Sedimentary microfacies and lithologic trap types of Neogene Hanjiang Formation in Enping Sag

Hanjiang Formation of Neogene is the main reservoir section of oil and gas in Enping Sag of Pearl River Mouth Basin. With the improvement of exploration degree, searching for lithologic oil and gas reservoir is an important direction of oil and gas exploration in the future. In order to systematically study the development types of lithologic traps in this area, under the guidance of the theoretical model of "sedimentary sequence", the high-level system tract, transgressive system tract and low-level system tract are divided. The key sedimentary units are enhanced by well-seismic combination, core observation and RGB attribute fusion technology, and the fine sedimentary microfacies are studied. Six sedimentary microfacies are identified: braided channel, gully channel, meandering channel, estuary bar, coastal sand ridge and far sand bar On the basis of microfacies sand body characterization, combined with structural characteristics, three lithologic trap types developed in this area are summarized, i.e., structural-lithologic trap, lithologic trap of multi-sand body type and lithologic trap of upward dip pinchout type. Among them, structural-lithologic trap with channel sand as reservoir in the middle and southwest of sag is the most potential target type for exploration.