Compositions and method for controlling precipitation when acidizing sour wells
US4888121A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 5, 1988 |
| Grant date | Dec 19, 1989 |
| Priority date | — |
| Expiry date | Apr 5, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S507/934
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A precipitation control additive composition, an acidizing composition for treating a sour well and a method of treating a sour well are provided. An iron sequestering agent, such as aminopolycarboxylic acids, hydroxycarboxylic acids, cyclic polyethers, and derivatives thereof and a sulfide modifier, such as aldehyde, acetal, hemiacetal, and many other compounds capable of forming aldehydes in solution are added to a treating solution. The iron sequestering agent cobines with iron present in the solution while the sulfide modifier combines with sulfides present in the solution. By combining with both iron and sulfides present in the solution, the combination of an iron sequestering agent and a sulfide modifier effectively inhibits precipitation of ferric hydroxide, ferrous sulfide and free sulfur from the solution. As a result, formation and other serious damage is prevented.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.