Compositions comprising water soluble copolymer and cesium salt of a carboxylic acid
US6656989B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | May 19, 2000 |
| Grant date | Dec 2, 2003 |
| Priority date | — |
| Expiry date | May 19, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08K5/098
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Novel polymer compositions are disclosed, along with their use as well service fluids, for example as completion fluids, work-over fluids or drilling fluids, comprising water soluble copolymers having sulfonate groups and carboxylate groups, along with alkali metal salts of carboxylic acid. Exemplary copolymer has 5 to 95 wt. % structural units derived from 2-acrylamido-2-methylpropanesulfonic acid or salt thereof, and 5 to 95 wt. % structural units derived from acrylic acid or salt thereof. A salt of the polymer may be used, such as the sodium, potassium, ammonium and calcium salts. Exemplary alkali metal salts of the polymer composition include sodium, potassium and cesium salts of formic acid and/or acetic acid in amounts suitable to develop high temperature viscosity suitable for such well servicing fluids. The polymer composition is hydrateble/soluble in a brine of sodium and/or potassium and/or cesium salts of formic and/or acetic acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.