486208.2 24.31 313.22 11.28 300.18 5349428. 142392224. 2063.1 26579.6 27.00 27.00 504969.1 24.39 302.58 10.86 289.04 5349256. 142396448. 2149.9 26667.1 StabCAD Ver. 4.20 GULF OF MEXICO FPSO -- INTACT STABILITY ANALYSIS Page 4 * * * Intact Stability Downflooding Point Table * * * Intact Draft .............. 21.50 M Displacement .............. 401784.3 M.Tons Center of Gravity (X,Y,Z) = 154.20; 0.00; 17.60 M Angle of Tilt Axis ........ 0.00 Deg Downflooding Points Height Above Water (M) -------------------------------------------- Downflooding Angle = 26.17 Deg @ HATCH Weathertight Angle = 21.96 Deg @ VENT H E E L A N G L E S ------- ------- -------------------- --------------------------------------------------------------------------------------------- DF PT. Type Description 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 ------- ------- -------------------- --------------------------------------------------------------------------------------------- 1 Int/Dam HATCH 11.5 11.1 10.7 10.3 9.9 9.5 9.0 8.6 8.2 7.8 7.3 6.9 2 Int/Dam HATCH 11.5 11.9 12.3 12.7 13.1 13.5 13.8 14.2 14.6 15.0 15.3 15.7 3 Int/Dam HATCH 11.5 11.2 11.0 10.7 10.4 10.1 9.9 9.6 9.3 9.0 8.7 8.4 4 Int/Dam HATCH 11.5 11.8 12.0 12.3 12.5 12.8 13.0 13.2 13.5 13.7 13.9 14.2 5 WeaTight VENT 11.5 11.0 10.5 10.0 9.5 9.0 8.5 7.9 7.4 6.9 6.4 5.9 6 WeaTight VENT 11.5 12.0 12.5 13.0 13.5 13.9 14.4 14.9 15.4 15.8 16.3 16.7 7 WeaTight VENT 11.5 11.0 10.5 10.0 9.5 9.0 8.5 7.9 7.4 6.9 6.4 5.9 8 WeaTight VENT 11.5 12.0 12.5 13.0 13.5 13.9 14.4 14.9 15.4 15.8 16.3 16.7 9 WeaTight VENT 11.5 11.0 10.5 10.0 9.5 9.0 8.5 7.9 7.4 6.9 6.4 5.9 10 WeaTight VENT 11.5 12.0 12.5 13.0 13.5 13.9 14.4 14.9 15.4 15.8 16.3 16.7 11 WeaTight VENT 11.5 11.0 10.5 10.0 9.5 9.0 8.5 7.9 7.4 6.9 6.4 5.9 12 WeaTight VENT 11.5 12.0 12.5 13.0 13.5 13.9 14.4 14.9 15.4 15.8 16.3 16.7 13 WeaTight VENT 11.5 11.0 10.5 10.0 9.5 9.0 8.5 7.9 7.4 6.9 6.4 5.9 14 WeaTight VENT 11.5 12.0 12.5 13.0 13.5 13.9 14.4 14.9 15.4 15.8 16.3 16.7 ------- ------- -------------------- --------------------------------------------------------------------------------------------- H E E L A N G L E S ------- ------- -------------------- --------------------------------------------------------------------------------------------- DF PT. Type Description 12.0 13.0 14.0 15.0 16.0 17.0 18.0 19.0 20.0 21.0 22.0 23.0 ------- ------- -------------------- --------------------------------------------------------------------------------------------- 1 Int/Dam HATCH 6.5 6.0 5.6 5.2 4.7 4.3 3.8 3.4 2.9 2.5 2.0 1.6

A-29

2 Int/Dam HATCH 16.0 16.4 16.7 17.1 17.4 17.7 18.0 18.4 18.7 19.0 19.3 19.5 3 Int/Dam HATCH 8.1 7.8 7.5 7.2 6.9 6.6 6.3 6.0 5.7 5.4 5.0 4.7 4 Int/Dam HATCH 14.4 14.6 14.8 15.0 15.2 15.4 15.6 15.8 15.9 16.1 16.3 16.4 5 WeaTight VENT 5.3 4.8 4.3 3.7 3.2 2.7 2.1 1.6 1.1 0.5 0.0 -0.6 6 WeaTight VENT 17.2 17.6 18.1 18.5 18.9 19.3 19.7 20.2 20.6 20.9 21.3 21.7 7 WeaTight VENT 5.3 4.8 4.3 3.7 3.2 2.7 2.1 1.6 1.1 0.5 0.0 -0.6 8 WeaTight VENT 17.2 17.6 18.1 18.5 18.9 19.3 19.7 20.2 20.6 20.9 21.3 21.7 9 WeaTight VENT 5.3 4.8 4.3 3.7 3.2 2.7 2.1 1.6 1.1 0.5 0.0 -0.6 10 WeaTight VENT 17.2 17.6 18.1 18.5 18.9 19.3 19.7 20.2 20.6 20.9 21.3 21.7 11 WeaTight VENT 5.3 4.8 4.3 3.7 3.2 2.7 2.1 1.6 1.1 0.5 0.0 -0.6 12 WeaTight VENT 17.2 17.6 18.1 18.5 18.9 19.3 19.7 20.2 20.6 20.9 21.3 21.7 13 WeaTight VENT 5.3 4.8 4.3 3.7 3.2 2.7 2.1 1.6 1.1 0.5 0.0 -0.6 14 WeaTight VENT 17.2 17.6 18.1 18.5 18.9 19.3 19.7 20.2 20.6 20.9 21.3 21.7 ------- ------- -------------------- --------------------------------------------------------------------------------------------- H E E L A N G L E S ------- ------- -------------------- --------------------------------------------------------------------------------------------- DF PT. Type Description 24.0 25.0 26.0 27.0 28.0 29.0 30.0 31.0 32.0 33.0 34.0 35.0 ------- ------- -------------------- --------------------------------------------------------------------------------------------- 1 Int/Dam HATCH 1.1 0.6 0.1 -0.4 -1.0 -1.5 -2.1 -2.6 -3.2 -3.8 -4.3 -4.9 2 Int/Dam HATCH 19.8 20.0 20.3 20.5 20.6 20.8 20.9 21.1 21.2 21.3 21.4 21.4 3 Int/Dam HATCH 4.4 4.0 3.6 3.2 2.8 2.4 2.0 1.6 1.1 0.7 0.2 -0.2 4 Int/Dam HATCH 16.6 16.7 16.8 16.8 16.9 17.0 17.0 17.0 17.0 17.0 17.0 17.0 5 WeaTight VENT -1.1 -1.7 -2.3 -2.9 -3.5 -4.2 -4.8 -5.4 -6.1 -6.7 -7.4 -8.1 6 WeaTight VENT 22.0 22.4 22.7 23.0 23.2 23.5 23.7 23.9 24.1 24.3 24.5 24.6 7 WeaTight VENT -1.1 -1.7 -2.3 -2.9 -3.5 -4.2 -4.8 -5.4 -6.1 -6.7 -7.4 -8.1 8 WeaTight VENT 22.0 22.4 22.7 23.0 23.2 23.5 23.7 23.9 24.1 24.3 24.5 24.6 9 WeaTight VENT -1.1 -1.7 -2.3 -2.9 -3.5 -4.1 -4.8 -5.4 -6.1 -6.7 -7.4 -8.0 10 WeaTight VENT 22.0 22.4 22.7 23.0 23.2 23.5 23.7 23.9 24.2 24.3 24.5 24.7 11 WeaTight VENT -1.1 -1.7 -2.3 -2.9 -3.5 -4.1 -4.8 -5.4 -6.0 -6.7 -7.3 -8.0 12 WeaTight VENT 22.0 22.4 22.7 23.0 23.2 23.5 23.7 24.0 24.2 24.4 24.5 24.7 13 WeaTight VENT -1.1 -1.7 -2.3 -2.9 -3.5 -4.1 -4.8 -5.4 -6.0 -6.7 -7.3 -8.0 14 WeaTight VENT 22.0 22.4 22.7 23.0 23.2 23.5 23.7 24.0 24.2 24.4 24.5 24.7 ------- ------- -------------------- --------------------------------------------------------------------------------------------- H E E L A N G L E S ------- ------- -------------------- --------------------------------------------------------------------------------------------- DF PT. Type Description 36.0 37.0 38.0 39.0 40.0 41.0 42.0 43.0 44.0 45.0 46.0 47.0 ------- ------- -------------------- --------------------------------------------------------------------------------------------- 1 Int/Dam HATCH -5.5 -6.1 -6.8 -7.4 -8.0 -8.6 -9.2 -9.8 -10.4 -11.0 -11.6 -12.2 2 Int/Dam HATCH 21.5 21.5 21.6 21.6 21.6 21.6 21.6 21.5 21.5 21.5 21.5 21.4 3 Int/Dam HATCH -0.7 -1.2 -1.7 -2.2 -2.7 -3.2 -3.6 -4.1 -4.6 -5.1 -5.6 -6.1 4 Int/Dam HATCH 16.9 16.9 16.8 16.7 16.6 16.5 16.4 16.3 16.2 16.1 16.0 15.8 5 WeaTight VENT -8.8 -9.4 -10.1 -10.8 -11.5 -12.2 -12.9 -13.5 -14.2 -14.9 -15.6 -16.2 6 WeaTight VENT 24.8 24.9 25.0 25.1 25.1 25.2 25.3 25.3 25.4 25.4 25.4 25.5 7 WeaTight VENT -8.7 -9.4 -10.1 -10.8 -11.5 -12.1 -12.8 -13.5 -14.2 -14.8 -15.5 -16.2 8 WeaTight VENT 24.8 24.9 25.0 25.1 25.2 25.2 25.3 25.4 25.4 25.5 25.5 25.5 9 WeaTight VENT -8.7 -9.4 -10.1 -10.7 -11.4 -12.1 -12.8 -13.5 -14.1 -14.8 -15.4 -16.1 10 WeaTight VENT 24.8 24.9 25.0 25.1 25.2 25.3 25.4 25.4 25.5 25.5 25.6 25.6 11 WeaTight VENT -8.7 -9.4 -10.0 -10.7 -11.4 -12.1 -12.7 -13.4 -14.1 -14.7 -15.4 -16.0 12 WeaTight VENT 24.8 25.0 25.1 25.2 25.2 25.3 25.4 25.5 25.5 25.6 25.6 25.6 13 WeaTight VENT -8.7 -9.3 -10.0 -10.7 -11.4 -12.0 -12.7 -13.4 -14.0 -14.7 -15.3 -16.0 14 WeaTight VENT 24.9 25.0 25.1 25.2 25.3 25.4 25.4 25.5 25.6 25.6 25.7 25.7 ------- ------- -------------------- --------------------------------------------------------------------------------------------- H E E L A N G L E S ------- ------- -------------------- --------------------------------------------------------------------------------------------- DF PT. Type Description 48.0 49.0 50.0 51.0 52.0 53.0 54.0 55.0 56.0 57.0 58.0 59.0 ------- ------- -------------------- --------------------------------------------------------------------------------------------- 1 Int/Dam HATCH -12.8 -13.4 -14.0 -14.6 -15.1 -15.7 -16.3 -16.8 -17.4 -17.9 -18.5 -19.0 2 Int/Dam HATCH 21.4 21.3 21.2 21.2 21.1 21.0 20.9 20.8 20.7 20.6 20.5 20.4 3 Int/Dam HATCH -6.6 -7.1 -7.5 -8.0 -8.5 -9.0 -9.5 -9.9 -10.4 -10.9 -11.3 -11.8 4 Int/Dam HATCH 15.7 15.6 15.4 15.3 15.1 15.0 14.8 14.7 14.5 14.3 14.1 13.9 5 WeaTight VENT -16.9 -17.5 -18.2 -18.8 -19.4 -20.1 -20.7 -21.3 -21.9 -22.5 -23.1 -23.7 6 WeaTight VENT 25.5 25.5 25.5 25.5 25.5 25.5 25.4 25.4 25.4 25.3 25.2 25.2 7 WeaTight VENT -16.8 -17.5 -18.1 -18.7 -19.4 -20.0 -20.6 -21.2 -21.8 -22.4 -23.0 -23.6 8 WeaTight VENT 25.5 25.6 25.6 25.6 25.5 25.5 25.5 25.5 25.4 25.4 25.3 25.3

