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Expired Canadian patentCanada

Low pressure responsive apr tester valve

CA 1195237 A · Owner: Halliburton Company · Inventors: Beck, Harold K.

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

An annulus pressure responsive tester valve including a pressure assisted isolation valve which includes a pressure differential metering cartridge to control the rate at which the isolation valve returns to the fluid pressure in the annulus between the wellbore and testing string thereby continuously controlling the rate of expansion the inert gas within the gas chamber and the attendant operation of the tester valve regardless of any temperature effect by cold fluids pumped therethrough.

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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 October 15, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 15, 2002.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledFebruary 23, 1983
GrantedOctober 15, 1985
Term endedOctober 15, 2002
Patent numberCA 1195237 A
Classification (IPC)E21B34/10 +2 more

Timeline

Timeline From CIPO dates

1984198619881990199219941996199820002002Application filedFeb 23, 1983Patent grantedOct 15, 1985Term endedOct 15, 2002

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.