Low-frequency variable-pressure oil reservoir exploitation method, device and system for residual oil in pores

Abstract

The invention provides a low-frequency variable-pressure oil reservoir exploitation method, device and system for residual oil in pores. The method comprises the steps that a distribution diagram of gas in an oil reservoir and a pressure distribution diagram between injection and production wells in the gas injection process are obtained; according to the distribution diagram of the gas in the oil reservoir and the pressure distribution diagram between the injection and production wells in the gas injection process, the placement position of a low-frequency variable-pressure well shaft device in the oil reservoir is determined; the pressure is intermittently increased and decreased at the preset frequency through the placement position of the low-frequency variable-pressure well shaft device in the oil reservoir, and the distribution state of the residual oil in the oil reservoir at the placement position is changed; and the residual oil in the oil reservoir with the distribution state of the residual oil changed is exploited through a steam injection well and a production well. According to the scheme, the short-time high-pressure effect of a near wellbore zone is caused by the high flow speed of the low-frequency variable-pressure well shaft device, the effects of desorbing the residual oil and changing the direction of a main seepage channel are achieved, and after gas drive fluid channeling, the exploitation degree continues to be increased through a method of expanding the swept volume.

Description

technical field [0001] The invention relates to the technical field of oilfield development, in particular to a low-frequency variable pressure reservoir exploitation method, device and system for residual oil in pores. Background technique [0002] Gas flooding technology is an advantageous technology in the late stage of water flooding development and the development of low-permeability reservoirs. It has the advantages of low seepage resistance, fast recovery of formation pressure, and obvious oil displacement effect. The channel flows along the high-permeability channel in the reservoir. Once the gas is pointed and forms a channel in the reservoir, after the production from the production well, the gas injected later will hardly play the role of oil displacement. However, in the oil reservoir, some pores including channeling channels still contain residual oil with relatively high saturation. The existing technology has methods to block part of the channeling channels, b...

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Problems solved by technology

[0003] The embodiment of the present invention provides a low-frequency variable pressure reservoir exploitation method, device and system for remaining oil in pores, which solves the problem that the remaining oil with relatively high saturation contained in some pores of channeling channels cannot be recovered in the prior art. mining technical issues

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