A-30

9 WeaTight VENT -16.8 -17.4 -18.0 -18.7 -19.3 -19.9 -20.5 -21.2 -21.8 -22.4 -22.9 -23.5 10 WeaTight VENT 25.6 25.6 25.6 25.6 25.6 25.6 25.6 25.5 25.5 25.4 25.4 25.3 11 WeaTight VENT -16.7 -17.3 -18.0 -18.6 -19.2 -19.9 -20.5 -21.1 -21.7 -22.3 -22.9 -23.5 12 WeaTight VENT 25.7 25.7 25.7 25.7 25.7 25.7 25.6 25.6 25.6 25.5 25.5 25.4 13 WeaTight VENT -16.6 -17.3 -17.9 -18.5 -19.2 -19.8 -20.4 -21.0 -21.6 -22.2 -22.8 -23.4 14 WeaTight VENT 25.7 25.7 25.7 25.8 25.7 25.7 25.7 25.7 25.6 25.6 25.5 25.5 ------- ------- -------------------- --------------------------------------------------------------------------------------------- H E E L A N G L E S ------- ------- -------------------- --------------------------------------------------------------------------------------------- DF PT. Type Description 60.0 61.0 62.0 63.0 64.0 65.0 66.0 67.0 68.0 69.0 70.0 71.0 ------- ------- -------------------- --------------------------------------------------------------------------------------------- 1 Int/Dam HATCH -19.6 -20.1 -20.6 -21.1 -21.6 -22.1 -22.6 -23.1 -23.6 -24.1 -24.5 -25.0 2 Int/Dam HATCH 20.3 20.1 20.0 19.9 19.7 19.6 19.4 19.2 19.1 18.9 18.7 18.5 3 Int/Dam HATCH -12.2 -12.7 -13.1 -13.6 -14.0 -14.4 -14.9 -15.3 -15.7 -16.1 -16.6 -17.0 4 Int/Dam HATCH 13.8 13.6 13.4 13.2 13.0 12.7 12.5 12.3 12.1 11.9 11.6 11.4 5 WeaTight VENT -24.3 -24.8 -25.4 -26.0 -26.5 -27.0 -27.6 -28.1 -28.6 -29.1 -29.6 -30.1 6 WeaTight VENT 25.1 25.0 24.9 24.8 24.7 24.6 24.5 24.4 24.2 24.1 23.9 23.8 7 WeaTight VENT -24.2 -24.8 -25.3 -25.9 -26.4 -27.0 -27.5 -28.0 -28.5 -29.0 -29.5 -30.0 8 WeaTight VENT 25.2 25.1 25.0 24.9 24.8 24.7 24.6 24.4 24.3 24.2 24.0 23.9 9 WeaTight VENT -24.1 -24.7 -25.2 -25.8 -26.3 -26.9 -27.4 -27.9 -28.5 -29.0 -29.5 -29.9 10 WeaTight VENT 25.3 25.2 25.1 25.0 24.9 24.8 24.7 24.5 24.4 24.3 24.1 24.0 11 WeaTight VENT -24.0 -24.6 -25.2 -25.7 -26.3 -26.8 -27.3 -27.9 -28.4 -28.9 -29.4 -29.9 12 WeaTight VENT 25.3 25.3 25.2 25.1 25.0 24.9 24.7 24.6 24.5 24.3 24.2 24.0 13 WeaTight VENT -24.0 -24.5 -25.1 -25.6 -26.2 -26.7 -27.2 -27.8 -28.3 -28.8 -29.3 -29.8 14 WeaTight VENT 25.4 25.3 25.2 25.2 25.0 24.9 24.8 24.7 24.6 24.4 24.3 24.1 ------- ------- -------------------- --------------------------------------------------------------------------------------------- H E E L A N G L E S ------- ------- -------------------- --------------------------------------------------------------------------------------------- DF PT. Type Description 72.0 73.0 74.0 75.0 76.0 77.0 78.0 79.0 80.0 81.0 82.0 83.0 ------- ------- -------------------- --------------------------------------------------------------------------------------------- 1 Int/Dam HATCH -25.4 -25.9 -26.3 -26.7 -27.2 -27.6 -28.0 -28.4 -28.7 -29.1 -29.5 -29.8 2 Int/Dam HATCH 18.3 18.1 17.9 17.7 17.5 17.3 17.0 16.8 16.6 16.3 16.1 15.8 3 Int/Dam HATCH -17.4 -17.8 -18.2 -18.5 -18.9 -19.3 -19.7 -20.0 -20.4 -20.7 -21.1 -21.4 4 Int/Dam HATCH 11.2 10.9 10.7 10.4 10.2 9.9 9.7 9.4 9.2 8.9 8.6 8.4 5 WeaTight VENT -30.6 -31.1 -31.5 -32.0 -32.4 -32.9 -33.3 -33.7 -34.1 -34.5 -34.9 -35.2 6 WeaTight VENT 23.6 23.4 23.3 23.1 22.9 22.7 22.5 22.3 22.0 21.8 21.6 21.3 7 WeaTight VENT -30.5 -31.0 -31.4 -31.9 -32.3 -32.8 -33.2 -33.6 -34.0 -34.4 -34.8 -35.1 8 WeaTight VENT 23.7 23.5 23.4 23.2 23.0 22.8 22.6 22.4 22.1 21.9 21.7 21.4 9 WeaTight VENT -30.4 -30.9 -31.3 -31.8 -32.2 -32.7 -33.1 -33.5 -33.9 -34.3 -34.7 -35.0 10 ` WeaTight VENT 23.8 23.6 23.4 23.3 23.1 22.9 22.7 22.4 22.2 22.0 21.8 21.5 11 WeaTight VENT -30.3 -30.8 -31.3 -31.7 -32.2 -32.6 -33.0 -33.4 -33.8 -34.2 -34.6 -35.0 12 WeaTight VENT 23.9 23.7 23.5 23.3 23.2 23.0 22.8 22.5 22.3 22.1 21.9 21.6 13 WeaTight VENT -30.2 -30.7 -31.2 -31.6 -32.1 -32.5 -32.9 -33.3 -33.7 -34.1 -34.5 -34.9 14 WeaTight VENT 24.0 23.8 23.6 23.4 23.2 23.0 22.8 22.6 22.4 22.2 22.0 21.7 ------- ------- -------------------- --------------------------------------------------------------------------------------------- H E E L A N G L E S ------- ------- -------------------- ------------- DF PT. Type Description 84.0 85.0 ------- ------- -------------------- ------------- 1 Int/Dam HATCH -30.2 -30.5 2 Int/Dam HATCH 15.6 15.3 3 Int/Dam HATCH -21.7 -22.1 4 Int/Dam HATCH 8.1 7.8 5 WeaTight VENT -35.6 -35.9 6 WeaTight VENT 21.1 20.8 7 WeaTight VENT -35.5 -35.8 8 WeaTight VENT 21.2 20.9 9 WeaTight VENT -35.4 -35.8 10 WeaTight VENT 21.3 21.0 11 WeaTight VENT -35.3 -35.7 12 WeaTight VENT 21.4 21.1 13 WeaTight VENT -35.2 -35.6 14 WeaTight VENT 21.5 21.2 ------- ------- -------------------- -------------

