Subsea master valve for use in well testing
CA 1260384 A · Owner: Schlumberger Technology Corporation · Inventors: Meek, Dale E.; Doremus, Bernard
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In accordance with illustrative embodiments of the present invention, a new and improved subsea test tree includes a hydraulically operable control unit and shut-in valve unit that are releasably latched together. The control unit includes an integral retainer valve system at the upper end thereof. The main shut-in valve which is a, ball valve, is a fail-close device under the influence of a spring and nitrogen pressure. Additional assistance in close the valve may be provided if needed by hydraulic pressure applied to a surface control line. Internal pressure may be vented prior to unlatching the control unit in case of an emergency.
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
- Granted September 26, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 26, 2006.
- 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.