Method for removing alkaline sulfate scale
US5458860A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1994 |
| Grant date | Oct 17, 1995 |
| Priority date | — |
| Expiry date | Sep 9, 2014 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF28G9/00
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The present invention relates to the use of low frequency sonic energy within the range of 1.25 to 6.5 KHz, preferably less than 2.0 KHz and most preferably 1.25 KHz, for enhancing the dissolution of alkaline earth metal scales from well bores using a scale-removing solvent comprising an aqueous alkaline solution having a pH of about 8 to about 14 and containing EDTA or DTPA and a catalyst or synergist, preferably an oxalate anion. When the scale deposit is contacted with the scale removing solvent while simultaneously transmitting low frequency sonic energy through the solvent, substantially more scale is dissolved at a faster rate than previously possible.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.