Phase Interference in Multiphase Flow in Thin Gaps
Abstract
An immense quantity of hydrocarbon fuel is trapped in the fractured reservoirs, which is challenging to recover due to a number of issues such as heterogeneity of the reservoir’s properties, higher permeability of fractures than that of the matrix, and multiphase flow through the fractures. On average, the recovery of oil from these reservoirs is relatively low and there is a requirement to improve the performance of recovery processes in these systems. The research documented in this thesis deals with multiphase flow, in particular parallel flow of oil and water, in fractures, modelled as a single narrow gap Hele-Shaw cell. The effects of additives such as polymer, surfactant, and rod-like nanoparticles have been examined to determine how they impact the nature of the interfaces between the oil and water and the amount of oil displaced from the gap. Differential pressure, flow rates and images of the flow structures were acquired to provide a basis for both quantitative and qualitative analyses of the flows. In the case of co-injection of water and oil, different flow structures observed changed with phase flow rates – oil entrapment occurred in several forms including trapped connected oil as well as irregular and immobile droplets. The relative permeability and hysteresis observed in the experiments demonstrated the dependence of the flow on the direction of wetting phase saturation change. Surfactant (sodium dodecyl sulfate) addition to the water revealed that with the associated interfacial tension reduction, oil displacement improved and oil droplets formed at the oil-water interface. The addition of polymer (polyethylene oxide) to the water raised the viscosity of the aqueous phase which in turn improved the displacement of oil. Another key observation was the adsorption of polymer on the plates of the Hele-Shaw cell which changed the wettability of the plates leading to enhanced oil displacement. The addition of cellulose nanocrystals (CNC) to the water significantly improved oil displacement due to viscosity enhancement of the aqueous phase as well as reduction of the interfacial tension. Microscope observation also revealed the formation of a microemulsion adjacent to the oil-water interface.
Description
Keywords
Engineering--Petroleum
Citation
Raza, S. (2016). Phase Interference in Multiphase Flow in Thin Gaps (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/27327