Method and apparatus for measuring the resistivity of earth formations
CA 2009562 C · Owner: Gounot, Marie-Therese · Inventors: Gounot, Marie-Therese; Trouiller, Jean-Claude
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a logging method and apparatus for determining the electrical resistivity of an earth formation traversed by a borehole (11). The resistivity is determined using a measuring pad (20) which has a central electrode (A0b) operable to deliver a measuring current. The measuring current is focused radially by means of two focusing systems: an active focusing system (M, A1) which focuses the measuring current in a first direction; and a passive focusing system (A0) which focuses the measuring current in a second direction perpendicular to said first direction.
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 February 8, 1990 and granted July 27, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 8, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 8, 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.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.