Energy & Fuels, Vol.35, No.4, 2914-2935, 2021
Review of Density Measurements and Predictions of CO2-Alkane Solutions for Enhancing Oil Recovery
Enhancing oil recovery by injecting CO2 into the reservoirs is a widely employed technique in the oil industry. The density of solutions is a key property to affect the performance and design of CO2-enhanced oil projects. A comprehensive review is presented on the available density data and correlations of the equation of state (EOS) for CO2-alkane binary and ternary solutions in this paper. A sufficient set of data is available for CO2-alkane binary solutions, especially for CO2-decane solutions; however, for the rest of the CO2-alkane binary solutions, data of density are limited to a certain range of pressure and temperature at the phase-equilibrium and compressed-liquid states. The data have been used for EOS validations and the development of EOS correlations. Furthermore, data on CO2-alkane ternary solutions are limited. The temperatures and pressures in the seven available data sets reach 373.2 K and 19 MPa, respectively, which are limiting the development of EOS correlations. No density data are available for CO2-heptadecane/nonadecane binary solutions. From the validations of four selected EOS correlations, viz., Soave-Redlich-Kwong (SRK), Peng-Robinson (PR), Benedict-Webb-Rubin-Starling (BWRS), and perturbed-chain statistical associating fluid theory (PC-SAFT) EOSs, the SRK EOS is recommended for predicting the density of CO2-heptane/decane/tetradecane binary solutions. The rank of the correlations is SRK EOS, PC-SAFT EOS, PR EOS, and BWRS EOS.