Shear-sensitive plugging fluid for plugging and a method for plugging a subterranean formation zone
US6818598B2 · kind B2 · utility
11Cited by
7References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 14, 2002 |
| Grant date | Nov 16, 2004 |
| Priority date | — |
| Expiry date | Jul 18, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S507/903
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A plugging fluid for plugging a subterranean formation zone surrounding a drill hole comprises an emulsion comprising a dispersed aqueous phase containing an aqueous base and a continuous hydrophobic phase containing a polymer consisting of a grafted cellulose ether derivative, a surfactant and a crosslinking activator of the polymer. The polymer is preferably 2-hydroxyethyl cellulose grafted with vinyl phosphonic acid. Upon shearing, preferably through the drilling bit, the emulsion inverts so that the rupture of the emulsion droplets releases the crosslinking activator into the water phase thus forming a gel structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.