Abstract: A drill hole logging system (5) incorporates a computing system (58) at the surface and a deployment mechanism (40) for conveying a logging tool (10) configured to measure one or more geophysical parameters into a drill hole (20). A transmission means (57) communicates commands and data representing the geophysical parameters between the surface computing system and the logging tool. A borehole caliper (300) is employed to profile the inside of the borehole.

Abstract: A magnetic susceptibility and conductivity tool (10) which incorporates a transmitter coil (4) energized with a time-varying current from a transmitter coil drive (13). The transmitter coil drive receives a clock signal and induces a data signal (99) including a primary mutual coupling signal and a formation coupling signal. A receiver coil (1) outputs a receiver coil voltage induced by the data signal. A transmitter coil current sense circuit (15) receives current from the transmitter coil and outputs a digital coil current voltage signal. A synthetic null circuit (14) receives the digital current voltage signal and multiplies the digital current voltage signal with a predetermined constant (28) for amplitude of a base primary mutual coupling signal and shifts phase with a predetermined phase offset (27) to output a synthetic null signal (104).

Abstract: A magnetic susceptibility and conductivity tool (10) which incorporates a transmitter coil (4) energized with a time-varying current from a transmitter coil drive (13). The transmitter coil drive receives a clock signal and induces a data signal (99) including a primary mutual coupling signal and a formation coupling signal. A receiver coil (1) outputs a receiver coil voltage induced by the data signal. A transmitter coil current sense circuit (15) receives current from the transmitter coil and outputs a digital coil current voltage signal. A synthetic null circuit (14) receives the digital current voltage signal and multiplies the digital current voltage signal with a predetermined constant (28) for amplitude of a base primary mutual coupling signal and shifts phase with a predetermined phase offset (27) to output a synthetic null signal (104).

Abstract: A drill hole logging system (5) incorporates a computing system (58) at the surface and a deployment mechanism (40) for conveying a logging tool (10) configured to measure one or more geophysical parameters into a drill hole (20). A transmission means (57) communicates commands and data representing the geophysical parameters between the surface computing system and the logging tool. A borehole caliper (300) is employed to profile the inside of the borehole.

Abstract: A sensor gimbal system employs one sensor gimbal on which a sensor is mounted. The sensor gimbal is configured to orient a sensitive axis of the sensor with respect to a survey instrument. A sensor motor assembly is configured to rotate the sensor gimbal between a first hard stops and a second hard stop. A dowel pin extends from the mating bevel gear to engage the hard stops. A flex circuit has a flex cable from a sensor PCB, on which the sensor is mounted, to an electronic circuit board.

Abstract: A borehole logging instrument sonde employs a case in which support electronics including a processor are mounted. A rotatable platform is mounted within the case and carries an inertial measurement unit (IMU) and a roll axis gyroscope. A motor is adapted to rotate the rotatable platform within the case. The processor receives an input from the roll axis gyroscope and provides an output to the motor responsive to the input for control of rotation of the platform to space stabilize and isolate the IMU from the roll of the instrument sonde.

Abstract: A borehole logging instrument sonde employs a case in which support electronics including a processor are mounted. A rotatable platform is mounted within the case and carries an inertial measurement unit (IMU) and a roll axis gyroscope. A motor is adapted to rotate the rotatable platform within the case. The processor receives an input from the roll axis gyroscope and provides an output to the motor responsive to the input for control of rotation of the platform to space stabilize and isolate the IMU from the roll of the instrument sonde.