Patents Assigned to PGS Tensor, Inc.
  • Patent number: 6272435
    Abstract: In one embodiment of the present invention, a method of generating a zero-offset trace, at a zero-offset location on a processing plane, for a time sampled recording is provided. The time sampled recording has a source and receiver, and a source coordinate and a receiver coordinate associated therewith. The time sampled recording also has an amplitude and a sampled time associated therewith. The method comprises reading the source and receiver coordinates and determining an ellipsoid dependant upon the source-receiver offset, the sampled time, and the velocity of the medium. The ellipsoid has the source as one focus and the receiver as the other focus. The method further comprises determining a set of normal points on the ellipsoid and determining the distance between each of the normal points and the zero-offset trace location and dividing twice the distance by the velocity of the medium, wherein the zero-offset travel time for each normal point is determined.
    Type: Grant
    Filed: September 23, 1999
    Date of Patent: August 7, 2001
    Assignee: PGS Tensor, Inc.
    Inventor: Vigen Ohanian
  • Patent number: 6263285
    Abstract: A method and system of amplitude spectra estimation for seismic data using up-going and down-going wavefields includes gathering up-going and down-going wavefields, separating the up-going and the down-going wavefields from each other and crosscorrelating the up-going wavefields and the down-going wavefields. From the result of the crosscorrelation of the up-going wavefields and the down-going wavefields, an estimate of the amplitude spectra in the frequency domain of the seismic data can be obtained. In this method for amplitude spectra estimation, the gathering may include or may be accomplished by providing pressure and particle velocity detectors to distinguish between the up-going and the down-going wavefields. Also, in this method for amplitude spectra estimation, the gathering may include measuring the down-going waves and the separating may include removing the down-going waves from the seismic data.
    Type: Grant
    Filed: September 15, 1999
    Date of Patent: July 17, 2001
    Assignee: PGS Tensor, Inc.
    Inventor: Joel Starr
  • Patent number: 6246637
    Abstract: A system and method of processing seismic signals wherein seismic data resulting from a reflected seismic wave is received at a multi-component receiver. A mask trace is generated as a function of the seismic data received at the multi-component receiver, and a single type of seismic signals from the seismic data received at the multi-component receiver is identified and extracted utilizing the mask trace. Generating the mask trace further includes multiplying the seismic data received at two of the components of the multi-component receiver to produce a first result. A positive/negative sign of the first result is identified to produce a first binary result. The first binary result is divided by a scaling factor to produce the mask trace.
    Type: Grant
    Filed: September 28, 1998
    Date of Patent: June 12, 2001
    Assignee: PGS Tensor, Inc.
    Inventor: Maurice Gidlow
  • Patent number: 6212477
    Abstract: Method and systems are provided for processing c-wave data resulting in less sensitivity to errors in p-wave velocity analysis. Therefore, according to one aspect of the invention, a process is provided for processing c-wave data, the process comprising: providing zero-offset gather without a hyperbolic movement correction; performing migration on the zero-offset gather; performing velocity analysis on the migrated zero-offset gather; and performing NMO on the migrated data using the velocity from the velocity analysis.
    Type: Grant
    Filed: May 10, 1999
    Date of Patent: April 3, 2001
    Assignee: PGS Tensor, Inc.
    Inventors: Xianhuai Zhu, Suat Altan, Matthew A. Brzostowski, Weizhug Wang
  • Patent number: 6208587
    Abstract: Methods are provided for automatic detection of linear seismic events and the detected events are used in correction of statics and geometry error.
    Type: Grant
    Filed: July 10, 1997
    Date of Patent: March 27, 2001
    Assignee: PGS Tensor, Inc.
    Inventor: Federico D. Martin
  • Patent number: 6182015
    Abstract: A method and system for processing first and second seismic traces includes rotating the first seismic traces and the second seismic traces to forty-five degrees in the time domain. In one embodiment, the rotated first time domain traces and second time domain traces are transformed to the frequency domain to obtain an amplitude spectrum for each rotated first time domain trace and an amplitude spectrum for each rotated second time domain trace. Each amplitude spectrum is squared to obtain a power spectrum for each transformed and rotated time domain trace. The phase of each transformed rotated time domain trace to zero. The power spectrum for each transformed rotated time domain trace is then averaged. Each transformed rotated time domain trace is divided into time windows. A power spectrum for each window is obtained for the entire of each transformed rotated time domain trace. The power spectra of each window of the transformed rotated time domain trace is summed to obtain a summed first power spectrum.
