Study On The Conductivity-Saturation Model In Complex Pore Structure Reservoirs

Considerable amount of research has been put on the reservoirs with complex pore structure for a very long time.This paper studies the pore structure and electrical characteristics based on previous research.Based on the electrical imaging logging data,this paper analyzes and studies different reservoir types and pore structures and their characteristics on FMI images combining with the actual reservoirs.In order to extract and describe the fractures,we use the improved Hough transform and introduce a new method of sinusoidal function cluster.As for the holes in the reserviors,we add the prior information in the Hough transform to improve the efficiency and accuracy.Meanwhile,we analyze the electrical characteristics of reservoirs under 2-d and3-d conditions by using the extracted fractures structure and the equivalent medium models.In the two dimensional cases,the effective conductivities predicted by Maxwell approximation and differential methods depend on the pore aspect ratios and the conductivity ratios of different phases,and all these methods satisfy the reciprocity theorem.The differential method satisfies the H-S boundary condition,and Maxwell approximation exceeds the H-S boundary as the inclusion concentrations increasing.In the three dimensional cases,the effective conductivities obtained by Maxwell approximation and differential method fall well within the boundary condition when the value of inclusion concentrations is small.The self-consistent method could help make up for this defect,which considers the interaction among the phases and could get accurate results even when the value of inclusion concentrations is larger.After analyzing and studying the electrical characteristics of the reservoirs,we introduce the oil and gas saturation.The saturation by inverting and combining with the actual logging data could guide the actual productions.