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Expired Canadian patentCanada

Annular and concentric flow wellhead isolation tool and method of use thereof

CA 1281280 C · Owner: Stinger Wellhead Protection, Inc. · Inventors: Mcleod, Roderick D.

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

Apparatus for isolating the wellhead equipment from the high pressure fluids pumped down to the producing formation during the procedures of fracturing and acidizing oil and gas wells utilizes a central mandrel concentric inside an outer mandrel and an expandable sealing nipple to seal the outer mandrel against the casing. The sealing nipple is provided with passageways to allow fluids to be pumped down the tubing and/or the annulus between the tubing and the casing in an oil or gas well.

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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 March 12, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 12, 2008.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledSeptember 26, 1989
GrantedMarch 12, 1991
Term endedMarch 12, 2008
Patent numberCA 1281280 C
Classification (IPC)E21B43/12 +2 more

Timeline

Timeline From CIPO dates

1990199219941996199820002002200420062008Application filedSep 26, 1989Patent grantedMarch 12, 1991Term endedMarch 12, 2008

Sources & verification

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