FGN 21.02.071

Content

• Examples on Offshore lifting operations– Module lifting– Jacket installation– Installation of sub-sea equipment

• Overview of important issues.– Lift in air versus sub-sea operations– Dynamics– (Weather windows – statistics)

FGN 21.02.072

Grane jacket, Apr. 2003

FGN 21.02.073

Grane process module installation, Apr. 2003. Lift-off from barge.

FGN 21.02.074

Grane process module installation, Apr. 2003. Approaching jacket.

FGN 21.02.075

Grane process module installation, Apr. 2003. Landing on jacket.

FGN 21.02.076

Grane process module installation, Apr. 2003. Living quarter.

FGN 21.02.077

”Building-blocks” of a process platform

FGN 21.02.078

Jacket installation, Self-floater and launching from barge

FGN 21.02.079

Crane assisted jacket installation

FGN 21.02.0710

Crane assisted jacket installation, side view

FGN 21.02.0711

Crane assisted jacket installation, plane view.

FGN 21.02.0712

Tandem lift from barge

FGN 21.02.0713

Fram module lift. Model test setup

FGN 21.02.0714

Fram module. Model testing

FGN 21.02.0715

Installation of Fram West moduleThe Fram West module (900 tons)lifted onboard Troll C. May 2003

FGN 21.02.0716

Simulation of Fram module installation

FGN 21.02.0717

Heavy versus light lifts• Heavy lifts: Coupled dynamics, No heave compensation, W > 1000 tonnes)

– Multibody dynamics

• Light lifts: (Minor coupling, Heave compensation possible, W <100 tonnes)– Static deformation of lifting wire in current– Vertical oscillations of a mass wire system– Mathieu instability.

FGN 21.02.0718

Example: Saipem7000Semisubmersible crane and pipelaying (J-lay) DP vessel

Dimensions:Length: 198 mBreadth: 87 mDepth to main deck: 45 mTransit draft: 10.5 mOperational draft: 27.5 m

Ballast system:Computer controlled system comprising 4 x 6,000 t/h ballast pumps, fully redundant.

Lifting facilities main crane:Fully revolving. Main blocks tandem lift: 14,000 tMain block single lift: 7,000 t revolving at 40 m Aux.1 block: 2,500 t revolving at 74 m rad.Aux. 2 block: 900 t revolving at 115 m rad.Lowering capability to 450 m below sea levelWhip hook: 120 t revolving at 150 m rad.

FGN 21.02.0719

Examples on heavy lifts, modules

Module Hook weight (t) Lift date Vessel Kittiwake deck (Shell)

6 900 May 90 DB102

Miller M7 (BP) 6 200 July 91 DB102 Piper PUD (EEC)

10 750 Mar 92 DB102

Gannet deck ( Shell)

9 600 Apr 92 DB102

Piper WM/DSM (EEC)

6 825 Apr 92 DB102

Bruce P10 (BP) 8 750 Aug 92 M7000 Bruce P20 (BP) 8 180 Aug 92 M7000 Bruce drill deck (BP)

7 520 Aug 92 M7000

Saltire deck (EEC)

10 300 Sept 92 DB102

Tiffany M1 (Agip)

8 140 Nov 92 M7000

Tiffany M2 (Agip)

6 070 Nov 92 M7000

North Everest (Amoco)

8 500 Nov 92 DB102

Lomond (Amoco)

8 600 Dec 92 DB102

Scott P1 (Amarada)

10 000 Apr 93 DB102

Scott UQ (Amarada)

8 000 Apr 93 DB102

East Brae (Marathon)

8 500 Spr. 93 DB102

Nelson (Shell) 9 600 Aug 93 DB102 Dunbar (Total) 9 400 Mid 94 DB102

FGN 21.02.0720

Crane assisted jacket installationsJacket Water depth

(m) Hook weight (t) Lift date Vessel

Veslefrikk (Statoil)

175 9 050 May89 M7000

Gyda (BP) 66 8 770 Sept 89 M7000 Kittiwake (Shell) 85 5 300 May 90 DB102 Gannet (Shell) 94 7 500 June 91 DB102 Bruce PUQ (BP) 121 9 425 May 92 M7000 Bruce D (BP) 121 7 950 May 92 M7000 Unity (BP) 127 6 500 Jul 92 DB102 Beryl riser (Mobil)

