Cel The aim of the project is to develop a standard design for a new type of floating platform which is suitable for providing a number of functions (such as drilling, workover and production) in a range of water depths including deep water. The platform is a variable draught semi-submersible STAbilised PLAtform (STAPLA) and the results from the marriage of two existing technologies, namely semi -submersibles and jack-up platforms. By incorporating a variable draught facility, it is intended to combine the restricted motion response characteristics normally associated with purpose built deep draught vessels and the inshore maintenance/modification capabilities of conventional semi-submersible designs. The benefits of STAPLA, compared to similar alternative floating systems, are being investigated and evaluated in terms of: improved motion behaviour; wider operating capabilities and reduced downtime; and lower capital and operating costs.From a review of existing floating productions systems, initial topsides design criteria have been established to enable model testing to be carried out and to provide a basis for discussions with operators, certifying authorities, etc. The typical weight and space profile produced is for a facility capable of producing 100,000 bopd (or gas equivalent) in a hostile environment. To be self sufficient within supply boat cycles, the platform topsides includes separation of crude oil, water injection, gas lift, generation, utilities, living quarters for 120 people with helicopter access, flexible riser platform, diving back-up and seawater/fire water lift pumps. The deck area is approximately 90 metres by 90 metres and the total topsides operating weight of the initial STAPLA vessel is approximately 20,000 tonnes (including deck steelwork).Environmental criteria have been established for a number of potential locations identified in European waters for the deployment of STAPLA (Nothern north sea, Haltenbanken, Tromso Patch, West of Shetland Porcupine Basin, Celtic Sea and the Mediterranean), hydrodynamic model tests have been carried out at 1:100 scale to establish a preferred vessel configuration.The testing programme fully demonstrated the substantial reduction in motion response that can be obtained on having the pontoons located at a deep draught. However, while Design 1 has excellent motion response characteristics, the steel content is high.The following tasks were to quantify the steel content of Design 1 and to correlate analytical motion response with the model test results. The results of these two activities enabled the Design 1 to be developed in order to achieve a compromise between motion and steel content. This design development led to Design 2.It was concluded that both STAPLA designs provide motion responses which are considerable better than conventional semi-submersibles and compare fabourably with those of a tension leg platform (TLP). The motion responses of STAPLA Designs 1 and 2 are 20 % and 40 % respectively, of greater flexibility, of those existing floating production facilities.A compromise hull configuration has been established which provides the best balance of cost/weight low motion responses whilst using existing technology. This has particularly been achieved by a refuction in operating draught from 80 m to 50 m.Mooring system will consist of a length of heavy chain, partially on the seabed, linked to the vessel by means of a wire (or synthetic) rope.A review of riser systems has identified a bouyant rigid riser with flexible lines linked to the vessel as being the present preferred riser configuration.As part of Phase IIA a complete reassessment of the required payload has been made with reference to existing vessels.Steel weights have been estimated for columns, pontoons and deck from parametric equations and by comparison with existing vessels.The work is divided into three phases with two 'break points' at the ends of Phases I and II when progress towards meeting the project aims will be assessed and the content of subsequent phases may be modified/updated to incorporate any new findings. Phase I - Feasibility studies and definition of design premise Phase I of the work consisted of the following tasks :- Defining the design premise. This included establishing design information on field specifications, environmental criteria, topsides facilities, structural configuration (desk, hull, legs and jacking mechanism), design codes and marine operations.- Carrying out hydronamic model testing to demonstrate the anticipated improved motion response characteristics at an early stage in the project.- Setting up and using stability and vessel response analysis software to carry out a limited parametric study.- Analysing critical structural components, including the potoon raising/lowering mechanism. Phase II - Parametric studies and component refinementThe overall objective of Phase II is to develop a particular STAPLA design to a level acceptable to certification Authorities for concept approval.Phase II will be split into two :(1) Phase IIA : This consists of two main areas of activity :- detailed development of the STAPLA concept- parallel development of the systems on which a STAPLA unit will rely.The first area will consist of analytical parametric studies. Other tasks that will be undertaken are stability analyses. The second area will include the development of active and/or passive positioning systems, rigid and flexible riser systems, subsea equipment required for use with a STAPLA unit and potential export systems specifically applicable for use with a STAPLA unit.(2) Phase IIB : This will be established from the conclusions of Phase I and may, if necessary, consist of structural tests on components which are unique to the STAPLA concept due to its variable draught.Phase III - Conceptual Design and Marketing :Phase III will entail development and finalisation of the design to the level required for conceptual engineering purposes. The detailed planning of a marketing strategy will be part of Phase III with back-up provided from comparative technical and economical appraisals between STAPLA and alternative floating platforms. Program(-y) ENG-HYDROCARB 1C - Programme (EEC) of Community projects in the hydrocarbons sector, 1973-1985 Temat(-y) 1.9 - PRODUCTION SYSTEMS Zaproszenie do składania wniosków Data not available System finansowania DEM - Demonstration contracts Koordynator Wimpey Offshore Wkład UE Brak danych Adres 27 Hammersmith Grove Brentford London Zjednoczone Królestwo Zobacz na mapie Koszt całkowity Brak danych
