Electron transfer agents in well acidizing compositions and methods
US6415865B1 · kind B1 · utility
Inventor
Key dates
| Filing date | Mar 8, 2001 |
| Grant date | Jul 9, 2002 |
| Priority date | — |
| Expiry date | Mar 8, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S507/934
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
An acidizing composition and a method of acidizing a hydrocarbon bearing subterranean formation in the presence of ferric ions are provided. The acidizing composition includes a strong mineral acid solution, an electron donor agent, a primary electron transfer agent and a secondary electron transfer agent. The primary electron transfer agent is a source of rhenium ions. The secondary electron transfer agent is a source of iodide ion or iodine. The electron donor agent and primary and secondary electron transfer agents function together to reduce ferric ion present in the mineral acid solution to ferrous ion which in turn prevents ferric hydroxide and/or free sulfur from precipitating out of the solution and reduces the formation of sludge in crude oil in the formation. The particular electron transfer agents used in connection with the invention function with virtually all known electron donor agents.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.