Primary well cementing methods and apparatus
CA 2233468 A1 · Owner: North, John C. · Inventors: North, John C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides improved primary well cementing methods and apparatus. The methods basically comprise the steps of releasing a displacement plug into the casing to be cemented and pumping a first displacement fluid behind the displacement plug while measuring the quantity of the first displacement fluid required to land the displacement plug on a float collar or the like connected near the bottom of the casing, releasing a bottom cementing plug into the casing and pumping a cement slurry behind the bottom cementing plug in a predetermined quantity and then releasing a top cementing plug into the casing and pumping a second displacement fluid behind the top cementing plug in a …
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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 27, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 27, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 27, 2020.
- 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.