Effects of caves on resistivity of vuggy carbonate reservoirs

The pore structure characteristic parameters of carbonate reservoirs were extracted, and matrix resistivity of vuggy formation was calculated by the percolation network simulation. A segmented cross-scale resistivity calculation method was established, in which the finite element method was used to simulate the resistivity of vuggy reservoirs. The mathematical models of cave porosity and water saturation with rock resistivity in vuggy carbonate reservoir were established, and the relationships between them were obtained. Experimental results verified the reliability of the simulation results. The method presented provides new technical means and research method for the resistivity log interpretation of vuggy carbonate reservoirs. The matrix porosity, cavity porosity and matrix pore water saturation are the key factors determining the resistivity of reservoir rocks.