焦作煤田煤层气赋存地质特征与有利区块分析

Coal Bed Methane Accumulation Geologic Characteristics and Exploitation Prospects of Jiaozuo Coal

根据煤田地质勘查和煤层气参数井资料,对焦作煤田煤层气赋存的地质条件和煤层气储层特征进行分析,认为煤田内主要储层为山西组二1煤,煤层的含气量与煤层厚度、煤层的上覆有效地层厚度、煤层割理的发育程度、顶、底板围岩的性质有关,受断裂构造的控制将煤田分成了南、中、北三个构造断块、其中南部和中部断块气含量高,应用层次分析法经计算得到该煤田的综合评价,且优选出恩村井田、古汉山-位村井田、九里山为有利区块,其成藏条件优越,通过试井得出破裂压力与闭合压力差值小,且不利于通过压裂产生有效延伸长度和导流能力的裂缝,故应采用多级脉冲加载压裂技术,以保证压裂改造效果,达到改善储层导流能力的目的。

According to the parameters of coal geology exploration and coal-bed methane wells information,the geologic condition and reservoir characteristics of Jiaozuo coal Coalbed Methane is analysed,and the major reservoir is the Shanxi Coal Group II-1 coal seam.The gas content is related with coal seam thickness、overlying effective strata thickness of coal seam、the development level of coal cleat、the top and bottom surrounding rock characters.In the control of fracture structure the coal is divided into southern、central and northern three tectonic fault block,and in which the southern and Central fault block of high gas content.Applying Analytical Hierarchy Process（AHP） the comprehensive score of the coal is calculated.En-cun、Guhanshan^Wei-cun and Jiulishan mine field are favorable zones,generate and reservoir condition is good.By well testing the difference between fracture pressure and closure pressure is small,and does not facilitate the adoption of an effective fracturing extension length and conductivity of the cracks,it should adopt a multi-level pulse for fracturing technique to ensure the fracturing effect,to achieve the purpose of improving the capacity of reservoir diversion.