Improved casing shoe
CA 2214749 C · Owner: Brit Bit Limited · Inventors: Strong, Phillip; Wardley, Michael
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A casing shoe (30) for use in guiding a casing into a wellbore comprises a generally cylindrical body (32) having a box portion (34) at its rearward end for connection to a casing string and having a generally rounded nose portion (36) at its forward end. The forward end of the shoe includes cutting structures (42, 44) in the form of raised flutes extending along the sides of the cylindrical body and on the nose portion. The flutes may be provided with cutting elements such as polycrystalline diamond compact elements (48) at least at the forward ends of the flutes (42) extending along the cylindrical body. These flutes may also be configured to serve as stabilising pads and , …
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 11, 1996 and granted August 27, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 11, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 11, 2018.
- 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.