南祁连盆地东北部木里地区三叠系尕勒得寺组烃源岩评价

Triassicgalede temple group hydrocarbon source rock evaluation in Muli area northeast of the southern Qilian basin

南祁连盆地东北部木里地区2008年11月5日DK-1孔首次发现天然气水合物,之后分别在DK-2、DK-3孔中再次钻遇天然气水合物,并经激光拉曼测试证实为天然气水合物,取得了找矿工作的重大突破,表明盆地已经具备生烃潜力。三叠系尕勒得寺组在木里地区分布较广,岩性以泥岩为主,碳酸盐岩为辅。通过残余有机碳来表示有机质丰度,有机碳含量平均为11.82%,平均在2.4%左右,属于中等~好烃源岩;烃源岩热解氢指数HI和降解潜率D分析后确定南祁连盆地木里地区烃源岩有机质类型为Ⅲ型。岩石热解参数特征来评价烃源岩的成熟度结果显示最高热解峰温(Tmax)为547~580℃,平均为564℃,反应烃源岩处于成熟演化阶段的上限。综上所述,三叠系烃源岩有较好的生烃潜力,评价三叠系尕勒得寺组烃源岩的生烃潜力具有重要的科学、经济和环境意义,同时也为开辟青海东北部油气地质调查新区与工作部署提供依据。

In Muli area northeast of the basin in southern Qilian DK-1hole first discovery of natural gas hydrate in November 5 ,2008 ,respectively in DK-2 ,DK-3 holes drilled gas hydrate again .The laser Raman test confirmed that natural gas hydrate .It achieved a major breakthrough in prospecting work and Indicated that the basin already has hydrocarbon generation potential .The Triassic Galede Temple group is widely distributed in the Muliarea ,lithology is mainly mudstone ,carbonate supplement .It said organic matter abundance through residual organic carbon ,organic carbon content is 11 .82% ,the average is about 2 .4% , which belongs to the middle to the good hydrocarbon source rock ;Hydrocarbon source rock pyrolysis hydrogen index HI and potential degradation rate of D analysis to determine the types of organic matter in Muli area south of hydrocarbon source rocks of Qilian basin is type III .The characteristics of pyrolysis parameters of rock for hydrocarbon source rock maturity evaluation showed the highest pyrolysis peak temperature (Tmax ) 547~580 ℃ ,the average 564 ℃ ,and reaction of hydrocarbon source rocks is in a mature stage of the upper limit .In summary ,Triassic hydrocarbon source rocks had good potential of hydrocarbon generation .There are scientific ,economic and environmental significances of hydrocarbon poten-tial evaluation of Triassic Galede hydrocarbon source rock temple group ,and also provides the basis for the development of northeast Qinghai petroleum geological survey new area and work deployment .