Modelling of a CO2 Injection Well Bottom-hole Pressure in a Rectangular Saline Formation

CO2 storage in saline aquifers is one of the promising options to reduce CO2 emissions into the atmosphere. A suitable saline formation for CO2 storage should have sufficient injectivity to allow the desired commercial injection rate without exceeding the formation fracture pressure and/or top seal’s threshold pressure. In this study, we present a new analytical model to predict the bottom-hole pressure of a well in a rectangular bounded formation. The solutions are valid for a horizontal, homogeneous saline formation of uniform thickness. CO2 is injected at constant rate into a brine-filled formation. The analytical model is capable of taking into account the effects of brine dry-out around the well and the relative permeability on the bottom-hole pressure. The well is completed across the entire formation and can be located arbitrarily in the formation which helps to assess the effect of well location on injectivity as well as multi-well scenarios. Comparison with the numerical simulation validates the capability of the analytical model in prediction of the bottom-hole pressure.