Alkali metal tungstate compositions and uses thereof
US7273832B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 9, 2002 |
| Grant date | Sep 25, 2007 |
| Priority date | — |
| Expiry date | Jun 23, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S507/925
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Fluids, such as completion fluids, containing at least one alkali metal tungstate and optionally at least one chelating agent are described. Methods of removing a filter cake from a well bore surface, which may include one or more alkaline earth metal sulfates, is also described, wherein the method includes contacting the filter cake with the completion fluid of the present invention. A drilling fluid or mud is also described wherein the drilling fluid contains at least one alkali metal tungstate. The drilling fluid preferably further contains at least one emulsifier or surfactant and at least one hydrocarbon-based fluid. The various fluids of the present invention can contain other conventional ingredients and optionally at least one alkali metal formate. The present invention permits the fluids to be essentially solids free due to the use of the alkali metal tungstate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.