Water Injection in Water-Wet Fractured Porous Media: Experiments and a New Model with Modified Buckley-Leverett Theory

This study examines water injection in water-wet fractured porous media and its modeling using the Buckley-Leverett theory. New experimental data on water injection in Berea and Austin chalk matrix block(s) are presented. Water injection in Austin chalk with a permeability of 0.01-0.04 md and porosity of 5% results in about 20% recovery from the rock matrix. In the second part of the paper, we use the Buckley-Leverett displacement in a dual-porosity model to simulate the literature data as well as experimental data from this work. A new model is devised for the simulation of water injection in fractured porous media. A major element of the new model is the multiplication of the transfer flux by the fracture saturation with a power of 1/2. This simple model can account for both cocurrent and countercurrent imbibition and computationally it is very efficient. The results of the proposed model and the fine-grid simulation are in good agreement with the experimental data.