Objective
The main objectives of this project are to design a downhole pump which is reliable, has a service life which exceeds those of conventional electrical submersible pumps (ESP), is easy to install, retrieve, transport and maintain and has operational flexibility. In producing a pump with these characteristics a further consideration is to keep the capital and operational cost in comparison with ESP's.
The project's main innovation is using a turbine instead of an electric motor as the prime-mover for the downhole pump. Although the use of a downhole turbine is not an innovation in itself, as turbines have been used as prime-movers for downhole drill assemblies, the very high supply pressure, high speed and the use of production oil as the turbine working fluid are new concepts.
A range of hydraulically powered downhole pumps for a flow range between 1000 BPD and 10000 BPD and for heads up to 700 ft are now available and are suitable for water lift applications primarily related to enhanced oil recovery operations. Product performance and the potential for high reliability has been demonstrated. At present, a design study sponsored by a number of oil companies and the department for Energy, is being advanced with respect to a wireline retrievable downhole pump in a subsea completion. This study is being carried out as a joint venture between Weir and Cooper Offshore Engineering Limited, with Cooper being involved in the wellhead design work. A programme to develop and test a prototype hydraulic drive downhole pump, incorporating wear resistant materials has been successfully completed, thus proving the capability of the pump for oil lift applications with high sand content in the reservoir fluids.
Pumpsets have been suplied to QGPC for two contracts at ElShargi. The first contract's pumpset lifted water from the aquifer for re-injection to the oil wells for secondary oil lift. The pumpset for the second contract was designed for direct injection from the aquifer to the oil reserves. This design involved crossovers in the completion so that the power fluid and aquifer water were kept separated.
Development of the concept, for a downhole pump driven by an advanced design high speed, high pressure, hydraulic drive turbine, began in 1979 with the support of British Petroleum, BNOC, and the Department of Energy. The main incentive in development of such a downhole pumping system was the increasing concern being expressed by the oil industry with regard to the unreliability of electrosubmersible downhole pumps.
Initially two prototype pump sets were designed and manufactured for test, to demonstrate the mechanical integrity and reliability of the machine. Both prototypes were laboratory tested and effectively demonstrated a high reliability with long life and no sensitivity to frequency of start/stops, after a total of 440 hours trouble free running. The prototypes then went for field trials with one being installed in a geothermal well at Marchwood Power Station, Southampton towards the end of 1981. Following 2000 hours of field testing with over 400 start-stops the downholepumpset was pulled. The pump was check performance tested in the laboratory and inspected with no measurable wear evident. The prototype was then modified to suit operating conditions in an ADCO water lift well in Abu Dhabi where it ran successfully for more than 1500 hours without incident.
The next stage of the pump development was to produce pumps for commercial applications. The two main applications identified were oil lift and water lift for re-injection. The oil lift development was funded by the department of energy and its aim was to develop a pump capable of handling production flow rates in the range of 2000 bbl/day to 10,000 bbl/day. The pump was specifically to be designed for marginal wells where high lifts were required, and where pumping conditions may be particularly adverse. It was also to access the feasibility of a conceptual subsea completion. The other development for a downhole pumping system handling aquifer water was funded by the EEC and its aim was to design a pump capable of re-injecting aquifer water for secondary oil purposes. In this field of application, produced flows required are generally high (15,000 bbl/day to 100,000 bbl/day), downhole conditions are frequently hot, corrosive and erosive through the presence of abrasive suspensions in the produced water. Each of the above developments has required detailed engineering developments of both the downhole pumpset and the system. The developments have also required full size prototype manufacture and test.
Programme(s)
Topic(s)
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
G44 4EX Glasgow
United Kingdom