Modeling Water Vaporization During CO2 Reinjection into a Sour Gas Reservoir

This work tackles the issue of water vaporization around the CO2 injectors. Indeed, CO2 is dehydrated before being reinjected into the gas field in order to limit corrosion risks in the facilities. This leads to water vaporization in the near well areas, and could also lead to CO2 injectivity impairment due to salt plugging. The key findings of this study are listed below. 1/ Modelling water-gas interactions for a gas development leads to reviewing the hydrocarbon volumes in place due to the presence of vaporized water in the gas phase. 2/ Flow models taking into account gas-water interactions can predict condensed water flow rates with time in order to contribute to the design of surface facilities. 3/ In the case of dry CO2 reinjection, significant fractions of the gas pool will be fully dehydrated. This result requires verifying potential implications in term of geomechanical or petrophysical behaviour of the rock, once dehydrated. 4/ A tentative modelling of water imbibition towards the dehydrated zone shows a limited flow of formation water, meaning that no salt blocking is expected to derive from this process.