A-31

StabCAD Ver. 4.20 GULF OF MEXICO FPSO -- INTACT STABILITY ANALYSIS Page 5 * * * Intact Stability Parameters * * * Draft at no Heel .......... 21.50 M Displacement .............. 401784.3 M.Tons Center of Gravity (X,Y,Z) = 154.20; 0.00; 17.60 M Wind Speed ................ 51.40 M/Sec Wind Direction is Normal to Tilt Axis Range of Stability ........ 82.42 Deg Downflooding Angle ........ 26.17 Deg @ HATCH Weathertight Angle ........ 21.96 Deg @ VENT ----------------------------------------------------------------------------------------------------------- /--Angles w.r.t.--/ Critical Yaw Angle /--- Angles ---/ /-- Yawed axis ---/ Downflood Of /- w.r.t. Ship-/ Righting Heeling /-- Center of Buoyancy--/ Heel Trim Height Tilt Axis Heel Trim Arm Arm LCB TCB VCB (Deg) (Deg) (M) (Deg) (Deg) (Deg) (M) (M) (M) (M) (M) ------------------- -------- -------- ---------------- ------- -------- -------------------------- 0.00 0.00 11.5( 5) 0.00 0.00 0.00 0.00 0.05 154.20 0.00 10.78 1.00 0.00 11.0( 5) 0.00 1.00 0.00 0.12 0.06 154.20 -0.24 10.79 2.00 0.00 10.5( 5) 0.00 2.00 0.00 0.24 0.06 154.20 -0.48 10.79 3.00 0.00 10.0( 5) 0.00 3.00 0.00 0.36 0.06 154.20 -0.72 10.80 4.00 0.00 9.5( 5) 0.00 4.00 0.00 0.48 0.06 154.20 -0.95 10.82 5.00 0.00 9.0( 5) 0.00 5.00 0.00 0.60 0.07 154.20 -1.19 10.84 6.00 0.00 8.5( 5) 0.00 6.00 0.00 0.72 0.07 154.20 -1.43 10.86 7.00 0.00 7.9( 5) 0.00 7.00 0.00 0.84 0.07 154.20 -1.68 10.89 8.00 0.00 7.4( 5) 0.00 8.00 0.00 0.97 0.07 154.20 -1.92 10.92 9.00 0.00 6.9( 5) 0.00 9.00 0.00 1.10 0.08 154.20 -2.16 10.95 10.00 0.00 6.4( 5) 0.00 10.00 0.00 1.22 0.08 154.20 -2.41 11.00 11.00 0.00 5.9( 5) 0.00 11.00 0.00 1.35 0.08 154.20 -2.65 11.04 12.00 0.00 5.3( 5) 0.00 12.00 0.00 1.48 0.09 154.20 -2.90 11.09 13.00 0.00 4.8( 5) 0.00 13.00 0.00 1.62 0.09 154.20 -3.15 11.15 14.00 0.00 4.3( 5) 0.00 14.00 0.00 1.75 0.09 154.20 -3.40 11.21 15.00 0.00 3.7( 5) 0.00 15.00 0.00 1.89 0.09 154.20 -3.66 11.27 16.00 0.00 3.2( 5) 0.00 16.00 0.00 2.04 0.10 154.20 -3.91 11.34 17.00 0.00 2.7( 5) 0.00 17.00 0.00 2.18 0.10 154.20 -4.17 11.42 18.00 0.00 2.1( 5) 0.00 18.00 0.00 2.33 0.10 154.20 -4.43 11.50 19.00 0.00 1.6( 5) 0.00 19.00 0.00 2.49 0.11 154.20 -4.70 11.59 20.00 0.00 1.1( 5) 0.00 20.00 0.00 2.64 0.11 154.20 -4.97 11.69 21.00 0.00 0.5( 5) 0.00 21.00 0.00 2.81 0.11 154.20 -5.24 11.79 22.00 0.00 0.0( 5) 0.00 22.00 0.00 2.96 0.11 154.20 -5.50 11.89 23.00 0.00 -0.6( 5) 0.00 23.00 0.00 3.11 0.12 154.20 -5.75 12.00 24.00 0.00 -1.1( 5) 0.00 24.00 0.00 3.24 0.12 154.20 -5.99 12.10 25.00 0.00 -1.7( 5) 0.00 25.00 0.00 3.35 0.12 154.20 -6.21 12.20 26.00 0.00 -2.3( 5) 0.00 26.00 0.01 3.46 0.12 154.20 -6.43 12.30 27.00 -0.01 -2.9( 5) 0.00 27.00 0.01 3.55 0.13 154.20 -6.63 12.41 28.00 -0.01 -3.5( 5) 0.00 28.00 0.01 3.64 0.13 154.20 -6.83 12.51 29.00 -0.01 -4.2( 5) 0.00 29.00 0.01 3.71 0.13 154.20 -7.01 12.61 30.00 -0.01 -4.8( 5) 0.00 30.00 0.02 3.78 0.13 154.20 -7.19 12.71 31.00 -0.02 -5.4( 5) 0.00 31.00 0.02 3.85 0.13 154.20 -7.36 12.81 32.00 -0.02 -6.1( 5) 0.00 32.00 0.02 3.90 0.13 154.20 -7.53 12.91 33.00 -0.02 -6.7( 5) 0.00 33.00 0.03 3.95 0.14 154.20 -7.69 13.01 34.00 -0.03 -7.4( 5) 0.00 34.00 0.03 4.00 0.14 154.20 -7.84 13.12 35.00 -0.03 -8.1( 5) 0.00 35.00 0.04 4.04 0.14 154.19 -7.99 13.22 36.00 -0.03 -8.8( 5) 0.00 36.00 0.04 4.07 0.14 154.19 -8.14 13.32 37.00 -0.04 -9.4( 5) 0.00 37.00 0.05 4.10 0.14 154.19 -8.28 13.43 38.00 -0.04 -10.1( 5) 0.00 38.00 0.05 4.13 0.14 154.19 -8.42 13.53 39.00 -0.04 -10.8( 5) 0.00 39.00 0.06 4.15 0.14 154.19 -8.55 13.64 40.00 -0.05 -11.5( 5) 0.00 40.00 0.06 4.16 0.14 154.19 -8.67 13.74 41.00 -0.05 -12.2( 5) 0.00 41.00 0.07 4.16 0.14 154.19 -8.78 13.83 42.00 -0.06 -12.9( 5) 0.00 42.00 0.07 4.15 0.14 154.19 -8.89 13.93

