Abstract: The present invention is an improved wellbore tool for coupling to a drill string at a threaded junction and adapted for use in a wellbore during drilling. A sensor is disposed in the wellbore tool for sensing a condition and producing a data signal corresponding to the condition. A self-contained power supply is disposed in the wellbore tool and coupled to the sensor for providing power to the sensor as required. The Hall Effect coupling transmitter means is carried by the sensor and for transmitting data from the Hall Effect coupling transmitter means to a Hall Effect coupling receiver carried by the drill string and disposed across the threaded junction from the wellbore tool, wherein data is transmitted across the threaded junction without requiring an electrical connection at the threaded junction.

Abstract: An improved method and apparatus of transmitting data signals within a well bore having a string of tubular members suspended within it, employing an electromagnetic field producing means to transmit the signal to a magnetic field sensor, which is capable of detecting constant and time-varying fields, the signal then being conditioned so as to regenerate the data signals before transmission across the subsequent threaded junction by another electromagnetic field producing means and magnetic sensor pair; the method and apparatus also having a battery saving switch that extends the life of the battery carried by the tubular member in a compartment that shields the battery from the well bore environment.

Abstract: An improved method and apparatus of transmitting data signals within a well bore having a string of tubular members suspended within it, employing an electromagnetic field producing means to transmit the signal to a magnetic field sensor, which is capable of detecting constant and time-varying fields, the signal then being conditioned so as to regenerate the data signals before transmission across the subsequent threaded junction by another electromagnetic field producing means and magnetic sensor pair.

Abstract: A drill pipe identification system automatically provides an identification number for each drill pipe as the drill pipe is being lowered into or withdrawn from the well. The system has a SAW identification device which is mounted in a cylindrical cavity which is formed within a tool joint of each section of drill pipe. The cavity has an aperture leading to the exterior of the tool joint to allow radio frequency signals to be received and reradiated. The SAW device receives signals from a transmitter and receiver, modulates the signals and reradiates them in a manner that corresponds to an encoded number in the SAW device.

Abstract: A method and apparatus allows dynamic data to be recorded in a drill string for later playback at the surface. The system includes a transducer located in a sub in the drill string which provides electrical responses to a analog to digital converter. A timer circuit provides timer pulses to the converter to cause the response to be converted into a digital value for storing in a recorder. The timer pulses are also used to address the memory location. The timer circuit has the ability to provide a variable number of timer pulses at a variable frequency and at variable intervals. A surface timer circuit provides simultaneous timer pulses to a counter to indicate at the surface which memory location is being filled at any given time.

Abstract: A depth determining device has features for informing the operator of the depth of the cutting tool of a hydraulic drilling machine. The drilling machine is for earth boreing and has a piston carried in a cylinder and secured to a driven kelly. The device has a transducer mounted at the top of the cylinder for transmitting a sound wave through hydraulic fluid to the tap of the piston and detecting the return of the wave at the top of the cylinder. A counter determines the elapsed time for the sound travel. The elapsed time is converted into depth and displayed.