Swellable polymer with anionic sites
US9267075B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jan 17, 2014 |
| Grant date | Feb 23, 2016 |
| Priority date | — |
| Expiry date | Mar 2, 2034 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B43/16
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The invention is directed to stable crosslinked water-soluble swellable polymers and methods for making same. More particularly, the invention relates to a composition comprising expandable polymeric particles having anionic sites and labile crosslinkers and stable crosslinkers, said particle mixed with a fluid and a cationic crosslinker that is capable of further crosslinking the particle on degradation of the labile crosslinker and exposure of the anionic sites so as to form a gel. A particularly important use is as an injection fluid in petroleum production, where the expandable polymeric particles are injected into target zone and when the heat and/or suitable pH of the target zone cause degradation of the labile crosslinker and the particle expands, the cationic crosslinker crosslinks the polymer to form a gel, thus diverting water to lower permeability regions and improving oil recovery.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.