Fts Batara mooring design

BETARA Condensate Terminal 3D Coupled Time Domain Mooring Analysis Mooring Chain Fatigue (FLS) Condition

Submitted 13th October 2005 BCD3-920-49-CAL-4-001-03 Rev A

ZEE Engineering Consultants Pte. Ltd. 882, Block A1, Pusat Dagang Setiajaya, N0. 9, Jln PJS 8/9, 46150 Petaling Jaya

Selangor Darul Ehsan, Malaysia. PetroChina Company Limited Website: www.zee-eng.com

Betara Condensate Terminal Mooring Chain Fatigue Analysis (FLS)

CONTENTS

1 INTRODUCTION 1.1 General Overview 1.2 Mooring System 1.3 Units 1.4 Standard Coordinate System 1.5 Abbreviations 2 SUMMARY CONCLUSION AND RECOMMENDATION 2.1 Fatigue Analysis Results 2.2 Conclusion 2.3 Recommendation 3 DESIGN CODES

4 DESIGN BASIS 4.1 FSO Vessel Details 4.2 Chain Data 4.3 Weak Link 4.4 SN Curves 4.5 Hawser Data 4.6 Environmental Condition and Loads 4.7 Marine Growth 4.8 Corrosion Allowance 5 FATIGUE ANALYSIS METHODOLOGY 5.1 Statutory Requirements 5.2 Analysis Method 6 RESULTS AND DISCUSSION 6.1 Fatigue Analysis Results 6.2 Conclusion 6.3 Recommendation 7 REFERENCES

APPENDIX A: ENVIRONMENT DATA [EXTRACT]

APPENDIX B: FATIGUE DAMAGE DETAILED OUTPUT

APPENDIX C: SIMULATION RESULT [ CDROM ]

REVISION AND AUTHORISATION RECORD

Rev

Date

Description

By

Chkd

Apvd

A 13 Oct 05 Issued for Comments GTR HP

BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005


1 INTRODUCTION This document reports on the partial results of a 3D coupled time domain analysis for a proposed Condensate mooring terminal, consisting of a FSO moored on the mooring dolphins with polyester hawsers on the starboard side and on anchor chains on the port side. The analysis was carried out within the framework of coupled time domain theory for moored floating vessels. As per the code requirements for permanent mooring system whereby analysis is required for the ultimate limit state (ULS), accidental limit state (ALS), and fatigue limit state (FLS); this reports conclude the methodology and the results for the analysis carried out for the FLS condition. The analysis carried out under the (ULS) and (ALS) condition is enclosed in report BCD3-920-49-CAL-4-001-02.

1.1 General Overview PetroChina International Jabung Ltd. plans for phased development of five (5) Jabung Block fields and associated Betara Production Complex located in Eastern Central Sumatra as illustrated in Figure 1.1. Included in the overall plan are new offshore terminals to replace the existing Batang Hari Marine Terminal (BMT) facilities, as total production rates from the five (5) fields will exceed the handling capacity of the existing terminal facilities. The new offshore terminal facilities will comprise of a Fixed Process Unit (FPU) and two (2) Floating Storage and Offloading (FSO) vessels, one for storage of refrigerated Propane and Butane (LPG) and one for storage of Oil and Condensate. The stored products will be periodically offloaded to export tankers.

FIGURE 1.1 BETARA COMPLEX DEVELOPMENT PLAN

BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005


1.2 Mooring System The FSO vessels will be permanently moored in two (2) locations approximately 1.5km apart, for a 22 years life service. Each mooring facility will consist of two lines of dolphins along with a set of piled anchors. Each FSO is moored to the North Side of the dolphins by mooring hawsers attached to the dolphins, with an anchor spread attached to the North Side of the LPG FSO. Export Tankers moor directly to the dolphins on the South Side of the terminal. Both the FSO vessels are positioned at a 90 heading, with their bows facing the East compass direction.

1.3 Units

The SI Systems of units is used throughout the document, unless otherwise specified. Time = seconds (sec) Angles = degrees (O) Temperature = degrees C (OC) Length = meters (m) Area = meters2 (m2) Volume = meters3 (m3) Velocity = meters/second (m/s) Acceleration = meters/second2 (m/s2) Stress or Pressure = Megapascal (mPa) Force = Kilo Newton (kN) Weight = Tonne (Te) /(Ton)

1.4 Standard Coordinate System

The sign convention and coordinate system adopted for this report are illustrated in Figure 1.4. The adopted sign convention is according to the ITTCs Standard [9]. The stern-on direction of wind, wave and current is 0 degrees. The roll axis for the vessel is the x-axis. It is oriented along the centerline of the vessel, running forward and aft. Longitudinal dimensions are measured along or parallel to this axis. The pitch axis is the y-axis. It runs transversely port and starboard. Besides being the axis for pitch, transverse dimensions are measured along or parallel to this axis. The yaw axis is the z-axis. It runs vertically and dimensions are measured along or parallel to this axis.

FIGURE 1.4 VESSEL COORDINATE SYSTEM

BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005


BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005

1.5 Abbreviations FSO Floating Storage and Offloading Vessel

RAO Response Amplitude Operators

QTF Quadratic Transfer Functions

FPU Fixed Process and Facility Platform

OCIMF Oil Companies International Marine Forum

IHL Indonesian Hydrodynamic Laboratory

LPG Liquefied Petroleum Gas

ULS Ultimate Limit State

ALS Accidental Limit State

FLS Fatigue Limit State

Shall Indicates mandatory requirement

Should Indicates preferred course of action

May Indicates optional course of action

TBA To be advised

TBC To be confirmed


BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005

2 SUMMARY CONCLUSION AND RECOMMENDATION

Mooring chain fatigue performance is an important design consideration for mooring terminal systems. Overly conservative design approaches can be costly, whilst less sophisticated analysis methods may not be truly representative, with the possibility of non-conservatism. The fatigue analysis of the mooring chains was carried out utilising the Visual Orcaflex version 8.6d, a marine dynamics program developed by Orcina. Fatigue analysis was performed following the procedures of deterministic irregular wave fatigue analysis using rainflow cycle counting method, as recommended in API RP 2SK [2], section 7.5.

The long term environment was represented by eight (8) environmental direction and five (5) reference wave classes, amounting to a total of forty (40) discrete design conditions. Each design condition consist of a reference direction and reference sea state characterised by a significant wave height, peak period, current velocity and wind velocity. The probabilities of occurrence of these conditions are detailed in section 4.6. Fatigue damage from first order loads and motions and low frequency motions were determined using Time Domain Cycle Counting method. In this approach, the combined low frequency and wave frequency tension spectrum is transformed into tension time history. RAINFLOW method is used to estimate the number of tension cycles and the expected value of tension range from which fatigue damage is estimated. This document reports the methodology and the results of the analysis carried out based on the statutory requirements for the mooring system to ensure that the individual mooring lines have adequate capacity to withstand cyclic loading.

2.1 Fatigue Analysis Results

A factor of safety of 10 is usually acceptable for component of major importance to structural integrity and inaccessible for inspection, and 3, for component that is accessible for inspection and maintenance [17]. The summary of the fatigue damage and the fatigue life along the arc length (reference from the fairlead) are enclosed in the following pages. The result indicates the fatigue factor of safety to exceed 10 for chains CH11, CH14, CH15 and CH16, while part of CH12 and CH13 exceed a factor of safety of 3. As for weaklink, CH11, CH12 and CH13 exceed a factor of safety of 3 while the rest exceed a factor of safety of 10.

2.2 Conclusion The mooring lines can be concluded as suitable for the stated purpose, however, the region where the factor of safety is above 3 and below 10 regular inspection and maintenance are required.


BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005

2.3 Recommendation

Based on the analysis undertaken, the following recommendations are listed as follows. o An inspection program to be formulated for the chains and weak-links.

