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INSTALLATION OF TOPSIDE USING FLOATOVER METHOD

Kuliah Tamu Fakultas Teknologi Kelautan - ITS2 November 2010

By. Ir. Ice Achmad Kurniawan

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Agenda

1.Why Floatover2.Floatover Concept3.Design Engineering4.Barge Equipment and Appurtenances 5.Floatover Sequences6. Procurement 7. Marine Spread

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1. WHY FLOATOVER

Conventional method: LIFTING

WHY FLOATOVER - Unavailability of suitable vessel with crane

capability to install heavy topside (>2000MT)- Cost and schedule advantages of installing pre-

commissioned, integrated, single-piece topsides. - Desire to reduce increasingly expensive offshore

hook-up and commissioning time - Now more demanding due to Scarce availability of

heavy-lift crane vessels for work in shallow waters

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2. FLOATOVER CONCEPT

- The topside module typically is placed on a barge or heavy transport vessel positioned within (internal slot of jacket) or around the legs (external) of a pre-installed jacket- The module then is settled onto the jacket legs by a combination of vessel ballasting and a mechanical lowering system. - The operation of incrementally transferring the

module loads from the barge to the jacket (MATING operation) - Undocking, sufficient clearance, vessel move out

from the jacket

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3. FLOATOVERT&I DESIGN ENGINEERING

1. Deck Mating analysis2. Barge Strength Check (load out & transportation

condition)3. Transportation Analysis4. Mooring Analysis5. Seafastening Design6. Floatover Rapid Ballast System Design7. Jacket Structural Analysis (allowable limit during

floatover)

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PROCESS DESIGN FLOW DIAGRAM

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MATING ANALYSIS

•To simulate the barge’s motion characteristic and to identify the loading on the jacket using a time domain analysis.•Multiple load cases were identified from the initial stage, docking, load transfer and undocking stage to represent the floatover method•The load impact result shall be within allowable jacket design load•Installation sea states criteria shall be established at up front stage as an input for the analysis. •Software use MOSES or LIFSIM

Seastate Input (Installation Criteria)Head/stern sea Hs = 1.00 m Tz up to 7.5 sQuartering sea Hs = 0.75 m Tz up to 7.5 sBeam sea Hs = 0.50 m Tz up to 7.5 s

Output will be used to determine the flaotover workability

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DSF-BARGE SEAFASTENING

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TOPSIDE-DSF SEAFASTENING

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LMU

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DSU

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PLAN LAYOUT LOAD OUT

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LAY OUT FENDERING SYSTEM

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JACKET ALLOWABLE IMPACT

LOAD

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4. FLOATOVER OPT.SEQUENCES• Standby - The vessel is a safe distance from the substructure but connected

to the mooring system, preparation rapid ballast system or the hydraulic jacks are under way

• Docking - The vessel enters the substructure and alignment• Pre-Mating - When ballasting the vessel to match the leg mating units

(LMU) with receptors on top of the substructure legs and removing the remaining tie downs, it is critical that the vessel motions be limited to suit the chosen LMU geometry. No weight transfer yet occurs

• Mating - The topsides is lowered onto the substructure by either rapid ballasting of the vessel or by contracting the hydraulic jacks. The topsides weight is transferred to the jacket completely

• Post-mating - A gap is created between the deck support units (DSU) and the vessel to ensure vessel motions will not cause contact between the two

• Exit - The vessel is removed from the jacket slot.• Post Floatover

- Removal of premooring system, clean up installation aids from jacket if required- Process of welding & NDT examination between topside leg with jacket transition pieces- Final Survey

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ANCHOR PATTERN

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ELEVATION

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5. BARGE SYSTEM AND APPURTUNANCES

1. Rapid Ballast System: to perform the load transfer in the available 12-hour tidal sequence, with specific rate. Can be external or internal (modified from existing barge ballast system)

2. Fendering system was designed to ease the transition through the jacket with sufficient clearances, which reduced the sway impact loading upon docking.

3. The surge fenders were installed to lock the barge in its final docking position.

4. LMU (elastomer-based leg mating unit): to reduce the vertical impact forces (designed to support 50%) of the deck load during load transfer.

