陕北斜坡延长组致密砂岩油藏形成机理及分布研究

Forming Mechanism and Distribution of Triassic Yanchang Formation Tight Sandstone Reservoir in North Shanxi Slope

通过对延长组烃源岩条件、沉积埋藏—热演化史、储集层特征综合分析,认为三叠系延长组两套优质烃源岩分布面积广,有机质含量高,早白垩世晚期为油气充注期,存在正常式、侧变式、顶生式三种生储盖组合类型。由于延长组烃源岩油气运移动力缺乏浮力作用,油藏主要分布在近生油坳陷的水下分流河道和河口坝砂岩储集层中。

Based on the comprehensive analysis of Yanchang formation source rock, sedimentary burial and thermal evolution history, reservoir characteristics, it＇s pointed out that two sets of high quality source rocks in Triassic Yanchang formation present the characteristics of wide distribution and high organic matter content. The late Early Cretaceous is hydrocarbon charging period. There are three kinds of source reservoir cap assemblage types including normal type, lateral type and terminal type. Due to the lack of hydrodynamic force, the reservoir is mainly distributed in the underwater distributary channel and mouth bar sandstone reservoirs near source depression.