Geochemical characteristics and oil source correlation of the paleogene source rocks in Menggangji Sag

Aim For the purpose of evaluation of the hydrocarbon generation potential in Menggangji Sag,Dongpu Depression.Methods On the basis of analysis about the abundance and the types of Paleogene(Es_1,Es_3) organic matters of 21 wells in Menggangji Sag,Dongpu Depression,and research about the source rock′s maturity and the thermal evolution history,evaluate the hydrocarbon generation potential of the source rocks by means of organic petrology,rock-evel,geochemistry,oil-source correlateion.Results Es_1 source rocks are middling-relatively bad;lower part of Es_3 source rocks in north of Menggangji Sag are middling-relatively better,and the upper parts are relatively bad or non-source rocks;otherwise,there are non-source rocks in south.There are two types of organic matters in Es_1 source rocks(Ⅰ,Ⅱ_1),and Es_3 is mainlyⅡ_1,Ⅱ_2;Most of Es_1 source rocks are in the lower-maturity stage,the upper part of Es_3 is in maturity stage,the lower in relatively high-maturity stage.It is found that the well pushen 8 crude oil should be formed of organic matter from lower part of Es_3.Conclusion It is concluded that the best source rocks are thought as the lower part of Es_3,the north of Menggangji Sag is the prospective areas for further hydrocarbon exploration.