Estimation of Carbon Dioxide Storage Capacity for Depleted Gas Reservoirs

The purpose of this study was to develop analytical equations to estimate CO2 storage capacity for depleted wet/dry gas reservoirs. The effects of CO2 injection on the changings of reservoir pressure and the mole fractions of CO2 and natural gas were studied from a verified pressure-volume-temperature process. There was a linear relationship between the corrected pressure term (pr/zmix) and the cumulative production term (Gpt-GinjCO2). The amount of CO2 storage can be analysed directly from the pr/zmix plot. The total volume of CO2 storage is larger than that of natural gas production from a depleted gas reservoir.