OIL AND GAS FIELDS FORMATION AND DISTRIBUTION OF SUBEI BASIN-RESEARCH COMPARED TO BOHAI BAY BASIN

Subei south Huanghai Basin and Bohai Bay Basin are distributed symmetrically on the side of Tanlu fault,and are separated by Lusu uplift.The basin evolution,hydrocarbon generation,resource abundant,oil and gas field scale are different between two basins since they are located on different tectonic setting.The isopicphase of crust mantle architecture,the hiatus of 18Ma from later Eocene to Oligocene,the lower evolution of organic matter,the strong reformation of fault activities etc resulted in the formation of the oil and gas bearing characteristics of “small,fragmental,poor,scattered” in Subei Basin.The differences of reservoir formation conditions and distribution between Subei Basin and Bohai Bay Basin demonstrate that Subei Basin is lack of the conditions to form large oil and gas field,and the exploration objects should predominantly be medial small scales.This has been verified by 25 years exploration, but the hydrocarbon from deep source rocks is of condition to form bigger gas fields.