Bottom hole blowout preventer
CA 2001387 A1 · Owner: Lineham, Donald H. · Inventors: Lineham, Donald H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A ball valve type bottom hole blowout preventer operates under normal drilling conditions in a fully open position with an unrestricted bore. This operating condition is maintained by a combination of spring and mud flow pressure acting against the upper surfaces of the valve. In the event of a well kick or blowout, pressures from gas or fluid volumes acting against the lower surfaces of the valve force it into the fully closed position. A system of ports and check valves within the blowout preventer forces hydraulic fluid from one chamber to another. The metering effect of these ports determines the rate of closure of the valve, thereby allowing normal running and pulling of the drill …
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 October 24, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 24, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 24, 2011.
- 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.