Copyright 2007, Offshore Technology Conference This paper was prepared for presentation at the 2007 Offshore Technology Conference held in Houston, Texas, U.S.A., 30 April3 May 2007. This paper was selected for presentation by an OTC Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper, as presented, have not been reviewed by the Offshore Technology Conference and are subject to correction by the author(s). The material, as presented, does not necessarily reflect any position of the Offshore Technology Conference, its officers, or members. Papers presented at OTC are subject to publication review by Sponsor Society Committees of the Offshore Technology Conference. Electronic reproduction, distribution, or storage of any part of this paper for commercial purposes without the written consent of the Offshore Technology Conference is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of where and by whom the paper was presented. Write Librarian, OTC, P.O. Box 833836, Richardson, TX 75083-3836, U.S.A., fax 01-972-952-9435. Abstract This paper presents the Technical and Organizational Challenges SOFRESID ENGINEERING have met to extensively engineer the modification and upgrade of GIRASSOL FPSO to accommodate the production of a new oil field : ROSA offshore Angola. Technical challenges came from the drastic limitation in additional weight, stability and available space of such an existing floating vessel, as well as operational constraints such as reducing shut down time, hook up operation and the need of a complete revamping of the Control and Safety System. Organizational challenges came from the limitation of lifting and installation means that drove the design optimization, the need of an extensive and accurate knowledge of the as built facilities. They were increased by the overall market situation leading to long procurement lead time and scarcity of Engineering resources. The main objective of this paper is to describe these challenges and the way SOFRESID ENGINEERING and TOTAL E&P ANGOLA have worked together under a new contracting strategy to overcome them by developing innovative solutions such as an intelligent 3D modeling coupled Laser Survey, continuous module design optimization, advanced lifting frame arrangement, and a proactive multi-center engineering organization. Introduction The ROSA field located in block 17 offshore Angola will be developed through the existing Floating Production Storage and Offloading ( FPSO ) GIRASSOL which needs modifications and additional facilities to accommodate such additional production.

GIRASSOL is the first very large FPSO ever installed: Production capacity : 220,000 bod, Storage capacity : 2,000,000 barrels, Water depth: 1,350 m, FPSO size: 300 m x 59 m x 30 m, FPSO weight: 350,000 t, Topside equipment: 25,000 t dry, Gas compression and reinjection at 350 bars (25 MW). Capacity increase will be significant, with a stream capacity which will jump up to 270,000 bod and water treatment facilities from 180,000 to 300,000 bwd to be injected in the field at 275 bars. SOFRESID ENGINEERING has been awarded by TOTAL E&P ANGOLA a comprehensive Engineering, Procurement services and ICSS supply contract to engineer the first ever done upgrade of a new built FPSO under operation. This contract is made of several elements such as Lump Sum for the Supply, Target cost for Engineering services, full Reimbursable for Vendor and Contractor Follow up and several Bonus / Malus clauses forming an innovating incentive scheme regarding Project Cost, Weight and Shutdown time. During this large Engineering work all provision have been taken for the execution of the project considering that construction, installation, hook up and commissioning on the FPSO will be accomplished in a SIMOPS mode (Simultaneous Operations and construction ).

OTC 19115

Extend the Capacity of a Jumbo FPSO: The ROSA Project Jrme Ribuot, Sofresid Engineering

3D model of GIRASSOL FPSO

with ROSA

2 OTC 19115

Objectives given by TOTAL E&P ANGOLA and shared by SOFRESID during all the project duration have been: to secure Safety of People and integrity of the Installation, to minimize Shut-down duration on GIRASSOL FPSO, to simplify offshore Hook Up operation, to ensure Operability of installation, to optimize Cost, Weight and Schedule. Therefore the project has been split into 7 modules, prefabricated onshore and installed by heavy lift barge during plant shutdown: Production header with corresponding gas lift risers and

water injection headers housed in modules M7A/B, Dead oil circulation system for preservation against

hydrate formation in flow lines and risers: o Pumps and associated diesel power generators

accommodated in module M1, as well as E&I building,

o Methanol injection package located in module M2,

HP Water injection facilities (pumps, water treatment) housed in module M4,

Desalination package in order to match crude export specification (HP pumps and biocide skid) in Module M5,

Dedicated first stage separator installed in module M6.

