Method to determine local variations of the earth's magnetic field and location of the source thereof
CA 2212925 C · Owner: Scientific Drilling International · Inventors: Towle, James N.; Van Steenwyk, Donald H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method to determine the earth's magnetic field vector along a sub-surface wellpath having unknown and possibly changing azimuth in the presence of, a magnetic disturbance caused by a magnetic source external to the wellpath includes estimating the three components of the earth field along the three axes of a magnetic sensor package by a polynomial function of measured depth along the wellpath. Magnetic survey accuracy is thereby improved. Upon removal of the earth's magnetic field from the measurements, the resultant magnetic field of the disturbance is determined and can be used to determine the position and orientation of the source of the disturbance.
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 August 13, 1997 and granted March 26, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 13, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 13, 2019.
- 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.