Proposed inspection procedures to be submitted for clients approval prior to installation of the weak-links.

o Stress Concentration Factor SCF of 1.0 was used in the analysis for both the stud and studless chains, which are applicable for chains in catenary.

o Manufactured components should be carefully inspected to ensure that there are no non-conformances which could accelerate failure, and increased factors of safety should be applied to the limiting allowable fatigue life of relevant components.

o Recommended "weak link" is shown in Fig 4.3 (Sec 4.3) but LTM shacklesto be used instead of "pear" shaped shackles.

CHAIN FATIGUE ANALYSISDISTRIBUTION ALONG CHAIN LENGTH

22 YEARS DESIGN LIFE

1

10

100

1000

10000

0 9 23 33 43 50 54 58 62 66 69 73 76 77 82 93 104 115 126 137 148 164 185 207 228 238

Chain Arc Length from Fairlead (m)

U

n

f

a

c

t

o

r

e

d

F

a

t

i

g

u

e

L

i

f

e

(

y

e

a

r

s

)

CH-11 CH-12 CH-13 CH-14 CH-15 CH-16

WEAK LINKINSPECTION NOT REQUIRED

INSPECTION REQUIRED

BELOW ACCEPTABLE LIMIT

ARC LENGTH DAMAGE

ARC LENGTH DAMAGE

ARC LENGTH DAMAGE

ARC LENGTH DAMAGE

ARC LENGTH DAMAGE

ARC LENGTH DAMAGE

A 0.00 0.05668 0.00 0.18233 0.00 0.14559 0.00 0.01453 0.00 0.01738 0.00 0.015561 9.22 0.05947 9.08 0.18674 9.08 0.14914 9.12 0.01525 9.13 0.01820 9.14 0.016242 23.44 0.06180 23.15 0.19227 23.16 0.15336 23.25 0.01611 23.27 0.01921 23.29 0.017193 33.44 0.06310 33.15 0.19552 33.16 0.15587 33.25 0.01663 33.27 0.01981 33.29 0.017734 43.44 0.06395 43.15 0.19779 43.16 0.15779 43.25 0.01692 43.27 0.02017 43.29 0.018015 50.34 0.06527 50.07 0.19878 50.08 0.15856 50.16 0.01696 50.17 0.02023 50.20 0.018056 54.13 0.06531 53.91 0.19908 53.91 0.15878 53.98 0.01690 53.99 0.02018 54.01 0.018007 57.93 0.06526 57.74 0.19919 57.75 0.15887 57.80 0.01681 57.81 0.02029 57.83 0.017938 61.72 0.06512 61.58 0.19911 61.58 0.15881 61.62 0.01667 61.63 0.02013 61.64 0.017809 65.52 0.06385 65.41 0.19886 65.41 0.15861 65.45 0.01650 65.45 0.01993 65.46 0.01762

10 69.31 0.06350 69.25 0.19839 69.25 0.15822 69.27 0.01626 69.27 0.01966 69.28 0.0174411 73.10 0.06307 73.08 0.19774 73.08 0.15771 73.09 0.01609 73.09 0.01924 73.09 0.0170012 75.50 0.10794 75.50 0.30882 75.50 0.24634 75.50 0.02484 75.50 0.02943 75.50 0.0260313 76.50 0.10768 76.50 0.30862 76.50 0.24619 76.50 0.02475 76.50 0.02925 76.50 0.0259514 82.46 0.06061 82.44 0.19561 82.44 0.15607 82.45 0.01497 82.45 0.01789 82.45 0.0154515 93.38 0.05340 93.32 0.18568 93.32 0.14981 93.34 0.01334 93.34 0.01597 93.35 0.0140016 104.30 0.04515 104.20 0.17087 104.20 0.13674 104.23 0.01214 104.24 0.01445 104.25 0.0126417 115.22 0.03892 115.08 0.15542 115.08 0.12384 115.12 0.01050 115.13 0.01297 115.14 0.0120218 126.14 0.03416 125.96 0.14028 125.96 0.11188 126.02 0.00915 126.03 0.01129 126.04 0.0114119 137.06 0.02790 136.84 0.12598 136.84 0.09872 136.91 0.00822 136.92 0.01021 136.94 0.0104020 147.98 0.02374 147.71 0.11066 147.72 0.08619 147.80 0.00752 147.82 0.00923 147.84 0.0097221 164.07 0.01531 163.78 0.09375 163.79 0.06725 163.87 0.00638 163.89 0.00726 163.91 0.0082022 185.32 0.00879 185.03 0.06881 185.04 0.04751 185.12 0.00466 185.14 0.00535 185.16 0.0063523 206.57 0.00571 206.28 0.04578 206.29 0.03380 206.37 0.00333 206.39 0.00399 206.41 0.0046824 227.82 0.00360 227.53 0.03540 227.54 0.02478 227.62 0.00236 227.64 0.00288 227.66 0.00353B 238.44 0.00360 238.15 0.03433 238.16 0.02461 238.25 0.00236 238.27 0.00286 238.29 0.00345

CH-14

Fatigue Damage TablesCH-15 CH-16CH-11 CH-12

SEGCH-13

ARC LENGTH Fatigue Life






A 0.00 352.86 0.00 109.69 0.00 137.37 0.00 1376.33 0.00 1150.58 0.00 1285.611 9.22 336.28 9.08 107.10 9.08 134.11 9.12 1311.32 9.13 1098.89 9.14 1231.632 23.44 323.61 23.15 104.02 23.16 130.41 23.25 1241.35 23.27 1040.98 23.29 1163.573 33.44 316.96 33.15 102.29 33.16 128.31 33.25 1202.64 33.27 1009.67 33.29 1127.804 43.44 312.74 43.15 101.12 43.16 126.75 43.25 1181.97 43.27 991.38 43.29 1110.665 50.34 306.43 50.07 100.61 50.08 126.14 50.16 1179.39 50.17 988.77 50.20 1108.156 54.13 306.22 53.91 100.46 53.91 125.96 53.98 1183.48 53.99 990.98 54.01 1110.937 57.93 306.45 57.74 100.41 57.75 125.89 57.80 1189.77 57.81 985.94 57.83 1115.308 61.72 307.14 61.58 100.45 61.58 125.94 61.62 1199.43 61.63 993.53 61.64 1123.869 65.52 313.23 65.41 100.58 65.41 126.10 65.45 1212.03 65.45 1003.73 65.46 1135.38

10 69.31 314.94 69.25 100.81 69.25 126.41 69.27 1229.70 69.27 1017.37 69.28 1146.7411 73.10 317.09 73.08 101.14 73.08 126.82 73.09 1243.13 73.09 1039.76 73.09 1176.4912 75.50 185.29 75.50 64.76 75.50 81.19 75.50 805.16 75.50 679.51 75.50 768.3113 76.50 185.73 76.50 64.80 76.50 81.24 76.50 808.01 76.50 683.74 76.50 770.6114 82.46 330.00 82.44 102.24 82.44 128.14 82.45 1335.78 82.45 1118.03 82.45 1294.8115 93.38 374.51 93.32 107.71 93.32 133.50 93.34 1499.17 93.34 1252.17 93.35 1429.0316 104.30 443.01 104.20 117.05 104.20 146.26 104.23 1647.68 104.24 1383.98 104.25 1582.0817 115.22 513.90 115.08 128.68 115.08 161.50 115.12 1904.21 115.13 1541.92 115.14 1664.3818 126.14 585.50 125.96 142.57 125.96 178.76 126.02 2185.03 126.03 1771.60 126.04 1752.4419 137.06 716.89 136.84 158.76 136.84 202.58 136.91 2433.04 136.92 1958.15 136.94 1923.9020 147.98 842.48 147.71 180.73 147.72 232.04 147.80 2659.33 147.82 2167.27 147.84 2057.8521 164.07 1306.22 163.78 213.32 163.79 297.38 163.87 3136.14 163.89 2755.44 163.91 2439.5422 185.32 2275.92 185.03 290.65 185.04 420.93 185.12 4296.23 185.14 3737.79 185.16 3147.8623 206.57 3502.96 206.28 436.89 206.29 591.67 206.37 6006.22 206.39 5011.64 206.41 4275.3824 227.82 5561.54 227.53 564.89 227.54 807.14 227.62 8459.69 227.64 6949.61 227.66 5660.10B 238.44 5552.29 238.15 582.58 238.16 812.53 238.25 8470.43 238.27 7000.68 238.29 5791.38

