Viscoelastic surfactant rheology modification
US7341980B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 2004 |
| Grant date | Mar 11, 2008 |
| Priority date | — |
| Expiry date | Dec 10, 2024 |
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 zwitterionic viscoelastic surfactant fluids by adding a rheology enhancer having the structure:R-(EO)x(PO)y—R′—OHin which R is an alkyl group that is straight chained or branched, saturated or unsaturated, and contains from 3 to about 18 carbon atoms, x is from 0 to about 14, y is from 0 to about 7, R′ is an alkyl group that contains from 0 to about 14 carbon atoms and is straight chained, branched if having more than 3 carbon atoms, saturated, unsaturated if having more than one carbon atom, the total number of carbon atoms in R plus R′ is from 3 to about 21, and the EO and PO groups, if present, may be in any order. The rheology enhancer also increases fluid viscosity and thermal stability. Preferred surfactants are betaines. The fluids are useful in oilfield treatments, for example fracturing and gravel packing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.