Different-well asynchronous water injecting oil extracting method for double fracturing horizontal wells through zipper-type crack distributing

Abstract

The invention relates to a different-well asynchronous water injecting oil extracting method for double fracturing horizontal wells through zipper-type crack distributing. The different-well asynchronous water injecting oil extracting method comprises the following steps that in an initial production stage, the two horizontal wells are simultaneously exploited for a period of time through natural energy; oil pipes of the two horizontal wells are taken out, and an injection allocation valve and an injection and extracting separating device are installed on a special position; a well opening oil extracting valve of the horizontal well I is closed, the injection allocation is opened, water is injected into an oil sleeve annular space, and the injected water enters an odd stage crack; the well opening of the horizontal well I is closed to stew the corresponding well, and crude oil and the injected water are imbibed and replaced; a well opening of the horizontal well II is opened to extract the oil; a well opening oil extracting valve of the horizontal well II is closed, the injection allocation valve is opened, and water is injected into the oil sleeve annular space, and the injected water enters an even stage crack; the well opening of the horizontal well II is closed to stew the corresponding well, and the crude oil and the injected water are imbibed and replaced; and the well opening of the horizontal well I is opened to extract the oil. The different-well asynchronous injecting and extracting method can effectively displace residual oil between the wells, between the cracks and in a dead oil area, and the swept volume is improved.

Description

technical field [0001] The invention belongs to the technical field of oil and gas reservoir development, and in particular relates to a zipper-type fracture-distributed double-fracture horizontal well and different well asynchronous water injection oil recovery method. Background technique [0002] In recent years, due to the drastic reduction in the recoverable resources of conventional oil and gas, the exploration and development of unconventional oil and gas has become a new focus, and tight oil is one of them. Tight oil reservoirs are usually developed by depletion at the initial stage of development, but the natural energy of tight oil reservoirs in my country is generally insufficient, and the depletion recovery method alone will cause a rapid drop in reservoir pressure and a rapid decline in production, so energy supplementation is required after a period of development , such as water injection development, etc. [0003] Due to the low porosity and permeability of t...

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Problems solved by technology

[0003] Due to the low porosity and permeability of tight reservoirs, poor formation connectivity, large seepage resistance, and high heterogeneity, a series of problems may occur when using conventional water injection methods and injection-production well patterns: the injection pressure of water injection wells Usually large, injection is difficult; water channeling is easy to form; and because the seepage resistance of the formation is relatively large, and the flow capacity of the injected water in the formation is poor, resulting in a relatively small swept volume and a relatively limited increase in production of a single well, etc.

Although this invention patent can increase the oil recovery rate, due to the single-well injection and production, for oil and gas reservoirs with a large oil layer area, the swept volume, sweep efficiency and recovery degree will be limited, thereby reducing the oil recovery. Realize the displacement of the dead oil zone in the formation

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