1HANDLING FUGITIVE EMISSIONS AT THE JUBILEE FIELD: SELECTING THE RIGHT SEALS AND OTHER

ALTERNATIVES

PRSENTED BY:

HERMINIA NCHAMA ELABRUKUM DANIEL

SUPERVISOR:

MR. ABDUL HAMEED MUSTAPHA

2OUTLINE

Limitations

Problem Statement

Introduction

Methodology

Discussions

Objectives

Conclusion and Recommendations

3OBJECTIVES

To know the potential breakdown of hydrocarbons related fugitive emissions in the world

To know how and why fugitive emissions occur Detecting and monitoring fugitive emissions To determine the current inventory methodologies for quantifying fugitive

emissions Selection of the right seals in reducing spurious emissions Other alternatives for controlling and minimizing fugitive emissions

4 PROBLEM STATEMENT

FE

Green house effects which leads to a

phenomenon called global warming

resulting in climate change

Health hazards caused by air

pollution

Economic loss of commodities

Risks of fire and accidents

5INTRODUCTION

Fugitive emissions are emissions of gases and vapours from pressurised equipment due to leaks and other unintended or irregular release of gases, mostly from industrial activities.

Sources of FE in the oil and gas industry include process equipment leaks, evaporation and flashing losses, venting and flaring and accidental releases.

Process equipment components that are sources of FE through leaks include Pumps, Compressors, Valves, Pressure relief valves and Pipe connections

6Global concern for FE

IEA in 2009 predicted that the world’s total energy demand will grow by 35% in the year 2030 higher.

Energy sector being the highest contributor to emissions.

Oil and natural gas industry expected to account for nearly 60%.

Thus FE must be minimized in order to address the global climate change challenge.

7The Jubilee Field

The FPSO can produce up to 120 M BOPD, 120 MMSCFD, storage capacity of 1.6 MM barrels of oil and injects 230 MM barrels of water a day.

Government of Ghana has a ‘zero flaring’ policy at the FPSO.

Out of the 120 units of gas produced per day, 20 are used to power the engines on the FPSO, 30 used for well injection and 70 are flared or vented.

Stack and FE campaign carried out to evaluate emission levels from the Gas Turbine Generators (GTGs), Emergency boilers and the Side Port Crane.

8Detection of FE

A variety of approaches are used for leak detection:

1. Soap solutions

2. Odorants

3. Portable analyzers

4. Static Leak Indicators; bag and streamer, color indicating tape, chronic leak monitoring

5. Electronic Screening Devices; gas monitors, ultrasonic leak detectors, laser or infrared detectors.

9

METHODOLOGYEmission inventory prepared to estimate the quantities of FE released from a facility.

Two guidelines that are applicable worldwide are:

1. The US EPA – API Assessment

2. The Intergovernmental Panel on Climate Change (IPCC) Assessment

The USA EPA-API Assessment is based on four methods:

Method 1. Average Emission factor method

10Cont. of Emission inventory methodology

Method 2. The Screening Value Range Method

11Cont. of Emission inventory methodology

Method 3. Correlation Equation Method

Method 4. Unit-specific Correlation Equation Method Particular sets of individual equipment components are selected for screening for

which screening and actual mass emissions are measured directly from.

12Key challenges during the assessment of FE

The identification of sources Measurement of FE Return on investment Lack of public engagement Technology

13Sealing system

Seals are devices installed in process equipment to isolate the fluid medium from being released into the atmosphere during the operation of the process equipment. Process equipment are normally under pressure.

Pump seals: They are used to mitigate leakages between the moving shaft and the stationary housing. E.g., Packing and Mechanical seals

Compressors seals: They are usually equipped with ports in the seal area to evacuate gases that maybe accumulated there. E.g.., Labyrinth and Mechanical contact seals

Valves: They are activated by a valve stem. E.g., Packing, Elastomeric O-rings and Bellow seals

Flanges: They are bolted, gasket-sealed junctions between sections of pipe and pieces of equipment.

14

SELECTION OF THE RIGHT SEAL Seal selection can be based on the fluid’s specific gravity and the maximum allowable

VOC emission levels

15

Selection factors for seals in the oil and gas industry Temperature: The temperature of the fluid contacting the seal. Temperature data will

limit the number of viable seals for an application.

