This paper focuses on the development of natural convection mass transfer induced by gas diffusion in a liquid-saturated vertical porous column. The porous column is confined with two impermeable end faces and an isosolutal side surface. Mass transfer by natural convection is studied by numerically solving the conservation equations of mass, momentum, and diffusing species. To describe the transient behavior of natural convection, transient and integrated Sherwood numbers, i.e., Sh t and Sh i, are defined on the basis of a parallel pure diffusion case. The evolution of the natural convection process is systematically studied for the aspect ratios ranging from 0.125 to 8 and Rayleigh numbers from 10 to 1000. It is found that the Sherwood number increases with increasing Rayleigh number, whereas it increases first and then decreases with increasing aspect ratio. The results confirm the assumption in a previous study that the effect of natural convection is negligible on the diffusion process in the gas effective diffusion coefficient measurement, and also provide important implications on how to prepare core samples in laboratory for gas effective diffusion coefficient measurements.

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At present, chemical flooding is one of essential enhanced oil recovery methods. In this study, three core flooding experiments (brine flooding, Alkaline, and Alkaline + Ionic Liquid slug flooding) were selected for history matching using CMG-STARS. Depending on the composition of the chemical slug, two pore volumes were injected into the porous medium to enhance the RF of heavy oil (14° API). We observed that the most challenging part of building up the model was relative permeability curves. So, the relative permeability values were tuned to end up with a successful match of cumulatively produced oil and water cut. Finally, history matching is significant to apply a wide range of assumptions and upscale the experimental results.

Surfactant/alkali flooding is one of the best chemical flooding methods to enhance oil Recovery Factor (RF). In this research, Ionic Liquid/Alkali (ILA) mixtures were chosen to address the chemical injection technique. The selected Ionic Liquids (ILs), [EMIM][Cl], [THTDPH][Cl], [EMIM][Ac], [BzMIM][Cl], [DMIM][Cl], [BzMIM][TOS], [dMIM][TOS] and [MPyr][TOS], were introduced to investigate their efficiency in improving the extraction of heavy oil (14o API) from an unconsolidated sand pack at room conditions. Second, these ILs were mixed with synthetic formation brine (3.37 wt. % salts)/alkali (Sodium Bicarbonate [NaHCO3]). Then, 1 Pore Volume (PV) of these composites were injected and flushed with 2 PV of formation brine. The study discussed the influence of cation type, anion type, the structure of the ILs, and the effect of combining ILs and alkali on the RF. The results revealed that these ILs are efficient chemicals for enhancing the RF. ILs with shorter alkyl chain and more aromatic rings are noticeably efficient in enhancing the RF. Finding the right composition ([DMIM][Cl] + NaHCO3) of the chemical slug could increase the additional RF up to 31.55 (% OOIP). The recovery factor results supported by the effects of IL types on the viscosity, Surface Tension (SFT), and Zeta Potential (ZP) supported.