A pre-pump oil-water separation single-unit double-pump injection-production system

Abstract

The invention discloses a single-unit double-pump injection and production system with oil-water separation in front of a pump. The single-unit double-pump injection and production system with oil-water separation in front of the pump comprises a sleeve pipe and a production pipe column. The production pipe column comprises a cable-through packer, a canned electric pump injection and production system, an oil-water separation reinjection device, an oil-water separator, an upper packer and a lower packer, wherein the cable-through packer, the canned electric pump injection and production system, the oil-water separation reinjection device, the oil-water separator, the upper packer and the lower packer are connected by an oil pipe. A positioning bypass is arranged in the upper packer; and aninsertion seal is arranged in the lower packer. The canned electric pump injection and production system comprises a tank body, wherein a submersible electric pump unit and a self-expanding packer are arranged in the tank body. The submersible electric pump unit comprises an upper pump, an upper protector, a single motor, a lower protector and a lower pump. The self-expanding packer is arranged between the lower protector and the suction port of the lower pump, the self-expanding packer is provided with an oil phase guide pipe, and the lower end opening of the oil phase guide pipe is connected with an oil-water separation reinjection device. According to the single-unit double-pump injection and production system with oil-water separation in front of the pump, the oil-water mixed liquid is separated in front of the pump, and the oil content in the reinjection water is greatly reduced. The single-motor double-acting electric submersible pump injection-production and lifting technologycan be used for realizing fixed proportion production and pressurized reinjection.

Description

technical field [0001] The invention relates to downhole oil-water separation and oil recovery water injection technology, in particular to an oil-water separation single-unit double-pump injection-production system before a pump. Background technique [0002] The downhole oil-water separation and reinjection technology began to be researched and field tested in the 1980s, and has been gradually improved and applied. For oil wells with high water cut and high liquid volume in the late stage of oilfield development, downhole oil-water separation technology is a low-cost and high-efficiency lifting technology. In particular, offshore oilfields have entered a period of high water-cut development. Faced with high water content in a single well, the investment and maintenance costs of surface produced liquid treatment equipment have increased year by year. When the cost is higher than the economic production cost, they are forced to shut down. [0003] The oil-water mixture is p...

AI Technical Summary

Problems solved by technology

Due to the independent flow channel establishment method and the oil-water separation method after the pump, there are some specific problems, such as the oil content in the water after separation is still high, which does not meet the water injection requirements of the oil field, and the process is complicated

The adjustment of injection-production parameters of a single-unit pump requires additional downhole measurement and adjustment tools to control the injection-production split ratio, and the construction cost of the quantitative injection-production process of the upper and lower pumps of the dual-unit electric pump injection-production system is expensive, etc.

At the same time, various forms of downhole oil-water separation systems use a booster pump to pressurize and then separate oil from water. Under the centrifugal shearing action of the electric pump, the molecular particle size distribution of the produced liquid is uniform, which is not conducive to oil-water separation, and eventually leads to downhole oil-water separation. Poor oil-water separation effect

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