Layout method of coal seam gas extraction engineering

Abstract

The invention provides a layout method of coal seam gas extraction engineering, which comprises layout steps of ground surface extraction engineering, layout steps of downhole coal seam roof extraction engineering and downhole coal seam floor extraction engineering, wherein the layout steps of the ground surface extraction engineering include observation and analysis of ground surface movement parameters, calculation of a ground surface movement scope of a coal excavation working face, and layout of the ground extraction engineering of coal seam gas in an area with small ground movement deflection according to calculation results; at the layout steps of the downhole coal seam roof extraction engineering, development heights of a caving zone and a fractured zone are determined according to overburden failure rules, and the downhole coal seam roof extraction engineering of the coal seam gas is laid in the middle lower part of the fractured zone above the caving zone; and at the layout steps of the downhole coal seam floor extraction engineering, a development depth of a floor failure zone is determined according to floor mining facture rules, and the downhole coal seam floor extraction engineering is laid in a complete rock layer zone in the lower part. The layout method of the coal seam gas extraction engineering is advantageous in that extraction effects can be improved, and the ground surface and downhole extraction engineering can be maintained more easily, so that maintenance cost is reduced.

Description

Technical field [0001] The invention relates to the technical field of coal mining, in particular to a method for laying out a coalbed methane drainage project. Background technique [0002] In coal mining, the extraction of coalbed methane is based on the stress changes after coal seam mining. The stress changes after coal seam mining, rock displacement, fracture deformation, fracture enhancement, and other mining characteristics, or the enhancement of artificial permeability technology. , Extracting coalbed methane (coalbed methane) in coal seams and their surrounding rocks. [0003] At present, the layout of coal-bed methane surface drilling in coal mining areas refers to the principle of surface oil and gas acquisition well pattern layout in the petroleum system. Generally, surface extraction wells are arranged at a well spacing of 200-400m, which is not combined with the law of surface rock formation in coal mining, which is easy to cause drilling. Destruction and scrapping. ...

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Problems solved by technology

[0003] At present, the layout of coalbed methane surface drilling in coal mining areas refers to the layout principles of surface oil and gas collection wells in petroleum systems. Generally, surface drainage wells are arranged at a well spacing of 200-400m, which is not combined with the movement of surface rock strata in coal mining, which may easily cause drilling problems. destruction and scrapping

The construction location of coal mine underground drainage engineering is mainly constrained by qualitative methods or simple numerical intervals, which are unscientific and unreliable. For example, the layout of surface wells in mining areas is still based on the layout of ground drilling in non-mining areas After entering the mining area, these drilling wells are affected by the movement of the rock stratum, and accidents such as well wall damage and even scrapping occur; in some mining areas, the high-level drilling site on the roof is arranged at the position of 10-15m on the coal seam roof. This spatial layout does not fully avoid mining. Due to the influence of dynamic stress concentration, caving zone and large mining fracture zone, the drainage effect is not satisfactory, and the engineering maintenance technology is difficult and expensive

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