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OTC 18681 From P-34 to P-50: FPSO Evolution C.C.D. Henriques, PETROBRAS; F.N. Brandão, PETROBRAS

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 April–3 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 PETROBRAS started to use ship-shaped processing and storage vessels (FPSOs) for offshore production in 1979, through the installation of a process plant over the deck of the P.P.Moraes oil tanker (later renamed to P-34). In April 2006, the P-50, PETROBRAS´ latest and most complex FPSO, ever, started production in Albacora Leste Field. In these last 25 years, the concept and design of our FPSOs suffered a large transformation, from the simplified production plants for up to 50,000 bpd used in the late 70s, through the large FPSOs converted in the mid-90s, up to the concept adopted in P-50 project. In this project, the concepts of modularization and selfcontained equipment packages allied to the life enhancement strategies adopted to guarantee an operational life in excess of 25 years, lead to a design that can be considered “top-of-class” for converted FPSOs. In this paper it will described how the design of PETROBRAS´ FPSOs evolved highlighting the modifications made in the design of P-50 main systems. Introduction PETROBRAS has a long history of using ship-shaped production units in its offshore projects starting in the end of the 80’s. Table 1 shows the list of our FPSOs in design, construction or operation and the FPSOs that were demobilized. At present, we have 11 FPSO/FSOs in operation, and we can divide the history of those Units into 3 phases, as can be graphically seen in figure 1 that shows the number of FPSO/FSOs that entered production in each year, since 1987: ƒ Phase I: In this period, from 1979 up to the beginning of the 90s, FPSOs were used mainly as Early Production Systems; ƒ Phase II: This period, up to the end of 90s, comprises the boom of FPSO construction and installation in the Campos Basin;

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Phase III: In this phase, the use of FPSOs was consolidated and a second generation of units was built, taking into account all the experience gathered in the first wave of FPSOs from the second phase. Nowadays we can see that a new FPSO Phase is beginning, with the development of P-57 project, our first newbuilt designed FPSO.

Evolution of FPSO Concept in Brazil Phase I: In the Campos Basin, the first CALM buoy was installed in the Enchova Field, in 1978 in order to allow the mooring of an oil tanker to receive the production from a drilling rig in a pilot production system. The first mono-hull floating production unit to operate in the Campos Basin (and one of the first FPSOs in the world) was the former tanker P.P.Moraes. This 33,000 dwt tanker was built in 1959, and, in 1975 it was jumboized to 54,000 dwt. Then, in 1979, a 60,000 bpd process plant was installed in P.P.Moraes to allow it to operate in the Garoupa field, moored by a tower-yoke system as can be seen in figure 2. In 1980, the tower failed from fatigue at the ballast tank, and a CALM buoy was then installed in the field, to moor the P.P.Moraes FPSO through a soft yoke (figure 3). In 1987, P.P. Moraes received a rigid yoke to connect to the buoy and was relocated to the recently discovered Albacora deep water field. The unit operated as a Pilot System for the Albacora Field up to March of 1993, with no significant downtime and relatively low OPEX (Ref. 2, 3, 4). During this period, floating productions systems based on semi-submersible platforms were the typical solution adopted in the Campos Basin deep water fields. These FPUs exported the oil to Tankers from our fleet, permanently connected to loading buoys. The first main project of this kind was the Pilot System for the Marlim Field, in 1992, where the Aframax Tanker Horta Barbosa was moored in 625 m of water depth, breaking the world record of deepest moored CALM buoy, at that time. The first tandem offloading operation ever done in the Campos Basin was performed in the FSO Horta Barbosa, proving that this kind of operation could be done safely, with conventional shuttle tankers, under Campos Basin environmental conditions. In 1993, P.P.Moraes left the Albacora Field in order to begin its modification process for the future installation in the Barracuda Field. P.P.Moraes was replaced by a Semi-Submersible, the FPU P-24, which exported the Albacora oil to the Aframax Tanker Jurupema, moored in a CALM buoy.

