Method and composition for sealing a subsurface formation
US11053428B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 2019 |
| Grant date | Jul 6, 2021 |
| Priority date | — |
| Expiry date | Oct 29, 2039 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2208/10
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method for plugging and sealing subsurface formations using alkaline nanosilica dispersion and a delayed activation chemistry is disclosed. In accordance with one embodiment of the present disclosure, the method includes introducing a mixture with a first pH into the subsurface formation. The mixture comprises an aqueous solution, an alkaline nanosilica dispersion and a water-insoluble hydrolyzable compound. The method further includes allowing the water-insoluble hydrolyzable compound to hydrolyze in the subsurface formation to form an acid at 70° C. or greater, thereby acidizing the mixture to a reduced second pH and causing the alkaline nanosilica dispersion to gel into a solid and seal the subsurface formation. A composition for sealing a subsurface formation is also disclosed. The composition includes an aqueous mixture including water, an alkaline nanosilica dispersion, and a water-insoluble hydrolyzable compound.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.