Shut-in tools
CA 2093899 C · Owner: Beck, Harold K. · Inventors: Zitterich, Craig L.; Beck, Harold K.; Bohan, William L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A downhole shut-in tool includes in one aspect a pilot valve which when opened places a differential pressure across a piston which in turn operably engages a shut-in valve element to close the shut-in tool. An electronic timer assembly and electric drive motor are provided for controlling the action of the pilot valve. The drive motor is controlled by a load sensor which senses that the motor has stalled when an actuator engages a movement limiting abutment. In another aspect a pilot valve is provided which can selectively communicate the pressure differential across the piston so as to repeatedly open and close the shut-in valve element. Efficient methods of drawdown and buildup testing …
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 April 13, 1993 and granted September 15, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 13, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 13, 2015.
- 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.