Downhole oil-water separation integrated injection-production device based on electric pulse and application method thereof

Abstract

The invention provides a downhole oil-water separation integrated injection-production device based on electric pulse and an application method thereof. The device comprises a production screw pump, an electric pulse oil-water separation device, an injection screw pump and an eye pipe which are serially connected on the oil pipe from top to bottom in sequence. A central pipe is connected under a lower single-flow valve, and the bottom ends of the central pipe and the oil pipe are sealed by a plug. A liquid outlet is arrange on that tubing wall between the low single-flow valve and the eye tube, and a water injection port communicating with the annulus of the oil sleeve is arrange on the tubing wall of the central tube located below the eye tube. Compared with the traditional downhole physical dehydration, the electric pulse oil-water separation device has the characteristics of good electric field stability and high dehydration efficiency. The invention integrates the functions of oil-water separation, production and injection, has simple surface technology, effectively reduces the water circulation link, saves the cost, and the separated water is injected into the formation, whichcan reduce the formation damage caused by the external fluid and timely replenish the formation energy within the control range of the well, thereby contributing to the long-term stable production ofthe oil well.

Description

technical field [0001] The invention belongs to the field of oil recovery technology, and in particular relates to an electric pulse-based downhole oil-water separation integrated injection-production device and an application method thereof. Background technique [0002] Most oilfields in my country adopt the water injection development method. As the oilfield development enters the middle and later stages, the water content of oil wells gradually increases. According to statistics, at present, the recoverable reserves of the old oilfields in my country with a water content of more than 80% account for 73.1% of the total reserves. . A large amount of crude oil with high water content is lifted to the ground for separation, treatment, gathering and transportation and reinjection, which will cause great production waste and economic loss. [0003] At present, there are two commonly used downhole oil-water separation devices, one is gravity separation and the other is cyclone ...

AI Technical Summary

Problems solved by technology

The advantage of gravity separation is that the project investment is low, and the disadvantage is that oil-water separation is carried out using the principle of natural sedimentation separation. Determining the position of the pump in the well and the position of the suction port of the separator leads to poor injection and production effects; the principle of cyclone separation is to use a hydrocyclone to perform high-speed spiral rotary motion to physically separate crude oil with high water content, and its disadvantage is high investment. Downhole separation efficiency is low, and it is difficult to maintain long-term effective injection, and the return on investment is low

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