Abstract: An assembly for dispensing a core separator ring on the top of a previously-cut core that is ejected from a core-cutting bit in a storage bin. The core separator assembly is integral with the forward end of the core ejector system.

Abstract: The relative amplitudes of seismic reflection data contains very useful information about the subsurface earth formations. Surface and subsurface-consistent amplitude processing identifies and corrects for the variability introduced by instrumentation and surface distortions. Dynamic amplitude decomposition, the subject of this disclosure, identifies and compensates for reflection amplitude fading due to subsurface transmission absorption media.

Abstract: A rotary servo valve includes a valve body having a longitudinal bore therethrough. A sleeve fits into the bore. The wall of the sleeve is perforated by two groups of port openings, each group includes a plurality of sets of radially-disposed ports. In each group, the central longitudinal axis of one set of ports is radially displaced from the central longitudinal axis of one other set of ports by a preselected angular displacement. At least a third set of ports in one group is in continuous fluid communication with a source of pressurized fluid; at least a third set of ports in the other group in continuous fluid communication with a return sump. A hollow rotary control member consists of two internal chambers. Each chamber includes a number of sets of apertures that are radially disposed around the walls of the chambers, spaced-apart by a preselected angular separation.

Abstract: In an induction logger, a method for nulling the output signal from a pair of series-coupled receiver coils by altering the magnetic flux distribution within the coils by use of one or more magnetic equalization bodies. The shape and aspect ratio of the equalization body are chosen to minimize temperature dependence of the initial permeability. Alternatively, a highly conductive equalization body may be used.

Abstract: A multi-dimensional assemblage of time/velocity functions are sampled for velocity as a function of incremental time. The samples are stored in a matrix arranged in columns along the time axis and rows across the velocity axis. The count of the number of samples resident in the respective cells of each row is indexed. A desired statistical operator is applied to the count indices in the rows to provide a family of filtered histograms in time-sequential order. The filtered histograms may be edited by delimiting acceptable velocities to lie between preselected percentiles.

Abstract: This invention provides a method for examining the geometry of the disposition of a plurality of sources and receivers over an area to be surveyed with a view to optimizing the array to avoid data shadow zones and to optimize the resulting seismic image. The method depends upon studying the statistical distribution of dip polarity in dip bins along selected CMP azimuths.

Abstract: A method for adaptively creating a filter for removing coherent environmental noise from a multitrace digitized seismic recording requires the presence, on the recording, of a limited sample of pure noise that is uncontaminated by desired signal. The pure noise sample is used to discover the location of the noise source and from that discovery, to extrapolate and reconstruct the characteristics of the noise envelope as it would appear on the seismic recording. The reconstructed noise envelope is used as a noise reference for input to a conventional iterative adaptive noise cancellation filter loop. For stability, the loop gain is minimized by temporally and spatially averaging the filter coefficients for each sample interval.

Abstract: Seismic data from co-located sensors of different genera are formatted into common velocity-receiver gathers and common pressure receiver gathers. A first ratio between the velocity signature amplitudes and the pressure signature amplitudes is measured within a fixed analysis window. A second ratio is measured between the pressure and velocity signatures for a weighting-zone window of limited extent. The first and second ratios are combined to form an equalization operator. The pressure and velocity signatures from within the weighting zone window are combined in the presence of the equalization operator to define a transient-free time-scale datum.

Abstract: This invention provides a hydraulically-actuated pipe clamp for sealing leaks in pipe lines located in remote or hazardous places. The pipe clamp consists of a split block having hinged jaws that may be clamped around a pipe by a hydraulic actuator. The jaws are then mechanically latched in place so that the clamp will remain closed after the hydraulic source has been disconnected.

Abstract: A discretized lithologic model of the subsurface is defined by a regular array of pixels. Each pixel corresponds to one of a finite number of possible lithoclasses such as sand, shale or dolomite. The lithoclasses are unknown except at a small number of sparsely distributed control pixels associated with borehole locations. Associated with each pixel there is a multivariate record of seismic attributes that may be statistically correlatable with the local lithology. A Monte Carlo method is used to simulate the lithoclass spatial distribution by combining the lithologic data at control pixels with the seismic-attribute data records. Using Indicator Kriging, a prior probability distribution of the lithoclasses is calculated for each pixel from the lithology values at neighboring pixels. The likelihood of each lithoclass is also calculated in each pixel from the corresponding conditional probability distribution of seismic attributes.

Abstract: This disclosure provides a method for measuring the velocities of water volumes flowing co-directionally in separate conduits nested such as in injection or production well-bores. The method allows an oxygen activation measurement of the velocity of the water flow in the tubing-casing annulus in the presence of water flowing in the tubing string in the same direction. The method allows continuous logging at variable or constant cable velocities or stationary logging. Based on the method of velocity gauging, the method isolates the signal from the annular flow and can produce a continuous log of linear and volumetric annular flow rates with depth.