A-32

43.00 -0.06 -13.5( 5) 0.00 43.00 0.08 4.13 0.14 154.19 -8.99 14.01 44.00 -0.06 -14.2( 5) 0.00 44.00 0.09 4.10 0.14 154.19 -9.08 14.10 45.00 -0.07 -14.9( 5) 0.00 45.00 0.09 4.06 0.14 154.19 -9.16 14.18 46.00 -0.07 -15.6( 5) 0.00 46.00 0.10 4.02 0.14 154.19 -9.24 14.26 47.00 -0.07 -16.2( 5) 0.00 47.00 0.11 3.97 0.14 154.19 -9.31 14.34 48.00 -0.07 -16.9( 5) 0.00 48.00 0.11 3.91 0.14 154.19 -9.38 14.42 49.00 -0.08 -17.5( 5) 0.00 49.00 0.12 3.85 0.14 154.19 -9.45 14.49 50.00 -0.08 -18.2( 5) 0.00 50.00 0.12 3.78 0.14 154.19 -9.51 14.56 51.00 -0.08 -18.8( 5) 0.00 51.00 0.13 3.71 0.14 154.19 -9.56 14.63 52.00 -0.08 -19.4( 5) 0.00 52.00 0.14 3.63 0.14 154.19 -9.62 14.70 53.00 -0.09 -20.1( 5) 0.00 53.00 0.14 3.55 0.14 154.18 -9.67 14.76 54.00 -0.09 -20.7( 5) 0.00 54.00 0.15 3.47 0.13 154.18 -9.72 14.83 55.00 -0.09 -21.3( 5) 0.00 55.00 0.16 3.38 0.13 154.18 -9.76 14.89 56.00 -0.09 -21.9( 5) 0.00 56.00 0.17 3.28 0.13 154.18 -9.80 14.95 57.00 -0.09 -22.5( 5) 0.00 57.00 0.17 3.19 0.13 154.18 -9.84 15.01 58.00 -0.10 -23.1( 5) 0.00 58.00 0.18 3.09 0.13 154.18 -9.88 15.07 59.00 -0.10 -23.7( 5) 0.00 59.00 0.19 2.98 0.13 154.18 -9.91 15.12 60.00 -0.10 -24.3( 5) 0.00 60.00 0.20 2.88 0.13 154.18 -9.94 15.18 61.00 -0.10 -24.8( 5) 0.00 61.00 0.21 2.77 0.13 154.18 -9.98 15.23 62.00 -0.10 -25.4( 5) 0.00 62.00 0.22 2.65 0.13 154.18 -10.00 15.29 63.00 -0.10 -26.0( 5) 0.00 63.00 0.23 2.54 0.12 154.18 -10.03 15.34 64.00 -0.11 -26.5( 5) 0.00 64.00 0.24 2.42 0.12 154.18 -10.06 15.39 65.00 -0.11 -27.0( 5) 0.00 65.00 0.25 2.30 0.12 154.18 -10.08 15.44 66.00 -0.11 -27.6( 5) 0.00 66.00 0.27 2.18 0.12 154.18 -10.10 15.49 67.00 -0.11 -28.1( 5) 0.00 67.00 0.28 2.06 0.12 154.18 -10.13 15.54 68.00 -0.11 -28.6( 5) 0.00 68.00 0.29 1.93 0.12 154.18 -10.15 15.59 69.00 -0.11 -29.1( 5) 0.00 69.00 0.31 1.81 0.12 154.18 -10.16 15.64 70.00 -0.11 -29.6( 5) 0.00 70.00 0.33 1.68 0.11 154.18 -10.18 15.68 71.00 -0.11 -30.1( 5) 0.00 71.00 0.35 1.55 0.11 154.18 -10.20 15.73 72.00 -0.11 -30.6( 5) 0.00 72.00 0.37 1.42 0.11 154.18 -10.21 15.77 73.00 -0.11 -31.1( 5) 0.00 73.00 0.39 1.29 0.11 154.18 -10.23 15.82 74.00 -0.12 -31.5( 5) 0.00 74.00 0.42 1.15 0.11 154.18 -10.24 15.86 75.00 -0.12 -32.0( 5) 0.00 75.00 0.45 1.02 0.11 154.18 -10.25 15.91 76.00 -0.12 -32.4( 5) 0.00 76.00 0.48 0.89 0.10 154.18 -10.26 15.95 77.00 -0.12 -32.9( 5) 0.00 77.00 0.52 0.75 0.10 154.18 -10.28 16.00 78.00 -0.12 -33.3( 5) 0.00 78.00 0.57 0.61 0.10 154.18 -10.28 16.04 79.00 -0.12 -33.7( 5) 0.00 79.00 0.62 0.47 0.10 154.18 -10.29 16.08 80.00 -0.12 -34.1( 5) 0.00 80.00 0.68 0.34 0.10 154.18 -10.30 16.13 81.00 -0.12 -34.5( 5) 0.00 81.00 0.76 0.20 0.09 154.18 -10.31 16.17 82.00 -0.12 -34.9( 5) 0.00 82.00 0.86 0.06 0.09 154.18 -10.31 16.21 83.00 -0.12 -35.2( 5) 0.00 83.00 0.98 -0.08 0.09 154.18 -10.32 16.25 84.00 -0.12 -35.6( 5) 0.00 84.00 1.14 -0.22 0.09 154.18 -10.33 16.29 85.00 -0.12 -35.9( 5) 0.00 85.00 1.37 -0.36 0.09 154.18 -10.33 16.34 ----------------------------------------------------------------------------------------------------------- StabCAD Ver. 4.20 GULF OF MEXICO FPSO -- INTACT STABILITY ANALYSIS Page 6 * * * Intact Stability Allowable KG * * * Draft at no Heel .......... 21.50 M Displacement .............. 401784.28 M.Tons Center of Gravity (X,Y,Z) = 154.20; 0.00; 17.60 M Yaw Angle Of Tilt Axis .... 0.00 Deg Downflooding Angle ........ 26.17 Deg @ HATCH Weathertight Angle ........ 21.96 Deg @ VENT * * * * * Wind Speed 51.40 M/Sec * * * * * ---------------------------------------------------------------------------------------------- Allowable Optimum Range Of Area /--Intercept--/ Condition KG Tilt Angle Stability Ratio 1st 2nd (M) (Deg) (Deg) /----(Deg)----/ ------------------------ ------------ ---------- --------- ------ ---------------

A-33

For Input KG = 17.60 26.17 26.17 18.96 0.46 81.76 Area Ratio = 1.40* 24.43 26.17 26.17 1.76 13.42 34.66 1st Intercept = 15.00* 24.43 26.17 26.17 1.76 13.42 34.66 2nd Intercept = 30.00* 24.43 26.17 26.17 1.76 13.42 34.66 ---------------------------------------------------------------------------------------------- StabCAD Ver. 4.20 GULF OF MEXICO FPSO -- INTACT STABILITY ANALYSIS Page 7 * * * Righting Arm And Heeling Arm Curves * * * Draft at no Heel .......... 21.50 M Displacement .............. 401784.3 M.Tons ---------------------------------------------------------------------- Heel Heeling Arm Righting Arm Data For Calculated KG (Deg) 51.40 0.00 17.60 24.43 24.43 24.43 ---------------------------------------------------------------------- 0.00 0.05 0.00 0.00 0.00 0.00 0.00 1.00 0.06 0.00 0.12 0.00 0.00 0.00 2.00 0.06 0.00 0.24 0.00 0.00 0.00 3.00 0.06 0.00 0.36 0.00 0.00 0.00 4.00 0.06 0.00 0.48 0.00 0.00 0.00 5.00 0.07 0.00 0.60 0.00 0.00 0.00 6.00 0.07 0.00 0.72 0.01 0.01 0.01 7.00 0.07 0.00 0.84 0.01 0.01 0.01 8.00 0.07 0.00 0.97 0.02 0.02 0.02 9.00 0.08 0.00 1.10 0.03 0.03 0.03 10.00 0.08 0.00 1.22 0.04 0.04 0.04 11.00 0.08 0.00 1.35 0.05 0.05 0.05 12.00 0.09 0.00 1.48 0.06 0.06 0.06 13.00 0.09 0.00 1.62 0.08 0.08 0.08 14.00 0.09 0.00 1.75 0.10 0.10 0.10 15.00 0.09 0.00 1.89 0.13 0.13 0.13 16.00 0.10 0.00 2.04 0.15 0.15 0.15 17.00 0.10 0.00 2.18 0.19 0.19 0.19 18.00 0.10 0.00 2.33 0.22 0.22 0.22 19.00 0.11 0.00 2.49 0.26 0.26 0.26 20.00 0.11 0.00 2.64 0.31 0.31 0.31 21.00 0.11 0.00 2.81 0.36 0.36 0.36 22.00 0.11 0.00 2.96 0.41 0.41 0.41 23.00 0.12 0.00 3.11 0.44 0.44 0.44 24.00 0.12 0.00 3.24 0.46 0.46 0.46 25.00 0.12 0.00 3.35 0.46 0.46 0.46 26.00 0.12 0.00 3.46 0.46 0.46 0.46 27.00 0.13 0.00 3.55 0.45 0.45 0.45 28.00 0.13 0.00 3.64 0.43 0.43 0.43 29.00 0.13 0.00 3.71 0.40 0.40 0.40 30.00 0.13 0.00 3.78 0.37 0.37 0.37 31.00 0.13 0.00 3.85 0.33 0.33 0.33 32.00 0.13 0.00 3.90 0.28 0.28 0.28 33.00 0.14 0.00 3.95 0.23 0.23 0.23 34.00 0.14 0.00 4.00 0.18 0.18 0.18 35.00 0.14 0.00 4.04 0.12 0.12 0.12 36.00 0.14 0.00 4.07 0.06 0.06 0.06 37.00 0.14 0.00 4.10 -0.01 -0.01 -0.01 38.00 0.14 0.00 4.13 -0.08 -0.08 -0.08 39.00 0.14 0.00 4.15 -0.15 -0.15 -0.15 40.00 0.14 0.00 4.16 -0.23 -0.23 -0.23 41.00 0.14 0.00 4.16 -0.32 -0.32 -0.32 42.00 0.14 0.00 4.15 -0.42 -0.42 -0.42

A-34

43.00 0.14 0.00 4.13 -0.53 -0.53 -0.53 44.00 0.14 0.00 4.10 -0.65 -0.65 -0.65 45.00 0.14 0.00 4.06 -0.77 -0.77 -0.77 46.00 0.14 0.00 4.02 -0.89 -0.89 -0.89 47.00 0.14 0.00 3.97 -1.03 -1.03 -1.03 48.00 0.14 0.00 3.91 -1.16 -1.16 -1.16 49.00 0.14 0.00 3.85 -1.30 -1.30 -1.30 50.00 0.14 0.00 3.78 -1.45 -1.45 -1.45 51.00 0.14 0.00 3.71 -1.60 -1.60 -1.60 52.00 0.14 0.00 3.63 -1.75 -1.75 -1.75 53.00 0.14 0.00 3.55 -1.90 -1.90 -1.90 54.00 0.13 0.00 3.47 -2.06 -2.06 -2.06 55.00 0.13 0.00 3.38 -2.22 -2.22 -2.22 56.00 0.13 0.00 3.28 -2.38 -2.38 -2.38 57.00 0.13 0.00 3.19 -2.54 -2.54 -2.54 58.00 0.13 0.00 3.09 -2.71 -2.71 -2.71 59.00 0.13 0.00 2.98 -2.87 -2.87 -2.87 60.00 0.13 0.00 2.88 -3.04 -3.04 -3.04 61.00 0.13 0.00 2.77 -3.21 -3.21 -3.21 62.00 0.13 0.00 2.65 -3.38 -3.38 -3.38 63.00 0.12 0.00 2.54 -3.55 -3.55 -3.55 64.00 0.12 0.00 2.42 -3.72 -3.72 -3.72 65.00 0.12 0.00 2.30 -3.89 -3.89 -3.89 66.00 0.12 0.00 2.18 -4.06 -4.06 -4.06 67.00 0.12 0.00 2.06 -4.23 -4.23 -4.23 68.00 0.12 0.00 1.93 -4.40 -4.40 -4.40 69.00 0.12 0.00 1.81 -4.57 -4.57 -4.57 70.00 0.11 0.00 1.68 -4.74 -4.74 -4.74 71.00 0.11 0.00 1.55 -4.91 -4.91 -4.91 72.00 0.11 0.00 1.42 -5.08 -5.08 -5.08 73.00 0.11 0.00 1.29 -5.24 -5.24 -5.24 74.00 0.11 0.00 1.15 -5.41 -5.41 -5.41 75.00 0.11 0.00 1.02 -5.58 -5.58 -5.58 76.00 0.10 0.00 0.89 -5.74 -5.74 -5.74 77.00 0.10 0.00 0.75 -5.91 -5.91 -5.91 78.00 0.10 0.00 0.61 -6.07 -6.07 -6.07 79.00 0.10 0.00 0.47 -6.23 -6.23 -6.23 80.00 0.10 0.00 0.34 -6.39 -6.39 -6.39 81.00 0.09 0.00 0.20 -6.55 -6.55 -6.55 82.00 0.09 0.00 0.06 -6.71 -6.71 -6.71 83.00 0.09 0.00 -0.08 -6.86 -6.86 -6.86 84.00 0.09 0.00 -0.22 -7.01 -7.01 -7.01 85.00 0.09 0.00 -0.36 -7.16 -7.16 -7.16 ---------------------------------------------------------------------- StabCAD Ver. 4.20 GULF OF MEXICO FPSO -- INTACT STABILITY ANALYSIS Page 8 Wednesday 4/30/2003 10:17:17 Input File Name:C:\STAB42\STABDATA\GOM\TEST3 Output File Name:C:\STAB42\STABDATA\GOM\TEST3.OT9 * * * Problem Description * * * Number Of Joints ............. 282 Number Of Plates ............. 403 Number Of Cylinders .......... 0 Number Of Stations ........... 0 Total Execution time = 0: 0: 1 (000)

