摘要
对塔里木盆地东部中-上奥陶统却尔却克组碎屑岩中多个泥岩样品的热解有机碳分析、英东2井岩心详细描述及多条二维地震剖面的综合解释表明,在巨厚的却尔却克组碎屑岩地层的中下部存在一套累计厚度约100m的海相烃源岩。这套烃源岩总有机碳含量可达1.23%;具有较高的自然伽马值和低电阻率值;在地震剖面上具明显的强相位反射特征。该套烃源岩在塔里木盆地东部均有分布,向东、西两方向分别超覆尖灭于罗西台地边缘和古城—轮古东台地边缘,在南北方向上,分别断失在车尔臣断裂、孔雀河断裂发育处,其中西北缘超覆在孔雀河斜坡处。却尔却克组海相烃源岩是在海侵背景下,大规模海底扇发育间歇期,水体相对安静时沉积的一套深水陆棚—盆地相泥岩。
Hydrocarbon source rocks usually occurred in a marine carbonate environment in Tarim Basin during Ordovician,no effective source rocks have been found in the Middle-Upper Ordovician thick marine clastic.The analysis of pyrolyzed organic carbon in some mudstones systematically sampled from the Queerquek Formation in the eastern Tarim Basin,the detailed observation and description of cores from the Queerquek Formation of Well Yingdong-2,and the comprehensive interpretation of various 2-dimensional seismic sections indicated that a suite of marine hydrocarbon source rocks with a total accumulated thickness of nearly 100m occurs at the middle and lower parts of the Middle-Upper Ordovician thick Queerquek marine clastic.This suite of source rocks,which has TOC as high as 1.23%,is electronically characterized by a higher natural gamma-ray value and lower electric resistivity,indicating a relatively pure mudstone,and is obviously of high amplitude reflection in seismic sections.Widely distributed in the eastern Tarim Basin,these source rocks overlapped and pinched out eastward in the Luoxi platform margin and westward in the Gucheng-Lungudong platform margin,respectively.Meanwhile,the distribution of these source rocks along the south-north strike disappeared at the Che＇erchen fault in the south and the Peacock River fault in the north,respectively,while on the northwestern rim they overlapped upon the Peacock River ramp.The marine source rock in the Queerquek Formation is a suite of deep-water shelf–basin facies mudstones deposited during the intermission of extensive development of submarine fans when transgression happened and water body was relatively quiet.
出处
《石油学报》
EI
CAS
CSCD
北大核心
2011年第1期32-40,共9页
Acta Petrolei Sinica
基金
中国石油天然气集团公司科技项目(041008100083)资助
关键词
塔里木盆地东部
奥陶系
却尔却克组
海底扇
深水陆棚
海侵
烃源岩
eastern Tarim Basin
Ordovician
Queerquek Formation
submarine fan
deep-water shelf
transgression
hydrocarbon source rock
