Chevron Research Company

Oke A Fredriksson

Elmer L Thomas

This invention relates to a method and apparatus for quick and convenient fault diagnosis of a geophone group-geophone cable complex of a geophysical data acquisition system used in the collection and recording of seismic information, such faults within each geophone group of such a system being identified, irrespective of the fact that a cable or cable segment is interconnected between the group under test and the fault-testing apparatus of the present invention.

Method and apparatus for diagnosing faults in the geophone group of a

This invention relates to an automatic method and apparatus for quick and convenient testing of one or more geophones of a geophysical data acquisition system through the generation and analysis of the impulse response characteristics of such geophones. In particular, geophone response characteristics related to first and second adjacent absolute peak amplitudes associated with the damped equation of motion of the geophone coils are detected and digitally indicated in a surprisingly accurate manner, irrespective of whether or not the testing is carried out in a laboratory or field environment.

Automatic method and apparatus for digitally indicating response

This disclosure relates to a non-recursive digital synthesizer for producing a surprisingly accurate synthesized sinusoid suitable for testing elements of a geophysical data acquisition system in either a laboratory or a field environment. In accordance with the present invention, [(C/2)+1]-discrete--16-bit binary words are stored in a read-only memory (ROM), representing discrete amplitudes of a digitized sinusoid in a frequency range of 1-500 Hz, and then accessed in succession to a digital-to-analog converter (DAC). A separate suppression circuit means at the output of the DAC is adapted to operate in synchronization with movement of the binary words through the DAC; in that way, glitches generated by the various digital elements of the synthesizer are suppressed. Result: accuracy of the generated sinusoid to the elements under test is assured.

Synthesizer for testing elements of a geophysical data acquisition system

Method and apparatus for estimating steam quality which involves sampling a steam-water mixture and utilizing volume relationships between the volume of initial sample and volume of the sample when water in sample is converted to steam.

Method and apparatus for measuring steam quality

An apparatus and a method are described with which the resonance frequencies of seismic detector elements, such as geophones, hydrophones, or sets of geophones or hydrophones, may be automatically determined and displayed with relatively high precision, e.g., to two decimal places. The apparatus is useful under rough field conditions, as well as under laboratory conditions.

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Fullerton, CA, United States of America

Oke A Fredriksson