山西沁水盆地煤层气成藏的微观动力能条件研究

煤层气成藏的微观动力能条件主要包括煤储层的孔隙—裂隙系统、煤储层的生气作用和储气作用两个方面。以山西沁水盆地为例,深入剖析了煤储层的孔隙—裂隙系统及其发育历程、煤储层的生气作用与能量聚散,阐明了煤层气成藏的微观动力能对成藏效应的控制作用。结果表明:构造作用对储层渗透率具有明显的控制作用,成烃增压致使能量聚集,成为盖层突破作用的主要驱动力,而能量放散则主要是通过煤储层孔隙—裂隙系统的产生、发展。根据上述研究成果,沁水盆地煤层气成藏的地质区划结果为:盆地南部的有利区带为阳城和晋城的北部地区,包括潘庄、樊庄、郑庄等地区;盆地中部的有利区带为安泽—沁源地区,位于盆地西斜坡的中南部;盆地北部的可能有利区带为寿阳东南部地区,位于榆次东北部和阳泉西南部之间。

Microcosmic Dynamical Energies of Coalbed Gas Reservoir Formation of Qinshui Basin,Shanxi Province

The microcosmic dynamical energies of coalbed gas reservoir-forming action mostly showed in two aspects that one was the pore-fracture system, and the other was the hydrocarbon-generated action and the gasstorage action. Taking the coal reservoir in Qinshui Basin as a case, the paper went deep into anatomising the pore-fracture system and its developing evolution, the hydrocarbon-generated action and energy accumulationemission, and clarified the controls of various microcosmic dynamical energies to coalbed gas reservoir formation. The researching results indicated that the tectonic action had obvious controls to coal reservoir permeability, and the energy accumulation of hydrocarbon-generated action was the important power to the cap-rock breaking action, and the energy emission mostly showed in the forming and developing of the pore-fracture system. According to the aforementioned research, we could find the geological regionalization of coalbed gas reservoir formation in Qinshui Basin, which is shown that the advantaged area in the south of the Basin is Yangcheng and north Jincheng, including Panzhuang, Fanzhuang and Zhengzhuang; the advantaged area in the middle of the Basin is Anze-Qinyuan region which lies in the centre and south of the western slope of the Basin; in the north of the Basin, the likely advantaged area is the southeast Shouyang which lies in the middle of northeast Yuci and southwest Yangquan.