The mains characteristics of the pipeline system are:

• The design allows the oil to be pumped from the PRA-1 to the FSO for storage before it is redirected to the monobuoys for offloading operation. Notwithstanding, the system is also able to bypass the FSO, exporting the oil directly to the monobuoys.
• The 20-inch pipeline system is fully piggable. The pig launcher and pig receiver are located in the PRA-1 facilities.
• The pipelines between the PLEM-FSO and the PLEM-MB1 and between the PLEMMB1 and PLEM-MB2 are thermally insulated.
• Diver-assisted spool piece tie-ins are required for subsea connection of the pipelines to the PRA-1 and to the PLEMs.

T he design work was developed in the Rio office and was delivered to PETROBRAS in May, to report the following activities:

A. Basic Design of the Pipelines

• Wall Thickness Design
• Wall Thickness Design
• On Bottom Stability Design
• Installation Feasibility Analysis
• Lateral Thermal Buckling Analysis
• Cathodic Protection Design
• Free Span Assessment
• Spool Piece Tie-in Design
• Preparation of the Alignment Sheet Drawings
• Preparation of the Spool Piece Tie-in Drawings
• Preparation of Bill of Materials, including all Requisition Forms
• Specification for Manufacturing of Pipes, Bends and Coatings
• Specification for Correction of the Free-Spans
• Specification for Construction and Installation of the spool pieces
• Specification for As-built Survey
• Specification for Hydrotesting

• General Arrangement Analysis
• Internal Piping Design
• Structural Design
• Foundation Analysis
• Cathodic Protection Design
• Specification for the Ball Valves, including the Hydraulic Actuated Valves
• Specification for Construction

The main challenge of the work, besides accommodating the fast track development, was providing a solution to mitigate the potential for thermal lateral buckling due to the high temperature of the fluid (50ºC) contained within insulated pipelines. The proposed solution contemplates splitting the pipeline sections into two and inserting intermediate tie-ins at the middle point of their routes. During pipelaying, the BGL-1 will install a dummy flanged spool piece, 21 meters long that afterwards will be replaced by pre-fabricated Uspools pieces by divers. The system has been designed to avoid subsea metrology during installation of the U-spools.

The pipelaying is scheduled for 2006 and bids are in progress for the complementary work that is comprised of fabrication and installation of the PLEMs, correction of free spans, fabrication and installation of the spool piece tie-ins, hydrotesting and as-built survey.

Johnny Reed
CEO

Location and Field Architecture
The Okume Complex field is located offshore Equatorial Guinea, West Africa, and consists of the Elon, Okume, Oveng and Ebano reservoirs in water depths ranging from 27 to 500 meters. The development includes two separate mini-TLPs at the Okume/Ebano and Oveng reservoirs and three shallow water wellhead platforms at Elon. A single Central Processing Facility at Elon will handle crude from all four fields. Pipelines in the field will consist of gas lift, water injection, low-pressure gas and produced liquid pipelines that vary in diameter from 4 inches to 10 inches. Production from the field will be tied back to the existing Sendje Ceiba FPSO via a 12-inch oil export pipeline system. Flexible risers will be installed at the two mini-TLPs and the FPSO. Tie-in spools will connect the pipelines to the rigid risers at the wellhead platforms. The subsea development also includes a Pipeline End Manifold (PLEM), a control umbilical to a subsea gas injection well and a power cable between satellite platforms #2 and #3. Installation of the subsea facilities will commence 3rd quarter 2006.

INTEC Scope of Services

The INTEC scope of services entails:

• Detailed design and engineering of the pipelines, risers and subsea facilities
• Procurement support for equipment and services
• Construction and survey support
• Project management support

The impetus for this session is the understanding that economic production from ever-increasing water depths and offset distances will require deployment of new and/or improved long-distance delivery systems (LDDS). For these systems, it is important to emphasize “delivery” rather than “production”, industry’s traditional focus. The design, deployment, and operation of these LDDS systems is long-distance delivery management (LDDM). Key points made by the panel to the media audience are summarized below.

The objective of LDDM is to enhance overall profitability of ultra-deepwater and/or very long offset (deep-offset) developments. LDDM will require a stepchange beyond conventional/ current technology. Changes in electrical and mechanical components/systems, in chemicals used, and in system operating procedures will be needed. For a number of reasons, it will be desirable to minimize or eliminate the number of surface-piercing, high CAPEX, structures used.

