Abstract: A method and an apparatus for recording the depth of a well logging apparatus is provided. The method and apparatus include the direct acquisition of broad depth information from the logging system conversion of the broad depth information to an acceptable digital signal and recording that signal on the audio track of a video cassette recorder. A microcontroller is used to convert broad depth information from either the logging system or the video cassette recorder (in the playback mode) to actual depth and depth rate for use by other displays and plotters.

Abstract: A method and an apparatus for recording the depth of a well logging apparatus is provided. The method and apparatus include the direct acquisition of broad depth information from the logging system conversion of the broad depth information to an acceptable digital signal and recording that signal on the audio track of a video cassette recorder. A microcontroller is used to convert broad depth information from either the logging system or the video cassette recorder (in the playback mode) to actual depth and depth rate for use by other displays and plotters.

Abstract: A circuit for physical placement within an underground well to amplify low level differential DC voltage signals measured at a well casing is disclosed. The circuit incorporates an instrument amplifier with a first switching device before the amplifier and an inverter after the amplifier in the signal path. A second switching device selectively connects one of the amplifier and inverter outputs to a low-pass filter. The switching devices operate synchronously under control of an operating clock signal so that DC error terms associated with the amplifier are converted into a substantially AC error signal while maintaining the signal being amplified as a DC signal. The duty cycle of the operating clock signal is established to cause the substantially AC error signal to include a DC component of appropriate polarity and magnitude to compensate for DC error terms associated with the inverter and low-pass filter.

Abstract: A method and apparatus for increasing the effective bandwidth of an acoustic return resulting from logging operations. The real time acoustic return is stored in memory. A transmitted acoustic return is produced for transmitting over a logging cable by transmitting the acoustic return out of the memory and onto the cable at a rate which is slower than real time.

Abstract: An adaptable, accurate, high resolution centrifuge core measuring method using a single strobe flash per measurement uses a microprocessor controller to control the measuring method, not a computer. The controller, not the camera clock, decides when the camera data should be read. The camera data is read into and stored in the controller, not a computer. The controller reads the camera array, controls centrifuge speed, determines alignment of the proper catch tube, flashes the strobe, determines lapse time, rereads the pixels, stores and analyzes the pixel information and the other steps of the method. The controller is capable of operating in many modes. But at any point, for operator intervention the controller is adapted to let the computer intervene.

Abstract: A mobile dynamometer includes a slotted disk (12) and slotted disk (14) disposed on a rotating shaft (10) a predetermined distance apart. A slot (16) is formed in the periphery of the disk (12) and a slot (18) is formed in the periphery of the disk (14). A light source (20) and a light sensor (22) are mounted stationary with respect to the shaft and proximate the periphery of the disk (12). When the slot (16) passes proximate the source (20) and the sensor (22), a signal is generated. A light source (24) and a detector (26) are mounted proximate the periphery of the disk (14) such that passage of the slot (18) thereby generates a signal. The signal generated by the sensors (22) and (26) are two state signals. The time duration between the signals is measure and the angular deviation of the two disks (12) and (14) can be calculated therefrom. Measurement of this angular deviation determines the amount of twist on the shaft portion (28) between the two disks (12) and (14).