Comparative Study On The Coal Seam Gas Content Assay Method

The coal is the body of our energy.One-time energy consumption structure in China, coal accounts for about70%. According to the authoritative department forecast, it will still accounted for more than50%in2050, coal will have been the dominant energy source in our country with a long time.95%of the coal mineare underground mining in our country, the restriction of the objective factors suchas geological occurrence conditions of coal seam, Coal mine gas disasters is serious, gas accident is the biggest threat to coal mine safety production. Coal seam gas content is one of the main parameters of coal seam gas, is the mine gas emission prediction and important basic parameters of the coal and gas outburst prediction. So the coal seam gas content determination is the foundation of the management of coal mine gas accident. This article in xinji mining area is first and second coal mine as the research object, on the basis downhole measured gas content during the production, based on the determination results of gas content measurement method comparative analysis, find out several other gas content determination method of error correction coefficient. Research results show that:less than500m,500～600m,600～700m depth of the three segments,the correction coefficient of coalbed gas content in geological exploration period is1.225,1.240,1.315,and spceulate the correction coefficient of700-800m,800～900m,900～1000m,1000～1100m,1100～1200mdepth of the three segments is1.350,1.395,1.440,1.485,1.530. The correction coefficient of the indirect method of coalbed gas content measuremen is1.188; the correction coefficient of gas emission inverse computation gas content is1.519. Through the analysis of geological exploration period and indirect method for determining the error factors of gas content, gas content measurement in the process of geological exploration period was mainly affected by the following factors:the choice of determination location,the air tightness of experimental apparatus,the insertion time of needle,reading the time interval,the prediction error of loss the main factoraffected the indirect method to calculate the error of the gas content is the influence factors of coal seam gas pressure determination and The influential factors of coal isothermal adsorption experiment. In the gas content of actual measurement, pay attention to the above factors, reduce errors as much as possible, make the determination results are more accurate.