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The modification of these oil tankers that worked as FSOs almost continuously for more than 5 years was minimal. The FSOs/FPSOs of this phase were typically fast-track and limited scope conversions of mid-size tankers (Panamax or Aframax size), for temporary production or storage, without any gas exportation or water injection facilities, moored by CALM buoys. Other important characteristics of those units are shown in Table 2. We can consider this first phase, the beginning of our learning curve - P.P.Moraes was a floating lab to test the design and the operation of an FPSO. The most important lessons learned from this phase were related to the best way to moor ship-shaped floating units in the Campos Basin, the behavior of those units under beam seas conditions and the effect of the movements over the process plant. Long 15 years after the first use of P.P. Moraes as a production unit, we decided, in 1994, to use this ship in a large Pilot System for the giant Barracuda Field renaming the old lady to FPSO “PETROBRAS-34”. Due to the large number of risers (34), it was decided to use a turret system to moor the FPSO. This was the first turret moored FPSO in the Campos Basin (Fig.4). A new process plant, including Gas Compression facilities was installed at the FPSO that began operation in 1997 and operated continuously for more than 6 years until its demobilization in 2003 (Ref.1 and 9). We can consider P-34 conversion as the transition design from Phase I to Phase II. In this project, the unit was still midsized, for an Early Production Project, without Water Injection facilities. On the other hand, the unit already showed points that would characterize the large FPSOs of Phase II, such as the extensive refurbishment scope, the large turret mooring and the unit conversion done in one big Lump-sum, Engineering Procurement and Construction (EPC) Contract. Phase II In the beginning of the 90s, the continuous increase in production output from the Campos Basin led to a reevaluation of the Basin export system, since the existing pipelines were already operating at maximum capacity. For the transport of oil from the new Marlim and Albacora giant deep water fields, it was concluded that using FPSOs would be more attractive than the standard solution of FPUs (based on semi-submersible platforms) which would require duplication of the existing onshore pipeline network (Ref. 6, 7). So, we began, almost at the same time, the conversion of 4 FPSOs, namely Vidal de Negreiros (P-31) for the Albacora Field, and Cairu (P-32), Henrique Dias (P-33) and Jose Bonifacio (P-35) for the Marlim field. All of them were based on conversion of VLCC tankers (Very Large Crude Carriers) from our own fleet. A few months later, a fourth FPSO for the Marlim Field (P-37) was also contracted. For the first time in Brazil, FPSOs were to be used as permanent production facilities for the full life of the oilfields (20 years). In order to comply with this task, the Units were all converted from large sized tankers (VLCCs) that received large process plants (100,000 bpd) installed in a production deck (“pancake”) over the ship’s deck, with full Gas Compression, Water Treatment and Water Injection facilities. All Units comprised large diameter internal turrets with a big