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Appendix III: Mooring/Mimosa & Cost Analysis

Input Procedure for Mimosa Data was input into MIMOSA through four files. The first file is the “mass, wind, and current coefficients” file, this file contains information such as the vessels mass and various quadratic coefficients for calculation of the wind and current forces on the vessel. These coefficients were obtained from the environmental loading calculations. The second file used is the environmental data file; this file contains basic environmental parameters such as the peak period and significant wave height. The third input file is of the vessels frequency induced motion in the form of a “SESAM interactive file” (*.sif). This file is produced in another SESAM program WADAM that computes wave analysis and diffraction on a structure. The final file needed is the mooring system file, which contains the particulars of the mooring system such as the line characteristics of the mooring system. In the trial run a mass, wind, and current coefficients file was created. The quadratic coefficients were calculated using in an EXCEL spreadsheet from the environmental loading results of the preliminary FPSO design. Wave drift coefficients and the vessel frequency response were input in a WADAM output file for a 2 million barrel capacity FPSO provided by Haliburton.

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Mimosa Mass, Wind, and Current Coefficients Input

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Environmental Data Macro File MODIFY SYSTEM ' SYSTEM ENVIRONMENTAL CO ' MODIFY SYSTEM Wind ' MODIFY ENVIRONMENT n ' Choose type (D, H, N or A) 39.9 ' Wind speed (m/s) 0 ' Wind direction (deg) Current ' MODIFY ENVIRONMENT 1.4 ' Current velocity ( m/s ) 0 ' Current direction ( deg ) 8 ' Number of current layers, NLCUR: ! ' ZLEV, CURVEL, CURDIR for layer no: 1 0 ' Level for current specification (m) 1.4 ' Current velocity component (m/s) 0 ' Direction of current (deg) ! ' ZLEV, CURVEL, CURDIR for layer no: 2 45 ' Level for current specification (m) 1.4 ' Current velocity component (m/s) 0 ' Direction of current (deg) ! ' ZLEV, CURVEL, CURDIR for layer no: 3 60 ' Level for current specification (m) 1.4 ' Current velocity component (m/s) 0 ' Direction of current (deg) ! ' ZLEV, CURVEL, CURDIR for layer no: 4 80 ' Level for current specification (m) .8 ' Current velocity component (m/s) 0 ' Direction of current (deg) ! ' ZLEV, CURVEL, CURDIR for layer no: 5 100 ' Level for current specification (m) .2 ' Current velocity component (m/s) 0 ' Direction of current (deg) ! ' ZLEV, CURVEL, CURDIR for layer no: 6 200 ' Level for current specification (m) .2 ' Current velocity component (m/s) 0 ' Direction of current (deg) ! ' ZLEV, CURVEL, CURDIR for layer no: 7 300 ' Level for current specification (m) .1 ' Current velocity component (m/s) 0 ' Direction of current (deg) ! ' ZLEV, CURVEL, CURDIR for layer no: 8 1865 ' Level for current specification (m) 0 ' Current velocity component (m/s) 0 ' Direction of current (deg) Wave ' MODIFY ENVIRONMENT jo ' Wave spectrum (PM-1, PM-2, JO or DPS) 12.3 ' Sign. height ( m ) 14.2 ' Peak period ( s ) 1.25 ' Beta 2.98553 ' Gamma 0.7e-1 ' Sigma A 0.9e-1 ' Sigma B 0 ' Wave direction ( deg ) / ' Short-crested representation @ CLOSE

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Vessel Dynamic Wave Analysis (G12.SIF) IDENT 1.00000000E+00 1.00000000E+00 0.00000000E+00 0.00000000E+00 DATE 1.00000000E+00 0.00000000E+00 4.00000000E+00 7.20000000E+01 DATE: 31-MAR-2003 TIME: 16:01:36 PROGRAM: SESAM WADAM VERSION: 7.2-03 10-NOV-2000 COMPUTER: 586 WIN NT 5.1 [2600INSTALLATION: KELLOGG BGA6432 USER: HBB8792 ACCOUNT: TEXT 1.00000000E+00 0.00000000E+00 3.00000000E+00 7.20000000E+01 TAMU SR. PROJ. FPSO WBODCON 7.00000000E+00 1.00000000E+00 1.00000000E+00 1.00000000E+00 1.00000000E+00 1.00000000E+00 0.00000000E+00 WDRESREF 1.00000000E+01 1.00000000E+00 1.00000000E+00 2.00000000E+00 1.00000000E+00 1.00000000E+00 0.00000000E+00 2.00000000E+00 1.00000000E+00 1.67551613E+00 WDRESREF 1.00000000E+01 2.00000000E+00 1.00000000E+00 2.00000000E+00 1.00000000E+00 1.00000000E+00 0.00000000E+00 2.00000000E+00 2.00000000E+00 1.57079637E+00 WDRESREF 1.00000000E+01 3.00000000E+00 1.00000000E+00 2.00000000E+00 1.00000000E+00 1.00000000E+00 0.00000000E+00 2.00000000E+00 3.00000000E+00 1.47839653E+00 WDRESREF 1.00000000E+01 4.00000000E+00 1.00000000E+00 2.00000000E+00 1.00000000E+00 1.00000000E+00 0.00000000E+00 2.00000000E+00 4.00000000E+00 1.39626348E+00 WDRESREF 1.00000000E+01 5.00000000E+00 1.00000000E+00 2.00000000E+00 1.00000000E+00 1.00000000E+00 0.00000000E+00 2.00000000E+00 5.00000000E+00 1.25663710E+00 WDRESREF 1.00000000E+01 6.00000000E+00 1.00000000E+00 2.00000000E+00 1.00000000E+00 1.00000000E+00 0.00000000E+00 2.00000000E+00 6.00000000E+00 1.14239740E+00 WDRESREF 1.00000000E+01 7.00000000E+00 1.00000000E+00 2.00000000E+00 1.00000000E+00 1.00000000E+00 0.00000000E+00 2.00000000E+00 7.00000000E+00 1.04719758E+00 WDRESREF 1.00000000E+01 8.00000000E+00 1.00000000E+00 2.00000000E+00 1.00000000E+00 1.00000000E+00 0.00000000E+00 2.00000000E+00 8.00000000E+00 8.97597909E-01 WDRESREF 1.00000000E+01 9.00000000E+00 1.00000000E+00 2.00000000E+00 1.00000000E+00 1.00000000E+00 0.00000000E+00 2.00000000E+00 9.00000000E+00 7.85398185E-01 WDRESREF 1.00000000E+01 1.00000000E+01 1.00000000E+00 2.00000000E+00 1.00000000E+00 1.00000000E+00 0.00000000E+00 2.00000000E+00 1.00000000E+01 6.98131740E-01 WDRESREF 1.00000000E+01 1.10000000E+01 1.00000000E+00 2.00000000E+00 1.00000000E+00 1.00000000E+00 0.00000000E+00 2.00000000E+00 1.10000000E+01 5.71198702E-01 WDRESREF 1.00000000E+01 1.20000000E+01 1.00000000E+00 2.00000000E+00 1.00000000E+00 1.00000000E+00 0.00000000E+00 2.00000000E+00 1.20000000E+01 4.83321965E-01 WDRESREF 1.00000000E+01 1.30000000E+01 1.00000000E+00 2.00000000E+00 1.00000000E+00 1.00000000E+00 0.00000000E+00 2.00000000E+00 … … …

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Example 8 Line Synthetic Input VESSEL POSITION Text describing positioning system 'vessel CG position coordinates with respect to global WL coordinate system. 'x1ves x2ves x3ves head 0 0 0 0 LINE DATA 'iline lichar inilin iwirun intact 1 1 1 0 1 'tpx1 tpx2 75 0 'alfa tens xwinch 22.5 1810 0 LINE DATA 'iline lichar inilin iwirun intact 2 1 1 0 1 'tpx1 tpx2 75 0 'alfa tens xwinch 67.5 1810 0 LINE DATA 'iline lichar inilin iwirun intact 3 2 1 0 1 'tpx1 tpx2 75 0 'alfa tens xwinch 112.5 1810 0 LINE DATA 'iline lichar inilin iwirun intact 4 2 1 0 1 'tpx1 tpx2 75 0 'alfa tens xwinch 157.5 1810 0 LINE DATA 'iline lichar inilin iwirun intact 5 3 1 0 1 'tpx1 tpx2 75 0 'alfa tens xwinch 202.5 1810 0 LINE DATA 'iline lichar inilin iwirun intact 6 3 1 0 1 'tpx1 tpx2 75 0 'alfa tens xwinch 247.5 1810 0 LINE DATA 'iline lichar inilin iwirun intact 7 4 1 0 1 'tpx1 tpx2 75 0 'alfa tens xwinch 292.5 1810 0

