Effect of surface wetting behavior of ceramic proppant on the two‐phase flow across the interface of sandstone and fracture

Abstract

AbstractThe objective of this study was to gain an understanding of water‐oil two‐phase flow from sandstone reservoirs to propped hydraulic fractures. The effects of PC (code for provider) oil‐wet and water‐wet fracture proppants on the competing flow of water and oil from Parker Berea and Upper Gray Berea sandstones to proppant‐packed fractures were experimentally investigated in this study. Water and oil were simultaneously injected into core sample, and the injection volume at water breakthrough was used as a measure of phase flow efficiency. The PC oil‐wet ceramic proppants were found to have the property of attracting‐oil‐repelling‐water (AORW) effect on the water‐oil two‐phase flow from sandstones to proppant‐packed fractures. This effect is explained by the theory of oil and water channels in the sandstones. Oil‐wet proppant particles contact oil channels in the sandstone and attract oil into the fracture owing to the affinity between the oil‐wet surface and the oil in the oil channel. The AORW effect of PC oil‐wet proppant was found to drop as the water cut in the sandstone increases. This is attributed to the fact that there are more water channels in high water‐cut sandstones than in low water‐cut sandstones, reducing the chance for the oil‐wet proppant to contact oil channels and attract oil. The PC oil‐wet proppant was found to behave differently in different types of sandstones. Its AORW effect is higher in low‐permeability sandstones than in high‐permeability sandstones. This may be because there are more oil channels in low‐permeability sandstones than in high‐permeability sandstones, increasing the chance for the oil‐wet proppant to contact oil channels and attract oil.