5. DSU (Deck Support Unit), elastomer to reduce vertical impact between DSF and topside during the deck load transfer

6. DSF (Deck Support Frame), structure to support topside during load out, transportation and floatover

7. Barge Motion Monitoring System, electronic system to monitor motion of the barge (6 degree of freedom, the motion will be compared with mating analysis)

8. Positioning System 9. Wave Rider Buoys

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BARGE GENERAL LAYOUT

1. S45 PREPARATION AND FENDERING SYSTEM 2. LINKBEAMs & LIGHT SKIDBEAMs FABRICATION 3. 3RD PARTY MARINE SPREADS CHARTER

(Various)4. EXTERNAL RAPID BALLAST SYSTEM 5. SURVEY AND POSITIONING 6. WEATHER FORECAST 7. CATERING SERVICE 8. INSTALLATION AIDS 9. VSAT LINK SERVICE10. AGENCY SERVICE11.ROV 13. NDT

6. PROCUREMENTS

1.1 X TRANSPORTATION BARGE (S45)2.1 X TOWING TUG 14,200BHP3.2 X AHT 10,800BHP C/W KARMFORKS 4.1 X AHT 7000BHP5.1 X AWB (Accommodation Work Barge),

120PAX CAPACITY, 120T CRANE6.1 X CREW BOAT, 80 PAX CAPACITY7.1 X ZODIAC BOAT

7. MARINE SPREAD

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1.Project Description

18" x 100 km

ADGF PLEM

BELANAKFPSO/ FSO

KERISI

24" x 93 km

WHP-K

KERISIPLEM

NORTH BELUT

WHP-D

WHP-C

22" x 10 km

gas phase - 16" x 37 kmliquid phase - 12" x 37 km

gas phase - 16" x 23 kmliquid phase - 12" x 23 km

DUYONG

CPP

16" x 0.5 km

MALAYSIA

INDONESIA

HIUSUBSEA

CPP Topside

The NBCPP topside is a large, complex integrated deck with a not to exceed weight of 14,000 MT. The field is located approximately 60km east-north-east of

the Belanak FPSO installed in the Belanak Field, located on the Block B of the Indonesian sector of the Natuna Field.

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Load out of CPPTopside on S45

Transportation of CPP TopsideSailaway

Installation of CPP Topside using Floatover method

on CPP Jacket

2.Project Phases

Location:S45 mobilize to

Topside Fabrication Yard

Location: Block B of Natuna Sea – Indonesia

The NBCPP is located in 95.2 m water depth

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3. Scope of Work

Main Scope of Work:

• Provision of expertise, manpower, plant, equipment, Contractor’s Spread, consumables and all other items necessary to transport CPP Topside components from the fabrication yard to the North Belut offshore Site and install them safely and efficiently.

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4.Project Key Milestones

Date Activity

11 June 2007 Contract Effective Date

3 Jan 2009 S45 transfer to Sintai for Fendering System and Preparation Work

1 May 2009 S45 mobilized to PTMI Yard

16 May 2009 CPP Topside loaded out onto S45 barge

1st June 2009 Sailaway of CPP Topside

6th June 2009 CPP Topside Installed using Floatover method

7th June 2009 All vessels demobilized from site

5.Interfaces with Other Company’s

ContractorNo Description PT Technip PT Mc Dermot PT Saipem

1All loadout planning,

engineering and AFC dwg R X

Review + supply barge data, check barge

strength and stability for load out

2 Load out operation   X  

3Structural Load out Analysis

(Reaction load) X   R

4 Transportaton Analysis R   X

5 Mating Analysis R   X

6Installation Aids fixed by

welding to jacket structures R

Supply material, Fabricate and pre

installDesign and supply AFC

dwg and MTO

7 DSF DesignSupply material,

Fabricate R

8 CPP Topside DesignSupply material,

Fabricate  

9 LMU (OKI)Design,

Fabricate Install  

10 Seafastening R

Supply material, Fabricate and

installDesign and supply AFC

dwg and MTO

11External Rapid Ballast System Floatover R

R, may request to use assistance Design and install

R = ReviewX = Responsibility

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