Method for relieving pressure and eliminating outburst of ground butting well

Abstract

The invention relates to the field of coal-bed gas and safety production of coal mine, particularly to a method for relieving pressure and eliminating outburst of a ground butting well for downward putting a continuous oil pipe through the ground butting well for hydraulically spraying coal bodies so as to relieve original pressure of a coal bed, enhance the air permeability of the coal bed, eliminate the outburst danger of downhole coals and gas, and increase the yield of the coal bed. The aim of the invention is to overcome defects in the prior art and provide a method for relieving pressure and eliminating outburst of the ground butting well, which is capable of enhancing the air permeability of the coal bed, eliminating the gas pressure of the coal bed, controlling the outburst danger of the coals and the gas, and increasing the yield of the coal bed by aiming at the conventional condition of difficulty in increasing the air permeability, relieving the pressure and eliminating the outburst in the coal bed of a development region of construction coals. According to the invention, continuous oil pipe operation and hydraulic spray operation can be carried out from a ground horizontal well; coal powder and water can be eliminated from a vertical well; intraformational pressure relief is carried out on downhole coal bodies from ground control operation; the coal bodies are liberated; and the purposes of relieving the pressure and eliminating the outburst are finally achieved; in the executing process of the operation, the coal bodies are subject to large-area pressure relief and outburst elimination directly from a ground drilling well; operators are prevented from facing outburst coal bodies in a close distance downhole; the personal safety of workers is ensured; and the method provided by the invention is an intrinsic safety type method.

Description

technical field [0001] The present invention relates to the fields of coalbed methane and coal mine safety production, in particular to a coiled tubing that is connected to the ground and drilled into the well to perform hydraulic jetting on the coal body, thereby removing the original pressure of the coal seam, improving the gas permeability of the coal seam, and eliminating the danger of underground coal and gas outbursts , a method for pressure relief and outburst elimination of ground-connected wells to increase coalbed methane production. Background technique [0002] Structural coal is relatively developed in most mining areas in my country. The coal seams in these areas are characterized by soft coal quality, poor coal seam permeability and high gas emissions. Gas control and coalbed methane development in areas where structural coal is developed are recognized as global problems. At present, there are two main means of gas control: one is to reduce the reservoir pres...

AI Technical Summary

Problems solved by technology

At present, there are two main means of gas control: one is to reduce the reservoir pressure, resulting in gas desorption, seepage and output under the action of pressure difference, such as: surface drilling drainage and pressure reduction gas recovery technology and downhole drilling negative pressure drainage gas However, the traditional vertical wells and horizontal wells for extracting gas from the ground cannot effectively relieve pressure and increase permeability in areas with soft coal, low permeability and high gas; the other is to create stress by disturbing the original confined coal seam. Release the space, increase the pores (cracks) in the coal on a large scale, reduce the pressure of the adsorbed gas and quickly desorb it, and expand the gas seepage and output channels, such as: protective layer mining technology and hydraulic loosening and other internal pressure relief and anti-outburst measures

Protective seam mining technology is one of the most effective regional outburst prevention technologies, but it is limited by geological conditions and is generally used in mines where coal seam groups are mined. It is not suitable for single coal seams and coal seams with large interlayer spacing; hydraulic loosening is a The anti-outburst measures of intralayer pressure relief and permeability enhancement have played a certain effect in low-permeability coal bodies, but in the implementation process, there are often problems such as frequent gas overruns and easy artificially induced outbursts, so regional pressure relief cannot be carried out

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