Power sources for downhole electrical heating
CA 2015318 C · Owner: Bridges, Jack E. · Inventors: Dubiel, George T.; Bridges, Jack E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure, Electrical power sources and systems for heating in or adjacent to an oil well or other mineral well or for, heating other earth media, each comprising an A.C. heating generator that generates an A.C. heating current at a selected heating frequency substantially different from the conventional 50/60 Hz frequency used by power companies; the heating generator may comprise an A.C. to D.C. converter for developing an intermediate D.C. output of predetermined amplitude from a conventional 50/60 Hz A.C. input and a, solid state switching circuit for repetitively sampling the D.C. output of the converter at the selected heating frequency, usually in a range of 0.01 Hz …
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 April 24, 1990 and granted February 8, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 24, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 24, 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.