FORMATION AND DISTRIBUTION OF OIL AND GAS FIELDS IN SUBEI BASIN

Subei\|South Huanghai basin and Bohaiwan basin are distributed symmetrically on two sides on Tanlu fault and separated by Lusu uplift. The basin evolution, hydrocarbon formation, resource abundance, oil and gas field scale of two basins are different since they are located on different tectonic setting. The in\|phase of crust\|mantle architecture, the hiatus of 18 Ma 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 with special characteristics of small, fragmental, poor, scattered in Subei basin. The differences of reservoir formation conditions and distribution of Subei basin and Bohaiwan basin demonstrate that Subei basin is short of the conditions to form large oil and gas fields. The exploration objects should predominately be medial\|small oil and gas fields, which has been verified by exploration in 25 years. The hydrocarbon from deep source rocks is of condition to form bigger gas fields.