Hydraulic fracturing and methane in-situ blasting cooperative fracturing permeability-increasing method

Abstract

The invention relates to a hydraulic fracturing and methane in-situ blasting cooperative fracturing permeability-increasing method which is suitable for shale gas reservoir exploitation. The method comprises the steps that horizontal drilling construction is conducted on a to-be-constructed area, and then cracks are formed around the hole wall of a horizontal drill hole through energy-gathered perforation; the cracks around the horizontal drill hole continue to be expanded in a hydraulic fracturing mode, and methane extraction is conducted after fracturing fluid is discharged; after methane gas is reduced, in-situ blasting fracturing is conducted on methane participating in the horizontal drill hole; after blasting, the cracks in the horizontal drill hole continue to be expanded, so that the methane continues to seep, and then extraction continues to be conducted; and blasting fracturing and extraction operation are repeated, so that blasting cooperative fracturing permeability increasing is achieved, and the shale gas exploitation effect is greatly enhanced. The method is reasonable in design, high in construction operation feasibility and suitable for fracturing transformation of unconventional oil and gas reservoirs such as shale gas reservoirs, coal bed gas reservoirs and tight sandstone gas reservoirs.

Description

technical field [0001] The invention relates to a fracturing and anti-permeability method, and is especially suitable for a hydraulic fracturing and methane in-situ combustion and explosion synergistic fracturing and anti-permeability method used in the exploitation of shale gas reservoirs. Background technique [0002] Shale gas refers to a kind of unconventional natural gas that exists in organic-rich mud shale and its interlayers in an adsorbed, free or dissolved state, and is called the three major unconventional gas reservoirs together with coalbed methane reservoirs and tight sandstone gas reservoirs , whose main component is methane, mixed with ethane and propane, has the characteristics of long mining cycle, cleanness and high efficiency, and has become one of the best alternative energy sources for coal in the process of industrial development. my country is rich in shale gas resources, with recoverable resources reaching 36.1 trillion m 3 , the efficient developme...

AI Technical Summary

Problems solved by technology

High-energy gas fracturing mainly uses the high-pressure gas generated by the explosion of gunpowder (such as fast-curing liquid explosive) or rocket propellant (such as unsymmetrical dimethyl hydrazine) to fracture the rock mass, creating micro-cracks in the reservoir, which has the characteristics of low cost and low pollution , but there are also problems such as poor safety of pyrotechnics, small scale of crack expansion, etc.

Images