Study On Sand Body Distribution Of The Second Member Of Kongdian Formation In Shenvsi Oilfield

The development of the second member of kongdian formation in Shenvsi oilfield is a braided river delta facies and lacustrine facie. The braided river delta is a nice reservoir with good potential of hydrocarbon generation. The related researches play a significant role in sedimentology field and oil-gas exploration nowadays.Combined with the pre-existing stratigraphic division project, the high resolution sequence stratigraphic frame with short-stage cycle(SSC) as the basic unit which has been built up by comprehensively utilizing the core and well logging data. The studied area has been divided into tenth SSCs according to Zheng Rongcai's standard stratigraphic division project.Through the methods of heavy minerals and detrital component, which is mainly supported by the Northwest Cangdong fault. On the basis of the theory mentioned above, the characteristics of braided river delta sedimentary were analyzed systematically and the microfacies were described separately.The study area mainly develops three microfacies, including the plain of braided river delta, the front of braided river delta and the pro-braided river delta. The front of braided river delta develops underwater distributary channel, between submarine distributary channel, the channel mouth bar and distal bar. Yet the sheet sand is undeveloped. The prodelta mud limitedly distributes among pro-braided river delta microfacies and usually joins with the shore-shallow lacustrine. Under the guidance of modern sendimentary theory, according to the spatial distribution characteristics, the deposition model of braided river delta sedimentary facie and lake has been built, combined with the sandstone thickness contour map and sand than contour map of the sand body distribution characterization. Finally, the distribution of sand bodies is induced, which provides support for the further exploration, reservoir evaluation and the reservoir fine description.