Patent ID: 6367565
Filing Date: 2002-04-09
Classification: E21B

Abstract:
A tool for detecting the properties of a subterranean formation being drilled and or the operation of a down-hole hammer, comprising:a. at least a portion of a drill string and or a throat; b. a fluid driven, percussive piston capable of producing a linearly reciprocating motion; c. at least a portion of the drill string and or the throat in communication with the percussive piston; d. a drill bit in communication with the piston, or the throat, or the drill string, or a combination thereof, and in communication with the subterranean formation being drilled; e. the motion of the piston at least partially comprising a transient response and a steady response; f. at least one transducer means for converting at least a portion of the motion of the piston into an electric signal; and g. a means for analyzing characteristics of the electric signal so as to provide a measurement of the transient response in order to detect the characteristics, including hardness, composition, and integrity, of the formation being drilled, and or to provide a measurement of the steady response in order to detect the piston's frequency, stroke length, and impact force.