Pre-judgment method for coal seam group gas combined drainage up to standard

Abstract

The invention provides a standard-reaching pre-judgment method for coal seam group gas combined extraction. According to the method, at the period of coal seam group gas combined extraction, based on the factors of changes of coal seam permeability and gas extraction parameter influences, extraction standard reaching of all coal seams can be pre-judged. According to the requirements in <temporary provisions for mine gas extraction standard reaching>, coal seam gas original relevant parameters are determined, gas extraction evaluation units are divided, a coal seam group gas combined extraction pre-judgment mathematics model is established, and standard-reaching pre-judgment software for coal seam group gas combined extraction is developed. Through numerical value calculation of the software, theoretical extraction amounts of all the coal seams, the residual gas content of all the coal seams and the content of gas, capable of being desorbed, of all the coal seams are obtained, and gas extraction standard-reaching conditions of all the coal seams are pre-judged. It is avoided that in combined extraction, the gas extraction amounts of all the coal seams can not be separately calculated; the combined extraction units are pre-judged, checking drilled holes are constructed on the units reaching the standard in extraction pre-judgment, and blindness of constructing the checking drilled holes is avoided.

Description

technical field [0001] The invention relates to underground gas drainage engineering technology in coal mines, in particular to a standard pre-evaluation method for combined gas drainage of coal seam groups. Background technique [0002] There are many kinds of coal resources in my country, and the coal seam group resources in the short distance are abundant. The combination of drilling through the seam and coal seam group gas extraction is an economical and efficient gas control technology. According to the relevant requirements such as the Interim Provisions on Drainage of Coal Mine Gas Drainage Meets Standards, it is necessary to judge whether the coal seams after drainage meet the standards. The drainage compliance pre-evaluation methods involved in the relevant standards of drainage compliance all need to measure the gas extraction volume of each coal seam separately, but there is currently a lack of layered metering devices in boreholes for combined gas drainage of coa...

AI Technical Summary

Problems solved by technology

The traditional coalbed methane drainage model is established under the condition that the permeability is constant during the extraction process, but according to the actual production on site, the permeability of the coal seam is constantly changing during the extraction process, and the existing model cannot meet the production requirements. actual

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