Impact of solutal Marangoni convection on oil recovery during chemical flooding

Abstract

AbstractIn this study, the impacts of solutal Marangoni phenomenon on multiphase flow in static and micromodel geometries have experimentally been studied and the interactions between oil droplet and two different alkaline solutions (i.e. MgSO4 and Na2CO3) were investigated. The static tests revealed that the Marangoni convection exists in the presence of the alkaline and oil which should carefully be considered in porous media. In the micromodel experiments, observations showed that in the MgSO4 flooding, the fluids stayed almost stationary, while in the Na2CO3 flooding, a spontaneous movement was detected. The changes in the distribution of fluids showed that the circular movement of fluids due to the Marangoni effects can be effective in draining of the unswept regions. The dimensional analysis for possible mechanisms showed that the viscous, gravity and diffusion forces were negligible and the other mechanisms such as capillary and Marangoni effects should be considered in the investigated experiments. The value of the new defined Marangoni/capillary dimensionless number for the Na2CO3 solution was orders of magnitude larger than the MgSO4 flooding scenario which explains the differences between the two cases and also between different micromodel regions. In conclusion, the Marangoni convection is activated by creating an ultra-low IFT condition in multiphase flow problems that can be profoundly effective in increasing the phase mixing and microscopic efficiency.