Fatigue Damage Tables

SEGCH-1 CH-2 CH-3 CH-4 CH-5 CH-6


BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005

3 DESIGN CODES

The most applicable design guidance, for mooring design of a permanently moored vessel, is fragmented between a number of Codes and Recommended Practices. The approach adapted for this particular project is the combined element of the following codes and standards, with the design basis governed by project design criteria and specifications. Codes and Standards

API RP 2SK : Recommended Practice for Design and Analysis of station keeping system for Floating Structures, March 1997.

DNV : DNV OS E301, Position Mooring, June 2001. OCIMF : Prediction of Wind Loads on Large Liquefaction Gas Carriers, 1995.

OCIMF : Prediction of Wind and Current Loads on VLCCs, 2nd Edition 1994. ABS : Criteria for Building and Classing Floating Production Installations, June 2000. NORSOK : Norsok Standard N-003, Actions and action effects, February

2004.

Project Specifications and Design Criteria

BCD3-900-49-CRT-4-001-00 Mooring Analysis Design Criteria BCD3-900-49-SPC-4-001-00 Mooring Chains Specification

BCD3-900-49-SPC-4-002-00 Mooring Hawser Specification BCD3-920-49-MOR-1-001-00 Condensate Terminal Mooring Layout Drawing

BCD3-920-49-MOR-1-002-00 Condensate Terminal Mooring Section Drawing


BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005

4 DESIGN BASIS

The fatigue analyses were performed in accordance with the design criteria detailed in the Mooring Analysis Design Criteria [10]. The selected environments are particularly severe combinations of waves, current and wind derived from extreme 100 years storm condition. The environmental data and the probability of occurrence were recommended by Institute Technology Bandung (ITB), in their report titled Metocean Desk Study [1]. For ease of reference, the information and data pertinent to the fatigue analysis undertaken are highlighted in the following sub-sections, along with additional design parameters utilised in the analysis.

4.1 FSO Vessel Details

The FSO vessel, GOLAR, was chosen as the most likely vessel to be used for the facilities. The Principal dimensions of the vessel are as follows.

Length Overall LOA : 267.00 m

Length Between Perpendiculars LBP : 256.00 m

Breadth (mld) BM : 46.20 m

Depth (mld) DM : 23.80 m

Draft Design (Full Load) TFL : 15.54 m

Draft Design (Ballast Load) TBL : 6.90 m

Displacement (Full Load) FL : 156,063.50 Ton Displacement (Ballast Load) BL : 65,000.00 Ton

4.2 Chain Data The mooring chains were assumed manufactured by Vicinay Cadenas S.A. The catalog breaking strength (CBS) of the chains were derived from the published data for studless type chains. The chain to seabed friction coefficients were assumed from information given in [12] and [13]. All data pertaining to mooring chain used in the analysis are as follows. Chain type : Studless

Chain nominal diameter : 127 mm

Catalog Breaking Strength (CBS) : 11516 kN

Axial stiffness (assumed) : 1.377e6 kN

Normal seabed friction (assumed) : 0.80

Axial seabed friction (assumed) : 0.56


4.3 Weak Link In order not to overload the mooring appurtenances, a weak link is installed in all the mooring chains. Three stud links of 81mm nominal diameter, connected to the main chain link by LTM shackles, were used as weak link, as illustrated in Figure 4.3. The stud links were assumed to be installed about 9.5 m from the fairlead. The stud links were assumed manufactured by Vicinay Cadenas S.A. The catalog breaking strength (CBS) of the chains were derived from the published data for stud type chains. All data pertaining to the stud chains used in the analysis are as follows. Fatigue calculations of the shackles were omitted. It should be noted that use of Pear Shaped Shackles is not acceptable for long term mooring. Link type : Stud

Link nominal diameter : 105 mm

Catalog Breaking Strength (CBS) : 8282 kN

Axial stiffness (assumed) : 7.645e5 kN

FIGURE 4.3 WEAK LINK ARRANGEMENT

4.4 SN Curves

The most common approach for the assessment of mooring chain fatigue is the stress-cycle (S-N) approach. The equation used to determined chain fatigue life is based on the following expression. Component capacity against tension fatigue: ( ) mDc sasn = The linearised logarithmatic form: ( )( ) ( ) ( )smasn Dc logloglog = where:

nc(s) = number of stress ranges (number of cycles)

s = stress range (double amplitude)

aD = intercept parameter of the S-N curve [6.0e10 for studless, 1.2e11 for stud chain as per DNV-OS-E301]

m = slope of the S-N curve [3.0 for both studless and stud chains as per DNV-OS-E301]

BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005


4.5 Hawser Data Marlow Ropes published data were used in the analysis. The axial stiffness of mooring hawser was estimated from load extension diagram for worked Superline. The load-extension dependency is almost linear, with stretch to break of 12% after repeated loading as illustrated in Figure 4.5. The relevant information is as follows. Hawser type : Superline

Hawser nominal diameter : 112 mm

CBS : 371 tonnes

FIGURE 4.5 POLYESTER ROPE AXIAL STIFFNESS

4.6 Environmental Condition and Loads

The proposed Condensate Terminal Facilities location is exposed to seasonal monsoon (Northeast and Southwest monsoons), with varying direction of wind, current and wave although certain directions are dominant with each monsoon period. The long term environment is represented by a number of discrete conditions. Each condition consists of a reference direction and a reference sea state characterised by a significant wave height, peak period, current velocity and wind velocity.

BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005


Waves. The design significant wave heights for the long term environmental events were represented by eight (8) discrete design conditions; each condition consists of a reference direction and a reference sea-state characterized by five (5) wave height distribution associated with a recommended wave period. The irregular random waves were represented in the analysis by the ISSC spectrum [7], expression of which is as follows. ISSC spectrum:

( )

= 4

45

42 21exp24

TzTzHsS

and :

21

115

++=

TpTz where :

Hs = significant wave height

Tz = average zero up-crossing wave period

Tp = spectral peak period

= encounter frequency = peakness parameter Table 4.4a represent the summary of the wave data for the various environmental directions used for the analysis.

DIRECTION (TO) Number of hours

Wave Height (m) 0.3-0.5 0.5-1.0 1.0-1.5 1.5-2.0 > 2 Total

Wave Period (s) 3.5 4.6 5.2 5.5 5.8

East 0O 1 1830 1694 47 0 3572 Northeast 45O 40 0 0 0 0 40 North 90O 6703 0 0 0 0 6703 Northwest 135O 3998 0 0 0 0 3998 West 180O 1 2406 2738 173 0 5318 Southwest 225O 1 1588 2688 294 0 4571 South 270O 8 5435 13573 8928 2 27946

Southeast 315O 1 1487 1238 146 0 2872

Wavy 55020 Waveless 120300

Unrecorded 0

Total 175320

TABLE 4.4a SIGNIFICANT WAVE DATA

BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005


Wind. Dynamic wind loads consist of a steady component and a time varying component known as the gust, which generates low frequency motion. The steady component of the wind speed is represented by a 1-hour average mean wind 10 m above sea level. The time varying wind is described by a wind gust spectrum. The gust spectrum was represented in the analysis by the API wind spectrum formulation as given in API RP 2A [5], expression of which is as follows.

