Method for imparting selectivity to otherwise nonselective polymer control gels
US4901795A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 25, 1988 |
| Grant date | Feb 20, 1990 |
| Priority date | — |
| Expiry date | Dec 25, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S507/935
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method for selectively closing pores in a formation's zone of greater permeability. A rehealable Xanthan or Alcaligenes biopolymer in an aqueous medium is combined with an organic or transition metal cross-linker which forms a first stage selective ex-situ gel. Second stage non-selective gel precursors are also included. The second stage gel comprises a polymer cross-linked with organic cross-linkers so as to form an in-situ gel more able to withstand formation conditions. The combination is injected into a formation after the first stage gel forms where it selectively enters a zone of greater permeability carrying therewith said non-selective gel. Once in the formation's zone of greater permeability, the gel reheals and forms a rigid gel having the desirable characteristics of the non-selective gel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.