Proppant with polyurea-type coating
US10208242B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 7, 2016 |
| Grant date | Feb 19, 2019 |
| Priority date | — |
| Expiry date | Nov 7, 2036 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K8/805
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Proppants for hydraulic fracturing of oil and gas wells are coated with a polyurea-type coating. In a preferred embodiment, the polyurea-type coating is formed by contacting a polymeric isocyanate with an amount of water a blowing catalyst at a rate and quantity sufficient to generate a reactive amine in situ on the outer surface of the proppant which thereby reacts with unconverted polymeric isocyanate to form a thin polyurea-type surface coating that is substantially solid and lacks foam or substantial porosity. Alternatively, the polyurea-type can be produced by selecting reactive amine compounds and isocyanates to develop the coated proppant. The coated proppants retain the discrete, free-flowing character of the original core solids but with the beneficial effects of the polyurea-type coating of the present invention.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.