Probing the generation mechanism of emulsion based on shearing actions between multiphase fluids in porous media

The generation, migration, and coalescence processes of emulsions in porous media of the actual formations are relatively complex. However, few studies have been reported about the generation mechanism of emulsions under shearing action, especially under shearing action between multiphase fluids. In this paper, the concept of emulsification caused by fluid shearing was proposed for the first time. An oil-water two phases flow model in porous media was established to study the generation process of emulsion caused by shearing actions between oil and water. Fluid flow velocity, pressure and distribution characteristics of oil and water during this process were recorded. The effects of flow velocity and oil-water interface properties on the generation process of emulsion were investigated. Combined with the microscopic visualization oil displacement model, the generation characteristics of emulsions in porous media were further explored. The results indicated that the complex flow between oil and water in porous media would cause shear emulsification of crude oil. With the increase of flow velocity of oil-water two phases, the shear emulsification capacity was gradually enhanced. The generation capacity of emulsion in the micro shearing unit was mainly affected by the flow velocity of the displacing phase, and the particle size of the emulsion was mainly affected by the flow velocity of the shearing phase. When the interfacial tension between oil and water was lower than 10(-1) mN/m, the shear emulsification rate did not change significantly. These results are of great significance for the supplement and improvement of the generation mechanism of emulsions in porous media, providing theoretical guidance for further enhancing oil recovery by regulating emulsification.

Automated summary

This paper proposes the concept of emulsification caused by fluid shearing and establishes an oil-water two phases flow model in porous media to study the generation process of emulsion under shearing action. The results indicate that complex flow between oil and water in porous media leads to shear emulsification of crude oil. The flow velocity and interface properties have an impact on the generation process of emulsion.