112 5 800 Jul 92 DB102

Scott JU (Amerada)

141 8 800 Mar 93 DB102

Nelson (Shell) 84 8 500 Spr. 93 DB102 East Brae (Marathon)

116 9 300 May 93 DB102

Dunbar (Total) 145 9 100 Mid 94 DB102

FGN 21.02.0721

Installation of subsea equipment, TOGI 1989

FGN 21.02.0722

Installation of subsea equipment, Troll pilot

FGN 21.02.0723

Installation of subsea equipment, Oseberg sør template, 2002.

FGN 21.02.0724

Offshore wind farms

20 x 2MW

FGN 21.02.0725

Offshore wind farms

FGN 21.02.0726

Weather windows

0 10 20 30 40 50 600.5

1

1.5

2

2.5

3

3.5

T ime (hours)

Hs (m

)Measured H

sH'

s

t1 t

2 t

3 t

4 t

5

FGN 21.02.0727

Weather windows

FGN 21.02.0728

Weather windows

FGN 21.02.0729

Five phases of crane operations. Some possible problems:

1) Lift off.

Snatch loads - Impacts Horizontal sliding.

2) In air.

Pendulum motion Collision – use of tugger lines

3) Crossing splash zone.

Dynamic loads, Snatch loads 4) Deeply submerged.

Vertical resonance. 5) Landing.

Vertical motions. Horizontal offset. Position / rotation control Impacts. Position control

1 2

3

4

5

FGN 21.02.0730

Multibody dynamics

xy

z(xt,yt,zt)

* (xG,yG,zG)(xl,yl,zl)

ls

η1

η2

η3

η4

η5

η6

η7

η8

η9

x = ( 1, 2, 3, 4, 5, 6, 7, 8, 9)T

M=

m+A11 0 A13 0 mzG +A15 −myG 0 0 0m+A22 A23 −mzG +A24 A25 mxG +A26 0 0 0

m+A33 myG −mxG +A35 0 0 0 0I44 +A44 −I45 −I46 0 0 0

I55 +A55 −I56 0 0 0I66 +A66 0 0 0

mL +a11 0 0mL +a22 0

mL +a33

Nine DOF:

Vessel - vesselLoad - Load

FGN 21.02.0731

Restoring matrix (1-2)

Cm =

Cm11 Cm12 0 0 0 Cm16 0 0 0Cm22 0 0 0 Cm26 0 0 0

0 0 0 0 0 0 00 0 0 0 0 0

0 0 0 0 0Cm66 0 0 0

0 0 00 0

0

Ch =

0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0

Ch33 Ch34 Ch35 0 0 0 0Ch44 0 Ch46 0 0 0

Ch55 0 0 00 0 0 0

0 0 00 0

0

Mooring part

Hydrostatic part:

xy

z(xt,yt,zt)

* (xG,yG,zG)(xl,yl,zl)

ls

η1

η2

η3

η4

η5

η6

η7

η8

η9

FGN 21.02.0732

Restoring matrix (2-2)

C vl =

wl 0 0 0 w

l z t − wl y t − wl 0 0 w l 0 − w

l z t 0 w l x t 0 − w

l 0

A E l e

A E l e y t − A E

l e x t 0 0 0 − A E l e

C vl44 − A E l e x ty t − w

l z t x t 0 w l z t − A E

l e y t

C vl55 − w l z t y t − w

l z t 0 A E l x t

C vl6 6 w l y t − w

l x t 0 w l 0 0

w l 0

A E l e

Coupling effects:x

y

z(xt,yt,zt)

* (xG,yG,zG)(xl,yl,zl)

ls

η1

η2

η3

η4

η5

η6

η7

η8

η9

FGN 21.02.0733

Eigenmodes and eigen-frequenciesUndamped eigenvalue problem

( )2 0ω

Motion response to harmonic excitation:

− + =M C x

1λ −=x M Cx

( )2

i tei

ω

ω ω=

− + +aFη

M B C

FGN 21.02.0734

Example• Vessel with:

m = 5.17E7 kg (xg,yg,xg) = (0, 0, -0.02L), L= 100m (r44,r55,r66)= (.33L,.32L,.35L), rij=0, ijg0

