沁中南煤层气典型低效区块地质单元划分

Geological Units Divided in Typical Low Efficiency Blocks of Coalbed Methane in Central-South Qinshui Basin

造成煤层气井低产低效的原因有地质及工程两大类,对低效井区开展地质单元划分是低产工程原因分析的基础,对落实低效井具体低产原因具有重要意义。选取沁中南典型低效区柿庄南区块,通过评价该区块各主要地质参数对生产井产气量的影响,优选出7类评价指标,构建了产量评价指标体系。在此基础上通过建立构造判断矩阵,根据1 000次正互反矩阵计算结果将柿庄南低效区块划分为5类地质单元。实际生产数据表明,地质单元划分结果与该区块产能特征吻合,为该区块工程低产原因分析及单井低产原因落实奠定了基础。

The causes of low productivity and low efficiency of coalbed methane well include two major categories:geology and engineering,the division of geological units in low efficiency wells is the basis for the analysis of low yield projects,it is of great significance for the implementation of low productivity wells.By selecting the typical low efficiency area which in Shizhuang south block,the influence of the main geological parameters of the block on gas production in the production well was evaluated,7 kinds of evaluation indexes were optimized,and production evaluation index system was constructed.On this basis,the construction judgment matrix was constructed,according to the results of the 1 000 positive reciprocal matrix,the south low efficiency block is divided into five types.The result shows that the result of geological unit division is consistent with the productivity characteristics of the block,meanwhile,it laid a foundation for low yield analysis of the project and the implementation of low yield of single well.