Abstract: The invention relates to measuring the bubble point of oil down a well drilled into an underground formation. The pressure is measured by an apparatus lowered down the well. The apparatus comprises a chamber (2) in which a small quantity of oil is confined in a volume which is variable by a needle (3) having portions of different diameters (3a, 3b) capable of being inserted to a greater or lesser extent into the chamber (2) under drive from a motor (7). Values of pressure inside the chamber and of chamber volume are respectively measured by a manometer (11) and by a displacement sensor (12) connected to the needle (3) and are transmitted to the surface.

Abstract: The first of a plurality of dynodes in a photomultiplier tube is made of a weldable nickel-beryllium alloy having a beryllium oxide layer thereon, formed into a desired shape from spot-welded segments. The dynode itself is then spot-welded to a support element. In one aspect of the invention, this first dynode has a scoop form. It is followed by a second dynode of spherical shape, made of a copper-beryllium alloy. A flap made of nickel-beryllium is juxtaposed to intercept photoelectrons that otherwise may escape photomultiplication in either the first or second dynodes. Additional venetian-blind type dynodes are employed to obtain the required photomultiplication.

Abstract: In the representative embodiment of the invention disclosed herein, new and improved tool-orienting apparatus is adapted to be secured on a well tool that is to be moved through a highly-deviated well bore. To assure that the well tool will remain in a selected angular orientation as it is moved in a well bore, the orienting apparatus includes a pair of oppositely-directed generally-helical guide rails that are respectively terminated in lateral projections that are eccentrically located on one side of the orienting apparatus so that the unbalanced weight of a well tool carrying the orienting apparatus will cause the tool to roll over into a selected angular orientation when the tool is being moved through a deviated well bore interval with the lateral projections riding on the lower wall of the well bore interval.

Abstract: Connector assembly for use in a fluid medium comprising a male connector with a cylindrical pin with several axially spaced contact elements, and a female connector with a tubular housing and axially spaced annular contacts secured inside the housing. Seals with a flexible central portion are alternated with the contacts and with the latter define a bore to accommodate the pin. A chamber filled with dielectric liquid is defined within the housing as a rear extension of the bore, the entry of which is closed to external fluid by a sealing member. A free space is left around the flexible portion of each tubular seal, and each of said spaces communicates with the aforementioned chamber. Means are provided by which the pressure increases in the chamber when the pin is inserted. The pressure rise in the spaces around the seals increases the pressure force of the seals against the pin.

Abstract: A well-logging laboratory, for use with a well-logging tool which is suspended within a borehole by a wireline, includes a moveable frame upon which the wireless drum is mounted, and a moveable bulkhead is associated with the frame and various well-logging apparatus can be secured to the bulkhead, whereby the frame and bulkhead may be assembled as a modular unit, and moved within the well-logging laboratory as a modular unit.

Abstract: A connector assembly for mechanically and optically associating a first optical fiber, exposed to high pressure and/or temperature fluids, with a second optical fiber, disposed within a body having low pressure conditions therein, has a hermetically sealed rigid transparent window and at least one lens disposed between the two optical fibers.

Abstract: The flowmeter comprises a central mandrel suspended from a cable and centered in the fluid stream so as to leave an annular passage. Fluid stream contracting means are provided for forming a venturi in the annular passage, and a differential pressure gauge is provided in the central mandrel to produce a signal representative of the pressure head loss across the venturi, which signal is processed to derive the flow rate.

Abstract: In accordance with principles of the present invention methods and apparatus are provided for evaluating the quality of the cement bond in cased boreholes. Acoustic energy is used to excite the borehole-casing-annulus-formation system and the quality of the cement bond is determined by examining the ratios of the signals received by two longitudinally spaced apart receivers supported on a sonde. The acoustic energy is generated by two transmitters symmetrically disposed above and below the receivers along the sonde. The spacings between the receivers themselves and between the receivers and the transmitters are selected so as to enhance the correlation between the ratios of the received signals and the quality of the cement bond log. An additional receiver, supported on the sonde at a small distance from one of the transmitters, is employed to determine the quality of the cement bond in hard formations.

