Novel fracturing chemical supporting coal bed gas mining method

Abstract

The invention provides a novel fracturing chemical supporting coal bed gas mining method and belongs to the field of underground mineral resource mining. The novel fracturing chemical supporting coal bed gas mining method is characterized in that a supersaturated Ca(OH)2 aqueous solution is used as a fracturing solution; clay powder with the size being 300-500 meshes is added into the fracturing solution; segmental fracturing is conducted in the coal bed thickness direction; high-pressure CO2 is injected into a fracturing channel; the CO2 and Ca(OH)2 are utilized for a chemical reaction to generate a calcareous concretion supporting agent with high compressive strength in a fracturing seam, and the problem that existing supporting agents can hardly enter the fracturing seam is solved; the characteristics that the supercritical CO2 replaces and displaces coal bed CH4 is utilized; mine soaking is conducted; mining is conducted after the CH4 in a coal bed is fully replaced and displaced; and through the measures, production efficiency of coal bed gas resources is greatly improved, and capturing and storage of greenhouse gas CO2 are also achieved. The novel fracturing chemical supporting coal bed gas mining method is suitable for mining and utilization of underground coal bed gas or shale gas of different depths and different thicknesses, in particular for coal beds or shale beds of large thicknesses.

Description

technical field [0001] The invention relates to a method for exploiting coal bed gas integrating fracturing and chemical support, in particular to a novel fracturing chemical support method suitable for production increase coal bed gas extraction and shale gas exploitation. Background technique [0002] Coal seam gas drainage is the most direct and effective method to solve the problem of coal mine gas. In view of the low permeability of the coal seam, the main method of coal seam gas extraction is: first fracturing, simultaneously supporting the fracture with proppant, and then using the beam pump to extract the coal seam gas to the ground for collection and utilization. In recent years, researchers have found that CO 2 (especially supercritical CO 2 ) on the coal seam CH 4 It has an obvious displacement effect and can greatly increase the output of coalbed methane. But there are also studies that show that the effect of fracturing can seriously affect the CO 2 The con...

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Problems solved by technology

[0003] The purpose of a novel chemical propping method for fracturing in the present invention is to overcome the disadvantages and deficiencies in the prior art that the proppant cannot enter the deep part of the coal body crack, and disclose a method that can make the proppant penetrate into the deep part of the coal body crack, increasing the Coal permeability, to achieve efficient mining of coal seam gas

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