Process for preparing a heteropolysaccharide, heteropolysaccharide obtained thereby, its use, and strain ncib 11883
CA 1232559 A · Owner: Shell Canada Limited · Inventors: Evans, Michael W.; Godley, Andrew R.; Linton, John D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for preparing a heteropolysaccharide from strain NCIB 11883 and use of the latter e.g. as viscosity modifier in an aqueous system such as completion fluids work over fluids, stimulation fluids, and preferably in drilling fluids and use in connection with well-treatments, and enhanced oil recovery.
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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
- Granted February 9, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 9, 2005.
- 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.