Abstract: The invention relates to a tool having a valve (3c, 4c) for closing the tubing (100) of a well into which the tool has been placed. The valve member (4c) is controlled by means of a traction cable (17) via a hydraulic mechanism having two piston-and-cylinder assemblies (4b, 5e, 45; 1g, 4a, 41) which reduce the force applied on the valve member (4c) by the pressure of the fluid in the well and which amplify the force (f) applied thereto by the cable (17) in order to open said valve member.

Abstract: A novel neutron burst timing, detection, and calculation method and apparatus are disclosed for a Thermal Decay Time Logging System. A neutron bursting regime is provided which includes a short burst, long burst repetitive sequence. After a short delay from the short burst, a first series of time gates is provided for accumulating gamma ray counts. After a relatively longer delay from the long burst, a second series of time gates is provided for accumulating gamma ray counts. The thermal neutron decay time constant .tau. and the macroscopic capture cross-section .SIGMA. of the formation are determined through an iterative procedure by which the formation .tau. is estimated from the second series of time gates which have been stripped of borehole decay counts determined from the first series of time gates. Similarly, the borehole .tau. is estimated from the first series of time gates which have been stripped of formation decay counts determined from the second series of time gates.

Abstract: A digital induction resistivity logging tool is disclosed for digitally measuring both the in-phase (R) and quadrature (X) phase components in a receiver signal generated in response to transmitter induced currents flowing in the earth's sub-surface formations. The digital indication tool includes a digital sinewave generator for generating a highly phase stable, low distortion transmitter signal, the frequency of which is selectable from among a plurality of transmitter frequencies. One phase sensitive detector is used alternately to detect both the R and the X phase component signals. Automatic phase compensation is included to periodically compensate for both static and dynamic temperature dependent phase shift errors due to circuits of the tool involved in the component measurements. A floating point analog-to-digital converter capable of handling the wide dynamic range in the detected phase component signals is provided to convert the phase detector output into digital signals.

Abstract: A method of sonic logging in which there is established at a depth of interest in a borehole a set of peak matrices comprised of peak vectors representative of a plurality of different characteristics of sonic signals traversing an earth formation. A set of rules is established based upon borehole sonic characteristics including the utilization of past histories of slowness and coherence values of wave components of interest. The matrices are searched in accordance with the rules to identify the presence in the sonic signals of wave components of interest, such, for example, as casing, compressional, shear and Stoneley. The identified wave components are recorded as a function of depth of interest, and the aforesaid steps are repeated at each depth of interest.

Abstract: A method and apparatus for improving the quality of recordings from electrophotographic recording apparatuses by calculating the surface charge remaining on the recording medium adjacent the development electrode and adjusting the voltage of the development electrode to match the remaining surface charge; controlling the corona charger to operate at two levels, a first level for charging the surface of the recording medium and a second lower level at which neither light nor ions are emitted; controlling the fuser lamp in response to changes in ambient temperature, line voltage, and the rate of recording medium advancement to obtain optimum toner fusion without damage to the recording medium; deactivating the toner pump and air knife blower if the recording medium has not moved for a predetermined period of time, and further including a development electrode design for maintaining a uniform layer of toner adjacent the recording medium.

Abstract: A well logging sonde is disclosed which includes a collimating window design for the accurate detection of gamma rays of low and high energy which are back-scattered from a region near a source of gamma rays emitted into the formation. The sonde includes a tungsten support inner tube or shell surrounded by a length of "U" shaped steel. A conduit is formed in the wall of the shell at an angle with respect to its axis and is oriented symmetrically toward the opening of the "U" shaped steel support member. A closing member of a thin layer of titanium is welded to the open ends of the "U" shaped steel member. An arcuate tungsten pad is secured about the titanium closing member and partially about the exterior of the open ends of the "U" shaped steel support member. A conduit in the pad is aligned with the conduit of the inner shell to form a collimating window. A gamma ray detector of a length shorter than the "U" shaped steel section is mounted within the inner tube in the path of the collimating window.

