Method for determining best hole distributing mode for permeability increasing of carbon dioxide phase change cracking coal seam

Abstract

The invention discloses a method for determining the best hole distributing mode for permeability increasing of a carbon dioxide phase change cracking coal seam. The method comprises the following steps that a plurality of hole drilling distributing schemes of cracking holes and extraction holes are determined; the extraction holes are drilled, and networking is conducted; the cracking holes are drilled, and networking is conducted; reserved extraction holes are drilled, and networking is conducted; the multiple schemes are subjected to networking and are judged; and data are processed, and the best scheme is determined. The data of the pure gas total amount, the content of carbon dioxide in the extraction holes before and after cracking, the porosity of a coal sample before and after cracking, the specific surface area and a microstructure are processed to obtain the results of the permeability increasing effect, and the permeability increasing effects of all the schemes are compared to determine the best scheme. The method has the beneficial effects that through the distributing schemes of a plurality of hole distances, the data of the multiple schemes after cracking are collected, the flow, pressure and concentration of gas are monitored, the data of the content of the carbon dioxide, the porosity of the coal sample before and after cracking, the specific surface area and changing of the microstructure are compared and analyzed, and thus the best drilling hole distributing mode of the permeability increasing effect is obtained.

Description

technical field [0001] The invention relates to the technical field of mine gas drainage, in particular to a method for determining the optimal hole layout method for increasing permeability of carbon dioxide phase change fracturing coal seams. Background technique [0002] In recent years, most coal mines in my country have entered the stage of deep mining. The coal seam has complex occurrence conditions, high stress and high gas pressure, which reduces the gas permeability of the coal seam. With the continuous improvement of coal mine mechanization, a single gas drainage method can no longer effectively solve the hidden dangers of coal mine gas. At the same time, as a clean energy, gas can effectively improve and optimize my country's energy structure, reduce coal production costs, and reduce air pollution. Gas drainage technology is one of the main technologies to prevent and control gas disasters in coal mines. However, due to the common problems of complex occurrence ...

AI Technical Summary

Problems solved by technology

Therefore, the optimal hole layout methods corresponding to different coal seams are not the same. In order to quickly and accurately determine the optimal hole layout method, the present invention provides a method for determining the optimal hole layout method for phase change fracturing of liquid carbon dioxide to overcome Disadvantages that single hole measurement radius is easily disturbed by other factors

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