Estimation of Paleogene Wenchang Formation Resources and Exploration Direction in AB Depression,Pearl River Mouth Basin

AB Depression is one of the major petroleum contribution areas in Peal River Mouth Basin,and it is significant to the research of source rock characteristics and petroleum resources.Source rocks of Wenchang Formation have large thickness and wide distribution area,with Ⅰ-Ⅱ1 organic matter which reaches 2.27% on average and develops in middle-deep lacustrine facies.There are relatively few geochemical data in AB Depression.The third sequence as the basic unit goes on estimating quantity of hydrocarbon generation and quantity of resources of Wenchang Formation for the four sub-sags which are the A1,A2,A3 and A4,with the next area and comprehensive information.Resources of the four sub-sags are 1.007×10⁸,1.343×10⁸,2.545×10⁸ t and 1.705×10⁸ t respectively.Estimation result shows that A3sub-sag is the most favorable,A4sub-sag followed,A2sub-sag of again,A1sub-sag is minimal.The research area has updip pinch-out and lenticular trap.Because of the feature of oil and gas which has gathered nearby,the big oil and gas reservoir is located in north central of AB Depression.