Abstract: An optical fiber quick disconnect mechanism comprised of left and right separable portions is set forth. One portion is ideally anchored to a pressure isolating bulkhead at a drilled passage which is provided with threads partly along its length; a fixed portion of the quick disconnect mechanism can be anchored there. This enables division of an optical fiber into left and right portions which provide an optical path therethrough. The left and right optical portions are supported by alignment capillaries and the detachable portion of the equipment includes a threaded body which joins to the fixed portion.

Abstract: An igniter is set forth in the present disclosure for use with a coring gun assembly. A bullet equipped with a bottom and having an O-ring thereabout is positioned in a chamber at one end thereof for firing to take a core sample. At the opposite end, an igniter is positioned in the chamber resting primarily on a shoulder aligning an elongate cylindrical shell within the chamber and having an external O-ring for sealing purposes. An elongate electrically insulated conductive firing pin extends through said shell so that an external circuit can be connected thereto to create a firing pulse. The current flows through the pin and through a bridgewire disc positioned at the end of the pin which in turn ignites a prepackaged cylindrical explosive charge to fire the bullet.

Abstract: An unthreading apparatus is set forth which includes upper and lower mandrels which thread together at a threaded connection which is made of threads having the same pitch as the pipe making up the drill string. There is an internal stem or shaft passing through the upper and lower mandrels. The shaft is provided with upper and lower cylinders, thereby enabling fluid under pressure to be introduced into the cylinders to drive the shaft to and fro. Through a ratchet type mechanism, shaft movement is converted into an unthreading motion for the two mandrels and they unthread, coupling unthreading action to the pin and box at a threaded joint in the drill string above the sticking point of the drill string. This enables the present apparatus to unthread at a particular location because it is locked at that location to straddle a particular threaded joint.

Abstract: This disclosure is directed to a detector system for use in measuring while drilling (MWD) equipment. It comprises preferably duplicate chambers positioned to one another and mounted in a MWD system where they are subject to the same shock and vibration. The shock and vibration impinge on the two chambers, and cause two output signals to be formed. The two output signals are applied to a differential amplifier so that the microphonic portion of the signal is cancelled. This then leads to a differential output signal which carries in it the signals representing nuclear events detected by the similar or duplicate detector means. Alternately, a single chamber can be used if it is provided with two anode wires and they are connected to the differential amplifier for signal cancellation.

Abstract: This disclosure is directed to a scintillation crystal surrounded by a sleeve and having a window formed therein. The scintillation crystal has end located first and second photomultiplier tubes which provide output signals. A scintillation event observed in the crystal is seen by both photomultiplier tubes and both form output signals. The output signals have a relationship determining the point of impingement along the length of crystal of the photon gamma radiation; in turn, that photon is located relative to a surrounding shield having a helical window formed therein so that the relative angle of impingement can be determined. The relative angle is then converted into the absolute angle relative to the well borehole by referencing a north seeking gyroscope supported by the sonde. The output signals are also used to determine the energy of the impinging gamma radiation using well known pulse height analysis spectroscopy techniques.

Abstract: A fluid density measuring tool is set forth, a structure having a shielded sonde supporting a radiation source having a characteristic gamma ray emission pattern preferably in all directions of azimuth, and a cooperative first detector is disclosed. Ports aligned with the first detector and source preferably limit the gamma ray pathway primarily to the fluid surrounding the tool. Additional detectors are included, and they measure gamma radiation which involves a surrounding casing and other materials about the well. This provides sufficient measurement data enabling one to sort the data and thereby determine the bulk density of the fluid in the well.

Abstract: The present disclosure is directed to an improved telemetry system and data recovery telemetry receiver apparatus for installation with a logging cable supported sonde. In the sonde, a data stream is modulated onto a carrier after conversion by an encoder. Encoding involves conversion from a stream of binary data into four state symbols which are then encoded into seven duobinary levels. The availability of redundant levels permits correlation between encoded symbols and adjacent symbols. This is transmitted up the monocable to the surface and is recovered. The recovery involves amplification by an automatic gain control amplifier, conversion from an analog to digital form in an ADC, demodulation and reconstruction of the transmitted signal by means of a adaptive transversal filter equalizer featuring fractionally spaced sampling. Reconstructed output levels are then provided, and a slicer adjusts those values to the permitted seven levels. The data is then decoded.