Specific design has been developed also for Interconnecting thanks to an extensive use of 3D Laser Survey to update the existing 3D model and prepare smooth offshore works. Interconnections between new facilities and tie-in with existing :

Hydraulic power units for sub-sea facilities, Portside risers, Maintenance trolley (independent running tool), New chemical injection tanks and pumps, Nitrogen generation package, HP flare scrubber pumps, Gangway access platform for flotel mooring, Free fall lifeboat due to increased POB during

offshore installation works.

TECHNICAL CHALLENGES Available Space Available space on board was of course very limited, but it was also concentrated in only a few locations.

This difficulty was indeed turned into an opportunity when designing the modules and their installation aids. In fact the big modules will be installed on the very top of existing equipment and therefore they need significant supporting substructure. For Module M4 it was decided by the Engineering team to split this substructure apart from the module itself, which would allow it to be designed, fabricated and installed on board before the module itself.

As the module M4 is in the center of the area where most of the other modules were going to be installed, this substructure was also designed to participate in the stiffness of nearby modules. In particular this had allowed structural steel of modules M7A/B and M1 to be significantly reduced as these modules are rigidly linked with M4 and its substructure.

This allowed also the installation guides for modules M1 to be part of the substructure fabricated onshore and installed in advance during a single early lift operation without hot work on board.

Module M4 Water degasing &

Water injection

Module M4 Substructure

All ROSA modifications on board GIRASSOL extracted from the comprehensive 3D model depicting Modules and loose

Piping, Cable routing and main Equipment

OTC 19115 3

Deck reinforcement Most of ROSA modules are fitted side by side in a section of approximately 45 m x 25 m at the FPSO midship. This represents about 4, 750 additional tons in operation. In order to spread the loads to an acceptable load on the hull, 16 new primary columns and 6 reinforced primary columns have been installed.

Calculations have been performed with MOSES hydro-structural software. Extensive preparation work has been necessary to update the calculation files used for the design of GIRASSOL and minimize the reinforcement of the existing: As-built corrections to include a previous revamp

(JASMIN field production ), Accurate environmental conditions coming from

recent oceano and meteorological data thanks to the near by DALIA FPSO,

Hull deflection reduction using a more advanced theory model from GIRASSOL original calculations,

Day to day work with TOTAL E&P ANGOLA engineers to optimize the welds on existing structures.

Weight limitation & FPSO stability The weight limitation was a major constraint to prevent any storage reduction and to maintain the FPSO stability in any condition.

To balance any weight growth resulting from Engineering development, it was decided from the start to optimize some aspects of the design.

The reduction in piping size thanks to the use of Duplex and CS Gr X 60 versus API 5L Gr B for some piping classes has led to a saving of 230 tons on 515 tons originally.

The use of Hubs versus flanges for the tie-in of hook-up spools for 2 and above and piping class 1500 # and 2500 # has led to a saving of 100 tons on originally 170 tons.

This allowed also increasing number of non welded connections on board under SIMOPS.

Shut Down time / Lifting optimization One of the means developed during Engineering phase to reduce shut down time was to perform comprehensive optimization of the detailed lifting operations in order to reduce their time and complexity. As soon as the lifting contractor was selected SOFRESID and TOTAL E&P ANGOLA organized a thorough technical review and brainstorming with all parties involved in order to challenge lifting operations as well as modules design and this led to:

- reorganize some modules to reduce their width and weight ( M6 with an innovative design of the separator upper saddle used as structural frame of the module itself )

- re-group some other s ( M4A and M4B into M4 ). Then a specific concept was developed in order to reduce in-place weight by designing temporary lifting frames for the largest modules. This is a rather unusual design as it leads to add a very significant amount of temporary steel for construction and transport, but this eases the installation sequence itself by adding stiffness to the module. It saved the use of spreader bars and spreader frames ( and their installation time ) and save also space on the module itself as this lifting tool is part of the rigging itself. Of course after installation of the modules their lifting frames are dismantled, therefore SOFRESID designed a quick release system to speed up this operation ( with an ad hoc pin connector ).

