Study on the Induced Polarization Characteristics and Anisotropy of Reservoir Shale under Dynamic Fracturing

Abstract

Hydraulic fracturing, as a technique that utilizes pressurized fluids to break underground rocks, plays an important role in unconventional reservoir oil and gas development. Unlike microseismic monitoring, electromagnetic monitoring methods have been used to optimize
hydraulic fracturing design or achieve hydraulic fracturing monitoring. Researchers have conducted fracturing simulations under laboratory conditions, but so far, there has been limited research on the complex electrical resistivity characteristics of hydraulic fracturing shale,
especially the anisotropic characteristics of complex electrical resistivity. This article combines the hydraulic fracturing experiment of tight
reservoir shale in Longmaxi Formation to measure the complex electrical resistivity before and after shale fracturing, and studies the degree
of shale electrical change and anisotropic characteristics under hydraulic fracturing. The research results indicate that the induced polarization
characteristics of fractured reservoirs after fracturing are greatly influenced by the fracture surface, and the enhanced connectivity of reservoir
pore structure is the main reason for the decrease in resistivity. This study has laid a theoretical and experimental foundation for the exploration, development, and evaluation of reservoirs.