Combined pressure positive and negative pressure drainage technology for coal body in thick coal seam

Abstract

The invention provides a positive pressure and negative pressure combined gas drainage process by pressurizing a coal body of a thick coal seam. The process comprises the following steps of: 1) arranging and drilling holes: selecting drilling distances, array pitches, angles, hole diameters and hole lengths according to the occurrence situation and the drainage radius of a coal seam to be subjected to drainage; 2) carrying out drilling construction and sealing holes: determining angles and directions of a drilling machine to carry out the drilling construction to keep the stability of the drilling machine in a construction period; and sealing the holes after the drilling is finished; 3) injecting water into the coal body and pressurizing: pressurizing the water and injecting into the coal body to fill cracks in the coal body; and 4) carrying out gas drainage: carrying out the gas drainage after carrying out the drilling construction, sealing the holes and stabilizing, and injecting the water into the coal body and pressurizing. With the adoption of the process disclosed by the invention, the gas drainage effect is greatly improved, and the pre-drainage time of gas is greatly shortened, so that the exploiting time of coal is correspondingly increased; and meanwhile, the drainage efficiency is high, the gas concentration in an air flow in a production period is low, an over-limit alarming phenomenon is avoided, and the production efficiency is improved.

Description

technical field [0001] The invention relates to gas drainage technology, in particular to a technology for gas drainage combined with pressurized positive and negative pressure in thick coal seams. Background technique [0002] Coal mine gas control is the key and key work of gas mines, especially mines with high gas or gas outburst. It not only affects the progress of the project and production efficiency, but more importantly, it is related to the safety of the mine; it is related to the lives of employees and the property of enterprises. . Coal workers have been committed to the research of gas prevention and control technology. In terms of management, they have formulated a twelve-character policy of "determining production by wind, monitoring and monitoring, and drainage to meet standards". The State Coal Mine Safety Administration and the State Coal Mine Safety Administration have successively issued a series of The documents, regulations and methods of gas control ar...

AI Technical Summary

Problems solved by technology

It is the ultimate goal of extraction to maximize the extraction of gas from the coal body before mining through various methods and forms, and to reduce the amount of air discharge during mining. However, there is still room for improvement in the existing extraction process.