The paper describes a major R&D initiative by Esso Exploration and Production UK Limited for the development of deepwater production technology. The objective of this development programme is to ensure that technology is available to produce hydrocarbons in 600 to 10SO-metre water depths inharsh environments on the UK continental slope. The programme, begun in January of 1985, is a four-phase, multi-year design development and component prototype testing programme valued at four to five million pounds sterling.
The recently completed first two phases resulted in the conceptual design of an integrated system known as the Esso Deepwater Integrated Production System or EDIPS. The key building blocks of the system addressed in this design study include a tension leg platform, a floating production/ storage unit moored to a single anchor leg mooring (SALM) and a diverless maintainable manifold at the SALM base to commingle production from several subsea production installations. In describing the major conclusions from the conceptual design work, the paper highlights the technology areas where further work is required. Detailed engineering studies and component development work currently underway as part of the third phase of the programme are described, with focus on those projects dealing with diverless maintenance of subsea components and the deepwater SALM riser behavior.
The diverless maintenance systems designed for EDIPS utilize tool packages carried by remotely operated vehicles to replace valves and control pods, and could be cost effective even in shallow water depths. Use of guidelines and ROV tooling for diverless replacement of flexible piping on the SALM is also discussed.
One of the principal challenges in the design of the deepwater production riser has been the flexural response of the SALM and the attendant fatigue implications. Analytical conclusions from the Phase II work and a model test programme in Phase III to verify the analytical results are described.
The Esso Deepwater Integrated Production System (EDIPS) development programme was initiated by Esso Exploration and Production UK Limited in 1985 and involves several UK contractors. Technical input and coordination has been provided by Exxon Production Research Company. EDIPS brings together several major subsea and surface production systems into an integrated system. The programme objective is to assess, and extend as required, the technology available to produce hydrocarbons in 600 to 1050-metre water depths in a harsh environment.
It is not the intent of the EDIPS study to develop an optimum solution for a site specific application. Rather, the intent is to develop potential building blocks of a total system, identify technology development needs and undertake required critical component development, and examine the requirements to bring together the various elements into an integrated system. A hypothetical field development scenario was therefore assumed.