Phase Behavior of High Pressure and Temperature Gas Reservoirs: Water Solubility and Density Measurement and Modeling from (3.7 to 132) MPa and Temperatures from (422 to 478) K

摘要

New water content and gas phase density data were measured for two synthetic light and intermediate gas mixtures from (3,7 to 132) MPa at temperatures of (422 and 478) K. The Cubic-Plus-Association equation of state (CPA EoS) was implemented in this study to reproduce the measured data. Accurate predictions were generated for the compositions of the equilibrium liquid and vapor phases by the CPA equation once the cross-association between molecules of wa.ter and light saturated hydrocarbons was considered in the phase equilibrium calculations. The performance of the CPA equation with zero binary interaction coefficients between water and hydrocarbons in reproducing the water content data was satisfactory; however the predicted hydrocarbons solubility data were poor. By coupling the CPA equation with the concept 6f cross-association no improvement was observed in the gas phase density predictions compared to the predicted results of the CPA equation with zero or tuned binary interaction coefficients.