Inverse vertical seismic profiling using a measurement while drilling tool as a seismic source
CA 2198533 C · Owner: Masak, Peter C. · Inventors: Malone, David L.; Masak, Peter C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A reverse VSP system is provided and uses a frequency-controllable modulator of an MWD tool as a downhole seismic source. The modulator has a rotor and stator arranged to provide substantially sinusoidal outputs and is controlled to provide a "Vibroseis"-type frequency sweep (preferably from 1 Hz to 50 Hz). With the bit of the MWD tool in contact with the bottom of the borehole, the force generated by the frequency-controllable modulator will generate measurable axial compressional (P-) waves. These waves which move through the formation are detected by an array of geophones on the formation surface and a reference signal is obtained by, a kelly-mounted accelerometer or strain gauge. The …
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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 26, 1997 and granted June 11, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 26, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 26, 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
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.