Geological Evolution of Huangyan Area in Xihu Sag and the Influence of Oil and Gas Migration in Fault Zone

Geological evolution of Huangyan area can be divided into four stages:Extension stage from Paleocene to Eocene, basement fault controlled the fault blockactivatio n;Subsidence stage from Oligocene to Mid-Miocene, fault block activation only occurred in early-middle Oligocene;Structure reversion stage in Late Miocene, formed the huge reversal anticline, NNE and EW trend cover fault;Regional subsidence stage from Pliocene to Quaternary, the EW trending reactivated.Active faults in Late Miocene and Pliocene-Quaternary has st rongly impacted on the oil and gas migration and accumulation in Huagang formation.