Pore-Level Investigation of Heavy Crude Oil–Water/Chemicals Displacements in Heterogeneous Porous Media in the Presence of Ultrasounds

Despite numerous studies, fundamental understanding of how pore-level displacements in heavy crude oil–water/chemicals systems are controlled by ultrasonic radiation is not well understood, especially for heterogeneous porous media. In this study, a series of water/chemical flooding were performed on a heterogeneous rock-look-alike micromodel, which was initially saturated with the crude oil, and the pore-level displacements in the presence of ultrasounds are investigated. It has been observed that although the ultrasounds improve the recovery of oil adhered to the pores’ walls, the bypassed oil in the case of injection of surfactant and polymer solutions is relatively high. For the case of water injection, depending on frequency, the ultrasounds can profoundly improve the recovery efficiency up to 17% in comparison to the absence of ultrasounds by peristaltic movement of oil on the walls and forming the ganglia in invading phase, which first affect the minor fingers and then influence the major fingers by developing them through the untouched pores. In addition, some analyses on fingers development during water/chemical injections are presented. The results of this work help to better understand the role of ultrasound on displacement patterns in crude oil–water/chemical systems.