SEDIMENTARY MICRO-FACIES AND REMAINING OIL DISTRIBUTION IN THE SECOND DISTRICT OF SHAHEJIE FORMATION IN THE SHENGTUO OILFIELD

The properties of sedimentary microfacies and remaining oil distribution were analyzed on the core analysis and log interpretation. The second section of Shahejie Formation in the second district (Es\-2) in Shengtuo Oilfield developed the typical fluvial dominated delta deposition. The seventh sand group of Es\-2 is of the delta plain deposition and has developed underwater distributary river course, levee and interdistributary bay microfacies. The characteristics of braided river course in every substratum and rhythmic bedding are distinct. The eighth sand group is of the delta front deposition and has developed debouch bar and far bar microfacies. The bar top, bar host, bar side and far bar in rhythmic bedding appeared from shore to basin in turn. In this area, the distribution of remaining oil was controlled by the distribution of sedimentary microfacies in second section of Shahejie Formation. The remaining oil was mainly distributed in the middle and upper parts of distributary river course, the middle and down parts of inter channel thin sandstone and debouch bar in vertical. The remaining oil was distributed in the sandstone of river edge, the side and the top of bar in plane.