川东北地区侏罗系油气地质特征与成藏主控因素

基于四川盆地东北部(川东北)地区区域构造演化和侏罗系油气地质条件研究，分析了研究区侏罗系油气地质特征与成藏主控因素。认为川东北地区经历了从内陆克拉通之后的大型淡水坳陷湖盆阶段向大巴山前陆盆地阶段的转换过程。同时,通过对川北前陆盆地生烃演化与油气运移特征，大巴山构造演化与圈闭发育特征，及其对油气成藏作用分析，剖析了川东北地区侏罗系自流井组大安寨段、凉高山组、沙溪庙组油藏成藏主控因素和富集规律，指出川东北地区侏罗系油藏为成岩后期油藏，即成岩压实作用之后烃源岩才大量生烃，聚集成藏，表现为储层成岩演化与生烃演化的不协调性，导致研究区含油气层系多、发育不规则、油气分布分散而又不均匀，且油气层只产油气、不产水。

Characteristics of Jurassic Petroleum Geology and Main Factors of Hydrocarbon Accumulation in NE Sichuan Basin

Based on tectonic evolution and Jurassic petroleum geological conditions in NE Sichuan basin, we discussed the oil and gas geological characteristics and main tactors of hydrocarbon accumulation. NE Sichuan basin went through the transformational history from large fresh water depression basin after inland craton to foreland basin of Daba mountain. Based on hydrocarbon generation and migration in the foreland basin of north Sichuan, tectonic evolution and trap types in Daba mountain, we illustrated the main control factors of oil and gas accumulation in Daanzhai Member, Lianggaoshan Formation and Shaximiao Formation in Jurassic of the NE Sichuan. We pointed out that the formation of Jurassic oil reservoirs would be at the late diagenetic stage, since source rock started to generate a large number of hydrocarbons and accumulation after diagenesis compression, suggesting that diagenetic evolution of reservoir rocks would be out of harmony with hydrocarbon generation history. The result led to many oil and gas layers, with irregular, dispersed and uneven distribution for oil and gas, and no water produced. 