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Expired Canadian patentCanada

Method and apparatus for subsurface formation evaluation

CA 1304833 C · Owner: Schlumberger Canada Limited · Inventors: Marienbach, Edouard; Hache, Jean-Michel; Evans, Michael

CIPO record

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

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Abstract From the Canadian patent

Abstract, A measurement while drilling nuclear tool adapted to be coupled in the drill string to make formation evaluations and methods of using are described. A neutron source is positioned on the cylindrical axis of the tool while a connected gamma ray source is eccentered against an interior side of the cylindrical tool. Both sources can be axially removed from the tool along its interior. Novel source-detector configurations are provided in order to accommodate the constraints of the MWD environment. Gamma ray transparent windows are provided through both the drill collar and an external fluid excluder (stabilizer) at the positions of the gamma ray source and scintillator detectors. …

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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 July 7, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 7, 2009.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledDecember 14, 1988
GrantedJuly 7, 1992
Term endedJuly 7, 2009
Patent numberCA 1304833 C
Classification (IPC)G01V5/10 +2 more

Timeline

Timeline From CIPO dates

1989199219951998200120042007Application filedDec 14, 1988Patent grantedJuly 7, 1992Term endedJuly 7, 2009

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