چكيده به لاتين
Abstract:
According to statistics, oil will play many years a prominent role in the economy of our country, this reveals serious attention to research in this area. Determining the number of operating parameters of oil and gas reservoirs in economic terms, is important and will have a direct impact on the operation and management of reservoirs. In this study, a solution of water and surfactant as an effective parameter of surface tension injected into the micro model that has been saturated with oil with the rate of 10e-12 m3s-1 and oil recovery is calculated 57%. Laboratory result is used to verify computational fluid dynamics (CFD) simulation and 11 percent error is observed that is in acceptable range. OpenFOAM CFD simulation software and volume of fluid (VOF) model was used to investigate the two phase flow through porous media. The PISO algorithm for coupling of velocity and pressure equations and corrant number of 0.25 was considered. The effect of surface tension, viscosity ratio, the speed of injection, throat size, density and contact angle on the flow regime, oil recycling, fluid motion through the pores and throats studied with using CFD. The simulation results show that in small amounts of viscosity ratio (lower than 0.1), high speed stream (higher than 1e-5 ms-1) and low levels of surface tension (lower than 1 mNm-1) viscous fingering occurs. In high interfacial tension (higher than 7.5 mNm-1) capillary fingering observed. In water wet media the fluid will tend to adhere to walls and the rapid growth of finger have been seen along the walls. In oil wet media thin fingers with a large number of branches can be seen. With the increasing density, significant changes, not observed in recovery factor. So that by increasing the in situ fluid density from 800 to 1000 Kgm-3 only 7 percent recovery added. Throat size has a significant impact on the flow, trapped fluid and finger width, so that by increasing the size of throat, thicker fingers are formed at later times.
Keywords: Micro model, enhance oil recovery, computational fluid dynamics, porous media simulation, volume of fluid
