Abstract: There is disclosed herein a stress relieved intermediate insulating layer consisting of one or more layers of spun-on glass lying over a metalization pattern. The spun-on layers are allowed to crack from thermal stress imposed upon the structure. The cracks in the spun-on layers are then filled with a glass layer deposited by CVD or LPCVD.

Abstract: A process and structure are disclosed which are suitable for forming large arrays of Schottky diodes at desired locations between mutually perpendicular strips of aluminum and strips of metal-silicide. The invention is particularly useful in creating read-only memories and programmable logic arrays, and allows fabrication of Schottky diodes more compactly than previous structures.

Abstract: A high resolution method and apparatus for measuring the depth of a tool suspended from a cable inside a borehole are described. The tool includes accelerometers for measuring its acceleration and this measurement is combined with a cable depth measurement with which the amount of cable in the borehole is determined. A Kalman filter is employed to continually provide estimates of the velocity and depth of the tool from the accelerometer and cable depth measurements. A filter modifier alters operation of the filter during discontinuous motions of the tool such as when it is stuck and slips. A tool sticking detector senses when the tool is stuck and for how long to correspondingly modify the filter by forcing it to more strongly rely upon accelerometer measurements when the tool is stuck and gradually return to normal filter operation when the tool resumes movement after having been stuck.

Abstract: By establishing a slow compressional wave in subsurface formations, and then measuring the velocity of the slow compressional wave, one can obtain useful information about the porosity and formation factor of the formations through which the slow compressional wave has passed.

Abstract: An improvement in signal level reception of an electromagnetic pad-type device in relatively conductive formations can be achieved by providing a layer of dielectric material that abuts the borehole wall and serves to enhance injection into the formations and guiding of the electromagnetic energy.

Abstract: An apparatus and method for measuring properties of earth formations surrounding a borehole and, particularly, conductivity properties of the formations and certain properties of the invaded zone of the formations. In accordance with one embodiment of the invention, a logging device, movable through the borehole, has a transmitter coil and first and second spaced receiver coils mounted thereon. A short pulse of electrical energy is applied to the transmitter coil. Signals are induced in the first and second receiver coils. A conductivity property of the surrounding formations is then determined as a function of the times of occurrence of predetermined characteristics of the signals detected in the first and second receiver coils.

Abstract: The disclosure is directed to an apparatus and method for determining the velocity of acoustic wave energy propagating information surrounding a borehole. In accordance with one form of the apparatus, a transmitter is positioned in the borehole and periodically establishes acoustic wave energy in the surrounding formations. The acoustic wave energy is received at a plurality of spaced locations in the borehole and a plurality of signals are derived which are respectively representative of the wave energy received at the plurality of spaced locations in the borehole. Means are provided, for correcting a first portion of the signal from one of the receiver locations with first portions of signals from the other receiver locations. The time references of the first portion of the signals from the other locations are determined from an assumed velocity in conjunction with the time reference of the first portion of the signal from the one receiver location and the distance to each of the other receivers.

Abstract: An induction well logging apparatus and method is disclosed for determining dip and/or anisotropy parameters of formations surrounding a borehole. A transmitter is provided and includes a first transmitter coil having an axis which is substantially parallel to the borehole axis and a second transmitter coil having an axis which is substantially perpendicular to the borehole axis. A receiver is provided and includes first and second receiver coils having axes which are substantially mutually orthogonal. Each of the receiver coils is substantially perpendicular to the borehole axis. The transmitter and receiver are mounted in a mechanically passive manner on a support member adapted for movement through the borehole. The transmitter coils are energized in a manner which permits the separate detection at the receivers of the currents induced in the formations by each of the two transmitter coils.

Abstract: The invention is directed to induction logging apparatus and method for obtaining measurements dependent upon the vertical conductivity component of formations surrounding a borehole. The disclosed techniques can also be used to determine horizontal as well as vertical conductivity of the formations, and thereby achieve determination of formation anisotropy. A transmitter coil is provided with its axis substantially perpendicular to the borehole axis. A receiver coil is provided in spaced relation to the transmitter coil. The axis of the receiver coil is also substantially perpendicular to the borehole axis, and is preferably parallel to the axis of the transmitter coil. Means are provided for detecting signals induced in the receiver coil, these signals being a measure of the formation vertical conductivity. In a preferred embodiment of the invention, the detecting means is operative to detect both the resistive and reactive components of the signals induced in the receiver coils.