中上扬子地区海相隆坳格局与油气聚集保存

Characteristics of Paleo-structure and Hydrocarbon Accumulation of Marine Sequence in the Middle and Upper Yangtze Region

隆坳格局是海相油气聚集区及其保存条件的早期控制因素。综合地质、钻井、地震、测试等多种资料,编制关键界面埋深图、剥蚀程度图、古地质图、构造叠合图及构造演化剖面等,研究中上扬子地区海相隆坳格局特征,分析油气运移聚集和保存条件。结果表明:加里东期隆坳格局以EW向和NE向为主,出现鄂西坳陷、川南坳陷、黔东南坳陷、江汉盆地北部坳陷等四大坳陷以及江南—雪峰隆起、黔中隆起及乐山—龙女寺隆起等三大隆起;古隆起及扬子板块南、北缘长期稳定的大规模斜坡带控制了以下寒武统为烃源岩的油气运移和聚集;印支期对加里东期的构造反转作用明显,印支期的坳陷基本上位于加里东期古隆起之上;扬子地区的隆坳格局主要呈SN向和NE向,形成泸州隆起、川西坳陷、湘鄂西—黔西南坳陷;此时形成的古隆起控制了以下志留统和下二叠统为烃源岩的油气运移和聚集。

The uplift and depression patterns are early control factors of hydrocarbon accumulation and preservation conditions in marine sequence.Based on the geology,drilling,seismic and test data,the depth maps of critical interface,erosion degree maps,paleo geological map,superimposed tectonic map and evolution profiles of paleo-structure were compiled,and the uplift and depression patterns of marine sequence were studied,and the petroleum migration and accumulation,and preservation conditions were analyzed.The results show that the uplift and depression patterns in Caledonian are dominated by EW and NE directions,and appear four depressions including West Hubei depression,South Sichuan depression,Southeast Guizhou depression and North Jianghan Basin depression,and three uplifts including Jiangnan-Xuefeng uplift,Middle Guizhou uplift and Leshan-Longnusi uplift;paleo-uplifts and large-scale slope belts with long-term stability in the southern and northern edges of Yangtze Plate,controls the hydrocarbon migration and accumulation of Lower Cambrian source rocks;the tectonic inversionof Indosinian to Caledonian is obvious,and the Indosinian depression locates on the Caledonian paleo-uplift;the uplift and depression patterns in Yangtze region are dominated by SN and NE directions,forming Luzhou uplift, West Sichuan depression,and West Hunan and HubeiSoutheast Guizhou depression;the paleo-uplift formed controls the hydrocarbon migration and accumulation of Lower Silurian and Lower Permian source rocks.