High quality oil prone source rocks in Jiyang Depression

Source rocks of Jiyang Depression are investigated to characterize their sedimentary fabrics, sedimentary environments, biology developments, organic geochemistry, and hydrocarbon formation processes. Together with many years of exploration experiences, wire logs and well cores analyses discover three series of high quality oil prone source rocks in E2,3 Shahejie Formation. They all have good organic types, high abundance of organic materials and high hydrocarbon potentials. Distinctness also has been discovered in biomarkers, carbon isotope compositions and thermal evolutions, which can provide much help in oil/source rocks correlation. Based on the differences between common and high quality source rocks in hydrocarbon potential and in contribution to the hydrocarbon and petroleum pool formation, it is proposed that existing of high quality source rocks or not is the key determining factor for the occurrence of an oil rich depression. High quality source rocks have much significance for the oil and gas formation in terrestrial lake basins.