| Popis: |
The utilization of nanoparticles (NPs) as an agent for improved oil recovery (IOR) and enhanced oil recovery (EOR) has attracted a lot of attention over the past decade. NPs are known to have high mechanical and thermal stability and they can be tailored to meet the specifications of a given reservoir system. As a result, as opposed to polymers, NPs are suitable options for EOR processes as they are capable of withstanding high temperatures, pressures, shear and salinity in harsh environments often prevalent in subsurface oil reservoir systems. Researchers have made promising observations and results at laboratory scale, proving that nanoparticles possess the capacity and potential to reduce residual oil in the rock matrix thus increasing ultimate recovery. NPs have been observed to lower interfacial tension (IFT), reduce the viscosity of oil and alter wettability. This study presents an in-depth review of the oil displacement mechanisms that favour nanoparticle enhanced residual oil recovery. It goes on to review the causes and effects of NP retention in porous media. Processes carried out at laboratory scale and properly designed for reservoir fluids may fail when implemented at reservoir scale as a result of geological factors. Hence the review concludes by making recommendations for successful NP EOR projects. |
