FORMING OF GAS POOLS IN THE CHENJIAZHUANG SALIENT, THE BOHAIWAN BASIN

The Chenjiazhuang salient is located between Zhanhua sag and Dongying sag.Oil and gas exploration there started in the 1960s.Up to now,a lot of natual gas accumulations are found.The natual gas in this area has two sources.They are from the Bonan depression and the Lijin depression.The deep natual gas migrates upward along faults,forming palaeo-generated-newly-stored type of gas accumulation.The reservoir is mainly composed of the braided channel sedimentary sand in Guantao formation and meandering river sedimentary sand in Minghuazhen formation.Moreover,the capping beds over Guantao formation and Minghuazhen formation have developed.The conditions forming gas accumulation are excellent.The plane distribution of the shallow gas in this area is mainly controlled by structural setting and sedimentary facies.The longitudinal distribution of the gas is mainly controlled by the ratio of sandstone to mudstone in formations.Exploration of natual gas in Chenjiazhuang area has a widely promising future.