An improved cubic model for the mutual solubilities of CO2-CH4-H2S-brine systems to high temperature, pressure and salinity

The available experimental data of pure gas brine equilibrium and gas mixture solubility in water/brine are carefully reviewed and compared with the new model. From the comparison, the new model can accurately reproduce (1) the CO2-brine mutual solubility data at temperature from 0 °C to 250 °C, pressure from 1 bar to 1000 bar and NaCl molality (mole number in 1 kg water, molal is used for short) from 0 to 6 molal, (2) CH4-brine mutual solubility data at temperature from 0 °C to 250 °C, pressure from 1 bar to 2000 bar and NaCl molality from 0 to 6 molal, (3) H2S-brine mutual solubility data at temperature from 0 °C to 250 °C, pressure from 1 bar to 200 bar and NaCl molality from 0 to 6 molal, and (4) has good accuracy for gas mixture solubility in brine.