东濮凹陷文留地区天然气成藏模式

留地区气藏形成的基本条件是气源丰富、中低渗储集层发育、圈闭类型多样，且盖层条件优越。受地质结构特别是生储盖组合的控制，有煤成气藏和油型气藏两类天然气聚集型式。煤成气藏为石炭－二叠系煤系二次生气，通过断层垂向运移而聚集成藏，主要分布于２３盐下Ｅｓ４段圈闭中；油型气藏主要通过下第三系气源岩侧向运移聚集成藏，受构造、岩相变化影响，包括３种类型：Ｅｓ＾３３亚段东滚动背斜带的大型岩性－构造气藏、Ｅｓ＾

Forming Models of Gas Reservoirs in Wenliu Area of Dongpu Depression

The basic geologic conditions to form gas reservoirs in Wenliu area are the abundant gas sources, moderate to low permeability reservoirs,various traps and good seals Controlled by geological structures, especially by the assemblage of source,reservoir and cap beds, there are two types of gas accumulations in the area, coal formed gas and oil type gas reservoirs The former is secondary generating gas from Permo Carboniferous coal system,which migrates vertically through faults into traps mainly in Es 4 sub salt of Wen 23 salt bed, while the latter, affected by structural and lithofacies variations, migrates laterally through the Paleogene source rocks to be accumulated The oil type gas reservoir includes large lithologic structural gas pools in Wendong rollover anticline in Es 3 3, small faulted block condensate gas pools in the lower position of Es 2 member to Es 1 3 and local gas cap pools