API wind spectrum: ( )

( ) ( )2 5/

1 1.5 /p

p

f ffS fz f f

= / 3 +

and:

( ) ( ) ( )1 ,z I z V hr z = where:

S(f) = spectral energy density

z = reference elevation

f = frequency

(z)2 = standard deviation of wind speed

Table 4.4b represent the summary of the wind data for the various environmental directions used for the analysis.

Wind Speed

1 Hr 30 Min 10 Min 1 Min 3 Sec

U60 U30 U10 U1 UGUSTDIRECTION (TO)

(m/s) (m/s) (m/s) (m/s) (m/s)

EAST 0O 15.85 16.17 16.80 18.70 21.08

NORTHEAST 45O 14.99 15.29 15.89 17.69 19.94

NORTH 90O 12.32 12.57 13.06 14.54 16.39

NORTHWEST 135O 18.33 18.70 19.43 21.63 24.38

WEST 180O 12.20 12.44 12.93 14.40 16.23

SOUTHWEST 225O 16.27 16.60 17.25 19.20 21.64

SOUTH 270O 21.70 22.13 23.00 25.61 28.86

SOUTHEAST 315O 8.69 8.86 9.21 10.25 11.56

TABLE 4.4b WIND SPEED

BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005


BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005

Current. Current were modelled as varying velocity component at different water level but remaining constant with respect to time. Table 4.4c represent the summary of the current data at various water levels and the various environmental directions used for the analysis.

Current Speed

E NE N NW W SW S SE

0O 45O 90O 135O 180O 225O 270O 315ODEPTH FROM MSL (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s) (m/s)

0.00 (m) 1.13 0.31 0.37 0.61 1.07 0.35 0.65 0.41

2.10 (m) 1.11 0.30 0.36 0.59 1.06 0.34 0.62 0.40

4.20 (m) 1.11 0.30 0.35 0.58 1.05 0.34 0.61 0.39

6.30 (m) 1.10 0.30 0.35 0.57 1.05 0.34 0.59 0.39

8.40 (m) 1.09 0.30 0.34 0.55 1.04 0.33 0.57 0.38

10.50 (m) 1.07 0.29 0.32 0.53 1.03 0.32 0.54 0.37

12.60 (m) 1.06 0.28 0.31 0.50 1.01 0.31 0.51 0.35

14.70 (m) 1.03 0.27 0.28 0.46 0.99 0.30 0.45 0.33

16.80 (m) 0.99 0.26 0.25 0.40 0.96 0.28 0.38 0.30

18.90 (m) 0.94 0.24 0.21 0.32 0.92 0.25 0.28 0.26

21.00 (m) 0.87 0.21 0.15 0.21 0.87 0.21 0.15 0.21

TABLE 4.4c CURRENT SPEED PROFILE Mean Sea Level (MSL). The water depth, referenced to mean sea level (MSL) was considered as 22.0 m. The seabed was assumed to be flat in the analysis. Tide. The highest water level (HHWL) was considered as 1.90 m above MSL while the lowest water level (LLWL) was considered as 2.55 m below MSL in the analysis.


4.7 Marine Growth Marine growth of uniform 50 mm thickness was considered from the splash zone to the anchor point of the mooring chains in the mooring system. The marine growth was accounted for in the system by increasing the weight of the mooring line segment, and increasing the drag coefficients. The density of the marine growth was conservatively assumed to be 1325 kg/m3. The increase in the line segment and the increase in drag coefficient were calculated based on the following expression. Mass of marine growth:

( )[ ] .24

22growthnomgrowthnomgrowth DTDM +=

Weight of marine growth:

=

growth

seawatergrowthgrowth MW

1

Increased drag coefficient:

+=nom

growthnomDDgrowth D

TDCC

2

where: Mgrowth = mass of marine growth

Wgrowth = submerged weight of marine growth

CDgrowth = increased drag coefficient

Dnom = nominal diameter of chain

growth = density of marine growth seawater = density of seawater Tgrowth = marine growth thickness = 2.0 [for stud chain as per DNV-OS-E301] CD = 2.4 [for studless chain as per DNV-OS-E301]

BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005


4.8 Corrosion Allowance Corrosion allowance including wear and tear of 0.2 mm/year (50% of the chain corrosion allowance), as recommended in DNV-OS-E301, was considered for the entire length of the chain. The characteristic capacity of the chains, which forms the basis for the mooring calculations, were adjusted for reduction in capacity due to corrosion, wear and tear accordingly. The reduction in capacity was calculated based on the following expression.

=

nom

cornomcor D

TDCBSBS 2

where: BScor = corroded breaking strength

CBS = catalog breaking strength

Tcor = corrosion thickness for total design life Dnom = nominal diameter of chain

BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005


5 FATIGUE ANALYSIS METHODOLOGY

Mooring chain fatigue performance is an important design consideration for mooring terminal systems. Overly conservative design approaches can be costly, whilst less sophisticated analysis methods may not be truly representative, with the possibility of non-conservatism. Correctly calculating fatigue life of mooring system involving catenaries is a complex problem. First order loading and vessel motions, low frequency second order vessel motions, vessel springing and vibration due to vortex shedding can all contribute towards the long-term fatigue damage of catenaries in a mooring system. The interaction of all these loads must be assessed thoroughly to avoid unrealistic results. First order fatigue is evaluated in time domain since the non-linearities of the mooring system to be analysed was envisaged to be large. This approach is numerically demanding but considered necessary to achieve an adequate level of confidence in the results. The first order motions are described by vessel Response Amplitude Operator (RAOs). Low frequency motions are very much dependent on the mooring system configuration. Low frequency vessel motions are commonly considered insignificant in terms of fatigue due to their very long period in comparison to wave loading. However this assumption does not hold for many cases. In fact, for most cases involving non-symmetrical spread mooring, especially in shallow water, the low frequency motion can cause the highest quantities of damage.

5.1 Statutory Requirements In accordance with the API RP 2SK [2]: Fatigue design is required for permanent moorings only. A predicted mooring component fatigue life of three (3) times the design service life is recommended. The factor of three accounts for uncertainties in lifetime load predictions. In accordance with the DNV-OS-E301 [3]: The fatigue limit state is intended to ensure that each type of component in an individual mooring line has a suitable resistance to fatigue failure. The design equation for fatigue limit state in a permanent mooring is as follows. If the mooring line is regularly inspected ashore, then the safety factor of three (3) should be applicable.

01 FCd where:

dC = the characteristic fatigue damage accumulated during the design lifetime.

F = the single safety factor for fatigue limit state values of which is as follows.

BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005


Criteria 1:

5=F when 8.0Fd Criteria 2:

+=2.0

8.035 FFd when 8.0>Fd

where:

dF = the adjacent fatigue damage ratio, which is the characteristic fatigue damage dC in two adjacent lines taken as lesser damage divided by greater damage.

Fatigue damage from first order loads and motions and low frequency motions may be determined using either time or frequency domain analysis method; or the combination of both. Three (3) methods can be considered for combining fatigue damages due to the low frequency and wave frequency tensions, as follows. o Simple summation method. In this approach, low frequency and wave

frequency fatigue damages are calculated independently. The total damage is assumed to be the sum of the two.

o Combined spectrum. In this approach, the combined low frequency and wave frequency spectrum is first calculated. Fatigue damage is estimated using the combined root mean square (RMS) tension range.

o Time domain cycle counting. In this approach, the combined low frequency and wave frequency tension spectrum is transformed into tension time history. A special cycle counting method such as RAINFLOW method is used to estimate the number of tension cycles and the expected value of tension range from which fatigue damage is estimated.

