Method for extracting gas and preventing and extinguishing fire by using composite drill hole

Abstract

The invention discloses a method for extracting gas and preventing and extinguishing fire by using a composite drill hole, and belongs to a coal mine disaster prevention and control method. A drill site is arranged in a roof or floor rock roadway of a high-gas easy spontaneous combustion coal seam, a composite drill hole is constructed in the coal seam, and then coal mine disaster prevention and control are conducted according to the following stages that firstly, before the coal seam is mined, the gas in the coal seam is pre-pumped by using the composite drill hole, and the coal and gas outburst danger of the coal seam is eliminated; secondly, the coal seam is mined, and the goaf gas of a mined bed is extracted in a negative pressure mode by using the original composite drill hole; and finally, in a coal seam mining process, nitrogen or high-pressure cement paste is injected into a goaf of the mined bed by using the original composite drill hole again, and spontaneous combustion of residual coal in the goaf are prevented. According to the method, the purposes of gas extraction and fire prevention and extinguishing can be achieved by comprehensively utilizing the composite drill hole before and after the high-gas spontaneous combustion coal seam is mined, the working efficiency is high, the gas extraction rate is high, the fire prevention and extinguishing effect is good, and the engineering cost is saved.

Description

technical field [0001] The invention relates to a method for preventing and controlling coal mine disasters, in particular to a method for gas extraction and fire prevention and extinguishing by using composite boreholes. Background technique [0002] In the mining process of high-gas spontaneous combustion coal seam, due to its high gas content, the gas stored in the coal seam is affected by the mining pressure relief and gushes out in large quantities, and coal and gas outbursts and other dynamic disasters are prone to occur. Therefore, in coal seam mining Previously, measures were needed to eliminate the risk of coal and gas outburst in coal seams. After the coal seam is mined, due to the large degree of loose coal and rock in the goaf, a large amount of gas in the coal wall and working face will flow into the goaf, which will easily cause the gas in the goaf to exceed the limit; in addition, due to the influx of air, when the goaf After the oxygen concentration in the g...

AI Technical Summary

Problems solved by technology

However, the current gas drainage and fire prevention technology implemented in high gas and spontaneous combustion coal seams cannot make full use of the drainage boreholes, and when the pipeline is buried in the goaf, the pre-buried pipeline is easily damaged by the collapsed rock At the same time, when injecting nitrogen or high-pressure cement slurry into the goaf, it will affect the normal advancement of the working face. In addition, ordinary fire prevention measures cannot accurately locate the spontaneous combustion and ignition parts of the remaining coal, resulting in low fire prevention efficiency and high cost.

Images