Reuse method of abandoned coalbed methane wells in goaf

Abstract

The invention belongs to the technical field of ground extraction of coalbed methane, and particularly relates to a reuse method of abandoned coalbed methane wells in a goaf. The technical problem ofreuse of abandoned coalbed methane wells in the goaf is solved. The reuse method of the abandoned coalbed methane wells in the goaf comprises the steps that the part of a production casing of a coalbed methane well located in a heading face or a recovery face is cut, a peeping instrument is used for checking the deformation of the production casing in a first opening of an abandoned well in the goaf and a second opening of the abandoned well in the goaf, then the casing is milled to be shaped, a drill bit is conventionally drilled to 50m below a floor of a underlie coal seam, then drilling competition is performed, so that a third opening for new gas production is formed, then the production casing is lowered and fixed into the second opening of the abandoned well in the goaf by a hanger,and perforation, fracturing, pump lowering and drainage and extraction are performed. By adopting the technical scheme, it is possible to use a ground abandoned well in a coal mine goaf to efficientlyextract the underlie coalbed methane of the goaf, the safe and efficient mining of the coal mine is ensured, and meanwhile, cost reduction and efficiency increase during the development of coalbed methane are realized.

Description

technical field [0001] The invention belongs to the technical field of surface drainage of coal bed methane, and in particular relates to a method for reusing abandoned coal bed methane wells in goafs. Background technique [0002] In high-gas mines, coal mining safety hazards are extremely serious. Therefore, it is required to carry out gas drainage first to reduce its concentration to a safe level before mining. One of the main means of gas drainage is to set up coalbed methane pre-extraction wells on the ground. The coalbed methane wells go deep into the coal seam and directly drain the gas from the ground. This drainage method is highly efficient, and can also collect the collected methane gas for use as high-quality fuel. The traditional multi-layer coal mining method is a downward mining procedure of "thick first, then thin, top-down", and due to the formation of gobs during the coal mining process. The geological structure above the goaf has changed, causing a cons...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the technical problem of reusing abandoned coalbed methane wells in goafs, the present invention provides a method for reusing abandoned coalbed methane wells in goafs

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