摘要
通过分析塔里木、四川和鄂尔多斯三大海相盆地埃迪卡拉系—奥陶系,并对比参考东西伯利亚、阿曼和澳大利亚Officer三大国外盆地新元古界—寒武系的地层特征,将碳酸盐岩-膏盐岩组合划分成碳酸盐岩类和膏盐岩类互为夹层型、碳酸盐岩类和膏盐岩类互层型以及碳酸盐岩类、膏盐岩类和碎屑岩类共生型3种类型,明确了碳酸盐岩-膏盐岩组合的概念及内涵.结果表明:①碳酸盐岩-膏盐岩组合的油气通常来源于泥页岩和泥质碳酸盐岩两类烃源岩,咸化环境膏盐岩可促进烃源岩生烃.②主要发育膏云坪型、颗粒滩和微生物丘型两大类白云岩储集层,准同生期或表生期的大气淡水淋滤是储集层规模发育的主要控制因素,后期埋藏溶蚀作用对储集层有调整和改造作用.③碳酸盐岩-膏盐岩组合油气成藏模式可划分为盐下成藏模式、盐上成藏模式和盐间成藏模式3大类8小类模式.塔里木盆地塔中隆起北坡、麦盖提斜坡和玛扎塔格前缘隆起带寒武系、四川盆地东部—南部地区寒武系和鄂尔多斯盆地奥陶系盐间马家沟组四段等为未来的有利勘探领域.
Abstract
The Ediacaran-Ordovician strata within three major marine basins(Tarim,Sichuan,and Ordos)in China are analyzed.Based on previous studies focusing on the characteristics of the Neoproterozoic-Cambrian strata within the three major basins(Siberian,Oman,and Australian)overseas,the carbonate-evaporite assemblages in the target interval are divided into three types:intercalated carbonate and gypsum salt,interbedded carbonate and gypsum salt,and coexisted carbonate,gypsum salt and clastic rock.Moreover,the concept and definition of the carbonate-evaporite assemblage are clarified.The results indicate that the oil and gas in the carbonate-evaporite assemblage are originated from two types of source rocks:shale and argillaceous carbonate.The characteristics of the argillaceous carbonate in the saline platform environment are analyzed,and the results confirmed the capability of gypsum salt in the saline environment to drive the source rock hydrocarbon generation.The dolomite reservoirs are classified in two types:gypsum-bearing dolomite flat,and grain shoal & microbial mound.This study clarifies that the penecontemporaneous or epigenic leaching of atmospheric fresh water mainly controlled the large-scale development of reservoirs.Afterwards,burial dissolution transformed and reworked the reservoirs.The hydrocarbon accumulation in carbonate-evaporite assemblage can be categorized into eight sub-models under three models(sub-evaporite hydrocarbon accumulation,supra-evaporite hydrocarbon accumulation,and inter-evaporite hydrocarbon accumulation).As a result,the Cambrian strata in the Taizhong North Slope,Mageiti Slope and Mazatag Front Rise Zone of the Tarim Basin,the Cambrian stata in the Chuandong-Shunan area of the Sichuan Basin,and the inter-evaporite Ma-4 Member of Ordovician in the Ordos Basin are defined as favorable targets for future exploration.
基金项目
国家自然科学基金(U22B6002)
国家油气科技重大专项(2016ZX05-004)
中国石油天然气集团有限公司科技重大专项(2023ZZ02)
维普
万方数据