جستجوی مقالات مرتبط با کلیدواژه "phase field" در نشریات گروه "مهندسی شیمی، نفت و پلیمر"

Multiphase fluid flows occur when two or more fluids that could not be able to mix (such as air and water) find an interface. Multiphase flows can be categorized to single component multiphase fluids, e.g., water and vapor, and multi-component multiphase fluids such as oil-water mixture in porous media. These multiphase flow modeling methods that are divided into microscopic, mesoscopic and macroscopic approaches have been the major focus of this review paper by emphasizing on the methods of population balance model, level set, phase field, lattice boltzmann, size exclusion, front-tracking, and volume of fluid. As result of this study, it could be mentioned that the front-tracking and phase field methods could be accounted as methods with high accuracy and that level set and volume of fluid methods are conceptually simple, while the phase field methods are struggling with complex computational analysis. Achieving to the numerical instability like what happens to the lattice Boltzmann method is more probable than phase field and volume of fluid method. Less time is the main advantage of the lattice Boltzmann method while the population balance method is suffering from long time of analysis. Finally, selection of an appropriate methods most be excuted based on concept of problem, time, cost and accuracy of considering systems.

Carbon dioxide (CO2) gas flooding has long been regarded as a popular method of improving oil recovery as it can reduce the carbon footprint in the atmosphere through carbon storage and CO2 sequestration. Miscible flooding is considered the most efficient way to reach the maximum oil recovery factor. However, not only do not all oil reservoirs experience pressures above miscibility but also due to difficulty in retaining reservoir pressure in the desired region, numerous miscible flooding operations experience pressure decline below minimum miscibility pressure (MMP). In these circumstances, a near-miscible process seems to be attainable and practical compared with a miscible injection. In the current study, we exclusively focus on pore-scale near-miscible CO2-oil displacement. In this regard, the effective near-miscible region is determined based on the available criteria in the literature. Then at the lower-pressure limit of the defined near-miscible region, Phase-Field coupled with the Navier-Stokes equation as the numerical approach is implemented to investigate the CO2-Oil displacement by capturing the diffusive interface properties and hydrodynamic properties of fluids. Quantitative analysis of results, to better realize the pore-scale mechanism of oil recovery demonstrated that if the pressure conditions are maintained throughout the modeling in the effective near-miscible pressure region, almost significant amounts of by-passed oil in the pores from small to large to be recovered and the oil recovery increased from 50% to more than 90% approaching the results of miscible gas injection. This outcome can accentuate the significance of near-miscible CO2-EOR in operation applications.