Method of determining drillstring bottom hole assembly vibrations
CA 2084142 A1 · Owner: Jan, Yih-Min · Inventors: Paslay, Paul R.; Jan, Yih-Min
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Lateral vibrations of drillstring bottom hole assemblies are confirmed by sensing longitudinal and torsional accelerations or displacements of the drillstring at or near its top end during rotation and determining the lateral critical speed and displacement of the drillstring from the mode shape of the bottom hole assembly which occurs during forward synchronous whirl and longitudinal shortening of the bottom hole assembly resulting from such whirl. Lateral motion of the bottom hole assembly, while drilling, is estimated based on longitudinal and torsional measurements at the top of the drillstring. Radial displacement of the bottom hole assembly due to impacting of the borehole wall …
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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 November 30, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 30, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 30, 2014.
- 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.