Drill string shutoff valve
CA 2483174 C · Owner: Movaffagh, Behrooz · Inventors: He, Xiaoping; Chan, Kwong-Onn C.; Movaffagh, Behrooz
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A valve assembly connects into a drill string for opening and closing at least one inner passage within the drill string of the drill string. The valve assembly includes an annular valve assembly carried in an annular passage that moves between the open and closed positions in response to downward fluid pressure from the surface through the annular passage. The valve assembly also includes an inner valve assembly carried in an inner passage of the drill string. The inner valve assembly is a two-way valve that is actuated between open and closed positions by pressure pulses from the surface through the inner passage. The valve assembly can be used within coiled tubing.
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 September 30, 2004 and granted April 24, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 30, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 30, 2026.
- 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.