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swivel stack to receive the large number of risers that would bring the oil from subsea manifolds. Instead of leaving a floating hose in the water to export the oil, submerged hoses stored between offloading operations in a cradle alongside the ship were used to connect the FPSOs to dedicated Shuttle Tankers that were equipped with Bow Loading Systems (BLS). In the first units, the ship Main Steam Boiler was used to generate energy for the FPSO, as it was a common practice in the marine industry. However, after experiencing severe problems in the operation of P-31 boilers, we concluded that this equipment was too cumbersome to be used in an offshore permanent facility. So, beginning with the FPSO P-35, it was decided to fully remove the existing Steam System of the ship and install new Turbine Generators to supply the energy demand required by the FPSO. In order to comply with the expected field life where the FPSO would be designed to operate, all existing systems of the vessel were refurbished (“As-New” philosophy). Another life-extension strategy was to use some special materials, especially in marine systems, such as Copper-Nickel in the Firewater System, Centrifuged Cast Steel (CCS) in the Oil Cargo System and FRP in the Sea-Water Lift System. After this first series, when 5 FPSOs were contracted even before the first one had entered into operation, we contracted the conversion of two FSOs for the new Roncador (P-47) and the Marlim South (P-38) fields. Those Units had similar characteristics of the 5 FPSOs, such as turret moorings and full scope of marine conversion to comply with the long term design life. All those Units are still in operation today and the first one installed, the FPSO P-31, is in continuous operation for more than eight years, now. Despite the limitations that those Units present in the Oil and Water Treatment plants, some minor structural problems that were found in the hull (fatigue cracks inside tanks) and the operational problems in the oil export systems, those FPSOs have so far been presenting a very high operational efficiency, above the average of the Campos Basin Units (that include also fixed and semi-submersible production platforms). These results demonstrated that the use of FPSOs in the Campos Basin was a correct strategy, but also that there was some room for improvement in the design. Transition Phase II-Phase III: In the beginning of 2000, we began the project for two new FPSOs for the Barracuda and Caratinga Fields (P-43 and P48), in the Campos Basin. These projects can be seen as a transition from Phase II to Phase III, since we can already see points that would characterize the FPSOs of Phase III, such as the Spread Mooring System, the process plant modularization philosophy and the use of Moto-Compressors instead of Turbine Compressors. The reasons for adopting these solutions may be summarized as follows: 1) Elimination of subsea manifolds: aiming to reduce the subsea production losses and to take the subsea equipment supply out of the critical path of the project; 2) Spread Mooring: without the restrictions in the number of risers presented by the turret, the SMS allowed the connection of all risers and umbilicals (almost 100) directly to the Unit, aiming to eliminate the subsea manifolds;

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3) Plant Modularization: allowed the division of the plant construction work scope by several different yards, working in parallel, aiming to expedite the construction time; 4) Use of Moto-Compressors: aiming to increase the reliability of the Compression System and to reduce its commissioning time; 5) All-new conversion philosophy (adopted since P-37 project): aiming to guarantee the equipment and piping design life; 6) Metallization: Thermal Spray Aluminum was extensively used in pressure vessels and piping operating at high temperatures as well as in critical areas for maintenance, such as the flare boom and the crane pedestals, aiming to reduce the operational maintenance cost; 7) Cargo Handling System: a monorail was installed along the ship, from the quarters´ area up to the turret, passing through all the process plant, aiming to facilitate the movement of equipment and parts inside the FPSO. Phase III The main characteristics of the FPSOs of this phase that begun with the FPSO P-50, are shown in Table 2. It is important to stress that the development strategy for the P-50 project presented two basic differences from our previous offshore projects: i) The EPC Contract was divided into 5 separate packages (Compression, Generation, Process, Utilities and Conversion/Integration) as described in Ref. 13; ii) A longer FEED was developed, giving the opportunity to improve the FPSO design, taking into account all the experience we had gathered from the design and operation of previous FPSOs. Ahead you will find the main characteristics of the P-50 project, which were replicated in our next two FPSO projects (P-54 for the Roncador Field and P-53 for the Marlim Leste Field).

P-50 Project The Challenge We can understand the challenge that was presented in the P50 project analyzing the graphic shown in figure 5 that summarizes the increase in the capacity and complexity of the FPSOs from Phase I up to Phase III. With a topsides weight of almost 20,000 mtons, P-50 presents the largest and heaviest plant ever installed in an FPSO in Brazil. Figure 6 shows the evolution of the plant size from P-34 up to P-50 (figure 7). Due to the characteristics of the Albacora Leste reservoir (Ref. 8), P-50 plant also required some specific treatment modules that had never been used in our previous FPSOs: 1) CO2 Removal System: Due to the high CO2 content in the Albacora Leste oil, a CO2 Removal Unit was installed between the second and third stages of the gas compression system. The unit reduces the CO2 content from 5% to less than 2%, by means of an Amine (MEA) absorption process. 2) SRU – Sulphate Removal Unit: The Albacora Leste reservoir water analyses showed the presence of barium (70 mg/l) and strontium (500 mg/l) in the reservoir. Since those salts can be combined with the sulphate

