Objective The aim of the GA-SP Project is to develop and test full scale, a subsea processing system that will facilitate economic development of small hydrocarbon reservoirs. The system will include well stream commingling, multiphase separation and pumping, and will be engineered to be suitable for a wide range of reservoir fluid properties, shallow or deep water application, with control from the surface from either a low cost in-field floating platform or an existing remote fixed installation.Innovative aspects include:a) Subsea closed loop modulating control of process parameters.b) Hybrid diverless maintenance philosophy with vertical retrieval of insert components or complete modules.c) Single datum alignment of valved multi-port module interconnection.d) High and low pressure gas commingling in an ejector.e) Variable speed export pump, turbine driven using ambient sea water as a power transmission fluid.f) Nucleonic, capacitance and differential pressure instruments.Accurate, stable, control was achieved of first stage pressure and first and second stage gas and oil interfaces under all steady state and transient conditions. Oil and water interface level control and second stage pressure control were less satisfactory. Most equipment worked reasonably well with the exception of the gas ejectors. The use of two stage separation is therefore not recommended at the present time.The GA-SP Project which is also supported by a number of oil companies was executed in stages. The first stage, Front End Engineering and Preliminary Design, was concerned with outline definition of field scenario concepts and identification of major areas of novelty. The second stage, Detailed Design and Engineering , was concerned with development of a full scale prototype system which incorporates all of the key areas of novelty required to demonstrate the technical feasibility of the concept. The major tasks of this stage of work included:i) Development of Process Flow Diagrams, General Arrangement Drawings and Piping and Instrument Diagrams.ii) Building of Scale Models to show module details and interfaces.iii) Preparation of functional specifications for all equipment, systems, fabrication and assembly requirements.iv) Detailed engineering including hydraulic, mechanical and structural calculations, and preparation of drawings and schedules.v) Specification of onhsore tests facility requirements including a conditioning plant to provide a flow of simulated crude oil at 15,000 b/d and 35 bar.vi) Development of a computer simulation programme, to be used as a basis for predicting process/control response of the prototype, and subsequently, after correlation with test results, design of commercial systems.The main components of the prototype system include:a) Dummy Production Choke Module (PCM), with a single bay Secondary Distribution Module (SDM) incorporating the prototype Valved Multiported Connector (VCM).b) Separator Module, for two stage three phase separation, including four types of level detector from three manufacturers, and four sets of modulating control valves with hydraulic actuators from two manufacturing groups.c) Ejector skid unit, with two alternate ejectors for gas commingling; flow, pressure and temperature sensors, and (manual) recycle capabilities to the second stage separator and/or booster pump suction.d) Power system, comprising 3.3 kV transformer, switchgearand cable with a sea water charge pump driven by 500 H.P. 3.3 kV synchronous motor. The high pressure water drives a turbine, coupled to the oil export booster pump. A modulating control valve bypasses water to control speed of the turbine/booster pump in response to separator level control.e) Control and data monitoring system, comprising a topsides process control computer, a topsides data logging computer and printer, a topsides hydraulic power unit, a subsea pod for hydraulic fluid distribution and data transmission together with a variety of transducers, cables, connectors and junction boxes.The third stage of the GA-SP Project included procurement of the prototype facility, factory acceptance testing of the main components, its installation in a dry dock, commissioning and operation using simulated wellhead fluid. Programme(s) ENG-HYDROCARB 2C - Programme (EEC) of support for technological development in the hydrocarbons sector, 1986-1989 Topic(s) 1.9 - PRODUCTION SYSTEMS Call for proposal Data not available Funding Scheme DEM - Demonstration contracts Coordinator Goodfellow Associates Ltd EU contribution No data Address 124 Belgrave Road SW1V 2BL London United Kingdom See on map Total cost No data
