Sedimentary Microfacies of Chang10 Reservoir of Yanchang Formation in the Gao52 Area of Ansai Oil Field

The origins of the main sand bodies in Gao52 area of An sai Oil Field are interpreted jointly with studying field sections,core descriptions and logging date .The Chang-10 reservoir horizons in this area are delta plain,The main sedimentary microfacies include distributary channel, channel edge (levee, crevasse-splay), distributary estuary and flood plain, The distributary channel sands constitutes the dominated reservoirs.Grain size distributions of the sandstones are investigated by measurements in this sections, The overall grain size distributions are characteristic of delta sands on the basis of cumulative curve skewness standard deviation, C-M pattern , distribution scatter and depositional setting distinguish.Sedimentary microfacies of Chang10 reservoir of Yanchang Formation in the Gao52 area of An sai Oil Field was studied in combination with the area information of core microfacies profile and logging profile. The change regularity of microfacies were grasped and the relationship of Sedimentary microfacies and hydrocarbon were discussed.The results show: The reservoir physical property and reservoir oil saturation are controlled by microfacies.The distributary channel is the good reservoir,the reasearch of sedimentary microfacies in this paper can provide technology support for efficient development of this area.