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LINE DATA 'iline lichar inilin iwirun intact 8 4 1 0 1 'tpx1 tpx2 75 0 'alfa tens xwinch 337.5 1810 0 LINE CHARACTERISTICS DATA 'lichar 1 'linpty npocha 2 40 'nseg ibotco icurli 3 1 1 'anbot tpx3 x3ganc tmax fric 19.6 19.6 1865 18000 1 'iseg ieltyp nel ibuoy sleng nea brkstr 1 0 8 0 50 1 13710 2 0 130 0 2700 1 13345 3 0 15 0 150 1 13710 'iseg dia emod emfact uwiw watfac cdn cdl 1 0.1207 1.84E+10 2 2.722 0.87 2.4 0.16 2 0.221 1.00E+07 1 0.0327 0.11 1.2 0.16 3 0.1207 1.84E+10 2 2.722 0.87 2.4 0.16 LINE CHARACTERISTICS DATA 'lichar 2 'linpty npocha 2 40 'nseg ibotco icurli 3 1 1 'anbot tpx3 x3ganc tmax fric 19.6 0 1865 18000 1 'iseg ieltyp nel ibuoy sleng nea brkstr 1 0 8 0 50 1 13710 2 0 130 0 2700 1 13345 3 0 15 0 150 1 13710 'iseg dia emod emfact uwiw watfac cdn cdl 1 0.1207 1.84E+10 2 2.722 0.87 2.4 0.16 2 0.221 1.00E+07 1 0.0327 0.11 1.2 0.16 3 0.1207 1.84E+10 2 2.722 0.87 2.4 0.16 LINE CHARACTERISTICS DATA 'lichar 3 'linpty npocha 2 40 'nseg ibotco icurli 3 1 1 'anbot tpx3 x3ganc tmax fric 19.6 0 1865 18000 1 'iseg ieltyp nel ibuoy sleng nea brkstr 1 0 8 0 50 1 13710 2 0 130 0 2700 1 13345 3 0 15 0 150 1 13710 'iseg dia emod emfact uwiw watfac cdn cdl 1 0.1207 1.84E+10 2 2.722 0.87 2.4 0.16

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2 0.221 1.00E+07 1 0.0327 0.11 1.2 0.16 3 0.1207 1.84E+10 2 2.722 0.87 2.4 0.16 LINE CHARACTERISTICS DATA 'lichar 4 'linpty npocha 2 40 'nseg ibotco icurli 3 1 1 'anbot tpx3 x3ganc tmax fric 19.6 0 1865 18000 1 'iseg ieltyp nel ibuoy sleng nea brkstr 1 0 8 0 50 1 13710 2 0 130 0 2700 1 13345 3 0 15 0 150 1 13710 'iseg dia emod emfact uwiw watfac cdn cdl 1 0.1207 1.84E+10 2 2.722 0.87 2.4 0.16 2 0.221 1.00E+07 1 0.0327 0.11 1.2 0.16 3 0.1207 1.84E+10 2 2.722 0.87 2.4 0.16 'termination of input data END

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Example 16 Line Chain-Wire-Chain Input Vessel Position Text describing positioning system 'vessel CG position coordinates with respect to global WL coordinate system. 'x1ves x2ves x3ves head 0 0 0 0 LINE DATA 'iline lichar inilin iwirun intact 1 1 1 0 1 'tpx1 tpx2 75 0 'alfa tens xwinch 10 3275 0 LINE DATA 'iline lichar inilin iwirun intact 2 1 1 0 1 'tpx1 tpx2 75 0 'alfa tens xwinch 35 3275 0 LINE DATA 'iline lichar inilin iwirun intact 3 1 1 0 1 'tpx1 tpx2 75 0 'alfa tens xwinch 55 3275 0 LINE DATA 'iline lichar inilin iwirun intact 4 1 1 0 1 'tpx1 tpx2 75 0 'alfa tens xwinch 80 3275 0 LINE DATA 'iline lichar inilin iwirun intact 5 2 1 0 1 'tpx2 tpx3 75 0 'alfa tens xwinch 100 3275 1 LINE DATA 'iline lichar inilin iwirun intact 6 2 1 0 1 'tpx3 tpx4 75 0 'alfa tens xwinch 125 3275 2 LINE DATA 'iline lichar inilin iwirun intact 7 2 1 0 1 'tpx4 tpx5 75 0 'alfa tens xwinch

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145 3275 3 LINE DATA 'iline lichar inilin iwirun intact 8 2 1 0 1 'tpx5 tpx6 75 0 'alfa tens xwinch 170 3275 4 LINE DATA 'iline lichar inilin iwirun intact 9 3 1 0 1 'tpx6 tpx7 75 0 'alfa tens xwinch 190 3275 5 LINE DATA 'iline lichar inilin iwirun intact 10 3 1 0 1 'tpx7 tpx8 75 0 'alfa tens xwinch 215 3275 6 LINE DATA 'iline lichar inilin iwirun intact 11 3 1 0 1 'tpx8 tpx9 75 0 'alfa tens xwinch 235 3275 7 LINE DATA 'iline lichar inilin iwirun intact 12 3 1 0 1 'tpx9 tpx10 75 0 'alfa tens xwinch 260 3275 8 LINE DATA 'iline lichar inilin iwirun intact 13 4 1 0 1 'tpx10 tpx11 75 0 'alfa tens xwinch 280 3275 9 LINE DATA 'iline lichar inilin iwirun intact 14 4 1 0 1 'tpx11 tpx12 75 0 'alfa tens xwinch 305 3275 10 LINE DATA 'iline lichar inilin iwirun intact 15 4 1 0 1 'tpx12 tpx13 75 0 'alfa tens xwinch

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325 3275 11 LINE DATA 'iline lichar inilin iwirun intact 16 4 1 0 1 'tpx13 tpx14 75 0 'alfa tens xwinch 350 3275 12 LINE CHARACTERISTICS DATA 'lichar 1 'linpty npocha 2 40 'nseg ibotco icurli 3 1 1 'anbot tpx3 x3ganc tmax fric 0 19.6 1865 18000 1 'iseg ieltyp nel ibuoy sleng nea brkstr 1 0 8 0 50 1 16906 2 0 130 0 2800 1 16607 3 0 15 0 200 1 16906 'iseg dia emod emfact uwiw watfac cdn cdl 1 0.1365 1.84E+10 2 3.48 0.87 2.4 0.16 2 0.1429 2.11E+10 1 0.874 0.82 1.2 0.16 3 0.1365 1.84E+10 2 3.48 0.87 2.4 0.16 LINE CHARACTERISTICS DATA 'lichar 2 'linpty npocha 2 40 'nseg ibotco icurli 3 1 1 'anbot tpx3 x3ganc tmax fric 0 19.6 1865 18000 1 'iseg ieltyp nel ibuoy sleng nea brkstr 1 0 8 0 50 1 16906 2 0 130 0 2800 1 16607 3 0 15 0 200 1 16906 'iseg dia emod emfact uwiw watfac cdn cdl 1 0.1365 1.84E+10 2 3.48 0.87 2.4 0.16 2 0.1429 2.11E+10 1 0.874 0.82 1.2 0.16 3 0.1365 1.84E+10 2 3.48 0.87 2.4 0.16 LINE CHARACTERISTICS DATA 'lichar 3 'linpty npocha 2 40 'nseg ibotco icurli 3 1 1 'anbot tpx3 x3ganc tmax fric 0 19.6 1865 18000 1 'iseg ieltyp nel ibuoy sleng nea brkstr 1 0 8 0 50 1 16906 2 0 130 0 2800 1 16607 3 0 15 0 200 1 16906 'iseg dia emod emfact uwiw watfac cdn cdl

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1 0.1365 1.84E+10 2 3.48 0.87 2.4 0.16 2 0.1429 2.11E+10 1 0.874 0.82 1.2 0.16 3 0.1365 1.84E+10 2 3.48 0.87 2.4 0.16 LINE CHARACTERISTICS DATA 'lichar 4 'linpty npocha 2 40 'nseg ibotco icurli 3 1 1 'anbot tpx3 x3ganc tmax fric 0 19.6 1865 18000 1 'iseg ieltyp nel ibuoy sleng nea brkstr 1 0 8 0 50 1 16906 2 0 130 0 2800 1 16607 3 0 15 0 200 1 16906 'iseg dia emod emfact uwiw watfac cdn cdl 1 0.1365 1.84E+10 2 3.48 0.87 2.4 0.16 2 0.1429 2.11E+10 1 0.874 0.82 1.2 0.16 3 0.1365 1.84E+10 2 3.48 0.87 2.4 0.16 'termination of input data END

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Example 8 Line Synthetic Output MIMOSA Version 5.6-02 29-APR-2003 22:03 MARINTEK Page 1 Mooring analysis of 8 line synthetic system ****** ****** ****** ****** ** *** **** ******** ******** ******** ******** ************* ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ******* ********** ******* ********* ** ** ** ******* ********* ******* ********** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ******** ******** ******** ********* ** ** ** ****** ****** ****** ****** ** ** ** ** *************************** * * * M I M O S A * * * * Mooring Analysis * * * *************************** Marketing and Support by DNV Software Program id : 5.6-02 Computer : 586 Release date : 3-JUL-2002 Impl. update : Access time : 29-APR-2003 22:03:59 Operating system : Win NT 5.1 [2600] User id : jrp0803 CPU id : 0000200304 Installation : , ce220no03 Copyright DET NORSKE VERITAS AS, P.O.Box 300, N-1322 Hovik, Norway Input file : g12.sif * Vessel mass and added mass Text : TAMU SR. PROJ. FPSO Input file : g12.sif * HF motion transfer functions Text : TAMU SR. PROJ. FPSO Water depth used in calculation of roll, pitch and yaw : 1865.0 m

