呼和湖凹陷煤层气地质条件及资源潜力分析

Geological Conditions and Resource Potential Analysis of Coalbed Methane in the Huhehu Depression

通过对呼和湖凹陷煤层样品开展低温氮吸附实验、等温吸附实验和现场含气量测试,结合煤岩煤质和煤层分布特征分析,研究了呼和湖凹陷煤层气地质条件及其资源潜力。研究表明,呼和湖凹陷主要煤层以褐煤为主,变质程度低,储层内微孔和小孔最为发育,具有较大的比表面积及吸附能力,煤层顶底板泥岩厚度较大,研究区水文地质条件简单,有利于煤层气的保存,呼和湖凹陷煤层气资源潜力总体较好。综合考虑煤层厚度、含气性、储层物性、盖层因素和水文地质条件,建立了呼和湖凹陷煤层气有利区评价标准,优选出3个煤层气有利目标区。

Combining with the experiment of methane adsorption,low-temperature nitrogen adsorption,gas content test of the coal samples from Huhehu depression and the coal quality and distribution characteristics of the coal seam,geological conditions and resource potential of coalbed methane(CBM)were investigated in the Huhehu Depression.The results showed that the coal seam of Huhehu Depression with a low grade of metamorphic is mainly lignite.The reservoir is full of micropores and small pores,which have relatively large specific surface area and strong adsorption capacity.Mudstone thickness of the roof and floor of the coal seam is large and the hydrogeological condition of the study area is simple,which is beneficial to the preservation of CBM,indicating that the Huhehu Depression has good CBM resources potential.Overall,considering the thickness,gas content,physical properties,cap rocks,hydrogeologic condition of the CBM enrichment conditions,the favorable area evaluation criteria has been built and three optimum target areas in Huhehu depression were selected.