Development of corrosion-resistant wellbore components and remedial seal solutions is critical to mitigating wellbore loss of injected CO2 from geologic storage systems. Poor wellbore integrity impacts the performance of carbon dioxide sequestration reservoirs by unintentionally releasing the sequestered CO2 to the atmosphere. A particularly difficult sealing application is the emplacement of casing or liner patches. These are installed to seal off either intentional liner perforations or those caused by wear, collapse, or corrosion, while allowing access to the well below the patch. Patch performance is challenged by the thermal and chemically corrosive environment in CO2 injection wells, and to an even greater degree in enhanced oil recovery and geothermal wells, where drilling is reaching deeper into hotter and more corrosive environments. The objective of this proposed Phase I effort is to evaluate the viability of deploying self-sintering systems to form hollow cylindrical casing patches in-situ, as an alternative to cement, steel, or elastomeric patches. The constituents will be engineered to achieve ceramic-like patches with low permeability, high ductility, high corrosion resistance, and high strength, to seal perforated intervals of casing. The emplacement and deployment approach will be developed to allow insertion of the package to the zone of interest and formation of the patch. The Phase I effort will evaluate the materials and formation process to demonstrate the viability of forming ceramic well liner patches in place. The initial effort will include evaluation of candidate self-sintering systems expected to achieve desired material properties of mechanical strength, toughness, density, permeability, and corrosion resistance. Experiments conducted in standard casing will demonstrate the viability of the patch formation process and the resulting thermal response of the patch and well components. Poor well sealing has caused contamination in surface and subsurface water supplies, and negatively impacts the performance of reservoir regions planned for CO2 sequestration and injection. This technology will offer sealing capabilities unattainable by traditional cement-based techniques Key words: Casing patch, self-sintering, wellbore integrity Summary for Members of Congress: This project will develop high performance well casing patches for application in carbon sequestrations, enhanced oil recovery, and geothermal wells. The technology provides a high strength, high corrosion resistant well sealing material superior to conventional hydrating cements.
