西藏东北部比如盆地中生界油气苗的发现与意义  

Discovery and significance of Mesozoic oil and gas seepages in Biru basin,northeastern Tibet,China

作　　者：王先美 祁开令[2] 伍新和 江月星[2] 李吉选[2] 范志伟[2] 

机构地区：[1]中国石油化工股份有限公司石油勘探开发研究院,北京100083 [2]中国石油化工股份有限公司南方分公司,四川成都610041

出　　处：《地质通报》2010年第6期863-869,共7页Geological Bulletin of China

基　　金：中国石油化工股份有限公司海相前瞻性研究项目<青藏高原油气远景综合研究及有利区优选>(编号:YPH08038)资助

摘　　要：比如盆地位于西藏的东北部。野外石油地质考察期间,在比如盆地发现了大量的地表油气苗。油气苗均为干沥青,出露层位集中在中-上侏罗统拉贡塘组与下白垩统多尼组中,其他层位未发现油气苗。镜下观察结果显示,拉贡塘组与多尼组碎屑岩骨架颗粒之间发育有油气包体与不发光沥青。从地表出露形态与特点看,干沥青主要分布于断裂带、裂缝等构造强变形的部位。与青藏高原腹地同类残留盆地对比,比如盆地新生代构造变形更强烈,盆地抬升并遭受剥蚀的幅度更大。由此,提出高原找油可能面临的诸多难题,应该重点关注新生代构造与构造地貌演化对油气藏的影响。During field geological survey, many oil and gas seepages had been found in Biru basin, which is located in the central-east part of Tibet Plateau. All oil and gas seepages outcropped can be classified as solid asphalt, and target horizons are in Middle-Upper Jurassic Series Lagongtang Formation and Lower Cretaceous Series Duoni Formation. Under microscope, oil ＆ gas inclusions and nonluminous asphalt appear among framework grains of clastic rock in those two formations. By analysis of the shapes and the characteristics from outcrops, solid asphalt distributes near intensive deformation area, such as fault zone and fracture zone. Cenozoic structure in Biru basin had been undergone more intensive deformation and bigger uplift or much more denudation than the rest basins of the same kinds properties in the central of Tibet Plateau. Therefore, many problems would be faced during plateau oil-prospecting in the future, and impact of structural evolution and tectonic landform action on hydrocarbon-bearing pool should be stressed.

关 键 词：西藏 比如盆地 中生界 地表油气苗 强变形带 油气散失 构造演化 

分 类 号：P534.5[天文地球—古生物学与地层学] P618.13[天文地球—地质学]