The use of polymer-gel solutions for remediation of potential CO2 leakage from storage reservoirs

A polymer-gel based on Polyacylamide with Chromium as cross-linker was used and studied in order to ascertain its rheological characteristics at various concentrations of polymer over a range of temperatures and salinities representative of the subsurface conditions. Core flood experiments were carried out on a high permeability sandstone and fractured marble core samples to investigate the flow characteristics of the polymer-gel in porous/fractured media. Laboratory core-floods revealed significant reduction in permeability with different concentrations of polymer-gel in the injected water. Similar results were obtained for the fractured core wherein a permeability reduction of 90% was noted, demonstrating the suitability of the system for possible remediation of CO 2 leakage through the caprock. Results from reservoir simulations supported the feasibility of polymer-gel remediation at reservoir scale and identified the spatial extent of the leakage that can be remediated for various concentrations of polymer-gel solutions.