Shale reservoir fracturing method based on methane multistage burning and explosion

Abstract

The invention discloses a shale reservoir fracturing method based on methane multistage burning and explosion. Air and supercritical CO2 are used as working fluid, shale reservoir methane is used as fuel, and a reservoir is fractured by utilizing the high pressure effect generated by burning and explosion of a mixture of the air, the supercritical CO2 and the methane so as to realize yield increase transformation of a low-permeability shale reservoir. According to the shale reservoir fracturing method based on methane multistage burning and explosion, a conventional shale reservoir hydraulic fracturing transformation operation mode is expanded to an air pressure fracturing mode, a supercritical CO2 replacement mode and a methane multi-stage burning and explosion multi-fracturing mode, an initial fracture is formed in the shale reservoir through pressing by means of air-supercritical CO2 mixed fluid, and the air distribution concentration in the fracture is adjusted by adjusting the injection flow of supercritical CO2; and methane desorption is promoted by utilizing the strong adsorption capacity of supercritical CO2 to a shale matrix, so that sufficient fuel is provided for explosion fracturing in cracks, the operation space of explosion fracturing is expanded into the cracks from a shaft, the effective action range of explosion fracturing is favorably expanded, and thus green and efficient development of shale gas resources is realized.

Description

technical field [0001] The invention relates to the technical field of unconventional oil and gas development and shale gas reservoir stimulation and transformation, in particular to a shale reservoir fracturing method based on methane multi-stage detonation. Background technique [0002] Unconventional natural gas resources such as shale gas have become an important part of the world's energy supply. The realization of industrialized exploitation of this part of resources will be of great significance for alleviating the tense situation of energy supply and ensuring national energy security. Hydraulic fracturing technology is an important measure to efficiently develop unconventional natural gas, and it is also a necessary means to maintain its economical exploitation. However, with the continuous decline in the quality of newly proven reservoirs and the increasing attention to environmental issues involved in oil and gas production, hydraulic fracturing technology is gradu...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a shale reservoir fracturing method based on methane multi-stage detonation, so as to solve the problems existing in the prior art such as insufficient degree of reservoir fracture and unsatisfactory stimulation effect.

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