石油与天然气地质2026，Vol.47Issue(1)：44-63,20.DOI:10.11743/ogg20260104
羌塘盆地海相中生界石油地质条件与勘探潜力评价
Assessment of petroleum geology and exploration potential of the marine Mesozoic strata in the Qiangtang Basin
摘要
Abstract
To support ongoing hydrocarbon exploration of the marine Mesozoic strata in the Qiangtang Basin,we conduct surveys and reassessments of the regional petroleum geology.Accordingly,several benchmark sections of the basin's source rocks and reservoirs are established.The results indicate that the Qiangtang Basin contains three dominant source rock sequences(the Bolila,Bagong,and Quse formations),two suites of carbonate reservoirs(the limestone karst of the Bolila Formation and the dolomites of the Buqu Formation),three suites of sandstone reservoirs(the Bagong,Quemocuo,and Xiali formations)dominated by tight-sand reservoirs,and three suites of well-developed regional evaporite cap rocks(the Quemocuo/Quse and Xiali formations).Analysis of oil and gas shows reveals that the marine Mesozoic strata in the Qiangtang Basin experienced the hydrocarbon generation,migration,and accumulation processes.In this basin,oil-generating strata,reservoirs,and cap rocks are well-matched both temporally and spatially,forming two petroleum systems:the Upper Triassic-Lower Jurassic pre-salt system and the Lower-Middle Jurassic intrasalt system.Three hydrocarbon plays are identified in the basin.The first play consists of the source rocks of the Bolila Formation,the karst reservoirs of the Bolila Formation,and the mudstone cap rocks of the lower Bagong Formation.The second one is composed of the mudstone source rocks of the Bolila-Bagong formations,the sandstone reservoirs of the Quemocuo-Bagong formations,and the evaporite cap rocks of the middle-upper Quemocuo Formation.The third one comprises the source rocks of the Quse Formation,the dolomite reservoirs of the Buqu Formation,the sandstone reservoirs of the Xiali Formation,and the evaporite/mudstone cap rocks of the Xiali Formation.Three types of hydrocarbon resources occur in the Qiangtang Basin:conventional,shale,and tight hydrocarbons.In the Maqu area,play fairways cover an area of about 5×103 km2.An assessment of the hydrocarbon generation intensity and hydrocarbon accumulation coefficients(HACs)of source rocks in the Bolila-Bagong formations reveals that the Maqu area has conventional hydrocarbon resources of about 0.5×109 t when estimated using a minimum resource abundance of 100×103 t/km2.Meanwhile,the Bagong Formation contains shale oil resources of approximately 1×109 t.In the Biluocuo-Esima area,play fairways with an area of about 8×103 km2 are identified.An assessment of the hydrocarbon generation intensity and HACs of source rocks in the Quse and Bagong formations reveals that this area contains conventional hydrocarbon resources estimated at 0.8×109 t based on a minimum resource abundance of 100×103 t/km2.In this area,the Bagong and Quse formations are identified as play fairways for shale oil exploration,with shale oil resources of approximately 1.6×109 t and about 0.8×109 t,respectively.In the Shenglihe area,play fairways span an area of 5×103 km2,where the Quse Formation holds shale oil resources of about 1×109 t.关键词
源-储-盖/成藏组合/含油气系统/勘探潜力评价/海相/中生界/羌塘盆地Key words
source rock-reservoir-cap rock assemblage/hydrocarbon play/petroleum system/exploration potential assessment/marine facies/Mesozoic/Qiangtang Basin分类
能源科技引用本文复制引用
沈安江,付小东,熊绍云,王剑,宋春彦,胡安平,刘思琪..羌塘盆地海相中生界石油地质条件与勘探潜力评价[J].石油与天然气地质,2026,47(1):44-63,20.基金项目
地球深部探测与矿产资源勘查国家科技重大专项(2025ZD10054) （2025ZD10054）
国家自然科学基金企业创新发展联合基金项目(U23B20154) （U23B20154）
国家油气重大专项(2025ZD1400703). （2025ZD1400703）
