Downhole Determination Method of Coal Firmness Coefficient

Abstract

The invention discloses a downhole rapid measuring method of a coal firmness coefficient. The method includes the following steps of S1, collecting coal samples of a to-be-measured coal seam, screening out the coal samples with granularity of 1-3 mm, and smashing the screened-out coal samples according to optimal smashing parameters; S2, measuring the mass m of smashed coal dust with granularity of 0.5 mm or below to obtain the mass ratio x of the coal dust with granularity of 0.5 mm or below; S3, conducting smashing on the basis of the optimal smashing parameters to obtain the mass ratio xi of coal dust with granularity of 0.5 mm or below of different coal samples, and measuring the firmness coefficient fi through a comparison hammer dropping method to conduct index fitting to obtain regression coefficients a and b, and determining a calculation model; S4, introducing the mass ratio x of the coal dust with granularity of 0.5 mm or below and the regression coefficients a and b into thecalculation model to calculate the coal firmness coefficient. The method is low in measuring workload and rapid, simple, accurate and reliable in measuring process, and downhole rapid measuring is realized.

Description

technical field [0001] The invention relates to an underground measuring method of the firmness coefficient of coal. Background technique [0002] The solidity coefficient of coal is an important and must-measured mine basic parameter for gas control and risk identification of outburst coal seams. At present, the solidity coefficient of coal is mainly measured by the "drop hammer method", which requires on-site staff to take samples at the working face After that, the coal samples are transported to the gas parameter basic laboratory with relevant qualifications on the ground for measurement. The measurement time is long, the measurement results are greatly affected by human factors, and the measurement process is cumbersome, which will consume the energy and physical strength of the experimenters. It may lead to the diversity of the measurement results of the f value of the same coal sample, and it cannot meet the needs of rapid measurement and modern mines. With the contin...

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Problems solved by technology

[0002] The solidity coefficient of coal is an important and must-measured mine basic parameter for gas control and risk identification of outburst coal seams. At present, the solidity coefficient of coal is mainly measured by the "drop hammer method", which requires on-site staff to take samples at the working face After that, the coal samples are transported to the gas parameter basic laboratory with relevant qualifications on the ground for measurement. The measurement time is long, the measurement results are greatly affected by human factors, and the measurement process is cumbersome, which will consume the energy and physical strength of the experimenters. It may lead to the diversity of the measurement results of the f value of the same coal sample, and it cannot meet the needs of rapid measurement and modern mines. With the continuous improvement of mine mechanization, the mechanized rapid measurement of f value is the need for the construction of digital mines.

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