Numerical Simulation Study on Electrical Properties of Proppant-Containing Fracture Fillers

In the implementation of diagnosing fracturing fractures using electromagnetic methods, a lack of understanding of the electrical properties of fracture fillers can directly lead to incorrect diagnostic conclusions. This research utilizes finite element method (FEM) numerical simulation technology to analyze the electrical parameter characteristics of fracture fillers, specifically focusing on proppant particles arranged in a stacked configuration under pressure. The comparative analysis of the stacked structure mixture model reveals the shortcomings of the widely utilized equivalent medium formula, which fails to accurately characterize the low-frequency equivalent electrical properties of the fracture fillers. The findings indicate a significant disparity between the electrical properties of the filler and those of the proppant, suggesting that it is inappropriate to equate the electrical properties of the proppant with those of the fracture itself. As pressure increases, the conductivity of the fracturing filler exhibits a continuous rise, ultimately stabilizing at a constant value. The primary factor contributing to this phenomenon is the stacking contact of the proppant, which provides a coherent explanation for the previously observed alterations in the pressure curve associated with coal coke piezoresistivity measurements. Furthermore, it is important to note the overlap between the logging frequency and the frequency range of packing relaxation.