Abstract: A rotary ultrasonic transducer logging tool is set forth which has a transmitter connected to a transducer for transmitting pulses periodically, and a rotor with angle sensor connected thereto. One full revolution is divided into a specified number of incremental steps. The output of the receiver is supplied to an automatic gain control amplifier, then to an analog to digital converter. A gain control setting for the AGC amp is included. The AGC setting for the particular corresponding points in a first revolution of the transducer are used to provide settings for the AGC amplifier in the next revolution. A first buffer is used to store the data for the first revolution, a second buffer for the second revolution, and alternately back to the first buffer. These two buffers provide an output signal for a gain control buffer then input to the AGC amplifier. Alternate forms of gain control signal selection are used such as prior gain control settings.

Abstract: An improved detonation transfer apparatus is set forth. In one embodiment, it incorporates a transverse bulkhead having selected explosive materials on both sides thereof. The bulkhead is shaped into a concave lens to focus the shock wave toward a focal point so that one of the explosive materials directs a shock wave into the other of the explosive materials, thereby triggering sufficient shock wave pressure for detonation. In an alternate embodiment, a blasting cap transfers detonation to a first secondary explosive material which forms a flyer; the flyer travels across the space, impacting with a metal transverse bulkhead which in turn transfers a shock wave through the bulkhead into another explosive shaped in the form of a pellet. This has a high impedance reflector plate in it.

Abstract: A neutron generating system comprising a hermetically sealed housing containing an ionizable gas and a ring anode and target cathode of a Penning ion source. The housing is provided with a recess axially oriented relative to the ring anode and target cathode and adapted to accept a removable samarium/cobalt magnet such that degassing and sealing of the housing can be performed in the absence of the permanent magnet. The cathode target is an OHFC copper rod of substantially the same cross-sectional area as the target with one polished end of the rod containing a titanium film within the housing to serve as the target and the other end of the rod extending out of the housing such as to remove thermal energy from the target during operation. An ion screen between the anode ring and cathode target containing an axially positioned gridded aperture provides a broad ion beam of reduced power per unit area.

Abstract: A system for measuring the complex dielectric constant of a core sample is set forth. It incorporates a circular wave guide having a central axial transmitter coil. Equally spaced axial receiver coils are placed on both sides of the transmitter coil. The opposite polarity receiver signals are connected to an adder circuit to provide an output signal representing only the difference in the two received signals. By placing a standard such as air between the transmitter coil and one receiver coil, or core sample positioned between the transmitter coil and the other receiver coil provides a system for obtaining an output indicative of complex dielectric constant. Optionally, the system is operated in an oven to provide an elevated temperature, and can also be pressurized with a compressed fluid.

Abstract: Improved vertical resolution from pulse neutron logs is obtained by the disclosed process; a pulse of fast neutrons is emitted from a source and counts are taken at near and far dectors. This is done repetitively so that the interval between neutron bursts is conveniently divided into a number of gates, the preferred form being six contiguous gates. The count rate especially in gates 3-6 is obtained and is processed in a modified form to thereby enhance vertical resolution. While before vertical resolution was dependent in part in spacing of the detectors and source, improved vertical resolution is obtained to thereby locate thin beds which would otherwise be obscured.

Abstract: A second receiver coil system (45a,45b) at right angles to the primary receiver coil system (40) in an induction logging tool (10) detects the skewness in the logging tool field pattern caused by the presence of assymmetrical formation structures (30). This skew signal, which provides a composite measure of the asymmetry of the formation structures (30), can be used to correct for horns produced in formation conductivity logs when the logging tool sonde (14) traverses interfaces between dipping beds. The skew signal can also be used to determine the dip and strike angles between such dipping beds.

