Method for quickly measuring coal seam gas content based on diffusivity curve subtraction

Abstract

The invention discloses a method for rapidly measuring coal seam gas content based on diffusivity curve subtraction, relates to the technical field of coal seam gas basic parameter measurement, and can accurately, conveniently and rapidly measure coal seam original gas content. The method mainly comprises the following steps: a, field sampling; b, laboratory coal sample industrial analysis; c, a laboratory coal sample gas diffusion experiment; d, fitting of a coal sample gas diffusivity curve by the new model of the dynamic diffusion coefficient of the spherical coal particles; e, field desorption test; f, calculating of the original gas content of the coal sample. The method is different from the conventional method, avoids the gas content measurement error caused by the calculation errorof a desorption model, does not need to calculate the gas residual amount, and does not need to consider the gas loss amount. The determination process is simple and feasible, the determination timeis short, and the method is suitable for determining the original gas content of coal seams with various metamorphic degrees under various complex geological conditions.

Description

technical field [0001] The invention belongs to the technical field of coal mine gas disaster control and coal seam gas basic parameter measurement, and in particular relates to a method for quickly measuring the original gas content of coal seams based on a diffusivity curve subtraction method. Background technique [0002] Coal seam gas content is one of the basic parameters for mine gas control and development and utilization. The accuracy of its value is of great significance for the calculation of coal seam gas reserves, gas emission prediction, gas geological evaluation, comprehensive control and comprehensive utilization of coal mine gas. In 2009, the coal seam gas content, as the main indicator for regional outburst risk prediction and regional outburst prevention measures, was written into the "Regulations on the Prevention and Control of Coal and Gas Outburst", which highlighted the importance of coal seam gas content measurement in the coal mine production process....

AI Technical Summary

Problems solved by technology

Among them, the indirect method is relatively complicated. This method has disadvantages such as complex measurement process of coal seam original gas pressure, long measurement period, low success rate, and high cost, and cannot adapt to the measurement of coal seam gas content under complex geological conditions in my country; Hole sampling, the gas content of the coal seam is divided into three parts: the amount of gas loss during the sampling process, the amount of on-site desorption, and the residual amount

This method is limited by the fact that the amount of gas loss needs to be obtained through the regression of downhole desorption data, and professional equipment is required to measure the residual gas amount, and the direct downhole measurement method generally takes a long time to obtain the measurement results

All in all, these two methods have certain limitations to some extent, and are poorly adaptable to various coal seams with different characteristics.

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