Viscoelastic surfactant rheology modification
US7402549B2 · kind B2 · utility
11Cited by
14References
28Claims
0Family size
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Key dates
| Filing date | Dec 15, 2004 |
| Grant date | Jul 22, 2008 |
| Priority date | — |
| Expiry date | Aug 6, 2025 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2208/30
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method for shortening the shear recovery time of cationic, zwitterionic, and amphoteric viscoelastic surfactant fluid systems by adding an effective amount of a rheology enhancer selected from partially hydrolyzed polyvinyl ester and partially hydrolyzed polyacrylates. The rheology enhancer also increases fluid viscosity and very low rheology enhancer concentration is needed. Preferred surfactants are betaines and quaternary amines. The fluids are useful in oilfield treatments, for example fracturing and gravel packing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.