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present in the injected water, there was a high risk of scale formation that would clog the production wells. In the FPSO P-50, the installation of a Sulphate Removal plant allows the reduction of sulphate content in seawater from the original 2,800 mg/l concentration to 100 mg/l or less, with approximately 75% of efficiency. Another benefit of the SRU is that it reduces the probability of souring (generation of H2S inside the reservoir by sulphate reduction bacteria). P-50 Design Concept In order to face the challenges presented with the increasing size and complexity of the plant some objectives were pursued in the P-50 design. It was of paramount importance to improve the Unit’s constructability, operability and reliability (Ref. 10). The main strategies used to achieve these objectives were the modularization philosophy, the use of self-contained equipment packages and the lifeenhancement measures adopted, as explained below: Modularization In the first wave of FPSOs, the equipment skids were directly installed over a pancake structure over the ship-deck. Beginning with the P-37 project, the design was changed in order to divide the plant in large modules that would be built separately and would be later integrated over the ship. Modules Arrangement The modules arrangement typically presents the Gas Compression and Treatment in the bow. The Separation Modules are installed amid-ships followed by the Gas Generators. The Utilities (Electrical, non-electrical) and Water Injection Modules are installed more to the stern, closer to the FPSO quarters, as shown in figure 8. It is important to remark that the modularized design allowed the strategy of contracting the Generation and Compression Modules separately from the rest of the FPSO. This strategy was used first in P-50 and repeated in all our subsequent projects, because it allows a direct contact between our PETROBRAS and the equipment supplier, facilitating the design improvement and the commercial relationship. Module Support and Installation Instead of a truss structure supporting the plant “pancake” (figure 9), pyramidal stools (figure 10) were used to support the FPSO modules. All the necessary structural reinforcements to support the modules were done inside the tanks, in order to reduce the obstruction over the ship-deck. With this target in mind, only 4 supporting stools per module were used in P-50 instead of the 6 that were used in previous FPSOs (P37/43/48). On the negative side, this structural concept with large span module beams and huge stools resulted in a heavier structure – because of that, this concept is now under reevaluation and the use of truss structures is under analysis for new projects. The operation of lifting P-50 modules and their installation over P-50 was made by the crane barge Kasei in 2004. The lift of the Utilities Module (1,473 mtons) broke the record of the heaviest lift ever made in Brazil (this record was broken again in January, 2007, when the same crane-barge lifted a 1,644 mtons module from P-54).

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After the installation of P-50 modules over the ship stools, it was verified that the modules supports did not perfectly match the stools positions, due to the differences in the asbuilt dimensions of the modules, fabricated in many different sites, and the stools. It was necessary to install a large amount of reinforcements in the modules supports and in the stools which severely impacted the FPSO modules integration schedule. Three different kinds of problems were detected after the modules installation: ƒ Lack of support: In four modules, only 3 of the 4 supports made contact with the stool, due to vertical misalignment of the supports. In the worst case, one of the module’s support was found “floating” 26 mm above the stool top plate; ƒ Insufficient contact between the module support bottom plate and the stool top plate: this was a generalized problem that happened due to the lack of flatness of the plates, as it can be seen in the picture in figure 11. The “bending” of the plates´ edges was found to be much above the tolerance limits defined for the structural fabrication; ƒ Horizontal misalignment: in one third of the stools, the centerline of the module support was so displaced in relation to the center line of the stool, that there was not enough space for welding. These problems generated a lot of concern, because in our next FPSO project (P-54) the same exact design was being adopted, and the stools were already under fabrication. In P54, however, a more rigid dimensioning control was adopted, as well as some preventive measures, such as the grinding of the stools´ top plates. Fortunately, those measures proved to be effective, and we did not find the misalignment problems that were faced in P-50. Aiming to give more flexibility to construction and assembly, an improvement was adopted in our following FPSO project (P-53): a transition box (that was already used in previous projects such as P-37 and P-43) was installed over the top of the stool (figure 12), giving space for adjustments during the modules installation. Finally, in P-57 a more radical modification was conceived - a shorter stool was designed to support the leg of the module that was extended (figure 13). This is the same stool concept adopted in big FPSO projects in Africa, and, with this concept we are confident that the modules support adjustment will be much easier. Equipment Packages The intention of P-50 design was always to minimize the work inside the FPSO hull and to maximize the new buildings in the conversion in order to make the works easier and faster. The design of those systems, fully discussed in Ref. 10 and 11, is summarized below. 1) Marine Systems: P-50 was our first FPSO project that adopted hydraulic submerged cargo and ballast pumps. The benefits in terms of constructability for the project are evident, as there is no need to assemble neither a new cargo pump room, nor new cargo lines inside the tanks since all cargo lines will run over the deck. All cargo and ballast valves inside the tanks are also eliminated with this kind of pumps.

