川南筠连沐爱地区煤层含气量预测及控制因素分析

Coalbed Gas Content Prediction and Controlling Factors Analysis of Coalbed in Junlian Muai Area at South of Sichuan

利用已有钻孔煤层气资料通过相关关系拟合获得了研究区煤层底板标高与含气量间的预测模型.利用该模型及地震解释获得的煤层底板标高数据预测了研究区8号主采煤层含气量分布.经后期煤层气探井实测数据验证,其预测精度达到85%以上.预测结果分析表明,远离断层的井预测精度高,而靠近断层的井预测误差大,其误差值在-1.86~4.32 m^3/t之间.认为研究区煤层含气性总体受煤层底板标高（构造）控制,但复杂的小规模断层对煤层气具有聚集和散失双重作用,构造发育和展布规律应该是研究区煤层气靶区优选的首要考虑指标.

The model to predict the relation between coal seam floor elevation and gas content is established by fitting the existing data of coal seam gas. By using the model, the gas content distribution in main coal seam 8^# is predicted according to coal floor elevation data obtained through seismic interpretation. Through the latter data validation, the prediction accuracy is found to be above 85%. The result show that the greater the distance to fault the higher the prediction accuracy, in which the error is between - 1.86 m^3/t and 4.32 m^3/t. It is considered that the coal gas content is controlled by coal floor elevation, besides, the complex small-scale faults have two effects that may induce gathering or scattering of coal bed methane. So distribution of geologic structures should be considered as the priority for CBM target in the study area.