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Expired Canadian patentCanada

Kill fluid for oil field operations

CA 2016418 C · Owner: Marathon Oil Company · Inventors: Sydansk, Robert 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

A flowing crosslinked polymer gel is employed as a kill fluid or as an additive to a kill fluid in a process for preventing the intrusion of formation fluid into a wellbore while minimizing wellbore fluid leakoff in the formation during conventional oil field operations in the wellbore. The gel comprises an a carboxylate-containing polymer and a chromic carboxylate crosslinking agent.

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 May 9, 1990 and granted February 22, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 9, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 9, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMay 9, 1990
GrantedFebruary 22, 1994
Term endedMay 9, 2010
Patent numberCA 2016418 C
Classification (IPC)E21B43/22 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedMay 9, 1990Patent grantedFeb 22, 1994Term endedMay 9, 2010

Sources & verification

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