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Besides that, all the marine systems with connections to the cargo and ballast tanks, such as the cargo, auxiliary, loading and inert gas systems had their main headers built in a ring shape form instead of the traditional fishbone configuration seen in most FPSOs. The main target of this concept was to reduce the amount of transversal lines over the main deck, improving the arrangement of the Unit and the ventilation and access to this area. 2) Sea Water Lift System for Water Injection: The Sea Water Lift system for water injection uses flexible risers that go down to 30 m below the deck for water intake, aiming to obtain a better seawater quality for the injection system. However, such injection system represents only 20% of the total lift flow rate (the remaining is taken for cooling, industrial use, fire fighting, etc). So, we decided to use a dedicated system for this function, with submerged electrical lift pumps. Compared to the option of installing the pumps inside the pump room, this solution is much better in terms of constructability and operationability, and contributed for a more efficient arrangement since the pumps are closer to the water injection module. 3) Fire Fighting System: In our previous FPSOs, dry-mounted diesel hydraulic firewater pumps were used. In P-50, it was used a new concept of diesel hydraulic pumps where a submerged hydraulic booster pump was connected through a pipe-stack to the diesel driven lift pump that was installed in a dedicated compartment over the main deck. In this concept, the booster pumps and the pipe-stacks were installed inside internal steel caissons, fitted inside the ship’s original bunker tanks. The main objective of this concept was to avoid the installation of new pipelines (hydraulic and firewater lines) inside the Engine Room and to avoid the construction or conversion of compartments inside the Engine Room or the ship’s Original Steering Gear Flat for the installation of booster and lift pumps. 4) Offloading System: In our previous FPSOs, cradles were installed along the ship, from bow to stern, to store the offloading hoses, a system that has the disadvantage of increasing the congestion of the FPSO deck. The first FPSO to use an Offloading Hose Reel in the Campos Basin was the FPSO Seillean, a chartered Dynamically Positioned FPSO (Ref. 5) that was equipped with a Hydraulic Reel designed to store a 350m-long, 12-inch hose. As P-50 was moored in a fixed azimuth by the spread mooring system, two Offloading Stations were required, one at the FPSO Bow and the other at the Stern. Each Hose Reel is completely independent, with individual HPUs, what avoids the need of hydraulic lines along the Unit. The first Offloading operation in P-50 was successfully performed in 19 may, 2006, with the Ataulfo Alves Shuttle Tanker from our own fleet (Transpetro). 5) Chemical Products Injection System: P-50 Chemical Products Injection System was designed considering a centralized filling and distribution system for the chemical products, in order to increase the safety of the activities of receiving and handling these products.

