青海祁连山冻土区木里煤田天然气水合物气源分析

综合应用有机地球化学方法和有机岩石学方法，开展青海省祁连山冻土区木里煤田煤层瓦斯气样与天然气水合物实物样品气体实测数据的对比分析，揭示了二者的可比性和相似性。结合烃源岩评价和地质条件分析，探讨了木里煤田天然气水合物烃类气体来源，认为本区产出的天然气水合物属于偏煤型气的混合气成因，侏罗纪煤系煤层、炭质泥岩和油页岩是主要的烃源岩，石炭系暗色泥灰岩、下二叠统暗色灰岩、上三叠统暗色泥岩等为次要烃源岩。青藏高原多年冻土带找矿方向应集中于中等变质阶段（凝析气-湿气带）的煤系分布区，木里煤田西段、青海南部乌丽含煤带、西藏北部土门含煤带等地区是优选靶区。

Gas source analysis of natural gas hydrate of Muri coalfield in Qilian Mountain permafrost, Qinghai Province, China

By using organic geochemistry and organic petrology methods comprehensively,the contrastive study of gas measured data of coal bed methane and gas hydrate samples from Muri coalfield in Qilian Mountain permafrost area was carried out,the comparability and similarity of the both were revealed.Based on the hydrocarbon source rock evaluation and geological conditions analysis,the hydrocarbon gas sources of natural gas hydrate was discussed,which was considered that the gas hydrate in Muri coalfield belongs to the mixed gas genesis with dominant coal-typed gas,Jurassic coal seam,carbon mudstone and oil shale are major gas source rocks,and the Carboniferous dark marlite,the Lower Permian dark limestone and the Upper Triassic dark mudstone are minor gas source rocks.Gas hydrate prospecting target in Qinghai-Tibetan Plateau permafrost should concentrate on the middle metamorphic phase(condensate-wet gas zone) of coal distribution area,the western part of Muri coalfield,Wuli coal-bearing region in the southern Qinghai and Tumen coal-bearing region in the northern Tibetan are the optimum target areas.