1. School of Energy Science and Engineering,Henan Polytechnic University,Jiaozuo　 454000,China; 2. Collaborative Innovation Center of Coalbed Methane (Shale Gas) in Central Plains Economic Zone,Jiaozuo　 454000,China; 3. Exploration and Development Research Institute,Huabei Oilfield Company,Pet-roChina,Renqiu　 062552,China; 4. Exploration and Development Research Institute,Huabei Oilfield Company,PetroChina,Changzhi　 046000,China

为了发现地质构造对煤层气井产气效果的影响规律,以沁水盆地长治区块为研究对象,引入煤层厚度分异系数表征构造复杂程度,应用层次分析法对区块构造复杂程度系数进行了评价,依此进行了构造单元划分,结合各构造单元煤层气赋存的地质条件、储层物性和含气性等因素对煤层气井产能影响的模糊数学分析结果,建立了地质构造对煤层气井产能的AHP-模糊数学评价方法。研究表明按照地质构造复杂程度可将长治区块划分为构造简单区、构造较简单区和构造中等发育区3类,根据煤层气井产能的AHP-模糊数学计算结果,分值由高到低依次为:构造较简单区、构造简单区、构造中等发育区。即对于长治区块而言,构造较简单区内煤层气井的产能最大,其次为构造简单区,而构造中等发育区内煤层气井的产能最小。区内不同构造单元的煤层气井产气、产水效果,以及排采曲线特征表明,本次评价结果与实际相吻合,在一定程度上反映了构建的地质构造对煤层气井产能的AHP-模糊数学评价方法的合理性,可为区块煤层气井位优选和产能提高提供借鉴。

In order to understand the influence laws of geologic structure on the gas production of coalbed methane (CBM) well,the paper made the Changzhi Block,Qinshui basin,as an example,and introduced the variation coeffi- cient of coal thickness to express the complexity degree of geologic structure. Then the complexity degree of geologic structure was evaluated and structure network units were divided by means of analytic hierarchy process (AHP). Fur- thermore,based on the results of fuzzy mathematics analysis on the factors affecting CBM productivity,including the geological condition,reservoir physical property and gas content,the relative evaluation method of AHP-fuzzy mathe- matics about the influence degrees of geologic structure on the production effect of CBM wells were established. The re- search showed that Changzhi block could be classified as simple structure area,relative simple structure area and secondary development structure area by the complexity degree of geologic structure. The evaluation scores of productivity of CBM wells from high to low are relative simple area,simple area,secondary development area in order. In other words,there is the greatest productivity of CBM wells in the relative simple area,the second in the simple,and the least in secondary development area. Meanwhile the effect of gas and water production and production curves features show that this evaluation results are in agreement with actual situation. It reflects that the evaluation method of AHP- fuzzy mathematics which is established about the influence of geological structure to CBM productivity is reasonable. Finally the evaluation results could provide references for choosing wells and improving productivity.

国家自然科学基金资助项目(41372162)；河南省高校科技创新团队支持计划资助项目(14IRTSTHN002)；

ZHANG Xiaodong,ZHANG Shuo,SUN Qingyu,et al. Evaluating the influence of geological structure to CBM productivity based on AHP and fuzzy mathematics[J]. Journal of China Coal Society,2017,42(9):2385-2392.