松辽盆地继承性断裂带特征及其在油气聚集中的作用

松辽盆地沉积盖层发育三套断裂组合,即张性断块构造断裂组合、张性断块构造-滑脱型正断层组合断裂组合、扭动断裂组合。三套断裂组合主干断层具有继承发育特点,形成继承性发育断裂带。这些断裂带不仅控制了深部构造格局、中浅层沉积体系的发育与展布以及盖层的构造变形,而且对盆地油气系统中油气运移、聚集与保存发挥着重要作用,因此继承性发育断裂带周围是盆地油气的主要聚集区带。

CHARACTERISTICS OF INHERITED FAULT BELTS AND THEIR EFFECT ON HYDROCARBON ACCUMULATION

There are a series of inherited fault belts in Songliao basin. They are composed of three fracture systems: tensional fault block, extensional fault group tensional fault block, and wrench fault group. Inherited fault belts play an important role in not only the process of the formation and development of the basin, but also migration and accumulation of oil and gas.The fault belts have obvious differences vertically both in scale and in property. The faults of T2 T5 are growth faults, while the faults of T1 and some deep spreading faults are epi genetic, sliding faults. They have different scales on the reflections from T06 T5. T2 and T5 have more faults and the faults of T5 have larger scales. They form 6 large NNE trending fractures throughout the reflections and reach basement.The NNE trending fractures control the development of the rift basin’s primary and sub structures, forming EW trending strips. The NW trending fractures control the sub structures’ distribution, and cut the strips into blocks. The deep fractures are the crust’s breakage zones, subsidence regions and paths of ground thermal flows. They control the sedimentary system and source area.With the happening of late time tectonic movement, deep fractures cause a series of consecutive faults and folds, which act as passages and traps in the process of hydrocarbon’s migration. Deep fractures are long term developing faults, so they are both enrichment districts of oil gas in mutilayer and compound of oil bearing systems.