Among the three (3) methods above, time domain cycle counting method is considered to be more precise.

BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005


5.2 Analysis Method The characteristic fatigue damage, accumulated in a mooring line component as result of cyclic loading, is summed up from the fatigue damage arising in a set of environment states chosen to discretise the long term environment that the mooring system is subjected to, expression of which is as follows.

=== nii iC dd 1 where:

di = fatigue damage to the component arising in state i and the discretisation into state i=1,.n state.

The fatigue analysis of the mooring chains was carried out utilising the Visual Orcaflex version 8.6d, a marine dynamics program developed by Orcina. Fatigue analysis was performed following the procedures of deterministic irregular wave fatigue analysis using rainflow cycle counting method, as recommended in API RP 2SK [2], section 7.5. The long term environment was represented by eight (8) environmental direction and five (5) reference wave classes, amounting to a total of forty (40) discrete design conditions. Each design condition consist of a reference direction and reference sea state characterised by a significant wave height, peak period, current velocity and wind velocity. The probabilities of occurrence of these conditions are detailed in section 4.6. Each design condition was analysed analogously to the procedure detailed in [14]. Time domain simulations, for each design condition, were simulated for 400 seconds in time step of 0.001 second. The simulation time includes an additional 100 seconds ramp to minimise the starting transient effects. For each design condition, the time history wave train where defined such that the maximum wave height falls within the selected 400 simulation period.

BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005


The computed tension time history component obtained from each time domain simulations were converted to stress time history component by dividing the corresponding tension by the nominal cross-sectional area of the chain, where the cross-sectional area of the chains were computed based on the expression as follows.

42 2dAC=

where:

d = nominal diameter of chain

The stress component time history is analysed using the rainflow cycle counting technique, based on Palmgren Miner [15] & [16] law. This gives a number of stress ranges for half cycles. The associated single-occurrence load case damage value is as illustrated by the following expression.

( )( ) === nii iSDS 121 where:

= stress concentration factor S(i) = stress range

BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005


BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005

6 RESULTS AND DISCUSSION

The fatigue analysis was carried out based on the design codes and design criteria as detailed in section 3 and 4 respectively. The analysis methodology is enclosed in section 5. The summary results are enclosed in Appendix B while the detailed results, being to exhaustive to be included in this report, are enclosed in CDROM attached in Appendix C.

6.1 Fatigue Analysis Results

A factor of safety of 10 is usually acceptable for component of major importance to structural integrity and inaccessible for inspection, and 3, for component that is accessible for inspection and maintenance [17]. The summary of the fatigue damage and the fatigue life along the arc length (reference from the fairlead) are enclosed in the following pages. The result indicates the fatigue factor of safety to exceed 10 for chains CH11, CH14, CH15 and CH16, while part of CH12 and CH13 exceed a factor of safety of 3. As for weaklink, CH11, CH12 and CH13 exceed a factor of safety of 3 while the rest exceed a factor of safety of 10.

6.2 Conclusion The mooring lines can be concluded as suitable for the stated purpose, however, the region where the factor of safety is above 3 and below 10 regular inspection and maintenance are required.

6.3 Recommendation

Based on the analysis undertaken, the following recommendations are listed as follows. o An inspection program to be formulated for the chains and weak-links.

Proposed inspection procedures to be submitted for clients approval prior to installation of the weak-links.

o Fairlead/mooring line interface has not been included in the analysis. A conservative approach shall be taken to the design of the fairlead/mooring line interface to ensure that all relevant fatigue loadings (Tension -Tension & Tension - Bending) have been identified and that relevant components have adequate fatigue capacity.

o Stress Concentration Factor SCF of 1.0 was used in the analysis for both the stud and studless chains, which are applicable for chains in catenary. However, chains in the fairlead, a finite element analysis should be conducted to ensure that all relevant stress concentration factors have been identified and minimised. If required, the fatigue analysis shall be repeated with the new recommended SCF.


BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005

o Manufactured components should be carefully inspected to ensure that there are no non-conformances which could accelerate failure, and increased factors of safety should be applied to the limiting allowable fatigue life of relevant components.

o The use of pear shaped shackles is not acceptable for long term mooring system. Regular inspection program are required and the proposed inspection procedures to be submitted for clients approval.


BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005

7 REFERENCES

1. Metocean Desk Study for BCD Project by Institute Technology Bandung.

2. API RP 2SK: Recommended Practice for Design and Analysis of station keeping system for Floating Structures, March 1997.

3. DNV OS E301: Position Mooring, June 2001.

4. ABS: Guide for Building and Classing Floating Production Installation. June 2000.

5. API RP 2A : Recommended Practice for Planning, Designing and Constructing Fixed Offshore Platforms Working Stress Design.

6. BCD3-920-49-CAL-4-001-01 Rev 1: Betara Condensate Terminal. Validation Report of Computer Simulated Results with Model Test Results dated 01 September 2004.

7. Report No. 2001-1491: DNV Max Wave

8. OCIMF : Prediction of Wind and Current Loads on VLCCs, 2nd Edition 1994

9. ITTC : International Towing Tank Conference Publication (1987)

10. BCD3-900-49-CRT-4-001-00 : Mooring Analysis Design Criteria

11. Wichers, (1979): Slowly oscillating mooring forces in single point mooring systems. BOSS79 (Second International Conference on Behaviour of Offshore Structures).

12. Puech A, (1984). The Use of Anchors in Offshore Petroleum Operations. Editions Technique.

13. Taylor R and Valent P, (1984). Design Guide for Drag Embedment Anchors, Naval Civil Engineering Laboratory (USA), TN No N-1688.

14. BCD3-930-49-CAL-4-001-02, Betara LPG Terminal 3D Coupled Time Mooring Analysis, Intact (ULS) and Damage (ALS) condition.

15. Maddox S J, (1998). Fatigue strength of welded structures.

16. Rychlik I, (1987). A new definition of the rainflow cycle counting method.

17. API-RP-2RD : Recommended Practice for design of Risers for Floating Production Systems and TLPs.


BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005

APPENDIX A: Environment Data [Extract] See attached.

Revision 7 - September 2004

Metocean Desk Study for BCD Project S-1

. Summary

The present metocean (meteorological and oceanographic) study is commissioned by Zencomp Computing & Engineering Sdn. Bhd. to prepare metocean information that is needed as design basis for use in Betara Complex Development (BCD) Project in Jambi, Indonesia.

A summary of the findings of this study is presented in Table S.1 Table S.9. Comparison with relevant past metocean studies is discussed in Chapter 11 of this report.



North

Table S.1 A Summary of the Present Metocean Findings for North Direction

Metocean Parameter Values by Return Period (years)

Item Notation Unit 1 5 100

Wind Speed from North

1-hour mean U60 m/s 13.24 16.06 21.70

30-minute mean U30 m/s 13.50 16.38 22.13

10-minute mean U10 m/s 14.03 17.02 23.00

1-minute mean U1 m/s 15.62 18.95 25.61

3-second gust Ugust m/s 17.61 21.36 28.86

Maximum Individual Wave Propagating to North Height Hmax m 0.42 0.58 0.60

Period Tmax s 4.78 4.90 4.91

Length Lmax m 35.64 37.31 37.49

Steepness (H/L)max 0.01 0.02 0.02

Significant Wave Propagating to North

Height Hs m 0.25 0.34 0.35

Period Ts s 4.46 4.53 4.54

Length Ls m 31.08 32.01 32.12

Steepness (H/L)s 0.01 0.01 0.01

Astronomical Tide Highest water level (above MSL) HHWL m 1.90 *) Lowest water level (below MSL) LLWL m 2.55 *)

Storm Surge due to Wind from North

m 0.08 0.11 0.21

Current Speed Flowing to North ([Tide+Wind]-Induced) at 0.0 m depth (from MSL) V0 m/s 0.31 0.34 0.37 1.9 m depth V10 m/s 0.30 0.33 0.36 3.8 m depth V20 m/s 0.30 0.32 0.35 5.7 m depth V30 m/s 0.29 0.32 0.35 7.6 m depth V40 m/s 0.29 0.31 0.34 9.5 m depth V50 m/s 0.28 0.30 0.32 11.4 m depth V60 m/s 0.27 0.29 0.31 13.3 m depth V70 m/s 0.25 0.27 0.28 15.2 m depth V80 m/s 0.23 0.24 0.25 17.1 m depth V90 m/s 0.19 0.20 0.21 19.0 m depth V100 m/s 0.15 0.15 0.15

*) The concept of return period does not apply to astronomical tide.