Abstract: A marine seismic streamer cable retriever is activated promptly when the cable and its attached retriever exceed a pre-selected safe depth. In an alternative scenario, an electronics module in the cable retriever monitors the presence of through-cable communications traffic between a mother ship and the various sensors in the cable. If an interruption in communications traffic is detected, a clock starts a count-down and sends a warning to the operator aboard ship. At the end of a count-down period, absent prior operator intervention, the cable retriever is activated.

Abstract: A method for displaying seismic attributes in an open three-dimensional format is provided. The conventional two-dimensional variable-amplitude traces that represent the magnitude of a selected seismic attribute as a function of time are converted to three-dimensional format. The three-dimensional converted traces are hung beneath a model of their corresponding data-gathering stations to provide a forest of seismic traces in a wire-frame environment. The open configuration of the seismic traces permits the interpreter to see a perspective view of the structure of the subsurface of the earth from any desired viewing angle.

Abstract: A method for reducing the effects of reverberation on noisy seismic wavefields recorded from within a moisture-laden environment. The wavefield manifests itself as a pressure signature and a velocity signature that contains an embedded nose signature. The pressure signature is adaptively filtered and subtractively combined with the velocity signature to isolate a nearly pure noise signature. The nearly pure noise signature is added back to the original velocity signature with opposite sign to clear away the embedded noise, leaving a refined velocity signature. The refined velocity signature iteratively is scaled and summed with the pressure signature, incrementing the scale factor at each iteration and autocorrelating the sum. A coefficient of convergence is calculated after each summation. The coefficient of convergence that most closely approaches unity identifies the preferred scale factor.

Abstract: A pressure compensated hydrophone assembly consists of a hollow mandrel that has an outer surface. The central portion of the outer surface of the mandrel defines a concavity. A flexible, resilient piezoelectric film is wrapped several times around the mandrel. The volume between the inner wrap of the film and the concavity on the outer surface of the mandrel serves as a pressure compensation chamber. The hydrophone is responsive to varying hydrodynamic pressure fields but is substantially inert to acceleration forces, localized impacts and variations in hydrostatic pressure.

Abstract: A logging-tool assembly for generating both flexural wavefields and compressional wavefields in the sidewall formations encountered by a borehole. The assembly consists of a sonde constructed of a plurality of segments that are axially rotatable with respect to each other. Each one of two of the segments includes a compartment in which is mounted a dipole bender bar transmitting transducer. Two additional segments each contain one or more binaurally sensitive receiver transducers. Monopole transmitting and receiving transducers are also included in the respective appropriate segments. An acoustic isolator of novel construction acoustically separates the transmitting transducers from the receiving transducers.

Abstract: A piezoelectric film strip is wrapped a plurality of times around a flexible inert mandrel that has standoff collars on each end. The film-wrapped mandrel is hermetically sealed inside a hollow rigid inert cylinder. Electrodes provide electrical communication with the film strip which forms the active element of the transducer. Variations in hydrodynamic pressure flex the film strip in tension to generate a voltage.

Abstract: A hydrostatic rotary power transmission system that provides a stable rotation rate at very slow rotation speeds is provided. The system operates in two speed control modes, one being a normal mode for use in the rotation rate range of 50 rpm to the maximum rated speed and a second or fine speed control mode for use in the rotation range of <1.0 to 250 rpm. In the normal control mode, the rotation speed is a function of the displacement of the hydrostatic pump. In the fine speed control mode, the motor rotation rate is a function of the flow rate through a proportional-flow valve that is downstream of the motor.

Abstract: An improved tanker ship construction design includes a plurality of liquid cargo tanks distributed in two longitudinal sets along each side of a tanker ship. A plurality of fully protected ballast tanks are distributed longitudinally between the sets of cargo tanks. A passive, gravity-responsive, fluid transfer system provides very rapid fluid communication between selected cargo tanks and a adjoining ballast tanks. A gravity responsive fluid transfer system is provided between the respective ballast tanks.

Abstract: This invention discloses an adaptive deconvolution method for enhancing the vertical resolution of an MWD (measurement-while-drilling) electromagnetic resistivity logging tool. The tool measures the total differences between the voltages induced in a pair of spaced-apart receiver coils. A deconvolution filter, appropriate to the current position of the logging tool in the borehole, is derived according to the weighted average of the measured phase differences. Using the so-derived deconvolution filter, the measured phase differences are spatially deconvolved thereby to enhance the vertical resolution of the measurements by reducing the shoulder-bed effects.