Module M7B LIRIO CRAVO

Riser manifolds

Module M7A ROSA Riser manifolds

Module M1 Preservation

Module M4 Module M6 Separation

M4 installation

with Lifiting frame

4 OTC 19115

Hook up on a live FPSO Although most of the additional equipment has been designed as part of modules; a significant hook up is still to be performed on board during operation of the FPSO. To ease these operations and minimize offshore work a continuous optimization of the tie-ins has been performed by Process and Piping Engineers together with the Operations people from TOTAL E&P ANGOLA. This led to minimize actual number of tie ins and Hot Works on board ( out of shut-down time ).

Cargo Oil Tank (COT) inertage modifications Thanks to the mobilization of a comprehensive Engineering team, TOTAL E&P ANGOLA asked a concept Study to be launch for modifying the inertage of GIRASSOL Cargo oil tanks (2,000,000 barrels) and to stop the green-house gas venting to the atmosphere. After the concept approval by the Bureau Veritas, a fast track design and detailing was launch to procure all the material and implement all the modifications before the start-up of the hook-up works on the FPSO.

The objective was to stop emissions to the atmosphere and their detection on the FPSO which led to process shut-downs and associated loss of production during the first years of Production on GIRASSOL. This objective has been achieved with the replacement of the produced inert gas with process gas from the separation and downstream of the COT, its collection and compression back to separation with the installation of 2 ad hoc compressors.

Revamping of Control and Safety systems The existing Control and safety was re-engineered to further receive Rosa with a minimum of FPSO production disturbance. Change over of the Operating System from UNIX to

WINDOWS. Change operator stations to new ones supporting

Windows operating system to insure a better efficiency. During operations the network has been split into 3 sub-

networks supporting 1 common sub-network; 1 topside sub-network and 1 subsea sub-network to further support the integration of ROSA into GIRASSOL.

During a shut-down the existing Safety PLCs have been loaded with the modified existing program necessary to manage additional GIRASSOL equipment and the program necessary to interface Rosa.

During operations the existing GIRASSOL Process controllers have been loaded with the new configuration necessary to manage GIRASSOL additional equipment.

To perform such works SOFRESID has also engineered: The development of specific Procedures for the on line

and change over modifications, The on site modifications of GIRASSOL Safety System

to include ROSA Cargo Oil Tank Compressors, Life boat and further Rosa integration,

The modifications of GIRASSOL Process control to include ROSA loose items,

The update of the operators Displays to include ROSA The design and fabrication of GIRASSOL / ROSA

HARD HIPPS to meet SIL 4 requirements, The Development of a methodology to Commission the

Desalination at vendors premises.

1st stage separator

DS301

3rd stage separator DS 303

Crude Oil Tank TA 011/ . /024

VFD

M

SIC 2081

PIC 2081

PV 2081

PT 2081

COT VentT

M4 Lifting frame

bottom pile with Pin

connector being

removed

Additional loose equipment, piping, electrical and instrumentation routing

OTC 19115 5

All existing Control and Safety systems are then ready to operate GIRASSOL and Rosa equipment without any disturbance of the FPSO. Rosa facilities will be commissioned as a stand alone package through a temporary ICSS network and shall be connected to the GIRASSOL prepared network for a ROSA and GIRASSOL common start up.

ORGANIZATIONAL CHALLENGES As Built knowledge / Laser Survey The experience shows that the as-built documentation is difficult to maintain or assess on such a large plant like an FPSO. This was also true for GIRASSOL. No chance could be taken on the quality of the as-builts for a hook-up of that size on a live FPSO. Therefore, 2 extensive campaigns were launched to laser survey the areas to be modified for ROSA. A first campaign was launched when the Plot Plans, the equipment layouts, the P&IDs and the main routings were sufficiently developed to assess, which areas had to be surveyed. A second campaign was launched once most isometrics were issued IFC Before Survey to survey all areas while walking the isometric on board the FPSO. As a result of this second survey, all isometrics were re-issued IFC After Survey. The plots clouding the area pictured by the laser were injected into the 3D Model and easily superimposed to the modeling thanks to a specific software development performed by SOFRESID to have a 3D model directly and quickly workable by the design office. Procurement lead time The market situation and high level of activity of main suppliers has made the overall procurement process a bit too lengthy compared with the urgent need of extremely accurate Vendor information to be computed in the 3D model during the stringent optimization of the modules dimensions. Sofresid has then used its own experience and data base to assess final dimension, further checked together with suppliers thanks to the open discussion channel established in this regard.

