川南地区乐平组煤层含气量定量评价方法

Quantitative Evaluation Method of Coal Gas Content in Leping Formation in Southern Sichuan

川南地区乐平组煤层非均质性强,测井响应特征复杂,给煤层含气量评价带来很大挑战。为了定量评价煤层含气量,基于现有煤层含气量预测方法,结合川南地区筠连区块煤心实验室分析资料,通过线性回归优选影响含气量的测井敏感参数,对相关性小的参数构建复合参数,提高相关系数。分别建立基于兰氏方程和多元回归方法的含气量预测模型。预测结果与实验室测量值对比表明,2种模型在该研究区均适用,但吸附模型预测含气量更准确。

The Leping coalbed formation in southern Sichuan have strong heterogeneity, which results in complex logging response characteristics and brings great challenges to the evaluation of coalbed gas content. To quantitatively evaluate the gas content of coalbed, combining the existing gas content prediction method of coalbed with the analysis data of Qilian block in southern Sichuan by the coal core laboratory, the logging sensitive parameters affecting gas content interpretation are selected by linear regression. The parameters with small correlation are constructed into compound parameters to increase the correlation coefficient. The gas content prediction models based on the Lan’s equation and the multiple regression method are established respectively. By comparing the predicted results and the laboratory measurements, it is showed that both models are applicable in the study area, and the adsorption model shows higher accuracy.