Tubing collar position sensing apparatus, and associated methods, for use with a snubbing unit
CA 2022770 A1 · Owner: Smith, Michael L. · Inventors: Smith, Michael L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A snubbing unit used to raise or lower a collar-, connected series of tubing joints through a riser spool communicating with a well bore, is provided with an electromagnetic sensing system operative to detect and indicate the entry into position within and travel direction within a sensing spool between the upper and lower blowout preventers of each tubing collar. The sensing system includes upper and lower electromagnetic coils coaxially circumscribing the sensing spool and a, frequency generator for energizing the coils. First and second phase comparators are used to detect current phase alterations in the coils, caused by variations in the vertical proximity between each collar and the …
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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 August 7, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 7, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 7, 2012.
- 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.