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Expired Canadian patentCanada

Drill stem testing with tubing conveyed perforation

CA 2087866 C · Owner: George, Flint R. · Inventors: George, Flint R.; Barrington, Burchus Q.

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

A well test string includes an annulus pressure responsive tester valve and a tubing conveyed perforating gun including a tubing pressure actuated time delay firing mechanism. A compression set packer is disposed in the test string between the tester valve and the perforating gun. The packer includes a bypass valve for communicating the well below the packer with the tubing bore. The bypass valve is operably associated with the packer so that the bypass valve is open prior to setting the packer and so that the bypass valve is closed as the packer is set. The compression set packer also includes a one-way equalizer valve for allowing one-way fluid flow from the well below the packer to the …

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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

  • Filed January 22, 1993 and granted January 21, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 22, 2013.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 22, 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.
FiledJanuary 22, 1993
GrantedJanuary 21, 1997
Term endedJanuary 22, 2013
Patent numberCA 2087866 C
Classification (IPC)E21B47/00 +2 more

Timeline

Timeline From CIPO dates

1994199619982000200220042006200820102012Application filedJan 22, 1993Patent grantedJan 21, 1997Term endedJan 22, 2013

Sources & verification

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