Subsurface safety valve apparatus
CA 1070237 A · Owner: Schlumberger Technology Corporation · Inventors: Johnson, Joseph L.; Guidry, Shelby L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In accordance with an illustrative embodiment of the present invention, a subsurface safety valve assembly includes a dome precharged with a set reference pressure that tends to close the valve, and means responsive to both ambient pressure and to the pressure of a control fluid for holding the valve open under normal conditions, a decrease in either control fluid pressure or tubing pressure, or both, enabling the dome pressure to cause the valve to automatically close and shut-in the well. The valve does not employ a coil spring to cause closure which permits, installation at great depths in a well and a narrow spread, between valve opening and closing pressures.
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 January 22, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 22, 1997.
- 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.