Prediction of gas pressure in thin coal seams in the Qinglong Coal Mine in Guizhou Province, China

Abstract

AbstractThin coal seams in mines usually lack gas data. Thus, preventing and controlling gas outbursts of thin coal seams are difficult. In this study, a coal structure index, which is used to express the damage degree of coal, was estimated by logging curve. In accordance with the contour line of the floor of the coal seam, structural curvature was calculated to express the complexity of the coal seam structure quantitatively. Subsequently, relationships among the burial depth, thickness, coal structure index, structural curvature were analyzed on the basis of the gas pressure of coal seam. The gas pressure values of the coal seams of Nos. 22, 24, and 27 in the study area were predicted by multiple linear regression (MLR) and were then verified and analyzed. The deviation rate of the MLR method was 6.5%–19.7%, with an average of 13.0%. The average deviation rate between the predicted value and the measured value was 11.6%, except for the measuring point of No. 2, which had a large deviation. Results show that the prediction accuracy of the aforementioned method is acceptable and has practical value in the prediction of gas pressure in thin coal seams without measured data. The results in the gas pressure prediction provide a basis for evaluating the risk of gas outbursts in thin coal seams.