Modelling of CO2-foam Core Flooding Experiments

Abstract

This work presents results from simulation of core-flooding experiments with several commercially available surfactants for CO2-foam stabilisation, potentially applicable for CO2 mobility control in CO2 storage operations. The simulations are run with a CO2 foam module for MRST, based on a foam effect model developed by Vassenden and Holt. Efficient use of mobility control for CO2 at field scale could give a significant increase in storage capacity. It could counter the negative effects of the mobility contrast between injected CO2 and the resident formation brine, enabling more optimal filling of structural traps and delaying breakthrough of injected CO2 at wells where formation brine is extracted for pressure management purposes. Efficient mobility control and the associated sweep improvement can more than double the storage efficiency in a developed five-spot pattern of injection and pressure control wells. Partitioning of surfactant between the CO2 and brine phases will lead to gradually reduced surfactant concentration and eventually loss of foam-generation as the CO2 penetrated deeper into the reservoir. Adsorption of surfactant to mineral surfaces will also contribute to the reduced concentration. Investigation of realistic field-scale effects of mobility control by foam requires both careful measurement of partitioning and adsorption properties in laboratory experiments and a reservoir simulator capable of including such effects.