Abstract: An apparatus and method for the measuring the transverse dimensions of a hole such as in an oil well including a sonde on which an electro-acoustic transducer is mounted in an offcentered position in relation to the axis of the sonde. This transducer has two opposite active faces so as to simultaneously transmit acoustic pulses in diametrically opposite diections from the sonde. When the sonde is centered in the hole, the transducer picks up the echoes retransmitted by the wall of the hole in the two directions, at different times. A recording is made of these times and preferably also of an indication of the amplitude of each of these echoes to obtain both a diameter measurement and an indication of the condition of the hole surface. Several transducers are provided, superposed and oriented along various diameters distributed around the axis of the sonde.

Abstract: A microelectronics module and method for fabricating a microelectronics module has an electronic surface mounted device soldered to a thick film multilayer circuit disposed on an interconnect ceramic substrate, and the interconnect ceramic substrate is soldered to a co-fired multilayer ceramic substrate having a plurality of pin conductors brazed to the underside of the co-fired multilayer ceramic substrate.

Abstract: Induction logging sonde including transmitter and receiver solenoid coils mounted on a support and axially separated from each other. The support is made of conductive material and comprises at least one first longitudinal portion for mounting the coils and second longitudinal portions on each side of the first portion. At least the first portion has a substantially continuous and axisymmetric outer surface so as to favor the flow of eddy currents around the surface, whereby the electric field on that surface is substantially cancelled.

Abstract: Methods and apparatus, for processing signals derived along portions of the length of a borehole to determine the relative position of geological formation characteristics, effect the correlation of pairs of signals using substantially overlapping correlation intervals to obtain cross-correlation functions for each pair of signals. These cross-correlation functions are then displayed as a function of borehole depth for each pair of curves such that discontinuities in the cross-correlation functions are rendered obvious. From such discontinuities, zoning of the data is enabled through determination of the position of significant continuous intervals. Sequences of cross-correlation functions which belong to one of these intervals may then be used to directly determine the corresponding relative position of a formation characteristic. When applied to dipmeter signals, the method produces more accurate and geologically consistent dip and azimuth values for subsurface formations.

Abstract: A technique for producing measurements of physical characteristics of subsurface media near a borehole penetrating the earth is disclosed that uses multiple transducers positioned along a borehole tool. A number of transducers of a first type, such as transmitters, are separated from each other along the tool by a preselected separation, and a number of transducers of a second type, such as receivers, are separated from each other by the same separation and are positioned on the tool at a preselected distance from the transducers of the first type. The technique contemplates the use of appropriate circuitry for producing measurements, using different combinations of transducers, of physical characteristics of the subsurface media at different positions along the borehole.Furthermore, different combinations of measurements produced at different borehole positions may be compared or combined to produce improved measurements that are compensated for borehole effects and other errors.

Abstract: A dual resistivity and induction apparatus for the investigation of earth formations traversed by a borehole, comprises an electrode system, supported on a support member, comprising a central electrode and five pairs of electrodes respectively short-circuited and aligned symmetrically about the central electrode at increasing distances therefrom; the central electrode and the electrodes of the fourth and fifth pairs are called current electrodes, the electrodes of the first, second and third pairs are called voltage electrodes; a source of alternating current at a first frequency, f.sub.1, is coupled between the electrodes of the fifth and fourth pairs; a source of alternating current at a second frequency, f.sub.2, is coupled between the electrodes of the fifth pair and an electrode at electrical infinity with respect to the electrode system; a circuit arrangement coupled to the electrodes of the fourth pair for generating current at f.sub.