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.