Title: Injection of gel systems for CO₂ leakage remediation in a fractured reservoir

Authors: Peixi Zhu; Shayan Tavassoli; Jenny Ryu; Michael Pyrcz; Matthew T. Balhoff

Addresses: Hildebrand Department of Petroleum and Geosystems Engineering, The University of Texas at Austin, 200 E. Dean Keeton St., Stop C0300, Austin, TX 78712-1585, USA; Center for Subsurface Energy and the Environment, The University of Texas at Austin, 200 E. Dean Keeton St., Stop C0300, Austin, TX 78712-1585, USA ' Hildebrand Department of Petroleum and Geosystems Engineering, The University of Texas at Austin, 200 E. Dean Keeton St., Stop C0300, Austin, TX 78712-1585, USA; Center for Subsurface Energy and the Environment, The University of Texas at Austin, 200 E. Dean Keeton St., Stop C0300, Austin, TX 78712-1585, USA ' Hildebrand Department of Petroleum and Geosystems Engineering, The University of Texas at Austin, 200 E. Dean Keeton St., Stop C0300, Austin, TX 78712-1585, USA; Center for Subsurface Energy and the Environment, The University of Texas at Austin, 200 E. Dean Keeton St., Stop C0300, Austin, TX 78712-1585, USA ' Hildebrand Department of Petroleum and Geosystems Engineering, The University of Texas at Austin, 200 E. Dean Keeton St., Stop C0300, Austin, TX 78712-1585, USA; Center for Subsurface Energy and the Environment, The University of Texas at Austin, 200 E. Dean Keeton St., Stop C0300, Austin, TX 78712-1585, USA; Bureau of Economic Geology, Jackson School of Geoscience, The University of Texas at Austin, 2305 Speedway, Stop C1160, Austin, TX, 78712, USA ' Hildebrand Department of Petroleum and Geosystems Engineering, The University of Texas at Austin, 200 E. Dean Keeton St., Stop C0300, Austin, TX 78712-1585, USA; Center for Subsurface Energy and the Environment, The University of Texas at Austin, 200 E. Dean Keeton St., Stop C0300, Austin, TX 78712-1585, USA

Abstract: We perform a reservoir simulation study to investigate injection of gel systems, including cross-linked polymer gels and silica gels, as a treatment method for fracture sealing and leakage remediation in CO₂ storage reservoirs. An adsorption and permeability reduction approach was adopted to model the fracture sealing by the gel. The results show that for both gel systems a successful treatment can reduce CO₂ leakage by 10³ times over 25 years of post-treatment CO₂ injection. The effects of operating conditions, reservoir heterogeneity, and associated uncertainty on the treatment results were investigated by changing the injection time, injection rate, cross-linked polymer or silica concentration, reaction frequency factor, average reservoir permeability, and spatial correlation length. The simulation results show that selecting the appropriate operating conditions for specific reservoir properties are important to the success of CO₂ leakage remediation. [Received: March 23, 2020; Accepted: November 15, 2020]

Keywords: gel treatment; CO₂ storage; leakage remediation; silica gel; cross-linked polymer gel; heterogeneity; Dykstra-Parsons coefficient; spatial uncertainty; reservoir simulation.

DOI: 10.1504/IJOGCT.2022.119340

International Journal of Oil, Gas and Coal Technology, 2022 Vol.29 No.1, pp.52 - 74

Received: 23 Mar 2020
Accepted: 15 Nov 2020
Published online: 01 Dec 2021 *

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