Study On Fully Electric Intelligent Control Device For Downhole Formation Fluid

Intelligent well completion technology can control the fluid of different formations or layer in the same borehole, so as to realize the selectable and controllable mining of oil or gas reservoirs. It not only can improve the crude oil production of single well, but also can enhance oil recovery rate ultimately. Intelligent well completion has been applied for more than a decade abroad, but there is no mature intelligent well completion technology domestic. In view of the urgent necessary for domestic slim hole downhole formation fluid control, It has a broad application prospect to develop a fluid control device that can be entered in a ’’521 borehole.On the basis of the analysis of the slim hole limiting characteristics, a downhole fluid control device referred to as sliding sleeve valve is designed, which may be entered in a ’’521 borehole in accordance with the regular structure of ’’521 borehole. The device is driven by an electric motor, and its structure is a sliding sleeve with valve tube form, and its working mode is a continuous fluid control mode. A set of sliding valve model is made and its actuator circuit is developed.According to the requirements of formation measurement and control, some measurement modules are designed, which include circuit design and data acquisition software. Those modules are applied to measure formation parameters, such as temperature, pressure, electric motor parameters, etc.. And the related measurement module is also tested for performance. Based on the principle of differential transformer, a valve opening sensor equipment is designed and manufactured. Moreover, a temperature compensation method is given according to the equipment testing.A communication system of the fully electric intelligent well based on the CAN bus is designed to meet the communication requirement of ground monitoring system and downhole smart unit. Some design details, such as data frames, hardware and software are given.Measurement, control and communication modules are combined to form a downhole smart unit. The joint test of downhole smart unit and wellhead unit show that the designs achieve the expected goals. On the one hand, the ground monitoring system can real-time acquire downhole parameters, which meet the requirements of measurement and communication functions. On the other hand, the sliding sleeve valve can be remotecontrolled flexible, and the opening degree measurement feedback signal accurately.These studies provide a useful reference for the further study of the electric intelligent well technology, and a new intelligent well system model is studing recently.