Experimental Investigation of Temperature on Interfacial Tension and its Relation to Alterations of Hydrocarbon Properties in a Carbonated Water/ Hydrocarbon System

Abstract

The study addresses interfacial tension (IFT), and mass transfer in carbonated water (CW)/hydrocarbon systems, using the axisymmetric drop shape analysis (ADSA). Experiments and a mathematical model was used for CW+n-decane system of non-isobaric (10-70 bar) and non-isothermal conditions (25 o C, 35 o C, and 45 o C) using the axisymmetric drop shape analysis (ADSA). Further, the study addresses the inconsistencies of the reported in results reported in the literature between temperature and IFT. The experimental results (volume changes) and analytical equations have been used to develop a compositional model to estimate the mass of CO 2 diffused into hydrocarbon and the density of n-decane+ CO 2 as a function of time, pressure, and temperature. The obtained densities are then used to estimate real-time and the equilibrium IFT from the pendant drop experiments. The results indicated that for CW-n-decane system equilibrium IFT increases as pressure increases (10-60 bar), depicting an opposite trend to that observed for the CO 2-n-decane system. This was shown to be related to the density difference between the hydrocarbon and the carbonated water, and CO 2 solubility. Further, it was observed that the IFT was inversely related to temperature, which was credited to the changes in the kinetic energy and entropy. Among the three chosen temperatures, it was observed that the IFT at 35 o C did not display the same behaviour as that at 25 o C and 45 o C with pressure and temperature. Up to a certain pressure the IFT at 35 o C was lower than at 45 o C, and beyond this pressure, the IFT at 35 o C was greater than at 45 o C. The present article takes a step in resolving the controversy of IFT vs temperature and building the knowledge by carrying out a non-isothermal and non-isobaric study on the influence of temperature on the IFT in a system containing carbonated water and hydrocarbon. Further, the study gives an insight into the feasibility of carbonated water injection as a successful recovery process.

Enhanced Shale Oil Recovery by the Huff and Puff Method Using CO2 and Cosolvent Mixed Fluids

“…Finally, n -C 12 in the syringe was injected into the PVT cell to form a pendant drop, whose profile was captured by the camera. The recorded images were digitized to evaluate the IFT of the pendant drop. − …”