An improved simplified analytical model for CO2 plume movement and pressure buildup in deep saline formations

This study presents an evaluation of the three-region simplified analytical model of Burton et al. (2008) based on fractional flow and steady-state pressure gradient considerations for predicting CO2 plume movement and pressure buildup in deep saline formations. The saturation and pressure profiles as well as injection-well pressure buildup predicted by the analytical model are benchmarked against those from the numerical simulator STOMP to suggest improvements as needed for the simplified modeling approach. Good agreement is observed between the two approaches for predicting CO2 saturations. However, using a two-phase mobility based on average saturations as proposed by Burton et al. results in under-prediction of the pressure buildup. An improved method is presented for calculating a representative two-phase mobility based on the actual mobility profile in the two-phase region. This leads to a much better match between predictions of STOMP and the three-region model for both formation pressure profile and injection-well pressure buildup. (C) 2013 Elsevier Ltd. All rights reserved.