Simultaneous implementation method of ground borehole drainage for pressure relief gas and overlying rock isolation grouting filling

Abstract

The invention provides a surface drilling pressure relief gas extraction and overlying strata isolated grouting filling synchronous implementing method, and is suitable for extraction and filling under a building. A plurality of grouting drilling holes are formed in the surface and above the middle of a working face before exploitation of the coal working face, a plurality of gas extraction drilling holes are formed in the surface and above a boundary, overlying strata grouting filling is implemented by the grouting drilling holes in the exploitation process of the coal working face, pressure relief gas of an upper adjacent coal seam can be extracted by the gas extraction drilling holes, a gas extraction channel is isolated from a grout flowing channel by barrier action of a top upper adjacent coal seam, and synchronization of grouting and extraction is realized until grouting filling and gas extraction of all the drilling holes in the whole coal working face are finished. Pressure relief gas extraction and overlying strata grouting filling can be implemented synchronously, problems of grout filling and gas flowing disturbance are solved, and subsidence can be controlled while the gas is extracted.

Description

technical field [0001] The invention relates to a simultaneous implementation method of ground borehole drainage for pressure relief gas and overlying rock isolation grouting and filling, especially suitable for ground borehole drainage for pressure relief gas and overlying rock isolation grouting for drainage and filling under buildings Fill synchronization implementation method. Background technique [0002] In coal mining, coal mining will lead to the movement of overlying strata and gas migration, and when they develop to a certain extent, mining disasters will be formed, such as surface subsidence (collapse) and gas gushing (outburst). Therefore, controlling the movement of rock formations and extracting pressure relief gas have become two major problems that mining technology workers need to solve. Controlling the movement of rock formations and extracting pressure relief gas itself are two opposite processes, that is, the former needs to prevent the bending and defor...

AI Technical Summary

Problems solved by technology

However, such means and methods are not yet available in the prior art, either the ground drilling can only be used to extract the pressure relief gas from the upper adjacent coal seam and the overlying rock isolation grouting filling is abandoned. For example, patent CN200510040410.X discloses a Ground drilling method for gas extraction in mined areas and goafs, patent CN2014100893001 discloses a method for gas extraction in mined areas with top plugging and seepage down; or it can only implement overlying rock isolation grouting and filling without drainage Pressure relief gas, such as patent ZL201210164929.9 discloses a coal mining method for mining overlying strata in isolation, grouting and filling

Obviously, these two types of existing technologies can only achieve a single engineering purpose, and cannot use ground drilling to simultaneously realize pressure relief gas drainage and overlying rock grouting filling in the mining process of coal mining face

The existing overlying rock grouting filling technology requires a closed layer-separated space to be formed at the end hole of the grouting drilling, and this space cannot communicate with the vertical cracks in the overlying rock formed during the mining of the coal mining face, otherwise it will cause Grouting filling fails, and if the pressure relief gas in the upper adjacent coal seam is to be extracted simultaneously using the surface gas drainage borehole, it is required to install a considerable length of flower pipe in the surface gas drainage borehole to communicate with the mining in the upper adjacent coal seam At the same time, the gas drainage boreholes are required to directly reach the coal seam, which will cause the filling slurry to enter the gas boreholes along the flower pipe and further into the working face, which will not only lead to the failure of grouting filling, but also prevent the unloading Pressure gas is extracted to the ground

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