松辽盆地东南隆起区断层与油气运移及成藏

松辽盆地东南隆起区经过数次构造运动改造,形成复杂的断裂系统,按照断层的性质、规模、形成的时间顺序和空间展布特征及与油气的关系,将其分为早期断层、晚期断层、晚期活动的早期断层3类.早期断层中的控盆断层控制断陷的形成、演化;控制沉积断层控制有利源岩的分布部位.断层在活动时期是油气纵向运移通道,停止活动时期则不是;油气在横向上可以穿断层运移,断层在上倾方向上有非渗透遮挡层的条件下可以形成断层油气藏.早期断层活动时期早于生烃期,不是油气垂向运移通道,因此在源岩层系内可以形成早期原生油气藏,并且保存条件好;早期断层对圈闭的支解、分割作用,导致油气分布的复杂性、不连续性.晚期活动的早期断层和晚期断层活动时是油气的纵向运移通道,同时使深层的原生油气藏遭到破环、变为残余油气藏,并在浅层形成次生油气藏.晚期断层停止活动时,亦不是油气垂向运移通道,因此能够在源岩层系内形成晚期原生高产油气藏,保存条件好.断层活动时期与源岩排烃期(油气源)的匹配关系,决定油气的分布层位及油气藏的形成与破坏.

THE RELATIONSHIP BETWEEN FAULTS AND OIL-GAS MIGRATION AND RESERVOIRING IN THE SOUTHEASTERN UPLIFT OF THE SONGLIAO BASIN

The southeastern uplift of Songliao Basin has been reconstructed for several times by tectonization,and formed complex fault system.Based on the characters,scale,forming time and space of the fault and its relationship with oil and gas,fault system can be divide into three types: early-fault,late-fault and early fault of later moved.Fault-controlled basin controlled the forming and evolution of the faulted sag,and fault-controlled sediment controlled the distribution of the better source rocks.Faults cannot be favorable in oil and gas migration when they are stopped moved,otherwise oil and gas can migrate vertically.Fault reservoir can be formed when its above slope possess impervious formation.Early-faults aren't migration for oil and gas,so early primary oil and gas accumulation formed in source rocks with better preservation.Traps often destroyed by early-fault and resulted in complexity and discontinuous of the oil and gas distribution.Late-faults and early-faults of later moved are favorable vertical migrated channels,meanwhile,the faults destroyed the primary oil and gas accumulation and lead to remnant oil and gas accumulation in shallow strata.Late-faults aren't lengthways for oil and gas migration when they are stopped moved.So late primary oil and gas accumulation can be formed with better reservation.The relationship between faults activity stage and hydrocarbon expulsive stage controlled the distribution,forming and destroy of oil and gas accumulation.