Abstract: A method and apparatus in marine seismic surveying for towing an optical-electrical towing cable (leadin) and seismic array (streamer cable) at a perpendicular distance from the centerline of the towing vessel using a short, flexible adapter cable section which optically and electrically connects the leadin to the streamer cable and which attaches to pivoting arms of a removable towing bracket which carries the bending loads.

Abstract: A hydrophone-filter with the frequency response characteristics of a geophone utilizes a second order high pass filter wherein one capacitive element of the filter is the hydrophone itself. The filter includes an amplifier, wherein one input receives a biasing voltage from a resistive network, and the other input receives a signal provided by one or more hydrophones. The filter also includes one or more capacitive elements and one or more resistive elements. The natural frequency and slope of the filter depend upon the values of the capacitive elements of the circuit, including the capacitance of the hydrophones, as well as the values of the resistive elements of the circuit. Advantageously, the natural frequency of the hydrophone-filter remains constant even if the magnitude of the hydrophone's output changes.

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 removable bore liner is provided that substantially increases the dependability, flexibility and field-serviceability of seismic vibrators and other hydraulically actuated devices. A method for installing the removable bore liner in a seismic vibrator is also provided.

Abstract: The present invention is a method for improving the estimation of physical properties of a material based on the infrared spectrum of the material and the correlation between directly-measured properties of interest and the infrared spectra of a representative set of calibration specimens of the material. By intentionally introducing spectral distortion such as transmittance shifts, wavelength shifts, absorbance-baseline shifts and absorbance-baseline tilts into the infrared spectra of the representative specimens and then determining the correlation between the distorted spectra and the directly-measured properties before applying the correlation to the infrared spectrum of the sample being analyzed, the correlation is self-compensating for the types of distortion introduced.

Abstract: A method for determining water bottom reflectivity in dual sensor seismic surveys is disclosed. The method eliminates the need for a separate survey to collect calibration data. The method involves summing the pressure and velocity signals, and multiplying the result by the inverse Backus operator, and then solving for the ocean bottom reflectivity R utilizing an optimization algorithm.Also disclosed is a method for combining the dual sensor data which results in the complete elimination of the first order peg-leg multiples and the modulation of the sub-surface reflector strength with the ocean bottom reflectivity. The method involves summing the pressure and velocity signals, and multiplying the result by the inverse Backus operator containing the correct value for the ocean bottom reflectivity R found with the method described above.

Abstract: The invention is a wireline cable head adapted to be used on a wireline tool string which is conveyed into a wellbore by a coiled tubing. The cable head comprises a biased, piston-type check valve which enables fluid circulation from the tubing into the wellbore, but prevents fluid flow from the wellbore into the coiled tubing. The biasing means maintains a minimum differential pressure which must be pumped into the coiled tubing to enable fluid circulation from the coiled tubing into the wellbore. The cable head also comprises a bulkhead for maintaining hydraulic integrity of the cable head after the cable is extracted from the cable head.

Abstract: A depth migration method for seismic data involves a depth migration in the omega-x domain with an added transform in the wavelet domain. The input to the migration is one spike at a given time and x position (or Common Depth Point). This is as if instead of using a collection of seismic traces as input to the processing sequence, traces are used which would be all null except one which contains a spike. The processing sequence involved for seismic traces is the same as the one involved for the spike (or impulse). The only difference is the input itself being the seismic trace rather than the impulse spike.

Abstract: A self-orienting seismic detector for detecting vertical acceleration regardless of the device's horizontal orientation. The detector comprises a housing fitted with diaphragms capable of generating signals. A mass is internally suspended within the housing between the diaphragms by means of a filament which is connected at each of its ends to one of the diaphragms. Vertical motion of the detector causes internal displacement of the mass within the housing. Motion by the mass within the cylinder is translated by the filament to the diaphragms which generate signals which may then be recorded. The detector may be incorporated within or attached to an undersea cable to form a seismic detection system primarily suitable for placement on an ocean bottom, but which may be employed in a towed array. In a primary embodiment, the detector is sealed from external pressure changes such that the stresses placed upon the detector's diaphragms will be governed by particle acceleration changes rather than pressure changes.

Abstract: The invention is a system for determining position by measuring phases of suppressed carrier-waves implicit in radio signals received from earth-orbiting satellites which include receiving the signals from a plurality of satellites simultaneously by means of an omnidirectional antenna, separating the received signals into first and second portions representing different radio-frequency bands and correlating the first portion with the second portion to obtain data representing the phases of the carrier-waves for a plurality of the satellites simultaneously.

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 and apparatus for downhole formation testing is provided for acquisition of a phase intact sample of connate fluid by direct or indirect pumping for filling of pressure containing sample tanks that are removable from a formation testing and sampling instrument for phase intact transportation to a laboratory facility. One or more fluid sample tanks contained within the instrument are filled with connate fluid samples in such manner that during filling of the sample tanks the pressure of the connate fluid is maintained within the predetermined range above the bubble point of the fluid sample. The sample tank incorporates an internal free-floating piston which separates the sample tank into sample containing and pressure evacuation chambers. During indirect pumping a positive displacement piston pump draws fluid from the pressure evacuation chamber and permits formation pressure to shift the separator piston as the first variable volume chamber is filled with a connate fluid sample.

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: The present invention is a method for improving the estimation of physical properties of a material, based on the infrared spectrum of the material, by concatenating additional data obtained from other measurement techniques to the infrared spectrum to fill the voids in the spectral data resulting from a lack of sensitivity by infrared spectrometers to trace compounds in the material. The augmented spectral data then is used to produce a calibration model for estimating the physical properties of the material.

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: 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: The present invention provides a method for on-line real-time processing of processing navigational data for determining the location of sensor and receiver points in a navigational network having a number of different types of devices. Observations from these devices are obtained using a coordinate system that follows appropriate nominal sailing lines. Outlying observations are discarded using w-statistics for the observations. Any correlated observations such as compass azimuths are uncorrelated. The uncorrelated observations are then sequentially processed in an extended sequential Kalman filter, which provides the best estimate of the station coordinates. These estimated coordinates are then used to determine the location of the source and receiver points.

Abstract: There is disclosed in the present specification a method and apparatus for use of a downhole formation multi-tester instrument in the characterization of formation fluids, including measurement of the conductivity of water, often in the presence of hydrocarbons under dynamic flow conditions and determining the hydrocarbon volume of the formation fluid. Utilizing a coaxial transmission line as a flow tube within the formation multi-tester instrument an electromagnetic wave is generated which propagates through the formation fluid in a transverse electromagnetic mode. Measurement of the phase shift and attenuation of the electromagnetic wave at points within the flow tube allow characterization of the fluid inside the cavity of the flow tube for dielectric constant and conductivity. Dielectric constant and conductivity can then be related to fluid conductivity and hydrocarbon volume.

Abstract: The present invention discloses an apparatus for rotatably attaching a sensor to a cable. A cable mount having a groove about a substantial portion of its periphery is fixedly placed on the cable. A sensor mount having a key adapted to slide along the groove is rotatably placed on the cable in a manner which enables the key to remain in the groove when the sensor mount rotates about the cable.

Abstract: Doping the jacket of a data cable reduces the bulk volume resistivity of the jacket material allowing built-up static electricity to discharge. This reduces the likelihood of static charge interfering with data transmission.