延川南区块煤体结构对煤层气单井产量控制作用研究

Research on control action of coal structure on individual well production of CBM wells in South Yanchuan block

煤体结构是煤层气井单井产量高低的一个主要因素。以鄂尔多斯盆地延川南区块煤层气勘探开发实例为依托,从煤体结构入手,采用煤层气地质学、测井和岩体力学理论,根据煤体结构测井响应,将2号煤层划分为原生结构+碎裂结构(Ⅰ类+Ⅱ类)与碎粒结构+糜棱结构(Ⅲ类+Ⅳ类),并在此基础上分析了不同煤体结构在影响煤层气单井产量的几个重点环节中的控制作用。研究表明:原生结构煤、碎裂结构煤具有高渗透性、较高的抗伤害能力,有利于连续排采,对煤层气井产量影响较大。

Coal structure is one of the principal factors of determining the individual well production of CBM wells. Based on the ex- ample of CBM exploration and development in South ~anchuan block of Ordos basin, starting from the coal structures, with the help of coalbed methane geology, logging and rock mass mechanics theories, this paper classified coal structure into two categories： original texture＋cataclastic texture （type Ⅰ ＋ type Ⅱ ） and fragmented texture＋mylonitic texture （type Ⅲ ＋ type Ⅳ） in terms of vary- ing coal structure logging response, and on this basis analyzed the controlling actions of different coal structures on several key as- pects of affecting individual well production of CBM wells. The results showed that original texture coal and cataclastic coal are con- ductive to the continuity of drainage and greatly impact on the production of CBM wells due to the high permeability and high anti- damage capacity.