Experimental Determination of Interfacial Tension and Miscibility of the CO₂–Crude Oil System; Temperature, Pressure, and Composition Effects

Abstract

Interfacial tension (IFT) as one of the main properties for efficient CO2 flooding planning in oil reservoirs depends strongly on pressure, temperature, and composition of the reservoir fluids. Therefore, it is important to measure this property 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 (P max) of crude oil/CO2 systems at different temperatures are determined by applying the vanishing interfacial tension (VIT) technique. Besides, the effects of paraffins content and resin to asphaltene ratio of the crude oil on the IFT behavior are investigated. The results show that while the IFT has a decreasing trend with temperature at low pressures region, it has an increasing trend with temperature at high pressures. Also, MMP and P max were found to increase linearly with temperature. The results indicate that paraffin has a critical effect on the crude oil/CO2 IFT behavior. It was also found that the lower the ratio of resin-to-asphaltene is, the more is the possibility of asphaltene precipitation as determined by examining the IFT behavior of the solution. Moreover, the results verified that the higher is the molecular weight of heavier components of the crude oil, the higher are the MMP values obtained.

Experimental investigation of miscibility conditions of dead and live asphaltenic crude oil–CO2 systems

“…This different effect is due to the accumulation of colloidal particles at the interface of the two phases. In general, the composition of the gas phase and heavy components of crude oil is two key factors that can likely affect FCMP (Gu et al 2013;Hemmati-Sarapardeh et al 2013). Several researchers have also demonstrated that the pressure of miscibility conditions of the crude oil-CH 4 system is higher than that for the crude oil-CO 2 system (Kazemzadeh et al 2015;Tathed et al 2010).…”

Using an artificial neural network to predict carbon dioxide compressibility factor at high pressure and temperature

“…Among enhanced oil recovery (EOR) methods, CO 2 injection has gained much popularity due to its considerable effect on oil recovery enhancement and reducing the amount of greenhouse gas emissions by its sequestration in depleted oil reservoirs [1,2].…”

Impact of asphaltene and normal paraffins on methane-synthetic oil interfacial tension: An experimental study

“…Several methods for IFT measurements have been proposed in the literature such as capillary rise, Wilhelmy plate, maximum bubble pressure, drop weight, sessile drop, spinning drop and pendant drop (Zolghadr et al, 2013a;Hemmati-Sarapardeh et al, 2014;Andreas et al, 1938;Winkel, 1965). Among these methods, the sessile and pendant drop analyses are reported to be consistent and more reliable at high pressure and high temperature (HPHT) conditions, which may be encountered during oil recovery (Winkel, 1965;Rotenberg et al, 1982).…”