3626482 is referenced by 44 patents and cites 8 patents.

A method by which physical and mechanical characteristics of rocks are measured during drilling, comprises picking up a signal representing the vibrations of a train of rods forming part of drilling gear, selecting the components of the said signal which, after peak-clipping, are in a frequency band which is centered on, and preferably is related to, a characteristic frequency of the tool, establishing from the components thus selected, a value which is representative of the amplitude of the vibrations, and correlating this value with the drilling depth.

Method and apparatus for measuring lithological characteristics of rocks
Application Number
Publication Number
Application Date
October 23, 1969
Publication Date
December 7, 1971
Lutz Jean
Raynaud Michel H
Quichaud Claude Jean
Societe Anonyme dite Societe Nationale des Petroles d Aquitaine
E21b 49/00
E21b 47/00
E21B 12/02
E21B 44/00
E21B 12/00
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