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Fixed tanks that are supplied with products stored in large containers were installed in P-50. Flexible hoses link the containers or gallons of chemical product and the rigid supply line to the fixed tank to be fed. A connector that may be quickly actuated and the opening of two valves allow the transference of the product by gravity, preventing the operator to come in direct contact with the dangerous chemical products, making this operation safer than the conventional system of handling small chemical products containers. 6) Mooring System: The use of a spread mooring system in P-50 lead to an adequate and optimized subsea lay-out since all the wells could be directly connected to the side of the FPSO, thus, eliminating the need of subsea manifolds. The mooring system designed for P-50 is an 18-line, partially compliant spread mooring system, with 10 lines in the bow and 8 lines in the stern. Polyester ropes and steel chain in a semi-taut configuration compose all mooring lines. The concept and installation of P-50´s mooring system is fully described in Ref. 12. The mooring system comprises one winch for the bow lines and another winch for the stern lines. The mooring chain comes from vertical chain-pipes, passes through a horizontal sheave, the horizontal winch turn-down sheaves and then, down to the fair-leads. During the hook-up of the mooring lines, a big problem occurred with the turn-down sheaves: the sheaves plates begun to distort (Fig. 14), reaching very high deformations with risk of structural collapse, even before the pre-tension load was achieved. A detailed structural analysis showed that the sheave was not strong enough to resist the load imposed by the chain when it rotated around the sheave (Fig. 15). The sheaves had to be disembarked and reinforced to allow the conclusion of the pre-tension of the mooring lines. 7) Pull-In System: The Pull-in System comprises a lower riser structure, where I-tubes guide the flexible lines and an upper riser structure where the risers are supported. A pull-in structure over the upper riser structure supports the pull-in winches and pulleys. All those structures were installed at the port side of the Unit. The benefit of having the Mooring and Pull-in Systems located at the ends and sides of the FPSO is clear when we compare P-50 lay-out with P-53 layout. In P-53, a turret was used to moor the unit instead of a Spread Mooring System due to subsea layout optimization reasons. The large diameter turret for 75 risers/umbilicals weighting almost 10,000 tons was installed in the bow, between tanks 2 and 3. This position of the turret, chosen in order to reduce the movements imposed to the riser resulted in a negative impact in the Unit’s general arrangement: the gas treatment module had to be installed ahead of the turret and all the piping from the process plant had to go around the turret, to reach the module. A comparison between the piping weight of P-50 and P-53 demonstrates the advantage of P-50’s layout. Life Enhancement Strategies: 1) Material Selection Process: The Albacora Leste Field’s characteristics motivated the review of the material selection philosophy for the P-50 FPSO

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based on the feedback obtained from similar projects in the Campos Basin. Albacora Leste oil samples showed the presence of CO2 (from 2.5% to 5.6% mol) in the crude composition, as well as a high level of chloride. Besides, the required separation temperature of 110ºC resulted in a limitation of the material and coatings that could be used in the plant. During the Front-End Engineering Design stage of the project, a decision tree analysis for each stream of the process plant was performed, in order to decide the most suitable material for all piping and equipment of the plant. For a better assessment of CO2 corrosion and other effects, the plant was subdivided into 13 branches, from the inlet lines at the platform manifold up to the gas dehydration system. The equipment data was collected and filled in a worksheet with some key process parameters, such as pressure, temperature, CO2 percent mol, oil and water flow of all fluid in & outlet. The worksheet allowed the calculation of partial CO2 pressure and BSW%, and suggested the best material to be used, including special materials such as Duplex Stainless Steel. 2) Metallization and Coating: In our first FPSOs, it was necessary to repair large areas of the hull after a few years in operation in the site. We concluded that the problems were caused by the conditions in which the paints were applied at the shipyard, specially the high humidity that impaired the quality of the coating and provoked early paint warn out. So, we started to test new kinds of paints in our laboratories, looking for paints with resistance to humidity and salt presence in the substrate. After some years of tests, we finally found a kind of paint that fulfilled our needs, because it works with a different curing process, absorbing all the water present in the surface in this process. This paint was also more suitable to be used after hydro-blasting, which is a better surface preparation process (compared to dry-blasting) in terms of elimination of the salinity present in the surface. This kind of paint begun to be used in P-43 and was extensively used for the coating of P-50 hull as well as in all tanks, voids and in the structures of the modules. Since P-43 also, we adopted the philosophy of increasing the use of metallization (TSA) in order to enhance the life of piping and vessels that presented high rate of corrosion in former units. It was required that large structures such as crane boom and frame and flare boom as well as equipment with operation temperature above 90ºC, should be metallized with aluminum. 3) Structural Life: Since the Phase II FPSOs, we were improving our criteria for Plate Renewal in order to guarantee that the ship’s structure could withstand the corrosion and fatigue requirements for an excess of 20 years in the field, without dry-docking. In was required that no plates with thickness lower than the Substantial Corrosion thickness (as defined by the Classification Society) at the end of the design life should be allowed – non complying plates should be replaced. To comply with this requirement, the actual thickness measured were compared to the limits defined by a formula that took into account the predicted corrosion in 25 years and the minimum thickness required by the structural analyses. This

