Control Of Pressure Propagation In A Heterogeneous CO2 Storage Reservoir Using Water Production

Abstract

Injection of CO2 into a reservoir increases the pressure above initial values, resulting in overpressure of a hydrostatically charged formation. Without careful monitoring and management, excessive pressure can lead to a number of serious complications for a CO2 storage operations. Using numerical simulations with four distinct porosity/permeability distributions to represent reservoirs with random and structured heterogeneity. We initially consider the impact heterogeneity has on pressure propagation from a CO2 injection well; in particular the effect of channels on the lateral extent of the region of increased pressure. Subsequently, we investigate how heterogeneity influences the efficacy of water production as a pressure management tool and the optimisation of well positioning. For a channelized reservoir the most effective production well, which reduces the area of high pressure by up to 88%. Even in a randomised reservoir with no structured distribution of porosity and permeability, water production can still reduce the high pressure footprint by 60-88%. The location of the production well relative to the heterogeneity has been shown have a significant effect. The most effective production well location may not always be close to the target, but should be connected to the target by relatively high permeability pathways.