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MIMOSA Version 5.6-02 29-APR-2003 22:03 MARINTEK Page 2 Mooring analysis of 8 line synthetic system Duration for short-term statistics : 120.00 min. Input file : g12.sif * Wave drift force coefficients Text : TAMU SR. PROJ. FPSO Input file : wmc.dat * Current force coefficients Text : Mass, Wind, Curre Input file : wmc.dat * Wind force coefficients Text : Mass, Wind, Curre Input file : g8sb.inp * Mooring system data Text : Text describing positioning system MIMOSA Version 5.6-02 29-APR-2003 22:03 MARINTEK Page 3 Mooring analysis of 8 line synthetic system * EQUILIBRIUM POSITION * ------------------------ Relative to Relative to GLOBAL ORIGIN CURRENT Position OFFSET ................. 36.8 m 36.8 m DIRECTION (rel. North).. 0.0 deg 0.0 deg HEADING ................ 0.0 deg 0.0 deg X1 (North) ............. 36.8 m 36.8 m X2 (East) .............. 0.0 m 0.0 m The Vessel is moved to Equilibrium Position ! * STATIC EXTERNAL FORCES * --------------------------

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!--------------------------------------------------------! ! ! Surge comp. ! Sway comp. ! Yaw comp. ! !--------------------------------------------------------! ! Wind ! 4193.4 kN ! 0.0 kN ! 0.0000 kNm! ! Wave ! 3817.0 kN ! 0.0 kN !0.1238E-02 kNm! ! Current ! 162.1 kN ! 0.0 kN ! 0.0000 kNm! ! ! ! ! ! ! Fixed force ! 0.0 kN ! 0.0 kN ! 0.0000 kNm! !--------------------------------------------------------! ! Total ! 8172.5 kN ! 0.0 kN !0.1238E-02 kNm! !--------------------------------------------------------! TOTAL FORCE : 8172.5 kN Dir. rel. Vessel : 0.0 deg ------------------------- Dir. rel. North : 0.0 deg MIMOSA Version 5.6-02 29-APR-2003 22:03 MARINTEK Page 4 Mooring analysis of 8 line synthetic system * MAXIMUM LINE TENSIONS. HF MOTION * ------------------------------------------------ ** Line Dynamics Included ** Line ---- Top tension ---- Max. Direction Type No. Mean Max Safety Segm. tangent from hor. (kN) (kN) factor No. motion (m) plane (deg) 1 677.1 1367.4 10.03 3 4.20 -70.3 SAM 2 987.9 1518.2 9.03 3 3.94 -59.9 SAM 3 3213.7 3678.7 3.73 3 3.44 -45.8 SAM 4 5307.4 5775.8 2.37 3 3.45 -43.1 SAM 5 5309.3 5777.7 2.37 3 3.45 -43.1 SAM 6 3218.2 3682.5 3.72 3 3.44 -45.8 SAM 7 990.2 1553.5 8.83 3 4.16 -60.2 SAM 8 678.3 1435.0 9.55 3 4.54 -70.5 SAM SAM = Tensions are estimated with the Simplified Analytic Method HF max tension: Non-Rayleigh based Details on dynamic tension (in kN): ------------------------------------------------------- Line Standard Maximum Maximum Zero crossing No. deviation amplitude tension period (s) ------------------------------------------------------- 1 142.9 684.9 1367.4 15.14 2 150.6 528.2 1518.2 15.27 3 133.2 466.2 3678.7 15.77 4 134.0 468.4 5775.8 16.00 5 134.0 468.4 5777.7 16.00 6 133.2 466.1 3682.5 15.77 7 159.3 559.1 1553.5 15.25 8 156.7 751.4 1435.0 15.10 MIMOSA Version 5.6-02 29-APR-2003 22:03 MARINTEK

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Page 5 Mooring analysis of 8 line synthetic system * EQUILIBRIUM POSITION * ------------------------ Relative to Relative to GLOBAL ORIGIN CURRENT Position OFFSET ................. 74.1 m 38.6 m DIRECTION (rel. North).. 348.9 deg 338.2 deg HEADING ................ 0.0 deg 0.0 deg X1 (North) ............. 72.7 m 35.9 m X2 (East) .............. -14.3 m -14.3 m The Vessel is moved to Equilibrium Position ! MIMOSA Version 5.6-02 29-APR-2003 22:03 MARINTEK Page 6 Mooring analysis of 8 line synthetic system * MAXIMUM LINE TENSIONS. HF MOTION * ------------------------------------------------ ** Line Dynamics Included ** Line ---- Top tension ---- Max. Direction Type No. Mean Max Safety Segm. tangent from hor. (kN) (kN) factor No. motion (m) plane (deg) 1 584.5 1357.8 10.10 3 4.42 -76.3 SAM 2 1002.4 1532.7 8.95 3 3.94 -59.6 SAM 3 6157.9 6598.9 2.08 3 3.25 -42.5 SAM 4 BROKEN 5 8366.4 8823.7 1.55 3 3.37 -41.5 SAM 6 3364.0 3828.3 3.58 3 3.42 -45.5 SAM 7 647.5 1438.0 9.53 3 4.55 -72.3 SAM 8 564.4 1386.2 9.89 3 4.69 -78.0 SAM SAM = Tensions are estimated with the Simplified Analytic Method HF max tension: Non-Rayleigh based Details on dynamic tension (in kN): ------------------------------------------------------- Line Standard Maximum Maximum Zero crossing No. deviation amplitude tension period (s) ------------------------------------------------------- 1 136.3 779.8 1357.8 15.18 2 150.8 528.9 1532.7 15.29 3 126.0 441.0 6598.9 15.81 4 BROKEN 5 130.8 457.3 8823.7 16.01 6 132.7 464.3 3828.3 15.79 7 153.8 791.9 1438.0 15.28 8 140.4 826.1 1386.2 15.16

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Example 16 Line Chain-Wire-Chain Output MIMOSA Version 5.6-02 29-APR-2003 21:44 MARINTEK Page 1 Mooring Results of siteen line chain wire chain ****** ****** ****** ****** ** *** **** ******** ******** ******** ******** ************* ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ******* ********** ******* ********* ** ** ** ******* ********* ******* ********** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ******** ******** ******** ********* ** ** ** ****** ****** ****** ****** ** ** ** ** *************************** * * * M I M O S A * * * * Mooring Analysis * * * *************************** Marketing and Support by DNV Software Program id : 5.6-02 Computer : 586 Release date : 3-JUL-2002 Impl. update : Access time : 29-APR-2003 21:44:36 Operating system : Win NT 5.1 [2600] User id : jrp0803 CPU id : 0000200304 Installation : , ce220no03 Copyright DET NORSKE VERITAS AS, P.O.Box 300, N-1322 Hovik, Norway Input file : g12.sif * Vessel mass and added mass Text : TAMU SR. PROJ. FPSO Input file : g12.sif * HF motion transfer functions Text : TAMU SR. PROJ. FPSO Water depth used in calculation of roll, pitch and yaw : 1865.0 m MIMOSA Version 5.6-02 29-APR-2003 21:44 MARINTEK Page 2 Mooring Results of siteen line chain wire chain

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Duration for short-term statistics : 120.00 min. Input file : g12.sif * Wave drift force coefficients Text : TAMU SR. PROJ. FPSO Input file : wmc.dat * Current force coefficients Text : Mass, Wind, Curre Input file : wmc.dat * Wind force coefficients Text : Mass, Wind, Curre MIMOSA Version 5.6-02 29-APR-2003 21:44 MARINTEK Page 3 Mooring Results of siteen line chain wire chain * ENVIRONMENTAL CONDITIONS * ---------------------------- NOTE ! Propagation direction ( 0 deg : towards North ) ( 90 deg : towards East ) WIND NPD SPECTRUM Mean speed ........................ : 39.90 m/s Direction ......................... : 0.00 deg. CURRENT Velocity .......................... : 1.40 m/s Direction ......................... : 0.00 deg. Current profile used in comp. of line profile: Number Level Velocity Direction rel. (m) (m/s) north (deg) 1 0.00 1.400 0.00 2 45.00 1.400 0.00 3 60.00 1.400 0.00 4 80.00 0.800 0.00 5 100.00 0.200 0.00 6 200.00 0.200 0.00 7 300.00 0.100 0.00 8 1865.00 0.000 0.00 WAVE JONSWAP SPECTRUM,

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Significant wave height (HS) ...... : 12.30 m Peak period (TP) .................. : 14.200 s Phillip constant (ALPHA) .......... : 0.01292 Form parameter (BETA) ............. : 1.250 Peakedness parameter (GAMMA) ...... : 2.986 Spectrum width parameter (SIGA) ... : 0.070 Spectrum width parameter (SIGB) ... : 0.090 Direction ......................... : 0.00 deg Short-crested representation ...... : COS**0 NO SWELL Input file : g16wa.inp * Mooring system data Text : Text describing positioning system MIMOSA Version 5.6-02 29-APR-2003 21:44 MARINTEK Page 5 Mooring Results of siteen line chain wire chain * STATIC EXTERNAL FORCES * -------------------------- !--------------------------------------------------------! ! ! Surge comp. ! Sway comp. ! Yaw comp. ! !--------------------------------------------------------! ! Wind ! 4193.4 kN ! 0.0 kN ! 0.0000 kNm! ! Wave ! 3817.0 kN ! 0.0 kN !0.1238E-02 kNm! ! Current ! 162.1 kN ! 0.0 kN ! 0.0000 kNm! ! ! ! ! ! ! Fixed force ! 0.0 kN ! 0.0 kN ! 0.0000 kNm! !--------------------------------------------------------! ! Total ! 8172.5 kN ! 0.0 kN !0.1238E-02 kNm! !--------------------------------------------------------! TOTAL FORCE : 8172.5 kN Dir. rel. Vessel : 0.0 deg ------------------------- Dir. rel. North : 0.0 deg * EQUILIBRIUM POSITION * ------------------------ Relative to Relative to GLOBAL ORIGIN CURRENT Position OFFSET ................. 182.8 m 182.8 m DIRECTION (rel. North).. 0.0 deg 0.0 deg HEADING ................ 0.0 deg 0.0 deg X1 (North) ............. 182.8 m 182.8 m X2 (East) .............. 0.0 m 0.0 m The Vessel is moved to Equilibrium Position !

