Borehole surveying
CA 2229329 C · Owner: Natural Environment Research Council · Inventors: Kerridge, David John; Shiells, Gordon Malcolm
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A borehole survey is conducted at a drilling site (S) by a so-called Interpolated In-Field Referencing (IIFR) method in which: (a) absolute local geomagnetic field data is obtained by spot measurement of the earth's magnetic field at a local measurement site (R) which is sufficiently close to the drilling site (S) that the measurement data is indicative of the earth's magnetic field at the drilling site (S) but which is sufficiently remote from the drilling site (S) that the measurement data is unaffected by magnetic interference from the drilling site and other man-made installations; (b) timevarying geomagnetic field data is obtained by combining the absolute local geomagnetic …
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 September 10, 1996 and granted December 16, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 10, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 10, 2018.
- 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.