Application: Knowing how the seal is to be used and function it is expected to perform. E.g., selection of compression packing depends on the condition of the stem whether its motion is reciprocating or helical (insufficient loading)

Medium: Sensitivity of the media to the seal (compatibility)

Pressure: Internal pressure a seal must contain.

Size: Conforming to standards such as AMSE, API, ANSI

Speed: High speeds call for sealing materials that can withstand and effectively

dissipate frictional heat

16Other improved alternatives for detecting and

measuring FE Direct Inspection Absorption of Light (DIAL) can be used to remotely measure

concentration profiles of hydrocarbons in the atmosphere up to several hundred meters from the facility.

Optical Gas Imaging(OGI) operates much like a consumer video-camcorder and provides a real-time visual image of gas emissions or leaks to the atmosphere.

17

Direct Inspection & Maintenance (DI &M) Program

18

Leak Detection and Repair (LDAR) Program1. Determine which equipment leak regulations are applicable

2. Understand the overall approach of using both equipment standards and leak detection and repair standards

3. Determine if source complies with all the requirements of component identification, marking, monitoring repair, record keeping and reporting.

4. Evaluate source personnel’s calibration procedures and records

5. Evaluate field monitoring procedures used by source personnel to detect leaks from components

19

Leak repair and Economic Analysis

Where;

PBP = Pay Back Period (years)

Estimated repair cost or Cost of control = direct repair or replacement costs + gas vented during repair + cost of lost production due to shutdown ($).

Annual Leak Rate or Leak Rate = amount of gas/vapour emitted directly to the atmosphere or that leaked into a vent or flare system which does not have vent or flare gas recovery (m3/year).

Net Value of Lost Gas or Gas Price = current market price of the gas based on criteria specified by the midstream industry, processing fee or margin received ($/103m3).

In the case where the leak repair has a payback of less than a one year, it is economical to repair and must be repaired as soon as possible.

20

Sample calculation of a payback period for individual repairsTag ID

Component type

Nominal size

Stream type

Hydrocarbons leak rate(m3/hr.)

Hydrocarbons leak rate(103m3/yr.)

Net value lost $/103m3

Estimated repair cost($)

PBP

1991 Gate Valve 8 Wet Gas

0.0046 0.0407 149.60 353 58.0

1992 Flange 8 Wet Gas

0.0026 0.0228 149.60 100 29.3

1993 Ball Valve 0.5 Wet Gas

0.0028 0.0241 149.60 60 16.6

1995 Gate Valve 8 Wet Gas

0.0090 0.0785 149.60 353 30.1

1996 Gate Valve 8 Wet Gas

0.0015 0.0129 149.60 353 182.9

1997 Flange 8 Wet Gas

0.0036 0.0313 149.60 100 21.4

1998 3-Way Control valve

8 Wet Gas

0.0021 0.0187 149.60 350 125.1

21

Flaring at the FPSO in the Jubilee Field

0

10

20

30

40

50

60

Percentage of flared volumes to total produced gas volumes at the Jubilee Field

2011 2012 2013 2014

22

LIMITATION The oil and gas industry is very diverse and complex making it difficult to ensure

complete and accurate results for FE quantification.

Lack of data to compute the emission inventory of FE

23CONCLUSION

The challenge of reducing FE will require a long-term planning and steadfast commitments.

The amounts of flared volumes at the FPSO in the Jubilee Field exceeds the limit set out for the Jubilee Operator.

The best seal material to be used on the FPSO is Nitrile. This is because:I. It combines excellent resistance to hydrocarbon based fluids.

II. It has a good working balance properties.

The drawing out of a comprehensive DI&M and or LDAR program to be implemented at the FPSO will;I. Increase revenue to TGL through the reduction in the loss of sealable, valuable fluids.

II. Significantly contribute to the improvement of air quality in the immediate environs of the FPSO as well as to residential communities onshore

III. Improve maintenance routine and help TGL comply with environmental laws of the country and the world in a whole.

24

Recommendation and further work Stipulation and enforcement of regulations to reduce fugitive emissions

released from process equipment and other sources at oil and gas industries. Increase the development of alternative energy. Improving good management practice by including technology development

and deployment. Jubilee Field Partners are called upon to develop a comprehensive fugitive

emission inventory program and the elaboration of Emission Factors when developing their annual GHG emission inventory. GH EPA must regulate this campaign.