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MIMOSA Version 5.6-02 29-APR-2003 21:44 MARINTEK Page 6 Mooring Results of siteen line chain wire chain * MAXIMUM LINE TENSIONS. HF MOTION * ------------------------------------------------ ** Line Dynamics Included ** Line ---- Top tension ---- Max. Direction Type No. Mean Max Safety Segm. tangent from hor. (kN) (kN) factor No. motion (m) plane (deg) 1 2788.7 3204.4 5.28 3 4.39 -76.0 SAM 2 2857.4 3298.3 5.13 3 4.40 -74.8 SAM 3 2972.1 3458.9 4.89 3 4.41 -73.0 SAM 4 3191.0 3777.6 4.48 3 4.44 -69.9 SAM 5 3423.9 4142.6 4.08 3 4.49 -66.9 SAM 6 3824.8 5054.0 3.35 3 4.56 -62.9 SAM 7 4275.0 6398.4 2.64 3 4.60 -59.5 SAM 8 4821.4 8501.6 1.99 3 4.62 -56.6 SAM 9 4821.3 8492.9 1.99 3 4.62 -56.6 SAM 10 4274.7 6398.9 2.64 3 4.60 -59.5 SAM 11 3824.5 5053.4 3.35 3 4.56 -62.9 SAM 12 3423.7 4143.5 4.08 3 4.49 -66.9 SAM 13 3190.8 3777.1 4.48 3 4.44 -69.9 SAM 14 2972.0 3458.4 4.89 3 4.41 -73.0 SAM 15 2857.3 3299.4 5.12 3 4.40 -74.8 SAM 16 2788.7 3204.4 5.28 3 4.39 -76.0 SAM SAM = Tensions are estimated with the Simplified Analytic Method HF max tension: Non-Rayleigh based MIMOSA Version 5.6-02 29-APR-2003 21:44 MARINTEK Page 7 Mooring Results of siteen line chain wire chain Details on dynamic tension (in kN): ------------------------------------------------------- Line Standard Maximum Maximum Zero crossing No. deviation amplitude tension period (s) ------------------------------------------------------- 1 79.1 415.0 3204.4 14.75 2 82.5 440.1 3298.3 14.79 3 88.9 486.4 3458.9 14.85 4 102.7 585.4 3777.6 14.96 5 121.1 716.0 4142.6 15.06 6 192.5 1226.2 5054.0 15.18 7 316.3 2119.2 6398.4 15.26 8 529.5 3671.9 8501.6 15.31 9 528.4 3663.2 8492.9 15.31 10 316.4 2119.9 6398.9 15.26 11 192.4 1225.8 5053.4 15.18 12 121.3 717.2 4143.5 15.06 13 102.7 585.2 3777.1 14.96

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14 88.8 486.0 3458.4 14.85 15 82.6 441.2 3299.4 14.79 16 79.1 415.1 3204.4 14.75 * EQUILIBRIUM POSITION * ------------------------ Relative to Relative to GLOBAL ORIGIN CURRENT Position OFFSET ................. 206.5 m 36.6 m DIRECTION (rel. North).. 351.8 deg 306.2 deg HEADING ................ 0.0 deg 0.0 deg X1 (North) ............. 204.3 m 21.6 m X2 (East) .............. -29.5 m -29.5 m The Vessel is moved to Equilibrium Position ! MIMOSA Version 5.6-02 29-APR-2003 21:44 MARINTEK Page 8 Moorinr Results of siteen line chain wire chain * MAXIMUM LINE TENSIONS. HF MOTION * ------------------------------------------------ ** Line Dynamics Included ** Line ---- Top tension ---- Max. Direction Type No. Mean Max Safety Segm. tangent from hor. (kN) (kN) factor No. motion (m) plane (deg) 1 2758.2 3165.7 5.34 3 4.41 -76.5 SAM 2 2860.6 3304.3 5.12 3 4.40 -74.8 SAM 3 3009.9 3510.1 4.82 3 4.40 -72.5 SAM 4 3283.5 3909.8 4.32 3 4.41 -68.7 SAM 5 3587.3 4458.7 3.79 3 4.44 -65.1 SAM 6 4197.0 6051.2 2.79 3 4.48 -60.0 SAM 7 BROKEN 8 5834.9 13151.4 1.29 3 4.52 -52.8 SAM 9 5368.5 10966.2 1.54 3 4.56 -54.3 SAM 10 4314.1 6524.9 2.59 3 4.60 -59.3 SAM 11 3753.5 4889.2 3.46 3 4.58 -63.5 SAM 12 3332.0 4004.9 4.22 3 4.53 -68.0 SAM 13 3093.1 3644.1 4.64 3 4.49 -71.2 SAM 14 2882.6 3342.3 5.06 3 4.45 -74.4 SAM 15 2783.8 3203.7 5.28 3 4.44 -76.1 SAM 16 2736.6 3137.4 5.39 3 4.43 -76.9 SAM SAM = Tensions are estimated with the Simplified Analytic Method HF max tension: Non-Rayleigh based MIMOSA Version 5.6-02 29-APR-2003 21:44 MARINTEK Page 9

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Moorinr Results of siteen line chain wire chain Details on dynamic tension (in kN): ------------------------------------------------------- Line Standard Maximum Maximum Zero crossing No. deviation amplitude tension period (s) ------------------------------------------------------- 1 78.0 407.0 3165.7 14.76 2 82.8 442.8 3304.3 14.79 3 90.7 499.6 3510.1 14.85 4 108.0 622.1 3909.8 14.97 5 142.7 869.1 4458.7 15.08 6 280.1 1852.8 6051.2 15.22 7 BROKEN 8 1029.6 7312.8 13151.4 15.35 9 791.6 5587.6 10966.2 15.34 10 328.4 2206.5 6524.9 15.26 11 179.0 1130.7 4889.2 15.18 12 114.5 669.7 4004.9 15.05 13 97.7 550.2 3644.1 14.96 14 85.0 458.9 3342.3 14.85 15 79.6 419.0 3203.7 14.80 16 77.1 400.1 3137.4 14.76

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Cost Analysis

Appendix Table 5: 8 Line Polyester Cost Analysis

Mooring 8 Line Polyester

Line Unit cost ($/kN-m)

Length (m)

B.S. (kN)

Cost ($)

Fairlead Chain 0.034 50 13710 $23,307 Anchor Chain 0.034 200 13710 $93,228 Wire 0.02 Polyester 0.02 2700 13345 $720,630

Cost per

Line $837,165 Total $6,697,320

Appendix Table 6: 12 Line Wire-Chain Cost Analysis

Mooring 12 Line Wire-Chain

Line Unit cost ($/kN-m)

Length (m)

B.S. (kN)

Cost ($)

Fairlead Chain 0.034 50 19577 $33,281 Anchor Chain 0.034 1000 13094 $445,196 Wire 0.02 2000 16906 $676,240 Polyester 0.02

Cost per

Line $1,154,717 Total $13,856,603

Appendix Table 7: 16 line Wire-Chain Cost Analysis

Mooring 16 Line Wire-Chain

Line Unit cost ($/kN-m)

Length (m)

B.S. (kN)

Cost ($)

Fairlead Chain 0.034 66.5 16906 $38,224 Anchor Chain 0.034 200 16906 $114,961 Wire 0.02 2800 16607 $929,992 Polyester 0.02

Cost per

Line $1,083,177 Total $17,330,836

Appendix IV: Hydrodynamics of Motion and Loading

Surge Response

012345678

0 0.1 0.2 0.3 0.4 0.5

Frequency (rad/s)

Dis

tanc

e (m

)

Appendix Figure 17: Surge Response Spectrum

Heave Response

0123456789

0 0.1 0.2 0.3 0.4 0.5

Frequency (rad/s)

dist

ance

(m)

Appendix Figure 18: Heave Response Spectrum

Yaw Response

01E-172E-173E-174E-175E-176E-177E-178E-179E-17

0 0.1 0.2 0.3 0.4 0.5

Frequency (rad/s)

dist

ance

(m)

Appendix Figure 19: Yaw Response Spectrum

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Roll Response

0

5E-15

1E-14

1.5E-14

2E-14

0 0.1 0.2 0.3 0.4

Frequency (rad/s)

mot

ion

(m)

Appendix Figure 20: Roll Response Spectrum

Pitch Response

0

0.00002

0.00004

0.00006

0.00008

0.0001

0 0.1 0.2 0.3 0.4 0.5

Frequency (rad/s)

mot

ion

(m)

Appendix Figure 21: Pitch Response Spectrum

Sway Response

05E-141E-13

1.5E-132E-13

2.5E-133E-13

3.5E-13

0 0.1 0.2 0.3 0.4

Frequency (rad/s)

Dis

tanc

e (m

)

Appendix Figure 22: Sway Response Spectrum