Abstract
A newly developed CO2-brine interfacial tension(IFT)correlation has been successfully developed to more accurately estimate the CO2-brine IFT for a wide range of reservoir pressure,temperature,and formation water salinity.The new CO2-brine correlation is expressed as a function of CO2-water density difference(function of pressure and temperature),temperature,and the valence-weighted molality of the cations.The novel aspect of the approach was to both correlate with density difference and include accurate temperature dependence of the parameters.This prediction model originated from a CO2-brine IFT database from the literature that covers 1298 CO2-brine IFT data including 484 for pure water and CO2.To examine its predictive capacity,the new CO2-brine IFT correlation is compared with four commonly used IFT correlations in the literature.It is found that the new CO2-brine IFT correlation provides more comprehensive and accurate reproduction of the literature pure CO2-pure water IFT data with an average absolute relative error(AARE)of 2.4% and standard deviation(SD)of 3.2%.In addition,the newly developed CO2-brine IFT correlation results in the accurate prediction of the CO2-brine IFT with an AARE of 2.4% and a SD of 3.4%.
NSTL