Drill pipe with helical ridge for highly angulated wellbore
CA 2037449 A1 · Owner: Williams, Jerry G. · Inventors: Finnegan, John E.; Williams, Jerry G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract, The drilling of highly angulated wellbores (with a rotary rig having a drill string terminated with a bit wherein drilling fluid is employed) is improved by employing in the highly angulated drill string a length of drill pipe which has a helical ridge disposed thereabout such that the flight of the helical ridge is wound so as to rise from the bit with the rotation of the drill string and the height of the helical ridge above the length of the surface of the drill pipe is 1 to 15 percent of the diameter of the drill pipe.
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 March 1, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 1, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 1, 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.