Abstract：The existence of shale and complex pore structure leads to complexity of electric conductance law in shaly tight sandstone,making it extremely difficult to quantitatively evaluate resistivity and saturation of shaly tight sandstone reservoir.The key to reservoir resistivity evaluation is the accurate acquisition of Archie exponent.Many researchers have studied triple porosity exponent m,most of these researches focus on the impact of complex pore structure without taking shale affect into consideration.In this paper,based on Waxman-Smith shaly sandstone model and Aguilera triple porosity model,the authors propose a new triple porosity conducting model for shaly tight sandstone,which is composed of shale,fractures and non-connected vugs.In the model the effects of shale and complex pore structure on porosity exponent m are considered.By single factor analysis,it is found that triple porosity exponent m decreases as fracture porosity increases,increases as non-connected vug porosity increases,and decreases as shale content increases.The validation of experiment data proves that the proposed model can accurately describe the electrical conducting law of shaly tight sandstone and can quantitatively evaluate the porosity exponent m.
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