Encapsulated water absorbent polymers as lost circulation additives for aqueous drilling fluids
CA 1267075 C · Owner: Texaco Development Corporation · Inventors: Walker, Clarence O.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The disclosed invention is a novel drilling fluid additive for use in reducing lost circulation in wellbores and a method for employing the invention additive for reducing such lost circulation. The invention additive is a highly water absorbent polymer encapsulated by a reaction-preventive protective casing to prevent the polymer from expanding by absorbing water until it is desired to breach the casing. The reaction-preventive protective casing may be a film which will dissolve after a desired time of residence in the borehole or a film or waxy substance which will dissolve or melt at a desired temperature in the borehole, releasing the water absorbent polymer to expand by absorbing …
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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 March 27, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 27, 2007.
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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.