Filter cake removal fluid and method
US6886635B2 · kind B2 · utility
41Cited by
11References
29Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 28, 2002 |
| Grant date | May 3, 2005 |
| Priority date | — |
| Expiry date | Nov 17, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2208/18
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method for removing filter cake from a subterranean borehole comprising drilling the borehole with a drilling fluid that includes additives to form a filter cake having an oxidation-degradable component, preferably a polysaccharide. The filter cake is contacted with a clear brine containing a mixture of a persulfate salt in a variable density brine to degrade the polymers within the filter cake. The persulfate mixture breaks down the filter cake in well bores having temperatures ranging from about 65° F. to 165° F. Concentration of the persulfate sets the pace of the reaction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.