• Added mass matrix for vessel:

• Vessel restoring matrix:

• C11= 2.E05 N/m, C33= 7.85E06 N/m and C66=1.0E08A

m =

.7 0 0 0 0 01 0 0 0 0

1 0 0 0.1L2 0 0

.1L2 0.1L2

C =

C11 0 0 0 0 0C11 0 0 0 0

C33 0 0 00.05C33L2 0 0

0.05C33L2 0C66

FGN 21.02.0735

Example cont.

• Mass of load: ml=0.1m• Position of top of crane: (xt,yt,zt) = (.6L,0,.5L)• Length of wire (from top of crane to load): l=2L• Elasticity of line: AE=3.96E09 N• Added mass of load: (a1,a3,a3) = (.5ml,.5ml,2ml)• Submerged weight of load: w = .5ml*g

FGN 21.02.0736

Eigenperiods and eigenmodesUn-coupled

• Load alone: T0load = 49.14 49.14 5.56 sec

• Eigenvector:

• Vessel alone:T0vessel = 131.7 32.4 142.9 32.9 22.8 213.1 sec

• Eigenvector:

x0load =1 0 00 1 00 0 1

x0vessel =

−1 0.0219 0 0 0 00 0 1 0.0184 0 00 0 0 0 1 00 0 0.0031 −.9998 0 0

0.0037 0.9998 0 0 0 00 0 0 0 0 1

Surge pitch sway roll heave yaw

FGN 21.02.0737

Eigenperiods and eigenmodescoupled• Complete coupled system:

T0coupled = 4.3 23.6 37.1 51.7 138.3 30.4 146.8 46.0 239.7 sec.

_ _0.0097

-0.0206 -0.0737 -0.0934 0.6542 -0.0000 0.0000 -0.0000

x0coupled =

0.0000

-0.0000 -0.0000 -0.0000 0.0000 -0.0000 0.0593 -0.7758 0.0752 -0.0311

-0.1366 -0.8090 0.0522 -0.0084 -0.0000 0.0000 -0.0000 0.0000 -0.0000

0.0000 -0.0000 -0.0000 0.0000 0.0000 -0.8118 0.0040 0.2098 0.0030

0.4569 -0.4468 -0.4841 0.2109 0.0074 -0.0000 0.0000 0.0000 0.0000

-0.0000 -0.0000 0.0000 0.0000 0.0000 0.1337 0.2546 0.2303 -0.6570

-0.0031 0.1225 0.6559 0.9449 0.7562 0.0000 0.0000 0.0000 0.0000

0.0000 0.0000 -0.0000 -0.0000 -0.0000 -0.5653 -0.5774 -0.9473 -0.7533

0.8789 -0.3612 0.5721 -0.2319 -0.0078 0.0000 -0.0000 -0.0000 -0.0000

Eigenmode no. 1 2 3 4 5 6 7 8 9

Dominatingmode of motion

9 3 5 7 1 4 2 8 6

Name load Vertical

heave pitch load x-dir.

surge roll sway load y-dir

yaw

FGN 21.02.0738

Example cont. Force oscillations

F=[i*C11 0 C33 0 0 0 0 0 0] T 2% damping

0 50 100 150 200 250 3000

0.5

1

1.5

2

Absolute value of dynamic response in direction: 1

X11

(m)

Period (sec)0 10 20 30 40 50 60

0

2

4

6

8

10

12

Absolute value of dynamic response in direction: 3

x 3 (m)

Period (sec)

Period of oscillation (sec)

FGN 21.02.0739

Example cont. Force oscillations

0 20 40 60 80 1000

0.02

0.04

0.06

0.08

0.1

0.12Absolute value of dynamic response in direction: 5

x 5 (rad

)

Period (sec) 0 50 100 150 200 250 3000

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Absolute value of dynamic response in direction: 7

x 7 (m)

Period (sec)

Period of oscillation (sec)

0 20 40 60 80 1000

1

2

3

4

5

Absolute value of dynamic response in direction: 9

x 9 (m)

Period (sec)