Study on energy conservation water injection system of offshore platform based on jet pump

Abstract

In order to reduce energy consumption of water injection development of offshore platform, one idea of jet pumps with characteristics of suction replace the gate valve of water injection wells was introduced. Taking 14 injection wells at a platform in Bohai as the study object, three types of jet pumps which are called JP1, JP2 and JP3 were designed. The corresponding three-dimensional models were established and the Realizable k-ε model of ANSYS was applied to study the influence of jet pump nozzle-throat clearance on water injection rate. Moreover, the injection performance of structure-optimized jet pumps was tested. Three conclusions could be drawn. First, JP1, JP2 and JP3 express the best water injection performance with the optimal nozzle-to-throat clearance which is 4 mm, 5 mm and 6 mm. Second, the water injection rate could satisfy the demand of water injection platform and simulation results are similar to the experimental ones when the water injection rate range of three kinds of jet pump is 183–272 m3/d, 263–393 m3/d and 634–1149 m3/d respectively. Third, compared with the throttle valve water injection system at offshore platform, the jet pump water injection system could save about 1,150,000 kW h per year.