Northeast

Table S.2 A Summary of the Present Metocean Findings for Northeast Direction



Wind Speed from Northeast

1-hour mean U60 m/s 8.35 10.55 16.27

30-minute mean U30 m/s 8.52 10.76 16.60

10-minute mean U10 m/s 8.85 11.18 17.25

1-minute mean U1 m/s 9.85 12.45 19.20


Maximum Individual Wave Propagating to Northeast Height Hmax m 0.21 0.56 0.90

Period Tmax s 4.44 4.88 5.13

Length Lmax m 30.69 37.13 40.84


Significant Wave Propagating to Northeast

Height Hs m 0.36 0.33 0.53

Period Ts s 4.74 4.52 4.67

Length Ls m 34.95 31.91 34.03

Steepness (H/L)s 0.01 0.01 0.02


Storm Surge due to Wind from Northeast

m 0.04 0.07 0.17

Current Speed Flowing to Northeast ([Tide+Wind]-Induced) at 0.0 m depth (from MSL) V0 m/s 0.24 0.25 0.31 1.9 m depth V10 m/s 0.24 0.25 0.30 3.8 m depth V20 m/s 0.24 0.25 0.30 5.7 m depth V30 m/s 0.24 0.25 0.30 7.6 m depth V40 m/s 0.24 0.25 0.30 9.5 m depth V50 m/s 0.23 0.25 0.29 11.4 m depth V60 m/s 0.23 0.24 0.28 13.3 m depth V70 m/s 0.23 0.24 0.27 15.2 m depth V80 m/s 0.22 0.23 0.26 17.1 m depth V90 m/s 0.22 0.22 0.24 19.0 m depth V100 m/s 0.21 0.21 0.21




East

Table S.3 A Summary of the Present Metocean Findings for East Direction



Wind Speed from East

1-hour mean U60 m/s 7.41 8.73 12.20

30-minute mean U30 m/s 7.56 8.90 12.44

10-minute mean U10 m/s 7.85 9.25 12.93

1-minute mean U1 m/s 8.74 10.30 14.40


Maximum Individual Wave Propagating to East Height Hmax m 2.05 2.62 2.72

Period Tmax s 5.96 6.37 6.44

Length Lmax m 54.13 60.85 62.07


Significant Wave Propagating to East

Height Hs m 1.21 1.54 1.60

Period Ts s 5.24 5.54 5.59

Length Ls m 42.56 47.31 48.11

Steepness (H/L)s 0.03 0.03 0.03


Storm Surge due to Wind from East

m 0.02 0.03 0.07

Current Speed Flowing to East ([Tide+Wind]-Induced) at 0.0 m depth (from MSL) V0 m/s 0.98 1.02 1.13 1.9 m depth V10 m/s 0.98 1.01 1.11 3.8 m depth V20 m/s 0.97 1.01 1.11 5.7 m depth V30 m/s 0.97 1.01 1.10 7.6 m depth V40 m/s 0.97 1.00 1.09 9.5 m depth V50 m/s 0.96 0.99 1.07 11.4 m depth V60 m/s 0.95 0.98 1.06 13.3 m depth V70 m/s 0.94 0.96 1.03 15.2 m depth V80 m/s 0.92 0.94 0.99 17.1 m depth V90 m/s 0.90 0.91 0.94 19.0 m depth V100 m/s 0.87 0.87 0.87




Southeast

Table S.4 A Summary of the Present Metocean Findings for Southeast Direction



Wind Speed from Southeast

1-hour mean U60 m/s 7.17 9.71 18.33

30-minute mean U30 m/s 7.31 9.90 18.70

10-minute mean U10 m/s 7.60 10.29 19.43

1-minute mean U1 m/s 8.46 11.46 21.63


Maximum Individual Wave Propagating to Southeast Height Hmax m 2.21 2.77 2.84

Period Tmax s 6.07 6.48 6.53

Length Lmax m 55.94 62.68 63.49


Significant Wave Propagating to Southeast

Height Hs m 1.30 1.63 1.67

Period Ts s 5.32 5.62 5.66

Length Ls m 43.81 48.59 49.24

Steepness (H/L)s 0.03 0.03 0.03


Storm Surge due to Wind from Southeast

m 0 0 0.02

Current Speed Flowing to Southeast ([Tide+Wind]-Induced) at 0.0 m depth (from MSL) V0 m/s 0.38 0.39 0.41 1.9 m depth V10 m/s 0.37 0.38 0.40 3.8 m depth V20 m/s 0.37 0.38 0.39 5.7 m depth V30 m/s 0.36 0.37 0.39 7.6 m depth V40 m/s 0.35 0.37 0.38 9.5 m depth V50 m/s 0.34 0.36 0.37 11.4 m depth V60 m/s 0.33 0.34 0.35 13.3 m depth V70 m/s 0.31 0.32 0.33 15.2 m depth V80 m/s 0.29 0.30 0.30 17.1 m depth V90 m/s 0.26 0.26 0.26 19.0 m depth V100 m/s 0.21 0.21 0.21




South

Table S.5 A Summary of the Present Metocean Findings for South Direction



Wind Speed from South

1-hour mean U60 m/s 9.44 10.64 12.32

30-minute mean U30 m/s 9.63 10.85 12.57

10-minute mean U10 m/s 10.01 11.28 13.06

1-minute mean U1 m/s 11.14 12.56 14.54


Maximum Individual Wave Propagating to South Height Hmax m 2.64 3.33 3.66

Period Tmax s 6.38 6.88 7.12

Length Lmax m 61.06 69.37 73.21


Significant Wave Propagating to South

Height Hs m 1.55 1.96 2.15

Period Ts s 5.55 5.94 6.13

Length Ls m 47.47 53.80 56.93

Steepness (H/L)s 0.03 0.04 0.04


Storm Surge due to Wind from South

m 0 0 0

Current Speed Flowing to South ([Tide+Wind]-Induced) at 0.0 m depth (from MSL) V0 m/s 0.44 0.51 0.65 1.9 m depth V10 m/s 0.42 0.49 0.62 3.8 m depth V20 m/s 0.42 0.48 0.61 5.7 m depth V30 m/s 0.41 0.47 0.59 7.6 m depth V40 m/s 0.40 0.46 0.57 9.5 m depth V50 m/s 0.38 0.44 0.54 11.4 m depth V60 m/s 0.36 0.41 0.51 13.3 m depth V70 m/s 0.33 0.37 0.45 15.2 m depth V80 m/s 0.29 0.32 0.38 17.1 m depth V90 m/s 0.23 0.25 0.28 19.0 m depth V100 m/s 0.15 0.15 0.15




