Method for removing alkaline sulfate scale
US4980077A · kind A · utility
57Cited by
6References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 22, 1989 |
| Grant date | Dec 25, 1990 |
| Priority date | — |
| Expiry date | Jun 22, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S507/927
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Alkaline earth metal scales, especially barium sulfate scale deposits are removed from oilfield pipe and other tubular goods with a scale-removing composition comprising an aqueous alkaline solution having a pH of about 8 to about 14, a polyaminopolycarboxylic acid, preferably EDTA or DTPA and a catalyst or synergist comprising oxalate anion. When the scale-removing solution is contacted with a surface containing a scale deposit, substantially more scale is dissolved at a faster rate than previously possible.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.