河南省下二叠统山西组二_1煤煤层气地质特征

GEOLOGICAL CHARACTERISTICS OF COALBED METHANE IN Ⅱ_1 COAL IN LOWER PERMIAN SHANXI FORMATION,HENAN PROVINCE

从影响煤层气勘探开发的主要因素：煤厚、煤岩组成、煤级、煤体结构、裂隙系统、渗透性、吸附／解吸特性和含气量等方面对河南省的主采煤层——二１ 煤的煤层气地质学特征进行了详细论述，指出镜质组含量较高、割理比较发育、外生裂隙发育适中的原生结构煤和碎裂煤渗透性最好，是最有利的储层；外生裂隙发育适中的无烟煤是有利储层；碎粒煤为不利储层；糜棱煤为不可开发储层；临界解吸压力较高、含气量较高的中煤级煤分布区是煤层气勘探开发的首选地区。

From the aspects such as coal thickness,petrological component,coal rank,coal matrix structure,fracture system,permeabillity,adsorption/desorption features and gas content,which are the main factors having the influences on the exploration and development of coalbed gas,the detailed expound on the geological characteristics of coalbed methane in Ⅱ 1 coal,the main minable coal seam in Henan Province,is conducted.It is indicated that in both coal with original texture and fractured coal,which have higher vitrinite content,more developed cleats and moderately developed fractures,the permeability is best,is the most favorable reservoir;the anthracite with moderately developed fractures is the favorable one;the granulitic coal is the unfavorable one,and the mylonitic coal is the one could not be developed.The first selected area for exploration and development of coalbed methane is the area in where the medium ranks of coal with higher critical desorption pressure and higher gas content are distrbuted.