Gellable buffered aqueous composition and its use in enhanced petroleum recovery
CA 2013469 C · Owner: Burrafato, Giovanni · Inventors: Burrafato, Giovanni; Lockhart, Thomas Paul
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A gellable aqueous composition particularly suitable for reducing the permeability of high-permeability zones in an oil reservoir is an aqueous solution comprising:, - a) a water-soluble organic polymer cross-linkable by the effect of a polyvalent metal ion cross-linking agent; - b) a Cr(III) ion cross-linking agent; - c) a buffer agent free or substantially-free of ligand characteristics towards the cross-linking agent and chosen, from organic bases and carboxylic or sulphonic aromatic organic acids;, the solution pH being adjusted to a value within the range of about 2 to about 7.
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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 March 30, 1990 and granted August 11, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 30, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 30, 2012.
- 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.