塔里木盆地鸟山东断裂带构造特征、形成机制及油气地质意义

Structural characteristics,formation mechanism and petroleum geological significances of East Niaoshan fault zone,Tarim Basin

根据最新的三维地震资料,对塔里木盆地鸟山东断裂带进行了精细解释,分析了该断裂带剖面构造样式和平面展布特征,进而探讨了其发育演化模式和石油地质意义,拟为该区构造分析与油气勘探提供新思路。研究表明,鸟山东断裂带以古近系为界具有明显的深浅分层构造特征,同时沿断裂带走向又具有分段差异性:深层挤压—走滑逆冲断裂在南段主要由东向西逆冲,在北段逆冲方向主要为由西向东,浅层的逆冲滑脱断裂在各构造段均有发育。断裂带主要经历了4期构造变形,分别是早—中寒武世的张性正断裂活动、古近纪初的基底逆冲断裂活动、中新世的挤压—走滑断裂活动以及上新世末期—全新世的逆冲滑脱断裂活动。鸟山东断裂带具有挤压—走滑的性质,控制了构造圈闭的形成和改造;同时,断裂带沟通麦盖提斜坡深部寒武系烃源岩,可作为有利的油气运移通道。

Based on the latest 3 Dseismic data,the fine interpretation of East Niaoshan fault zone was made,the profile structural styles and plane distribution characteristics of the fault zone were analyzed,then the authors discuss its development evolution model and petroleum geological significance,to provide a new idea for the geological structure modeling and oil and gas exploration.The research results show that the East Niaoshan fault zone has clear layered features with Paleogene as the boundary,besides,the structural style of this fault zone is variable along its length.Deep compressional strike-slip thrust fault is mainly driven from east to west in the southern section,while the thrust direction of the north section is mainly from west to east,and the shallow decollement thrust fault develops in the whole fault zone.Four deformation stages of the fault zone are recognized,the Early-Middle Cambrian tensional normal faulting,the Early Paleogene basement thrust faulting and the Miocene compressional strike-slip faulting and the Late PlioceneHolocene shallow decollement thrust fault which was detached along the gypsum salt rock at the bottom of the Paleogene.The East Niaoshan fault zone has the properties of squeezing and sliding,controlling the formation and reformation of the structural traps;simultaneously,the fault zone connects the deep Cambrian hydrocarbon source rocks in the Markit slope,which can be used as a favorable oil and gas migration channel.