Study On Electrical Properties In Shaly Sandstone Based On Capillary Model

With the development of oil exploration, the oil and gas reservoirs in shaly sandstone have been found gradually, which have industrial flows of oil and gas. So shaly sandstone reservoir is the main source of oil-field to increase production. Compared with the norma sandstone reservoir, the electrical conduction mechanism of shaly sandstone reservoir have been changed. Especially, when the shaly and formation water and rock matrix containing conductive minerals or many other factors existed simultaneously in the same reservoir, the electrical conduction mechanism of the reservoir is more complicated. Therefore, electrical properties of shaly sandstone reservoir are an important research topic at home and abroad.In this paper, the electrical properties of shaly sandstone and the electrical properties of rocks during water flooding have been studied by numerical simulation, we itemize the main conclusions of my study: (1) Based on the physical properties of reservoir rocks and micropercolation mechanism of capillary model, we derived the relationship between physical properties of reservoir rock and parameters of microcapillary model. According to electrochemical kinetic theory in porous media, we deduced the resistivity expression of water-bearing shaly sandstone. (2)According to the seepage characteristics of reservoir fluid, we establish the oil capillary model to simulate oil shaly sandstone, deduced the expression of capillary model and resistivity expression of oil-bearing shaly sandstone. We study the influences of petrophysical parameters on the oil-bearing shale sandstone resistivity. At the same time, we analyze the influence of rock properties on Archie formula saturation index and resistivity index. (3)Application of constant pressure injection water rock power theory ,pushed out the water resistivity of rock equation about the water channeling before and after, numerical simulation of the reservoir permeability characteristics and the impact of injected water resistivity.Through the study of variation of rock resistivity in the shale sandstone and water flooding process, we deep understand the physical properties of the reservoir and provides a theoretical basis in log interpretation and technical guidance for the oil and gas exploration and development.