Development and Performance Evaluation of an Electrically Controlled Intelligent Water Control and Oil Recovery Tool for Offshore Oilfields

An intelligent water control and oil recovery tool with electrical control was developed to tackle the separate-layer water control and oil recovery difficulties of production wells in the high water cut stage of Bohai Oilfield and to improve the effect of oil production stabilization in the development of production wells. In designing the tool, a single-core cable was employed to ensure the power supply and communications, and multiple test channels in parallel were adopted to achieve real-time testing of the flow rate, water cut, temperature, and pressure. In addition, the ultrasonic time difference method was used to test the fluid production from a single layer, and the radio frequency method was applied to test the water cut in the fluid production of a single layer. With this tool, a real-time control could be achieved according to the water cut of each layer, and the water control and oil production stabilization could be achieved in the development of production wells. The performance tests of this tool demonstrated that the seal performance was reliable under 60 MPa, and it could operate normally at 120 ℃. The test range of water cut was from 0 to 100%, and the measuring accuracy was high for high flow rate, which satisfied the requirements of offshore oilfield applications. The developed tool provides a new water control tool for separate-layer oil production and the efficient and stable development of offshore production wells, and lays a foundation for its subsequent field application in offshore oilfields.