Closed well washing device

Abstract

The invention belongs to the petroleum exploitation field and provides a well washing device which can seal the annular space between the oil pipe and the casing and avoid the well washing water from polluting the oil layer. The sealing well washing device comprises an eccentric well washing valve and a leather cup packer; the leather cup packer is arranged on the oil pipe under the eccentric well washing valve; the leather cup packer divides the annular casing space between the oil and the casing into an upper part and a lower part; the eccentric well washing valve is provided with a pressure switch device used for controlling the conduction and closing of the annular casing space and the space inside the oil pipe. The well washing device avoids the well washing water from contacting with the oil layer while satisfying the well washing requirement of the pumping unit production well, maintains the porosity and permeability of the production layer without affecting the yield of the crude oil. The technical proposal provided by the invention is adopted so that the water consumption is less. Under the same condition, if the general well washing method is adopted, the water consumption is 23 cubic meters in volume and the time is 4-5 hours. If the technical proposal of the well washing device is adopted, the water consumption is only 5 cubic meters in volume and the time is 90 minutes.

Description

technical field [0001] The invention belongs to the field of oil development, and relates to a well washing device which closes the annular space between oil pipes and casings and prevents well washing water from polluting the oil layer. Background technique: [0002] At present, in the field of petroleum development, the well-flushing methods adopted by pumping unit oil production wells due to the wax deposition on the inner wall of the tubing are all open-type well flushing. This well cleaning method is to inject the heated well washing water directly into the annular space between the oil pipe and the casing until it reaches the bottom of the well, and then it is pumped out through the oil pipe by the oil pump, which causes the well washing water to contact the oil layer, thereby changing the pores of the oil layer Degree and permeability affect crude oil production. Especially for oil wells with low oil layer pressure, well flushing water may enter the oil layer, causin...

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Problems solved by technology

[0003] In order to overcome the shortcomings of the existing open well flushing methods, the present invention provides a closed well flushing device, which can solve the problem that the well flushing water directly contacts the oil layer

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