Composition and method for acidizing wells and equipment without damaging precipitation
US6534448B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 2, 2000 |
| Grant date | Mar 18, 2003 |
| Priority date | — |
| Expiry date | Feb 24, 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 an aqueous mineral acid solution, an electron donor agent and an electron transfer agent, the electron transfer agent being a source of molybdenum ions. When the aqueous mineral acid solution includes hydrochloric acid in an amount greater than approximately 17% by weight, the acidizing composition further includes a supplemental electron transfer agent, the supplemental electron transfer agent being a source of iodide ion or iodine. The electron donor agent and electron transfer agent 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.