哈拉湖地区天然气水合物成藏环境

Analysis of Natural Gas Hydrate Accumulation Environment in Hala Lake Area

基于青海哈拉湖地区AMT测量成果,借鉴前人对天然气水合物成藏环境研究的经验,对比木里地区天然气水合物成藏体系,认为哈拉湖南部基底隆起区为天然气水合物成藏潜力区。分析结果表明:潜力区冻土厚度较大且连续,能较好地阻止深部烃类气体的散逸,封盖条件较好;构造裂隙发育,为水合物运移、存储提供了空间;深部虽缺失石炭纪和侏罗纪沉积地层,但埋藏较深的二叠系-三叠系地层可作为本区主要气源层;地下水对冻土融冻变化影响较小。

Based on the result of AMT measurement inversion in Hala Lake area,Qinghai province and the previous studies on the gas hydrate accumulation environment,comparing the gas hydrate accumulation systems in Muli,it is considered that the basement uplift in the south of Hala lake is a potential area for natural gas hydrate accumulation.The results show that the frozen soil in the potential area is thick and continuous,which can prevent the hydrocarbon gas from escaping from the deep area and has good sealing conditions.Although the Carboniferous and Jurassic sedimentary strata are absent in the deep part,the deep permian-triassic strata can be used as the main gas source beds in this area.The groundwater has little influence on the change of freezing and thawing of permafrost.