Method of inhibiting corrosion in acidizing wells
CA 2075888 C · Owner: Mcdougall, Lee Allen · Inventors: Holifield, Phyllis Kay; Mcdougall, Lee Allen; Williams, Dennis Alexander
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Corrosion inhibitor additives are added directly to an aqueous acid solution used in acidizing subterranean formations. The additives comprise a bismuth compound a, quaternary compound, and a surfactant. The corrosion inhibitor is free of toxic Sb and acetylenic compounds.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed August 12, 1992 and granted October 23, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 12, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 12, 2014.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.