Deployment of silica gels to prevent CO2 leakage in the near wellbore environment

Sobhan Hatami, Stuart Walsh, Tom Hughes, Hamid Roshan

Research output: Contribution to conferenceAbstract


One of the major concerns associated with Carbon Capture and Storage (CCS) is the potential for leakage of CO2 from storage reservoirs. However, despite numerous studies focusing on leakage causes, the literature on remedial action remains scarce. In this work, we investigate the use of silica gel to engineer barriers to flow in fractures in and around wellbore region with the goal of reducing leakage risk or preventing active leakage.
Silica gels have excellent sealing functionality in harsh environments, are low-cost and non-toxic, and their deployment may be controlled by modifying the gelation time. We describe a series of experiments to study the ability for silica gels to block fracture conduits in cement plugs that have been in contact with super-critical CO2 and carbonated brine. Cement samples were prepared, cut longitudinally, and reacted with super-critical CO2 and carbonated. X-ray computed tomography (XRCT) was performed prior to and after reacting the samples to trace changes on the cement. Next, silica sol was injected in the fracture and the permeability of the samples was measured to test the efficacy of the sols in blocking the fracture path. XRCT and scanning electron microscopy were used to examine in detail the distribution of silica on the surface of the cement and its binding with different regions, created by the super-critical CO2-cement reaction.

The results suggest that silica gels could provide a potential mitigation strategy to reduce the risks associated with long-term CO2 storage.
Original languageEnglish
Number of pages1
Publication statusPublished - 2019
EventFall Meeting of the American-Geophysical-Union 2019 - San Francisco, United States of America
Duration: 9 Dec 201913 Dec 2019


ConferenceFall Meeting of the American-Geophysical-Union 2019
Abbreviated titleAGU 2019
CountryUnited States of America
CitySan Francisco
Internet address

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