Cement accelerator
CA 2036660 C · Owner: Carpenter, Robert B. · Inventors: Wilson, William N.; Carpenter, Robert B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of accelerating the set of retarded cement characterized by contacting the retarded cement slurry with a solution containing an effective amount of a compatible accelerator. The compatible accelerator is selected from the group consisting of triethanolamine diethanolamine and monoethanolamine. This may be employed in overwashing operations, treating retarded cement that is injected into open areas in the well or treating the set of a plug of retarded cement in a well to effect acceleration and/or viscosification of the cement. Also disclosed are specific uses.
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 February 19, 1991 and granted January 15, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 19, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 19, 2013.
- 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.