Scarcity of Resources / Multi center Due to the size of the project, the scarcity of the Engineering resources and the various competences available in the group of companies SOFRESID is belonging to, the project was executed in 2 main centers with the support of the Paris headquarter: SOFRESID Pau ( France, close to TOTAL support office) : project management, hosting the client TOTAL E&P ANGOLA, interface management, integration studies and brownfield design, procurement services, pre-commissioning, commissioning, maintenance engineering,

SIPS in Chennai (India ): modules design, Instrumentation data base management.

This organization was possible due to:

- common project working procedures which were developed on the basis of SOFRESID corporate quality systems (ISO certified basic practices),

- Implementation of a specific IT system based on existing infrastructures.

New servers had to be installed to accommodate project data bases for Document Control, CAD model and instrumentation data base. And a specific high speed communication line was established between the two offices.

All documents produced by SOFRESID and by vendors were stored in a central data base DOCUMENTUM located in Pau. Specific areas were created to exchange documents between the different sites: one to receive duplication from other sites and one for exported data.

Updating of the different data bases was realized through incremental back-up of produced documents in both sites of Pau and Chennai and associated daily duplications done.

This system was in operation from the very beginning of the project, it was very efficient and allowed the management of 6,600 documents (100 Giga Octets) and 22,000 associated exchanges with about 120 different vendors.

A shared demilitarized area was also provided to client for the flow of official dispatching to TOTAL E&P ANGOLA as an interface with their PETRODMS DCC system. Reconciliation with Company has also demonstrated the high quality and reliability of the system.

The same procedure was also applied to the back-up of the CAD PDS model of modules and interconnecting. Due to the huge size of Girasol FPSO model (about 80 GIGA Octets) and despite the increase of performances of the system to the possible maximum, SOFRESID had to set in place new CAD working procedures based on the use of limited areas model.

New operator

consoles at GIRASSOL

6 OTC 19115

CONCLUSIONS One of the key factors of the project success is the interface management system put in place by TOTAL E&P ANGOLA to deal with all interfaces between contractors ( SOFRESID in charge of Engineering and Procurement, others in charge of modules Construction, Subsea works, early small Lift, Installation, heavy Lift, Hook Up,) and Operation team thanks to identification at a very early stage of all and any interface and their easy follow up all along the various phases and project development. A continuous flow of technical data was established between all parties through Interface Task Sheet ( ITS ) formally registered and dispatched through a common Project Document Control system. For example SOFRESID had to deal with 250 ITS through 1,200 formal exchanges especially for getting approval of solutions proposed to other contractors. In addition and in order to secure the design of the modules with regard to installation constraints and risks, specific methods were developed by SOFRESID for interface management. With the help of the CAD model and use of laser survey for a better knowledge of existing facilities, acceptable installation volumes were modeled around the modules for review and endorsement by the installation contractor. This methodology allowed the selection of technology for all protruding items such as access stairs or ducts (loose versus hinge-able).

This way of working proved to be very appropriate and accurate as the installation of the modules onboard FPSO has been carried out successfully without any clash. Shut-down duration, complete ICSS change over and final added weight are also fully in line with the objectives set at the very start of the project. ACKNOWLEDGEMENT The ROSA field is operated by TOTAL under a Production Sharing Agreement awarded by SONANGOL to the Block 17 Contractor Group including Total, ExxonMobil, BP, Statoil and Hydro. The author would like to thank SONANGOL, TOTAL and the Block 17 Contractor Group for the confidence they placed in SOFRESID ENGINEERING team to engineering this first upgrade of such a large FPSO. The author thanks also all the personnel of SOFRESID, a subsidiary of SAIPEM, and TOTAL E&P ANGOLA resident engineers who restlessly gave their enthusiastic contribution to this very challenging project. ABBREVIATIONS FPSO Floating Production Storage and Offloading MW Mega Watt ICSS Instrumentation Control and Safety System bod Barrel of Oil per Day bwd Barrel of Water per Day SIMOPS SIMultaneous OPerationS and construction PLC Programmable Logic Controller HIPPS High Integrity Pressure Protection System SIL Safety Integrity Level IT Information Technology CAD Computer Aided Design

Installation Volume of Module M4 available for contractors

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