Hydrolyzed co-polymers of N-vinylamide and acrylamide for use as waterloss control additives in drilling mud
US4921621A · kind A · utility
31Cited by
12References
14Claims
0Family size
Assignee
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Key dates
| Filing date | Nov 7, 1988 |
| Grant date | May 1, 1990 |
| Priority date | — |
| Expiry date | Nov 7, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K8/5083
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Aqueous, clay-based drilling mud compositions are improved with respect to waterloss control by the addition of a hydrolyzed copolymer of acrylamide and an N-vinylamide. The copolymer, which is effective over a broad range of molecular weights, contains at least 5 mol percent of the N-vinylamide monomer moiety of which at least 5 mol percent is hydrolyzed to vinylamine units. Well drilling is improved by circulating through the bore hole a drilling mud containing this waterloss control additive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.