Research on Reservoir Sedimentary and Pore Characteristics of Chang 6 in Wuqi Oilfield

Abstract

In this paper, we utilized comprehensive geological analysis methods to identify sedimentary micro-facies in Wuqi Oilfield. Based on identification marks of sedimentary facies such as lithologic features, sedimentary structures and paleontological fossil, we classified the sedimentary micro-facies in this field into 4 types, including underwater distributary channel, mouth bar, distal bar and interdistributary bay facies. According to the observation of cores and casting thin sections, we made analysis on the pore characteristics of Chang 6 reservoir. The pore characteristic of target area is mainly intergranular space, which takes 3.27%, followed by feldspar and rock debris dissolution pore. The analysis shows that, the sedimentary thichness and grain size of underwater distributary channel are both quite big. The content of flake silicate mineral, for example, mica, is relatively low, but its porosity and permeability is high compared with mouth bar and distal bar. Interdistributary bay facies that has the lowest porosity and permeability are very strong.