Logging while drilling tools utilizing magnetic positioner assisted phase shifts
CA 2098677 C · Owner: Schlumberger Canada Limited · Inventors: Malone, David
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A LWD tool is disclosed comprising, an encoder for generating a signal in the borehole fluid flowing therethrough, a brushless DC motor coupled to the encoder a, position sensor coupled to the motor for sensing the rotational position thereof, motor drive electronics coupled to motor for driving the motor, a microprocessor coupled to the position sensor and to the drive electronics for controlling the drive signals to the motor based on the actual and desired positions of the motor, and a magnetic positioner which is coupled to one of the drive shafts of the system. By controlling the drive signal to the motor the speed of the, motor is controlled, thus effecting changes in frequency and/or …
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 June 17, 1993 and granted January 26, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 17, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 17, 2015.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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.