Interfacial tension of brine/CO_2 systems at reservoir conditions

摘要

This paper presents experimental IFT brine/CO_2 data obtained at high pressures and for different salt concentrations. Experiments were carried out at three different temperatures (liquid and supercritical CO_2). Our experimental results evidence the existence of a plateau in the IFT brine/CO_2 values independent of temperature and pressure. This was confirmed at the different salt molalities here studied. The linear increase of IFT brine/CO_2 with molal salt concentration has also been evidenced. A good understanding of the interfacial phenomena and its properties is fundamental to the accuracy of the performance prediction of any CO_2 storage operation. This IFT increase could be very important in the calculation of storage volumes based on the estimation of the CO_2 capillary entry pressure into the brine-saturated caprock (P_(CE)).