Abstract: An elongate multilink compound suspension arm is set forth for positioning a sensor parallel to and spaced from a sonde. In particular, it includes first and second approximately parallel arms pivotally connected to a third arm. There are control members additionally included which may be pushed or pulled as appropriate to cause extension arm assembly to move from a fully retracted position in a receptacle along the sonde to an angle extended outwardly and to the rear of the sonde. A sensor pad is supported at the back end and extends toward the back end of the sonde. The sensor pad is pivotally mounted, and is connected with a resilient means for urging the sensor pad into facial contact with the side wall of the borehole. The multilink system particularly enables the sensors on the sensor pad to maintain facial contact with the borehole at a variable distance from the sonde and parallel or at appropriate angles relative to the central axis of the sonde.

Abstract: An elongate gun assembly with multiple gun chambers is assembled with locking keys holdinhg several chambers in place. In each, a bullet with bottom is placed adjacent to an explosive charge. An elongate cable having two end loops connects with the assembly and passes through the bullet. The cable is anchored on the bullet, and the two ends are unequal in length. They enable retrieval after firing. A method of cable coiling and retrieval is set out.

Abstract: For use in a downhole oil well logging tool which is enclosed in a sonde and suspended on an armored logging cable, a means for measuring the macroscopic thermal neutron capture cross section of the borehole fluid is set forth. In the preferred embodiment, a neutron source adjacent to a neutron detector is positioned in a sonde. The entire surrounding region in the well borehole is used as a sample chamber. Fast neutrons from the source after collision with fluid nuclei impinge on the detector which provides an output signal which is indicative of neutron flux. The count rate is most significantly dependent on the thermal neutron capture cross section of the borehole fluid. An additional detector can likewise be spaced farther from the neutron source and provide an alternate count rate. Through the use of two detectors, minor perturbations induced by changes in the environment outside the borehole can be compensated. The neutron capture cross section can be determined for the borehole fluid.

Abstract: For use with a core sample tool removing a sample from a formation of interest, a sonde supported sample receiving chamber is disclosed. It includes a main valve for sample insertion into a cavity in a resilient sleeve. The sleeve is in a chamber connected by suitable valved passages to enable ambient pressure at the cavity to equal downhole pressure; by valve operation this pressure can be maintained after chamber removal and transfer.

Abstract: A measuring device for use in a producing well is set forth. It includes a sonde having upper and lower centralizers to define an annular flow space therearound. In the preferred embodiment, a motor driven sensor preferably a piezoelectric combination transmitter and receiver is, included to transmit and then receive ultrasonic pulses. They are transmitted downwardly from the housing into fluid flowing in the well. Reflective interfaces are defined by material differences. Gas bubbles droplets and particles in the fluid flow and phases between oil and water, etc. form reflective interfaces to create a scattering effect to transmitted ultrasonic pulses so that a return pulse is formed. The pulses encodes fluid flow velocity as a result of the Doppler shift.

Abstract: A method and apparatus for use in well perforating systems and disclosed for firing slapper on exploding foil initiator over relatively lengthy firing lines. Specially designed detonators or initiators of the exploding foil or slapper type are used wherein the type of material used and/or the geometry of the exploding foil causes electrical preloading of the firing lines from the firing pulse generator to the detonator or initiator. The preloading prevents premature inductive and resistive disposition of the high intensity firing pulse traversing the firing lines.

Abstract: A process for processing a dipmeter curve is shown in the preferred embodiment. In a curve, line segments are drawn between curve minima, a second set of line segments are drawn between minima in the first segments, and this is repeated to desired number of levels. When finished, line segments are numbered and become a branched tree. This tree is reorganized to form an event tree which is easily coverted into a stored digital value and is processed for correlation with other curves. The events are reduced in number by using area and length criteria. Correlation is limited to a selected range of shift centered on either zero dip or dip from nearby formation information.