Evaluation of Residual Resources of Coalbed Methane Exploitation Based on Principal Component Analysis and Entropy Method

This paper evaluated the remaining resources of CBM wells in the west 2nd block of Jincheng Sihe Coal Mine. Taking 14 wells as the research objects, six evaluation indexes including original gas content, coal thickness, buried depth, extraction time, cumulative water production and cumulative gas production were selected. Two principal components (coalbed methane resource factor, coalbed methane engineering drainage factor) were extracted from six evaluation indexes by principal component analysis and their scores were obtained. Then, the comprehensive scores of 14 wells are obtained by entropy method and principal component analysis method, and the reliability of the two methods is verified. The study shows that the cumulative production and original gas content of a single well are positively and negatively correlated with the comprehensive scoring value respectively. In other words, the higher the comprehensive score value is, the smaller the remaining coalbed methane resources within the single well influence range. It indicates that the prediction conclusion has a good fit with the original data. It proves that the principal component analysis method and the entropy weight combination method are reliability and applicability in the evaluation of remaining resources of coalbed methane mining.