Abstract: A tubing conveyed casing collar locator system that detects the casing collars in a wellbore and acoustically transmits the information through the tubing to the surface where it is detected and processed in a surface processor. The system comprises a downhole tool which comprises downhole sensors, a signal processor with memory, a drive circuit, a battery pack, and a signal generator. The surface system comprises a surface processor, depth system, and acoustic signal transmitter/receiver. The downhole tool detects casing collars as the tool is moved through the collar and acoustically transmits the data or stores the data in downhole memory according to programmed instructions. In one embodiment, the tool compares sensor signals from production elements, such as valves, to stored sensor signatures to uniquely identify the downhole element. In one embodiment, the downhole tool changes operating modes in response to surface command.

Abstract: A tubing conveyed casing collar locator system that detects the casing collars in a wellbore and acoustically transmits the information through the tubing to the surface where it is detected and processed in a surface processor. The system comprises a downhole tool which comprises downhole sensors, a signal processor with memory, a drive circuit, a battery pack, and a signal generator. The surface system comprises a surface processor, depth system, and acoustic signal transmitter/receiver. The downhole tool detects casing collars as the tool is moved through the collar and acoustically transmits the data or stores the data in downhole memory according to programmed instructions. In one embodiment, the tool compares sensor signals from production elements, such as valves, to stored sensor signatures to uniquely identify the downhole element. In one embodiment, the downhole tool changes operating modes in response to surface command.

Abstract: A pulse height analyzer for spectrocopy thermal multigate decay well logging systems is disclosed and has an input section comprising a peak time determining circuit locating a peak occurrence. The peak is determined relative to a threshold voltage determining circuit. On peak detection, a timing signal is formed for a control circuit. This operates a sample and hold switch at the output of an amplifier for the input. This switch inputs to an A/D converter driving a buffer. Various handshake signals cooperate with a telemetry system to transfer the peak time A/D valve for pulse height measurement.

Abstract: A control and power supply circuit is illustrated in the preferred and illustrated embodiment for providing power to a pulsed neutron generator tube. The preferred and illustrated embodiment includes power supplies and control circuits for providing operative power to the pulsed neutron generator tube. The system monitors the voltages supplied to a downhole sonde utilizing a shut regulator circuit which, with the remainder of the control circuitry set forth, properly and in controlled sequence empowers the pulsed neutron generator tube. The tube is provided with power to switch on and such power is switched off in timed sequence to avoid damaging the tube in the event of a malfunction or loss of power from the surface located power source for the sonde.

Abstract: For use in providing control of a pulsed neutron generator tube and its associated power supplies, the preferred and illustrated embodiment of the control circuit senses the operative condition of the pulsed neutron generator tube by observing external insulating gas pressure of the sealed tube to monitor for a loss of pressure, target current magnitude, pulsing of the ion source, current flow for the replenisher and operation of the high voltage power supply. This system functions as an interlock, thereby enabling operation of the tube if nominal operative conditions are achieved. Conversely, the absence of nominal operative conditions switches the equipment off to protect the tube from damage resulting from malfunction.

Abstract: A pulsed neutron well logging system is disclosed having a novel ion source control system providing extremely sharply time defined neutron pulses. A low voltage input control pulse is utilized to produce a relatively sharp rising high voltage ion source control pulse. Simultaneously a delayed quenching circuit control pulse is produced to rapidly quench the high voltage ion source control pulse after a predictable time delay from its onset. The resultant ion source control voltage (and hence neutron output) is sharply defined timewise.

Abstract: A pulsed neutron well logging system using a sealed off neutron generator tube is provided with a neutron output control system. The control system monitors the target beam current and compares a function of this current with a reference voltage level to develop a control signal. The control signal is used in a series regulator to control the replenisher current of the neutron generator tube.

Abstract: A pulsed neutron well logging system using a sealed off neutron generator tube is provided with a programmable digital neutron output control system. The control system monitors the target beam current and compares a function of this current with a preprogrammed control function to develop a control signal for the neutron generator. The control signal is used in a series regulator to control the average replenisher current of the neutron generator tube. The programmable digital control system of the invention also provides digital control signals as a function of time to provide ion source voltages. This arrangement may be utilized to control neutron pulses durations and repetition rates or to produce other modulated wave forms for intensity modulating the output of the neutron generator as a function of time.

Abstract: Electrical energy is induced into an earth formation by a transmitter in apparatus, adapted to be passed through a borehole traversing the earth formation. Clock pulses are also provided in the apparatus. At least two receivers provide signals corresponding to received electrical energy from the earth formation. A gating circuit provides groups of clock pulses in accordance with the signals from the receivers so that the number of clock pulses in each group corresponds to the dielectric constant of the earth formation.

Abstract: A torque meter for measuring the torque of a rotating shaft includes at least two sensing devices providing pulses corresponding to the rotation of the shaft. A pulse source provides clock pulses. A circuit receiving th pulses from the sensors and the clock pulses provides groups of clock pulses wherein the number of pulses in each group corresponds to the torque of the shaft.

Abstract: A dielectric well logging system includes a logging tool adapted to be passed through a borehole traversing an earth formation. The logging tool includes a transmitter which induces electric energy into the earth formation at a radio frequency. Two receivers in the logging tool spaced a predetermined distance apart provides intermediate frequency signals corresponding to the electrical energy received from the earth formation. The intermediate frequency signals are transmitted by way of a cable to the surface. Surface electronics include zero crossing detectors, each detector receives a different intermediate frequency signal from the cable and provides a detector signal whose change in amplitude is representative of the intermediate frequency signal passing through zero. A source provides clock pulses at a frequency substantially greater than the frequency of the intermediate frequency signals.