The Micro-Flow Mathematical Model Study on ViscoelasticPolymer Displacement Viscous Oil

Zhong Huiying; Zhang Weidong; Liu Yikun; Yin Hongjun

doi:10.3799/dqkx.2017.542

Abstract：With the development of economy and the rising demand for oil resources, the exploitation of viscous oil, bitumen and oil shale is an important challenge for the oil industry while the recoverable reserves of conventional crude is decreasing constantly. The viscous oil resources of our country is rich, but the polymer flooding is the main method enhancing viscous oil recovery due to restrictions of non-available steam generation facilities off-shore. So it is significant to study on micro flow mechanism deeply for further enhancing viscous oil recovery. The existing study on the polymer flow mechanism is mainly limited to the single phase flow in micro pore, and little study of viscoelastic polymer and oil two-phase flow characteristic has been done especially with viscous oil. In this study, we develop two phases of viscoelastic polymer and viscous oil solver on the OpenFOAM platform based on computational fluid dynamics, and we study the mechanism of viscoelastic polymer flooding viscous oil based on the solver. In this paper, the contraction model and mathematical model is established, including the continuity equation, momentum equation and constitutive equation of two phases, and interface equation solved by VOF (volume of fluid) method. The solver of viscoelastic and power law fluid is developed based on OpenFOAM. The saturation, velocity and stress distribution is drawn with different elastic polymer solutions. The results show that the front breakthrough time is slower, the sweep efficiency is larger and displacement efficiency is higher than water flooding. The elasticity of polymer can enhance oil recovery. The larger is the elasticity, the smaller the dead oil area in convex corner. The stronger of elasticity is, the lager of normal stress is. The elasticity can make the most of displacement oil when the polymer flows in contraction of the model. The results of this paper can supply the theoretical support basis on polymer design and filter, it is significant for implementation of polymer flooding in oil field.