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criterion resulted in the replacement of 1,750 tons of steel in P-50’s hull and 3,200 mtons in P-54. The life-enhancement strategy used in P-50 had the great benefit that, after conversion, the FPSO was considered by the Classification Society as “As New” (zero cycle of life) regarding inspection requirements. So, even tough the vessel was 25 years old, it was like its clock was reset to zero, which means a reduction in the inspection frequency with consequent benefits in terms of inspection costs and impact in the production.

The Future of FPSO Concept Phase IV P-57 is a purpose-built FPSO for the Jubarte Field, currently in bidding phase. P-57 presents a design concept very similar to P-50’s, including, for instance, submerged pumps, ring-shape marine headers, offloading reels, etc. The main difference is that P-57 is a specifically designed, new-built hull, with an optimized tank arrangement. Because of this characteristic, caused mainly by the lack of existing tankers suitable for conversion, we may consider that we are now moving to a new phase in FPSO concept development.

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Nomenclature BLS Bow Loading System BSW Basic Sediments and Water C&A Construction and Assembly CALM Catenary Anchor Leg Mooring CCS Centrifuged Cast Steel DICAS Differential Compliance Anchoring System FEED Front End Engineering Design FPSO Floating Production Storage and Offloading FRP Fiber Reinforced Plastic FSO Floating Storage and Offloading FPU Floating Production Unit HSE Health, Safety and Environment HPU Hydraulic Power Unit SMS Spread Mooring System SRU Sulphate Removal Unit VLCC Very Large Crude Carrier OPEX Operational Expenditure MEA Mono-Ethan Amine References 1.

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Conclusion FPSOs have been used by PETROBRAS for more than 25 years. After a long initial learning phase, a group of large FPSOs was built in the mid-90s. The operation of these FPSOs proved the concept to be a success, in terms of overall performance. However, some problems were detected, indicating that there were many opportunities for design improvement. In P-50, we had the opportunity to conceive a design with some important changes in the concept that was repeated in the two next FPSOs that we built, resulting in a benefit in terms of project standardization, significantly reducing P-54 conversion time, for example. Only small corrections in the design were required, which were quickly adopted in the new projects, avoiding the main problems found in P-50 construction and installation phases. PETROBRAS is by far the most experienced company in the operation of FPSOs. The history of the use of FPSOs in our company is one of continuous improvement that resulted in the successful concept adopted in P-50.

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Acknowledgments The author thanks PETROBRAS for permitting the publication of this paper. In addition, he acknowledges numerous colleges from our company who helped to continually improve our expertise on the development of deepwater fields.

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12.

13.

