Polyampholytes-high temperature polymers and method of use
US4959163A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 3, 1988 |
| Grant date | Sep 25, 1990 |
| Priority date | — |
| Expiry date | Nov 3, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S507/922
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method and composition for stimulating high temperature subterranean formations. The composition comprises a novel crosslinkable polymer containing anionic and cationic functional groups (a polyampholyte). The polyampholyte comprises a mixture of at least one from each of the following groups: PA1 Group I acrylamide, partially hydrolyzed acrylamide, N,N-dimethylacrylamide, N-substituted-(N'-dialkylaminoalkyl) acrylamides, aminoalkylacrylates, dialkylaminoalkylacrylates or mixtures thereof; PA1 Group II 2-acrylamido-2-methylpropane sulfonic acid, sodium salt, vinylphosphonic acid, partially hydrolyzed acrylamide or mixtures thereof; and PA1 Group III methacrylamidopropyldimethyl-2,3-dihydroxypropylammonium sulfate having the formula ##STR1## In the performance of the method, the polyampholyte is inverted into an aqueous liquid to form a viscous liquid which is buffered to about 4 to 6.5 and admixed with a crosslinking agent capable of crosslinking dihydroxypropyl functionalities. The crosslinked fluid then is introduced into a formation at a rate and pressure sufficient to fracture the formation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.