Abdolhossein Hemmati Sarapardeh - PhD student of Petroleum Engineering, Amirkabir University of Technology,
Shabab Ayatollahi - PhD of Chemical Engineering, Sharif University of Technology
Mohammad Hossein Ghazanfari - PhD of Chemical Engineering, Sharif University of Technology
Mohsen Masihi - PhD of Chemical Engineering, Sharif University of Technology

Interfacial Tension (IFT) as the main parameter for CO2 flooding efficiency in oil reservoirs depends strongly on pressure, temperature, and composition of the reservoir fluids. Therefore, it is important to measure this parameter at real reservoir conditions for successful field development plan. In this study, an axisymmetric drop shape analysis (ADSA) has been utilized to measure the equilibrium IFTs between crude oil and CO2 at different temperatures and pressures. Moreover, minimum miscibility pressures (MMP) and first-contact miscibility pressures (Pmax) of crude oil/CO2 systems at different temperature levels are determined by applying the vanishing interfacial tension (VIT) technique. The results showed that the IFT has a decreasing trend with temperature at low pressures region, while it increases with temperature at high pressures. Also, MMP and Pmax were found to increase linearly with temperature. However, first-contact miscibility pressures (Pmax) increases with temperature much faster than the MMP for the temperature range of this study. The increase of MMP or Pmax with temperature is attributed to the slope of the equilibrium IFT versus pressure.

Interfacial tension; Vanishing interfacial tension technique; Minimum miscibility pressure; First-contact miscibility pressure; Temperature