摘要
通过对桐湾运动性质、期次的分析,利用地震、钻井、露头等资料,采用"残余厚度法"与"印模法"刻画四川盆地筇竹寺组沉积前的侵蚀谷地貌形态,分析其油气成藏条件。四川盆地及邻区在晚震旦世—早寒武世发生了桐湾运动,共可分为3幕,均表现为区域性抬升与剥蚀,形成了3个假整合面。受其影响,在四川盆地中南部形成了近南北向展布的规模较大的德阳—泸州侵蚀谷,充填厚度较大的麦地坪组和筇竹寺组,成为寒武系烃源岩重要的生烃中心,与灯影组灯四段、灯二段两套风化壳岩溶储集层构成良好的成藏组合条件,有利于形成大气田,勘探潜力大。侵蚀谷成因机制与演化历史分析表明,震旦纪末期桐湾运动Ⅱ幕的逆冲-褶皱隆升、剥蚀作用以及早寒武世早期快速海侵背景下的拉张作用是形成侵蚀谷的关键。
Through analyzing the nature and periods of Tongwan tectonization, by using seismic data, drilling data and outcrop data, the pre-Qiongzhusi Formation eroded paleo-geomorphology was described with remaining thickness and moldic methods, and the hydrocarbon accumulation conditions were analyzed. The Sichuan Basin and its adjacent areas experienced Tongwan tectonization from late Sinian to early Cambrian which include three episodes that all manifested as regional uplift and erosion, forming three disconformities. Affected by that movement, a large scale Deyang-Luzhou eroded valley in N-S direction was formed in Central-Southern Sichuan Basin. In the valley, thick Maidiping Formation and Qiongzhusi Formation are important Cambrian source kitchens;they form good source-reservoir combinations with two sets of weathering karst reservoirs in Deng 2 and Deng 4 Member in Sinian Dengying Formation, favorable for the formation of large gas field with huge resource potential. The analysis of forming mechanism and evolution history of the eroded valley shows the thrusting-fold uplifting and erosion in the second episode of Tongwan tectonization in late Sinian period, and the extensional movement in the background of rapid marine transgression in early Cambrian are key to the formation of the eroded valley.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2014年第3期305-312,共8页
Petroleum Exploration and Development
基金
国家油气重大专项“四川、塔里木等盆地及邻区海相碳酸盐岩大油气田形成条件、关键技术及目标评价”项目(2011ZX05004)
中国石油勘探与生产专项“四川盆地乐山-龙女寺古隆起震旦系含油气评价及勘探配套技术研究”
关键词
桐湾运动
侵蚀谷
古隆起
灯影组
筇竹寺组
成藏组合
四川盆地
Tongwan tectonization
paleo-uplift
Sinian Dengying Formation
Cambrian Qiongzhusi Formation
source-reservoir combination
Sichuan Basin
