Process for recovering oil
CA 2005479 C · Owner: Borchardt, John Keith · Inventors: Lau, Hon Chung; Borchardt, John Keith
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for recovering oil from a reservoir penetrated by at least one injection well comprising injecting into the reservoir a gas-foam forming mixture comprising an aqueous surfactant solution and a gas mixture including a noncondensible gas displacing within, the reservoir the gas foam-forming mixture and withdrawing oil, from the reservoir wherein the surfactant contains at least 25 wt% olefin disulfonate.
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 December 14, 1989 and granted January 27, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 14, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 14, 2011.
- 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.