Acidizing stimulation method using a pH buffered acid solution
US7059414B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 2003 |
| Grant date | Jun 13, 2006 |
| Priority date | — |
| Expiry date | Dec 7, 2023 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K8/72
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method of stimulating subterranean formations in oil and gas wells using a high pH buffered acid system. The method may be used to treat sandstone formations wherein the pH buffered acid system is used as the preflush or overflush or both. The method consists of introducing into the well a hydrofluoric acid containing sandstone acidizing solution either prior to or subsequent to introduction of the pH buffered acid system. The pH buffered acid system may further be used in the treatment of carbonate reservoirs. The pH of the buffered acid solution is substantially equivalent to that of the pH of the acidizing solution. The buffered acid solution is void of either hydrofluoric acid or hydrofluoric acid precursors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.