Method for inhibiting or controlling inorganic scale formations
US7159655B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 2003 |
| Grant date | Jan 9, 2007 |
| Priority date | — |
| Expiry date | Mar 22, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S507/927
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A formulation containing a copolymer derived from a cationic monomer effectively inhibits and controls the formation of inorganic scales. The formulation has particular application in the removal of zinc sulfide and iron sulfide scales formed when zinc bromide brines are used as completion fluids. The copolymer exhibit high solubility in high-density brines, such as zinc bromide brines. The polymers may be introduced into an oil or gas well as a portion of a carrier fluid or with brine. The preferred copolymer for use in the invention contains an acrylamide unit and a diallyldimethylammonium salt and, optionally, an acrylic acid or a salt thereof. The weight average molecular weight of such inhibitor copolymers is generally between from about 500,000 to about 5,000,000.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.