二连盆地凹陷结构与成藏模式

二连盆地群由５１个相互独立、具有相似构造演化史的小断陷湖盆（凹陷）组成。根据这些凹陷的沉积发育特征及凹陷的内部结构特点，将它们划分为４种结构类型：单断断槽式，单断断超式，双断地堑式，双断地垒式。凹陷结构与油气分布之间有比较密切的关系。根据这种关系，建立了４种类型凹陷结构的成藏模式：单断断槽式以断槽为中心，油气近似环状分布；单断断超式油气主要向缓坡运移，形成比较单一的斜坡复式油气聚集带；双断地堑式主要在滑塌背斜近生油洼槽的一侧聚集，在最靠近主生油洼槽的断隆带形成复式油气聚集带；双断地垒式凹陷中，发育由大型构造地层及小断块圈闭油气藏组成的中央地垒复式油气聚集带。图５参２（王孝陵摘）

The depression structure and accumulation model in Erlian basin.

Erlian basin is composed of fifty one little faulted lake basins (depressions) that are independent from each other but have similar history of tectonic evolution and deposition development. These depressions are classified into four types of single fault with trough, single fault with onlap, double fault with graben and double fault with horst based on their sedimentary, characteristics and inner structural feature of depressions. There is a intimate relationship between oil distribution and depression structure. The accumulation models of these four types of depression are established according to this relationship: Oil and gas distributed around the trough like a ring in single fault with trough depression; in single fault with onlap depression, hydrocarbon migrated mainly towards the gentle slop on that the complex oil and gas accumulation belt formed; oil and gas accumulated at the limb of slide and collapse anticline and formed complex accumulation zone at the fault uplift nearest to the active generation trough in double fault with graben depression; and in double fault with horst depression, there is a composite oil and gas accumulation zone formed on the central horst, that is composed of large structural stratigraphical traps and little fault block reservoirs.