Southwest

Table S.6 A Summary of the Present Metocean Findings for Southwest Direction



Wind Speed from Southwest

1-hour mean U60 m/s 6.04 7.98 14.99

30-minute mean U30 m/s 6.16 8.14 15.29

10-minute mean U10 m/s 6.40 8.46 15.89

1-minute mean U1 m/s 7.13 9.42 17.69


Maximum Individual Wave Propag. to Southwest Height Hmax m 2.29 2.98 3.16

Period Tmax s 6.13 6.63 6.76

Length Lmax m 56.93 65.11 67.35


Significant Wave Propagating to Southwest

Height Hs m 1.35 1.75 1.86

Period Ts s 5.36 5.74 5.84

Length Ls m 44.44 50.54 52.17

Steepness (H/L)s 0.03 0.03 0.04


Storm Surge due to Wind from Southwest

m 0 0 0

Current Speed Flowing to Southwest ([Tide+Wind]-Induced) at 0.0 m depth (from MSL) V0 m/s 0.27 0.29 0.35 1.9 m depth V10 m/s 0.26 0.28 0.34 3.8 m depth V20 m/s 0.26 0.28 0.34 5.7 m depth V30 m/s 0.26 0.28 0.34 7.6 m depth V40 m/s 0.26 0.28 0.33 9.5 m depth V50 m/s 0.25 0.27 0.32 11.4 m depth V60 m/s 0.25 0.27 0.31 13.3 m depth V70 m/s 0.24 0.26 0.30 15.2 m depth V80 m/s 0.24 0.25 0.28 17.1 m depth V90 m/s 0.22 0.23 0.25 19.0 m depth V100 m/s 0.21 0.21 0.21




West

Table S.7 A Summary of the Present Metocean Findings for West Direction



Wind Speed from West

1-hour mean U60 m/s 7.64 9.92 15.85

30-minute mean U30 m/s 7.79 10.12 16.17

10-minute mean U10 m/s 8.10 10.52 16.80

1-minute mean U1 m/s 9.02 11.71 18.70


Maximum Individual Wave Propagating to West Height Hmax m 2.22 2.89 3.38

Period Tmax s 6.08 6.56 6.92

Length Lmax m 56.11 64.10 69.98


Significant Wave Propagating to West

Height Hs m 1.31 1.70 1.99

Period Ts s 5.33 5.69 5.97

Length Ls m 43.97 49.73 54.29

Steepness (H/L)s 0.03 0.03 0.04


Storm Surge due to Wind from West

m 0 0 0

Current Speed Flowing to West ([Tide+Wind]-Induced) at 0.0 m depth (from MSL) V0 m/s 0.98 1.01 1.07 1.9 m depth V10 m/s 0.98 1.00 1.06 3.8 m depth V20 m/s 0.97 1.00 1.05 5.7 m depth V30 m/s 0.97 0.99 1.05 7.6 m depth V40 m/s 0.97 0.99 1.04 9.5 m depth V50 m/s 0.96 0.98 1.03 11.4 m depth V60 m/s 0.95 0.97 1.01 13.3 m depth V70 m/s 0.94 0.95 0.99 15.2 m depth V80 m/s 0.92 0.93 0.96 17.1 m depth V90 m/s 0.90 0.91 0.92 19.0 m depth V100 m/s 0.87 0.87 0.87




Northwest

Table S.8 A Summary of the Present Metocean Findings for Northwest Direction



Wind Speed from Northwest

1-hour mean U60 m/s 7.65 8.17 8.69

30-minute mean U30 m/s 7.80 8.33 8.86

10-minute mean U10 m/s 8.11 8.66 9.21

1-minute mean U1 m/s 9.03 9.64 10.25


Maximum Individual Wave Propag. to Northwest Height Hmax m 0.43 0.63 0.92

Period Tmax s 4.79 4.93 5.14

Length Lmax m 35.78 37.86 41.03


Significant Wave Propagating to Northwest

Height Hs m 0.26 0.37 0.54

Period Ts s 4.47 4.55 4.68

Length Ls m 31.15 32.32 34.14

Steepness (H/L)s 0.01 0.01 0.02


Storm Surge due to Wind from Northwest

m 0 0 0

Current Speed Flowing to Northwest ([Tide+Wind]-Induced) at 0.0 m depth (from MSL) V0 m/s 0.36 0.42 0.61 1.9 m depth V10 m/s 0.35 0.41 0.59 3.8 m depth V20 m/s 0.35 0.40 0.58 5.7 m depth V30 m/s 0.34 0.40 0.57 7.6 m depth V40 m/s 0.34 0.39 0.55 9.5 m depth V50 m/s 0.33 0.38 0.53 11.4 m depth V60 m/s 0.32 0.36 0.50 13.3 m depth V70 m/s 0.30 0.34 0.46 15.2 m depth V80 m/s 0.28 0.31 0.40 17.1 m depth V90 m/s 0.25 0.27 0.32 19.0 m depth V100 m/s 0.21 0.21 0.21




All Direction

Table S.9 A Summary of the Present Metocean Findings for All Direction



Wind Speed

1-hour mean U60 m/s 11.90 16.32 22.74 30-minute mean U30 m/s 12.14 16.65 23.19 10-minute mean U10 m/s 12.61 17.30 24.10 1-minute mean U1 m/s 14.04 19.26 26.83 3-second gust Ugust m/s 15.83 21.71 30.24

Maximum Individual Wave

Height Hmax m 2.64 3.33 3.66

Period Tmax s 6.38 6.88 7.12

Length Lmax m 61.06 69.37 73.21


Significant Wave

Height Hs m 1.55 1.96 2.15

Period Ts s 5.55 5.94 6.13

Length Ls m 47.47 53.80 56.93

Steepness (H/L)s 0.03 0.04 0.04


Storm Surge m 0.08 0.11 0.21 Current Speed ([Tide+Wind]-Induced)

at 0.0 m depth (from MSL) V0 m/s 0.98 1.02 1.13 1.9 m depth V10 m/s 0.98 1.01 1.11 3.8 m depth V20 m/s 0.97 1.01 1.11 5.7 m depth V30 m/s 0.97 1.01 1.10 7.6 m depth V40 m/s 0.97 1.00 1.09 9.5 m depth V50 m/s 0.96 0.99 1.07 11.4 m depth V60 m/s 0.95 0.98 1.06 13.3 m depth V70 m/s 0.94 0.96 1.03 15.2 m depth V80 m/s 0.92 0.94 0.99 17.1 m depth V90 m/s 0.90 0.91 0.94 19.0 m depth V100 m/s 0.87 0.87 0.87



BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005

APPENDIX B: FATIGUE DAMAGE DETAILED OUTPUT

See attached.

CHAIN FATIGUE ANALYSISDISTRIBUTION ALONG CHAIN LENGTH

22 YEARS DESIGN LIFE

1

10

100

1000

10000

0 9 23 33 43 50 54 58 62 66 69 73 76 77 82 93 104 115 126 137 148 164 185 207 228 238

Chain Arc Length from Fairlead (m)

U

n

f

a

c

t

o

r

e

d

F

a

t

i

g

u

e

L

i

f

e

(

y

e

a

r

s

)

CH-11 CH-12 CH-13 CH-14 CH-15 CH-16

WEAK LINKINSPECTION NOT REQUIRED

INSPECTION REQUIRED

BELOW ACCEPTABLE LIMIT

ARC LENGTH DAMAGE

ARC LENGTH DAMAGE

ARC LENGTH DAMAGE

ARC LENGTH DAMAGE

ARC LENGTH DAMAGE

ARC LENGTH DAMAGE

A 0.00 0.05668 0.00 0.18233 0.00 0.14559 0.00 0.01453 0.00 0.01738 0.00 0.015561 9.22 0.05947 9.08 0.18674 9.08 0.14914 9.12 0.01525 9.13 0.01820 9.14 0.016242 23.44 0.06180 23.15 0.19227 23.16 0.15336 23.25 0.01611 23.27 0.01921 23.29 0.017193 33.44 0.06310 33.15 0.19552 33.16 0.15587 33.25 0.01663 33.27 0.01981 33.29 0.017734 43.44 0.06395 43.15 0.19779 43.16 0.15779 43.25 0.01692 43.27 0.02017 43.29 0.018015 50.34 0.06527 50.07 0.19878 50.08 0.15856 50.16 0.01696 50.17 0.02023 50.20 0.018056 54.13 0.06531 53.91 0.19908 53.91 0.15878 53.98 0.01690 53.99 0.02018 54.01 0.018007 57.93 0.06526 57.74 0.19919 57.75 0.15887 57.80 0.01681 57.81 0.02029 57.83 0.017938 61.72 0.06512 61.58 0.19911 61.58 0.15881 61.62 0.01667 61.63 0.02013 61.64 0.017809 65.52 0.06385 65.41 0.19886 65.41 0.15861 65.45 0.01650 65.45 0.01993 65.46 0.01762

