Reservoir Petrophysical Characterization in High Water Cut Stage in Gudao Oilfield

Reservoir sandstones have big pore space; wide throat size and high permeability in Guantao Formation, Gudao Oilfield. Reservoir pore textures can be divided into 6 types. The main clay minerals are I/S mixed and kaolinite in fine grain size sandstones. Water sensibility and flow sensibilities exist in reservoir. Comparing the very high water cut stage with early and middle stage of oilfield development, sandstones permeability increases several times, and the contents of clay and immovable water decrease obviously. Reservoir petrophysical parameters were different in 4 micro facies units controlled by fluvial facies in Gudao oilfield.