Dissolution of sulfate scales
US5059333A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 26, 1990 |
| Grant date | Oct 22, 1991 |
| Priority date | — |
| Expiry date | Jul 26, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S507/927
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The invention provides for the use of compositions to dissolve sulfate scales from surfaces containing these scales, comprising an aqueous solution of an aminopolycarboxylic acid (APCA) containing 1 to 4 amino groups, e.g., diethylenetriaminepentaacetic acid (DTPA) or ethylenediaminetetraacetic acid (EDTA), or a salt thereof, and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC) or a salt thereof. More particularly, the invention encompasses a method of removing sulfate scales from surfaces on which they have formed utilizing the foregoing solutions, particularly the removal of scales from equipment and wellbore surfaces associated with the operation of crude oil and gas wells.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.