Combined exploitation gas mixed source proportion quantitative determination method of coal seam group

Abstract

The invention discloses a combined exploitation gas mixed source proportion quantitative determination method of a coal seam group. The combined exploitation gas mixed source proportion quantitative determination method comprises the steps of dividing master control gas constituents of representing different target coal layers by measuring conventional gas constituent content, an isotope value thereof, rare gas constituent content and an isotope value thereof in a gas of each target coal layer control point in a control region and by an isotope geochemistry method; performing fitting to obtain master control gas constituent content and an isotopic contour map; obtaining main control gas constituent content and an isotope value thereof of each target coal layer of a combined exploitation driving hole by an interpolation method; and building a calculation model according to a chemical composition mass conservation principle, and quantitatively determining a mixing ratio of each target coal layer in the mixed source gas. By the method, the mixed source proportion of different target coal layers in the combined exploitation gas can be accurately calculated, the problem that the mixed source gas under a coal mine cannot be quantitatively determined is solved, a theoretical basis is provided for standard-reaching evaluation of coal layer gas exploitation, and the mine production safety is effectively guaranteed.

Description

technical field [0001] The invention belongs to the technical field of coal mine gas extraction and utilization, and in particular relates to a method for quantitatively determining the ratio of mixed sources of gas in coal seam group joint extraction. Background technique [0002] Pre-drainage of coal seam gas by drilling is the most commonly used technical measure in the prevention and control of underground gas disasters in coal mines and the development of coal bed methane. If the pre-extraction fails to meet the standard, carrying out mining activities will lead to serious consequences. Most of the coal mines in my country belong to coal seam group mining. Before coal mining in Shimen or coal roadway excavation, most mines arrange through-bed drilling holes in the roof and floor rock roadways to jointly extract gas from multiple coal seams. This method can improve the utilization of drilling holes. efficiency, reduce the cost of gas control, and economically and efficie...

AI Technical Summary

Problems solved by technology

However, the joint extraction of coal seam groups is the mixed gas of multiple coal seams. Relying on the existing measurement methods and devices for gas drainage of a single coal seam, it is impossible to separately measure the actual gas extraction volume of each coal seam in the coal seam group, which is also difficult. By calculating the residual gas content, desorbable gas content and gas drainage rate of each coal seam to determine whether the gas drainage of each coal seam is up to standard, laying a safety hazard for later coal mining activities

[0003] In the past, the volume of gas from each target coal seam in the joint drainage of coal seam groups was mainly based on the ratio of the actual length through each target coal seam during the drilling construction process to the cumulative coal penetration length of the drill hole, combined with the coal seam group combined The comprehensive calculation of the mixed volume of drainage is convenient for on-site application. However, this method regards each target coal seam as the coal body of the same nature for simple calculation, and does not consider the differences in coal body occurrence and gas parameters of each target coal seam. characteristics, resulting in a large discrepancy between the calculated mixed source ratio and the actual situation, which cannot effectively guide the evaluation of gas drainage standards for each target coal seam

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