Gellable aqueous composition and its use in enhanced petroleum recovery
CA 2013461 C · Owner: Agip S.P.A. · Inventors: Lockhart, Thomas Paul; Burrafato, Giovanni
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The permeability of high-permeability zones in a oil reservoir can be reduced by using a gellable aqueous composition with delayed gelation. The composition comprises:, - a) water; - b) a high-molecular weight natural or synthetic water-soluble polymer cross-linkable by means of Cr3+ ions; - c) a water-soluble inorganic Cr3+ salt; - d) a gelation-retardant organic ligand definable by the formula: (see fig. I), where:, R is a direct single bond or a saturated or unsaturated, linear or branched aliphatic hydrocarbon radical with from 1 to 6 carbon atoms, or a cycloalkyl radical with from 3 to 7 carbon atoms, or an aryl radical;, X is OH or OR' (where R' is an alkyl radical with from 1 to 5 …
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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
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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.