松辽盆地长岭断陷烃类气藏主控因素及分布

Main controlling factors and distribution of hydrocarbon gas reservoir in Changling fault depression of Songliao Basin

松辽盆地长岭断陷烃类气藏的分布主要受烃源岩分布和断裂发育特征两种因素控制。早期气藏的形成主要受控于烃源岩的分布,形成的是原生气藏;晚期气藏的形成主要是因为有沟通气源(沙河子组和营城组烃源岩)和圈闭的断裂作为油气运移的通道,形成的是次生气藏。目前已发现的主要含气构造(哈尔金、大老爷府及双坨子构造)在营城组末期已见雏形,大多数构造定型于嫩江末期,含气构造形成时间早于主生烃时间。伏龙泉构造形成于嫩江时期,定型于古近纪末期。烃类气藏主要形成于青山口—嫩江时期。营城组火山岩和登娄库—泉头组一、二段的碎屑岩储集层是未来烃类气勘探的主要目标。

The distribution of hydrocarbon gas reservoir in Changling fault depression was controlled by the distribution of hydrocarbon source rocks and development characteristics of faults.The formation of early gas reservoirs（original gas reservoir） mainly controlled by the distribution of hydrocarbon source rocks;the formation of later gas reservoir（secondary gas reservoir） was mainly caused by communicated gas source（the source rocks of Shahezi and Yingcheng Formations） and trapped faults as the migration pathway of hydrocarbon. The main gas-bearing structures（Haerjin,Dalaoyefu and Shuangtuozi structures）were already at fledgling stage in Yingcheng Formation,and most of the structures stereotyped at the last stage of Nenjiang Formation.The formation time of gas structures was earlier than the main hydrocarbon time.The Fulongquan structure formed during Nenjiang stage,and stereotyped in Late Paleogene.Hydrocarbon gas reservoir mainly formed during Qingshankou—Nenjiang stage.The volcanic rocks of Yingcheng Formation and the detrital rocks reservoir of the Denglouku Formation and the members 1and 2 of Quantou Formation were the main exploration target for hydrocarbon gas in the future.