Corner flow advancement in porous media
Preferential wetting of solids by one fluid can induce capillary driven flows in two phase fluid systems. The existence of geometrical inhomogeneities in the form of surface roughness can increase the curvature of the interface, hence, it may strengthen the capillary driven flow at the corners. Corner flow can play a significant role in many processes the involve two phase flow in porous media such as enhanced oil production from or gas storage in underground reservoir rocks. This dissertation addresses some of the issues related to the corner flow in porous media primarily from an experimental point of view. First, the existence of corner flow is stablished in systems where water (the wetting phase) is injected into the micromodel that is initially saturated with mineral oil. Before water reaches to the outlet port of micromodel, i.e. the breakthrough of water, the viscous forces are dominant in advancing the two-phase front. The images of experiments reveals the propagation of water ahead of the finger. However, the water propagation, driven by corner flow, continues until the capillary forces is balanced out by the resistance to move the viscous oil. In the second part of the thesis, the effect of corner flow on the heavy oil displacement experiments by water and a surfactant solution is studied. The experiments show that, in surfactant flooding systems, the corner flow contributes in the post-breakthrough heavy oil production by spreading of surfactants ahead of the water finger boundaries, hence, promoting the oil in water emulsification. Consequently, the emulsified oil droplets are mobilized and produced by the main water stream. Finally, the impact of corner flow on the gas (hydrogen) storage capacity of a water filled pore-network model is established. During the imbibition process, the corner flow leads to the trapping of significant volumes of hydrogen in larger pores. It is revealed that the gas storage increases by salinity in the designed pore-network model primarily as a result of a decrease in the volume of residual water fingers at higher salinities. Consequently, all salinities have a similar storage capacity, despite the differences during the drainage and imbibition processes.
Ghoreishi, S. A. (2023). Corner flow advancement in porous media (Unpublished master's thesis). University of Calgary, Calgary, AB.