Coal mining area gas extraction method

Abstract

The invention discloses a coal mining area gas extraction method, and belongs to the technical field of underground gas control of coal mining. The method can solve the problems that existing ground straight-hole drilling extraction is large in the number of constructed wells, is limited by complex ground topography conditions, and is large in the number of extraction equipment arranged on the ground. The method comprise the following steps that the position and hole number of ground mining wells are determined according to the position and length of a coal mining working face return airway; primary spud-in is adopted for drilling to 10 meters below bedrock, a surface casing is lowered for well cementation, and cement is raised to the ground; secondary spud-in is performed for drilling toa certain position on the upper part of the working surface of a main coal mining layer, an intermediate casing is lowered, secondary spud-in well cementation is completed, cement is raised to the ground, and waiting on cement setting for well cementation is performed; and holes are formed in the positions, parallel to the two sides of the return airway, of a final hole correspondingly, a drillingtool combination is formed by a single drill rod and a flexible nipple for drilling, and the drilling direction is parallel to the direction of the return airway. Underground goaf and mining area upper corner gas can be effectively reduced, coal mine safety production can be ensured, the coal mine production joining capacity is improved, and the coal mine productivity is released.

Description

technical field [0001] The invention belongs to the technical field of underground gas control in coal mines, and in particular relates to a coal and coalbed methane co-extraction technology, and ground construction drilling solves the goaf and mining area gas drainage process technology system formed by the back mining of underground working faces. Background technique [0002] my country is rich in coal resources. As the primary energy source, coal is long-term stable and will not change. However, my country's coal mining has long been constrained by the outburst of gas, which has caused mine production capacity, production connection, and underground safety issues to plague coal mine production. [0003] The gas in the goaf and mining area formed during the recovery process of the original surface drilling vertical well drainage working face is a low-cost construction technology, but due to the large number of construction wells, it is limited by the complex ground topogra...

AI Technical Summary

Problems solved by technology

[0004] The present invention provides a gas drainage method in coal mine mining area, aiming at the problems that the existing ground drilling vertical wells have a large number of construction wells, are restricted by complex ground terrain conditions, and are equipped with many drainage equipment on the ground.

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