Abstract: A well logging instrument comprises a focus section having a focus upper guard, a center electrode and lower focus guard. The bottom section of the instrument includes a pad device having electrodes on its borehole wall-engaging surface and adapted to be urged against the borehole wall and also having one or more pressure relief devices, for example, spring-loaded check valves, located therein to reduce differential pressure which might otherwise build up between the surface of the pad and the borehole wall. The remote electrode of the focus portion of the instrument is the armor surrounding the logging cable. The lower focus guard serves a dual function in that it is also the mini-focus remote electrode. Means are provided for measuring the potential between the focus guard and the cable armor and also between the microguard and the lower focus guard, both measurements then being sent up the logging cable to the surface electronics.

Abstract: The address scaler outputs of a multichannel analyzer are fed to two comparator circuits in an address decoder, one such address decoder being provided for each energy range of interest in the spectrum of detected gamma rays produced, or occurring, in earth formations surrounding a borehole. The address number from the multichannel analyzer is compared with two numbers preset by switches within the decoder, one group of switches and its associated comparator circuit being determinative of the lower boundary number, and a second group of switches and associated comparator circuit being determinative of the upper boundary number. The outputs from the comparators, one of which is inverted, are AND gated with a STORE pulse from the multichannel analyzer. If the address number from the multichannel analyzer falls within the lower and upper boundary numbers in coincidence with the STORE pulse, an output pulse is generated by the AND gate; otherwise, no output results.

Abstract: A well logging instrument comprises a focus section having a focus upper guard, a center electrode and lower focus guard. The bottom section of the instrument includes a pad device having electrodes on its borehole wall-engaging surface and adapted to be urged against the borehole wall and also having a plurality of pressure relief holes formed therein to reduce differential pressure which might otherwise build up between the surface of the pad and the borehole wall. The remote electrode of the focus portion of the instrument is the armor surrounding the logging cable. The lower focus guard serves a dual function in that it is also the mini-focus remote electrode. Means are provided for measuring the potential between the focus guard and the cable armor and also between the microguard and the lower focus guard, both measurements then being sent up the logging cable to the surface electronics.

Abstract: A pulsed neutron generator for well logging is provided having a resistor connected between the anode and cathode. The resistor provides a direct current path whereby corona current can flow between the cathode and a corona point without the necessity for the ion source to conduct. In an alternative embodiment, the secondary coil of a pulsing transformer is connected in series with a resistor between the anode and cathode. In an alternative embodiment, a corona regulator in series with the collector-emitter of a transistor is connected between the cathode and anode of the neutron source and the base drive to the transistor is provided by a light-responsive solar cell activatable by an external lamp. Circuitry is provided for utilizing the various neutron sources.

Abstract: The borehole instrument contains a pair of bellows which are equally spaced from a differential pressure transducer to provide equal temperature expansion of the liquid to provide a true reading on the transducer. A third bellows is connected between the borehole fluid and the exterior of the transducer housing to eliminate pressure buildup in or around the transducer. The instrument has utility in finding oil-water, gas-oil and gas-water interfaces and other combinations of fluid interfaces by measuring the differential pressure across the interface.

Abstract: A liquid fuel dispensing system having a plurality of dispensing pumps each generating electric pulses according to the volume of fuel dispensed and a central control where payment is made. A data transmission link couples each pump to the central control and each pump has a pulse store which accumulates pulses generated by the pump during a dispensing operation. A multiplexing unit at the central control samples the outputs from the pulse stores which are updated at each sampling.

Abstract: An earth borehole instrument having a plurality of pad members adapted to engage the borehole walls are pivotally connected through mechanical arms to a spring-loaded slidable collar on the instrument. Each of the pad assemblies has a bow spring on its inner surface which is fixedly attached to one of the mechanical arms and slidably attached to another of the mechanical arms supporting the pad. The hidden bow spring maintains the pad, serving as a wear link, in flat contact with the borehole wall. In alternative embodiments, hidden bow springs maintain one or more borehole wall-engaging wheels against the borehole wall.

Abstract: An earth borehole instrument has a plurality of wear link members adapted to engage the borehole walls which are pivotally attached through articulated mechanical arms both to a fixed collar and to a spring-loaded slidable collar on the instrument. The articulated arms for each wear link member consist of a pair of power arms which are each pivoted at a center point on the wear link adapted to engage the borehole wall and a pair of sensing arms which are pivotally connected, respectively, to the ends of the wear link. In an alternative embodiment, a bow spring is mounted on the underside of the power arms for maintaining the wear link flat against the borehole wall.

Abstract: The apparatus and method provides the ability to selectively treat a producing zone in a well and to gravel pack an annulus in the well casing outside a screen type liner pipe. A tubing string extending from the surface of the well bore is connected to a packer by a crossover valve. Flow down the tubing string is directed to an annulus below the packer, then inwardly through the screen type liner, then upward through the crossover into the annulus above the packer and then to the earth's surface. Communication from the crossover to the annulus above the packer may be selectively closed to permit a treating pressure to be exerted down the tubing to force a treating fluid into the producing zone. The treating pressure is isolated from the casing above the packer to protect the casing above the packer.

