Shale gas reservoir multi-branch well detonation pressure reinforced extraction method

Abstract

The invention discloses a shale gas reservoir multi-branch well detonation pressure reinforced extraction method. The shale gas reservoir multi-branch well detonation pressure reinforced extraction method comprises the following steps that firstly, a vertical well and a horizontal well are dug to extend into a shale reservoir, and a plurality of fishbone-shaped branch wells are laterally drilled at different positions of the horizontal well through a jet drill bit; then blasting materials are placed in the fishbone-shaped branch wells, and blasting hole packers are installed to form hole sealing sections; the explosive is ignited and detonated through an ignition head, and impact fracturing is carried out on shale around the fishbone-shaped branch wells by high-temperature and high-pressure gas and detonation impact waves generated by explosion, so that explosive cracks are generated around the fishbone-shaped branch wells; finally, hydraulic fracturing is adopted to enable fracturing fluid to enter the branch wells, crack expansion fracturing is carried out on the fire blast cracks around the branch wells to enable the adjacent fire blast cracks to communicate with one another, and finally a crack network is formed around each branch well; and after completion, the shale gas in the shale reservoir enters each branch well from the fracture network and reaches the horizontal well after being desorbed, and finally the shale gas extraction work is carried out on the shale reservoir through the vertical well and the horizontal well.

Description

Technical field [0001] The present invention relates to a multilateral well shale gas detonation pressure strengthening drainage method belongs to the field shale gas. Background technique [0002] Shale gas adsorption refers to the free state or dissolved excipient presence of a organic-rich shale interlayers and unconventional reservoirs, having a long exploitation period, cleaning, and high efficiency, it has become an industrial development process one of the best alternative to coal. China shale gas resource-rich, efficient development of shale gas resources, can add to our future natural gas demand gap. However, including shale gas, including unconventional reservoirs generally have low porosity and low permeability characteristics of the physical properties usually required for the implementation of the shale reservoir fracture network after fracturing can be put into production. [0003] Horizontal well fracturing segment multi-cluster is the main technical means to achie...

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Problems solved by technology

[0003] Staged multi-cluster fracturing of horizontal wells is the main technical means to achieve fracture network fracturing in shale reservoirs at the present stage. The United States has effectively stimulated shale reservoirs by using technologies such as horizontal well staged fracturing and simultaneous fracturing. Rock gas development has developed rapidly; however, my country's shale gas reservoirs are significantly different from those in the United States in terms of geological characteristics, reservoir depth, and fracturing technical conditions. The successful experience of shale gas exploitation in the United States cannot be directly applied to my country.

[0004] In recent years, some industry scholars have proposed to use the methane desorbed from the reservoir for in-situ methane detonation to improve the gas permeability of shale reservoirs and realize the commercial exploitation of shale gas. The impact force will make the wellbore vulnerable to damage, leading to problems such as wellbore collapse and wellbore scrapping, resulting in economic losses

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