Abstract:

Investigation of sedimentary structures，palaeontology associations and organic matter occurrence shows that the lacustrine deposition of Palaeogene upper E2-3s4 hydrocarbon source rocks is significantly controlled by the bottom anoxicity in
Jiyang Depression. Based on the previous studies on sedimentary organic facies and palaeo-oxygen facies，the source rocks are divided into four types of sedimentary organic facies including anoxic facies anaerobic facies，dysaerobic facies, and aerobic
facies，and the identification markers of each facies are summarized. Together with well logging data，the upper E2-3s4 source rocks are evaluated by single well，well-tie and distribution of sedimentary organic facies analyses. The results show great difference in the occurrence of the upper E2-3s4 hydrocarbon source rocks from the east to the west，and the upper source rocks in the east are obviously superior to those in the west. In addition，it is found that the distribution of excellent source rocks is mainly controlled by the northwest and northeast faulting movement. The finding will have great significance for making future exploration strategy and understanding deep subtle reservoir formation.

Key words: Sedimentary Organic Facies, Jiyang Depression, the Upper E2-3s4, Well Logging, Faulting