STRUCTURAL-DEPOSITIONAL FEATURE AND OIL-GAS RESERVOIR DISTRIBUTION IN THE TANGYUAN FAULT DEPRESSION

Developed on Premesozoic basement,the Tangyuan Fault Depression is a Mesozoic and Cenozoic Fault Depression.Basin controlled by two large faults toward NNE,cut by faults toward NW with divided zones between east and west and fault blocks between south and north.It exited Cretaceous and Paleogene two relatively dependent structure and oil-gas unit with fan delta-lake depositional system.The results illustrated that the Tangyuan Fault Depression went through three stages: early fault depression in Mesozoic,developing fault depression and late fault depression in Cenozoic.Its feature is giant sedimentary thickness,maximum 6 000 metres.Cretaceous and Paleogene are formation of interest.As a result of Yanshan event at the end of Cretaceous and Himalayas event at the late Cenozoic,prototype basin is subjected to strong deformation;prototectonics and sedimentary frames were obviously changed;oil-gas reservoirs were destroyed.Oil-gas reservoirs are principally controlled by faults and lithology.