The use of polymer-gel solutions for CO₂ flow diversion and mobility control within storage sites

This paper presents a study on the use of polymer-gel technology as an option to remediate non-conformal flow behaviour of CO₂ within the storage reservoir. Several polymer-gels with crosslinkers were tested. The rheology, gelation and working times of these polymer-gels at various concentrations were characterised under different temperatures representative of CO₂ storage reservoirs. Laboratory core flooding experiments were then carried out on high permeability core samples to test the suitability of polymer-gel solution for flow through and containment of CO₂ in porous media. The core samples saturated with brine were subjected to polymer-gel injection. Core sample permeability for CO₂ was then measured and the change in CO₂ permeability of the sample before and after polymer-gel injection was noted. Reservoir simulations for different scenarios of flow diversion were carried out using the permeability reduction results from the laboratory work on a realistic reservoir model with faults and high permeability channel structures.