چكيده به لاتين
Abstract:
Immiscible displacements in porous media is one of the most important fields in reservoir and mechanical engineering. The issue of secondary and tertiary recovery, by considering the continuous oil recovery and decreasing the reservoir pressure, has significant importance. However, formation and development of viscous fingering instability is one of the challenges during these processes. Displacement of more viscous fluid by a less viscous fluid leads to flow instabilities in their interface which is called viscous fingering. In this study the numerical simulation of viscous fingering in immiscible displacements in porous media using the Darcy’s law is investigated. First of all, the governing equations of two phase flow in porous media are non dimensionalised and important functions and non-dimensional numbers are derived. Then sixth order compact finite difference method and Hartley transform are used for solving transport and vorticity equations, respectively. Finally, variation of transversely averaged saturation, start time of instabilities and breakthrough time at different mobility ratios, capillary numbers and aspect ratios are considered. One of the noticeable results of this study is that start time of instabilities and the breakthrough time is increased by reduction in mobility ratio and capillary number. Furthermore, intensity of instabilities and fingers extension is increased by increasing the mobility ratio.
Keywords: immiscible displacements, porous media, viscous fingering, mobility ratio, capillary number, aspect ratio.