Carneiro, P.R.B., “Barracuda Field: New Records for Turret Moored FPSOs”, Deep Offshore Technology Conference DOT1995. Formigli, J. and Porciuncula, S. (1997) “Campos Basin: 20 Years of Subsea and Marine Hardware Evolution”, Offshore Technology Conference – OTC ’97 Mastrangelo, C.F. and Castro A.N.M. (1999). “Field Experience and Concepts to be Taken into Account in an FPSO Design”, SPE Annual Technical Conference and Exhibition – SPE ’97 Mastrangelo, C.F. and Assayag, S. (1999) “The Operational Experience of PETROBRAS in Offloading Operations with FPSO Units”, Deep Offshore Technology – DOT ’99 Henriques, C.C.D. “Roncador Field Early Production System – a 2000 m Water Depth Challenge”, Offshore Technology Conference – OTC 1999 Mastrangelo, C.F. “One Company's Experience on Ship-Based Production System”, Offshore Technology Conference – OTC 2000 Mastrangelo, C.F. and Henriques, C.C.D. “PETROBRAS Experience on the Operation of FPSOs”, International Society of Offshore and Polar Engineering – ISOPE 2000 Saliés, J.B. et al “Albacora Leste Field: Challenges of a UltraDeepwater Development”, World Petroleum Congress 2002 Mastrangelo, C.F. et al, “From Early Production Systems to the Development of Ultra Deepwater Fields – Experience and Critical Issues of Floating Production Units”, Offshore Technology Conference OTC-2003. Henriques, C.C.D., Santos, A.B. and Pimenta, J.M.H.A., “Improvements Achieved in the Project of FPSO P-50”, Offshore Technology Conference OTC-2004. Brandão, F.E.N. et al, “Albacora Leste Deep Water field: FPSO P-50 systems and facilities”, Offshore Technology Conference OTC-2006 Henriques, C.C.D., et al, “Albacora Leste Field Development – FPSO P-50 Mooring System Concept and Installation”, Offshore Technology Conference OTC-2006. da Silva, R.A.R., Galarza, J.A.V.C., Loureiro, J.E. and Martins, J.V., “Integrated Approach for Big Offshore Production Facility Construction Projects”, Offshore Technology Conference OTC2006

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Table 2 – FPSO Phases - Main Characteristics: Table 1 – FPSOs in design and operation: Units NT PP.Moraes FPSO P-34

FSO P-32 FPSO P-31 FPSO P-33 FPSO P-35

Garoupa Albacora

Prod. Capac. (bbl/d) 60,000 60,000

Barracuda

45,000

Field

Jubarte

60,000

Marlim

***

Albacora

100,000

Marlim

50,000

Marlim

100.000

Characteristic Start 1979 1987 Jul 97 Dec 06 Aug 97 May 98 Oct 98 Jul 99 May 00

Moor. System

WD (m)

Status

Tower Yoke

120 220

Demob. Demob.

Turret

840

Demob.

1350

Oper.

Turret

160

Oper.

Turret

330

Oper.

Turret

780

Oper.

Turret

850

Oper.

Turret

815

Demob.

Turret

189

Oper.

Turret

905

Oper.

Turret

1020

Oper.

DICAS

790

Oper.

Contracting Strategy Design Life Conversion Refurbishment Philosophy

***

Marlim

***

FPSO P-37

Marlim

150.000

FSO P-38

Marlim South

***

FPSO P-43

Barracuda

150.000

FPSO P-48

Caratinga

150.000

Feb 05

DICAS

1040

Oper.

FPSO P-50

Albacora Leste

180.000

Apr 06

DICAS

1240

Oper.

FPSO P-54

Roncador

180.000

Jul 07

DICAS

1400

Constr.

Jul 05 Aug 00 Dec 01 Dec 04

Processing Capacity (bpd) Ship size

Turret

Roncador FSO P-47

Units

Marlim Leste

180.000

Mai 08

Turret

1080

Constr.

FPSO P-57

Jubarte

180.000

Aug 10

DICAS

1280

Design

II – 1995-2001 P-31 / P-33 / P-35 / P-37

Size and Capacities < 60,000 ~100,000 Panamax, Aframax Small MotoCompressors (