Deep-offset developments inherently bring with them the potential for increased production risk, reduced system availability, higher development cost, higher OPEX, and/or reduced profitability. In view of these risks, robust attention to the entirety of the system, over the entire lifecycle of the development, is essential. LDDM will require increased focus on traditional systems engineering functions such as production system design, subsea production/transportation equipment application, and systems integration. With any subsea tieback development, flow assurance is critical to successful operation; flow assurance is even more critical for deep-offset developments.

The step-change in industry development of Long Distance Delivery Systems will require innovation in electrical and mechanical equipment (i.e. subsea separators, multiphase pumps and compressors, electric flowline/pipeline heating, subsea power distribution), chemicals (hydrate inhibitors, wax suppressants), and operational techniques (high assured flow rates, production gathering systems).

Developers will face tough questions in trying to decide what technologies to develop and adopt. Among the questions:

• Under what conditions do we separate water? It is not always the best systemwide thing to do.

• How can we dispose of water subsea? Disposing into the water environment may not be possible and the cost of disposal wells will be high.
• Under what conditions do we separate gas from oil? Removing gas from the oil stream increases viscosity (thereby increasing pumping power requirements) and requires separate flowlines and pressure boosting to transport the separated fluids.
• Do we worry too much? Systems will need to be robust, system operability will need to be well designed and understood, and reasonable contingency will need to be designed into the system. That said, there will be virtually no way to eliminate all risk. The industry will need to accept reasonable levels of risk.

This significant milestone is the culmination of 34 months of continuous contribution by INTEC technical specialists out of its UK office, as integrated members of the Burullus Project Team.

At 120 km, Simian and Sienna represent the world’s largest direct subsea tieback in production. Congratulations to the entire team for this outstanding achievement.

The week started with a welcome breakfast given by Chris Tam, followed by a visit to the OTC. An actual ongoing design project was selected as the main exercise of the workshop, which walked the participants through conceptual planning, pre-FEED, and FEED phases of a pipeline project offshore West Africa. These interactive sessions were augmented by technical presentations on Flow Assurance and Subsea Systems. Other highly appreciated contributions came from Dominick Basile, John Stearns, and Lanny Waguespack who gave interesting talks on leadership, project management and LNG.

Altogether, the participants walked away with an excellent and long lasting impression of INTEC's strengths, capabilities and the interesting challenges we face.

After days of intensive work, the week concluded with a Texas fish fry on a sunny afternoon at Hermann Park near downtown Houston’ a great end to a successful week.

(INTEC organizers and participants included: Sarah Watson, Hein Benninga, Raymond Rojas, Armin Tavassoli, Bryce Gerrits, Dominic Wright, Saifulbahari Hamid, Jacqueline Okeke, and Xandy Cuneo.)

Later that day, John Reed, CEO spoke on the LDDS topic at a special Topical Luncheon following the conference to a sold out crowd of 200. He noted the low-hanging fruit in even the deepwater provinces of the world has been picked over to a large extent, leaving new discoveries that tend to be smaller and located at increasingly greater distances from production facilities. INTEC Engineering urges industry leaders to make a step-change to deep-offset developments that incorporate optimum system design. The presentation available for viewing on the INTEC website.

To that end, INTEC calls for Long Distance Delivery Management (LDDM) to extend the life of existing deepwater floating systems for use as large central production facilities while also seeking the “holy grail” of LDDM: production from subsea systems directly to shore. To achieve these goals and bring more and more reserves into economic viability, the industry needs to work collaboratively, reaching beyond conventional technology to new levels of systems engineering.

SPE encourages these panel discussions for media because they are an effective forum for global industry issues impacting the deepwater frontier market.

Industry topics in previous INTEC OTC media conferences have included flow assurance, interface management and challenges associated with the Scarab Saffron West Delta Deepwater Development offshore Egypt, for which INTEC provided engineering and project management services

The following papers were presented at OTC:

• Large Diameter SCR Delivery Challenges , authored by J.P. Killeen, BP America Inc; K.C. Dyson, INTEC Engineering; K.D. Reeves, INTEC Engineering; D. Wolbers, Heerema Marine Contractors.
• The Challenging Design Aspects of the High-Pressure Tieback SCRs for the K2 Development in the Gulf of Mexico, authored by Luiz Fernando de A. e Souza, MCS; Saadar Miza, ENI Petroleum; Jianjun Xia, INTEC Engineering.