Abstract: By using a hill climbing technique, the input energy to the electrostatic precipitator electrodes is automatically increased until the electrode potential decreases. In response to the electrode potential decrease, the input energy is decreased. The electrode potential is controlled by an automatic voltage controller including an electrode potential sense circuit. The controller includes a digital store for increasing the count of the store and means responsive to the count in the store provide an output signal related to the count and means responsive to the signal from the electrode potential sensing circuit which is indicative of a fall in the electrode potential is used to reduce the count in the store. The count in the store is converted into an analog voltage used to control the duty cycle of thyristers and thus the precipitator electrode potential.

Abstract: Drill cuttings are effectively removed from the bottom of a bore before they can adversely affect the operation of the bit. The bit includes a body member rotatably supporting individual cutter members. A shield means projects from the body member proximate the cutter members. A first portion of the shield means has an outside diameter substantially equal to the outside diameter of the cutter means and substantially equal to the diameter of the bore and a second portion having an outside diameter substantially less than the outside diameter of the cutter members and substantially less than the diameter of the bore. A first passage extending through the bit is adapted to provide communication with a vacuum source to assist in removing the drill cuttings. A second passage extending along the length of the bit is adapted to provide communication with a gas pressure source to assist in removing the drill cuttings.

Abstract: A seven-segment display arrangement has one or more seven-segment display devices each with a common anode and a cathode for each segment, and a diode connected to each cathode is arranged so that on failure of a segment the cathode current is drawn by the diode and is used to initiate a warning signal. Principal application for the display is in a liquid fuel dispenser where the display may be mounted in encapsulated form on the dispensing nozzle.

Abstract: A well tool apparatus having a perforating section at its lower end has an upper section comprised of a reservoir containing a compatible perforating fluid and a pump for pumping such fluid down through the perforating section and out the lower end of the apparatus. A protective shield containing a sand control medium is provided for causing the perforating fluid to displace the well bore fluid in the region along the length of the perforating section, such displaced fluid being recaptured above a floating piston in the reservoir containing the perforating fluid. Means are provided for releasing the compatible perforating fluid into the annulus between the shield and the perforating section, the lower end of the shield having a gravel screen and a port for releasing the perforating fluid into the annulus between the apparatus and the casing to be perforated. Upon perforating, the sand control medium settles into place inside the shield to provide sand control for the formation being produced.

Abstract: Various functions of a production oil well are monitored to cause a switch closure for each normal cycle of the pump. Alternatively, the level of the fluid within the well is monitored to cause the switch closure. The switch closure activates a first oscillator whose count is compared with a variable frequency oscillator over a given period of time to ascertain the percentage of time of normal operation. The integrated time is adjusted to shut down the system when the percentage of time drops to or below the preselected amount. In response to the integration timer signal, a shutdown timer is turned on which restarts the cycle after a preselected amount of time. When the system is restarted by the shutdown timer, a pump-up timer is turned on which is adjusted to allow for a desired pump-up time. As the pump-up timer is allowing the system to recycle, the integration timer is reset and the recycling is completed if the requirements of the integration timer are met.

Abstract: A circuit for controlling the rectifier circuit in an electrostatic dust precipitator, the circuit being an oscillator circuit utilising a pair of alternately conducting transistors and a timing circuit controlling conduction of one of the transistors, the other transistor controlling the circuit output.

Abstract: A sensor associated with the production of an oil well generates a signal indicative of pumpable fluid available in the wellbore. The signal activates a first oscillator whose count is compared with a variable frequency oscillator having a frequency of approximately one-half that of the first oscillator. The comparison is made over a given period of time to ascertain the percentage of time the well has produced fluid. The integrated timer is adjusted to shut down the system when the percentage of time the valve is open drops to the preselected amount. In response to the integration timer producing a signal, a shutdown timer is turned on which restarts the cycle after a preselected amount of time. The length of shutdown time for the pumping unit is preset according to the well fill-in rate. When the system is restarted by the shutdown timer, a pump-up timer is turned on which is adjusted to allow for a desired pump-up time.

Abstract: A valve in the production flow line of an oil well closes a reed switch indicative of fluid being pumped through the line. The switch closure activates a first oscillator whose count is compared with a variable frequency oscillator having a frequency of approximately one-half that of the first oscillator. The comparison is made over a given period of time to ascertain the percentage of time the valve has been open and passing fluid. Theoretically, the valve should be open approximately fifty percent of the time because almost that much time is taken on the downstroke of the pumping assembly when no production is occurring. The integrated timer is adjusted to shut down the system when the percentage of time the valve is open drops to the preselected amount, usually equal to or less than around 50 percent. In response to the integration timer producing a signal, a shutdown timer is turned on which restarts the cycle after a preselected amount of time.