Study Of Source Rock Character And Hydrocarbon Accumulation In Sequence Stratigraphic Framework In Raoyang Sag

The theory and method of sequence stratigraphy are sufficiently used to improve sequence stratigraphy framework on the basis of system tract in Raoyang Sag. The relations of type, plane distribution and vertical superposition of sedimentary system controlled by sequence stratigraphy framework have been studied. The method to calculate total organic carbon (TOC) in source rock by logging is used to delicately portray the vertical characteristic of source rock cross section. The evaluation criterion of lacustrine source rock is based on the relationship between TOC and hydrogen index (HI). Combined with sequence stratigraphy, It's quite accuracy to predict the spatial distribution characteristic of lacustrine source rock. The study shows that the excellent source rock is firstly controlled by the change of lake level (third-order sequence), secondly affected by sediment supply rate and accommodation (fifth-order sequence or below). Therefore, system tract and sedimentary facies are the main controlled factors of the sedimentary characteristic and organic geochemistry parameter diversity of source rock. The results of oil-source correlation and the amount of resource show that excellent source rock plays important role in petroleum accumulation. 3D basin modelling technique and fluid potential inversion are used to model the process of petroleum generation, migration and accumulation, from the four exploration fields of Raoyang Sag, to realize the integrative evaluation of resource and target, to indicate the future replace exploration field.