10 69.31 0.06350 69.25 0.19839 69.25 0.15822 69.27 0.01626 69.27 0.01966 69.28 0.0174411 73.10 0.06307 73.08 0.19774 73.08 0.15771 73.09 0.01609 73.09 0.01924 73.09 0.0170012 75.50 0.10794 75.50 0.30882 75.50 0.24634 75.50 0.02484 75.50 0.02943 75.50 0.0260313 76.50 0.10768 76.50 0.30862 76.50 0.24619 76.50 0.02475 76.50 0.02925 76.50 0.0259514 82.46 0.06061 82.44 0.19561 82.44 0.15607 82.45 0.01497 82.45 0.01789 82.45 0.0154515 93.38 0.05340 93.32 0.18568 93.32 0.14981 93.34 0.01334 93.34 0.01597 93.35 0.0140016 104.30 0.04515 104.20 0.17087 104.20 0.13674 104.23 0.01214 104.24 0.01445 104.25 0.0126417 115.22 0.03892 115.08 0.15542 115.08 0.12384 115.12 0.01050 115.13 0.01297 115.14 0.0120218 126.14 0.03416 125.96 0.14028 125.96 0.11188 126.02 0.00915 126.03 0.01129 126.04 0.0114119 137.06 0.02790 136.84 0.12598 136.84 0.09872 136.91 0.00822 136.92 0.01021 136.94 0.0104020 147.98 0.02374 147.71 0.11066 147.72 0.08619 147.80 0.00752 147.82 0.00923 147.84 0.0097221 164.07 0.01531 163.78 0.09375 163.79 0.06725 163.87 0.00638 163.89 0.00726 163.91 0.0082022 185.32 0.00879 185.03 0.06881 185.04 0.04751 185.12 0.00466 185.14 0.00535 185.16 0.0063523 206.57 0.00571 206.28 0.04578 206.29 0.03380 206.37 0.00333 206.39 0.00399 206.41 0.0046824 227.82 0.00360 227.53 0.03540 227.54 0.02478 227.62 0.00236 227.64 0.00288 227.66 0.00353B 238.44 0.00360 238.15 0.03433 238.16 0.02461 238.25 0.00236 238.27 0.00286 238.29 0.00345

CH-14

Fatigue Damage TablesCH-15 CH-16CH-11 CH-12

SEGCH-13







A 0.00 352.86 0.00 109.69 0.00 137.37 0.00 1376.33 0.00 1150.58 0.00 1285.611 9.22 336.28 9.08 107.10 9.08 134.11 9.12 1311.32 9.13 1098.89 9.14 1231.632 23.44 323.61 23.15 104.02 23.16 130.41 23.25 1241.35 23.27 1040.98 23.29 1163.573 33.44 316.96 33.15 102.29 33.16 128.31 33.25 1202.64 33.27 1009.67 33.29 1127.804 43.44 312.74 43.15 101.12 43.16 126.75 43.25 1181.97 43.27 991.38 43.29 1110.665 50.34 306.43 50.07 100.61 50.08 126.14 50.16 1179.39 50.17 988.77 50.20 1108.156 54.13 306.22 53.91 100.46 53.91 125.96 53.98 1183.48 53.99 990.98 54.01 1110.937 57.93 306.45 57.74 100.41 57.75 125.89 57.80 1189.77 57.81 985.94 57.83 1115.308 61.72 307.14 61.58 100.45 61.58 125.94 61.62 1199.43 61.63 993.53 61.64 1123.869 65.52 313.23 65.41 100.58 65.41 126.10 65.45 1212.03 65.45 1003.73 65.46 1135.38

10 69.31 314.94 69.25 100.81 69.25 126.41 69.27 1229.70 69.27 1017.37 69.28 1146.7411 73.10 317.09 73.08 101.14 73.08 126.82 73.09 1243.13 73.09 1039.76 73.09 1176.4912 75.50 185.29 75.50 64.76 75.50 81.19 75.50 805.16 75.50 679.51 75.50 768.3113 76.50 185.73 76.50 64.80 76.50 81.24 76.50 808.01 76.50 683.74 76.50 770.6114 82.46 330.00 82.44 102.24 82.44 128.14 82.45 1335.78 82.45 1118.03 82.45 1294.8115 93.38 374.51 93.32 107.71 93.32 133.50 93.34 1499.17 93.34 1252.17 93.35 1429.0316 104.30 443.01 104.20 117.05 104.20 146.26 104.23 1647.68 104.24 1383.98 104.25 1582.0817 115.22 513.90 115.08 128.68 115.08 161.50 115.12 1904.21 115.13 1541.92 115.14 1664.3818 126.14 585.50 125.96 142.57 125.96 178.76 126.02 2185.03 126.03 1771.60 126.04 1752.4419 137.06 716.89 136.84 158.76 136.84 202.58 136.91 2433.04 136.92 1958.15 136.94 1923.9020 147.98 842.48 147.71 180.73 147.72 232.04 147.80 2659.33 147.82 2167.27 147.84 2057.8521 164.07 1306.22 163.78 213.32 163.79 297.38 163.87 3136.14 163.89 2755.44 163.91 2439.5422 185.32 2275.92 185.03 290.65 185.04 420.93 185.12 4296.23 185.14 3737.79 185.16 3147.8623 206.57 3502.96 206.28 436.89 206.29 591.67 206.37 6006.22 206.39 5011.64 206.41 4275.3824 227.82 5561.54 227.53 564.89 227.54 807.14 227.62 8459.69 227.64 6949.61 227.66 5660.10B 238.44 5552.29 238.15 582.58 238.16 812.53 238.25 8470.43 238.27 7000.68 238.29 5791.38

Fatigue Damage Tables

SEGCH-1 CH-2 CH-3 CH-4 CH-5 CH-6


BCD3-920-49-CAL-4-001-03 Rev A 13 OCT 2005

APPENDIX C: SIMULATION RESULT [ CDROM ]

See attached.

1 INTRODUCTION 1.1 General Overview 1.2 Mooring System 1.3 Units 1.4 Standard Coordinate System 1.5 Abbreviations 2 SUMMARY CONCLUSION AND RECOMMENDATION 2.1 Fatigue Analysis Results 2.2 Conclusion 2.3 Recommendation

1 3 DESIGN CODES 4 DESIGN BASIS 4.1 FSO Vessel Details 4.2 Chain Data 4.3 Weak Link 4.4 SN Curves 4.5 Hawser Data 4.6 Environmental Condition and Loads 4.7 Marine Growth 4.8 Corrosion Allowance

5 FATIGUE ANALYSIS METHODOLOGY 5.1 Statutory Requirements 5.2 Analysis Method

6 RESULTS AND DISCUSSION 6.1 Fatigue Analysis Results 6.2 Conclusion 6.3 Recommendation

7 REFERENCES APPENDIX A: Environment Data [Extract] APPENDIX B: FATIGUE DAMAGE DETAILED OUTPUT APPENDIX C: SIMULATION RESULT [ CDROM ]

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