    Type: Grant
    Filed: March 15, 1999
    Date of Patent: January 30, 2001
    Assignee: PGS Tensor, Inc.
    Inventors: Suat Altan, Jianchao Li, Xianhuai Zhu
  • Patent number: 6151275
    Abstract: A method and system of dual wavefield reinforcement or increasing the contributions to each image point in the seismic image can be accomplished by aligning the upward traveling energy, U, and the downward traveling energy, D, and then summing U and D in the stacking process. A method of dual wavefield reinforcement includes receiving seismic data having both up going and down going wavefields. The up going wavefields are separated from the down going wavefields. Pre-NMO and post NMO statics for each of said up going and said down going wavefields are calculated. The determined pre-NMO static is applied to each of the up going and the down going wavefields. NMO/DMO stacking velocities for the seismic data on an up going wavefield floating datum is determined.
    Type: Grant
    Filed: September 11, 1998
    Date of Patent: November 21, 2000
    Assignee: PGS Tensor, Inc.
    Inventor: Joel Starr
  • Patent number: 6061298
    Abstract: Methods and systems are provided for orientation of multicomponent geophones, for rotating traces, and for correcting polarity differences between traces. According to an example embodiment, a receiver orientation angle is assigned, based on a determination of an angle between one or more horizontal components and one or more sources.
    Type: Grant
    Filed: June 8, 1998
    Date of Patent: May 9, 2000
    Assignee: PGS Tensor, Inc.
    Inventors: Eric Madtson, Jianchao Li, Mehmet Suat Altan, Xianhuai Zhu
  • Patent number: 5930731
    Abstract: It has been found that, rather than merely recording raw data on the seismic vessel for processing on shore, the performance of certain processing on the vessel at a particular time addresses the problems. Specifically, performing pre-stack time migration on raw data as it is being recorded on a seismic ship provides the information needed for quality control of the acquisition process, as well as providing a starting point for velocity analysis in preparation for later depth migration.
    Type: Grant
    Filed: February 3, 1997
    Date of Patent: July 27, 1999
    Assignee: PGS Tensor, Inc.
    Inventor: Matthew A. Brzostowski
  • Patent number: 5825716
    Abstract: A method for eliminating the influence of multiple reflections in seismic data by determining an up going and down going vector wave-field from the vector wave-field, determining a product of the free surface refection coefficient and the down going vector wave-field, and adding the product to the up going vector wave-field. Also provided is a method for eliminating the effects of receiver coupling from seismic data taken in a survey by describing a first cross-equalization filter as a function of the reverberation period, describing a second cross equalization filter as a function of the seismic data, deriving an inverse coupling filter as a function of the first cross-equalization filter and the second-equalization filter, and applying the coupling filter to the seismic data.
    Type: Grant
    Filed: May 7, 1997
    Date of Patent: October 20, 1998
    Assignee: PGS Tensor Inc.
    Inventor: Joel G. Starr
  • Patent number: 5818795
    Abstract: A method of suppression of burst coherent noise in seismic data is provided comprising (a) comparing a threshold amplitude characteristic acceptance value for a time window of a reference trace to an amplitude characteristic of a test trace of a set of traces within the window and; (b) applying a non-zero scalar to the test trace in the time window if an amplitude of the test trace within the time window is not within the threshold amplitude characteristic acceptance value.
    Type: Grant
    Filed: October 30, 1996
    Date of Patent: October 6, 1998
    Assignee: PGS Tensor, Inc.
    Inventors: Keith Hawkins, Simon Rice Barnes, Gregory Peter Gwyn Fookes
  • Patent number: 5774416
    Abstract: In ocean bottom seismic exploration, it is common for co-located hydrophones and geophones to be deployed on the ocean bottom. One problem encountered is the water column reverberation. An improved method and device is proposed for attenuating water column reverberations using co-located hydrophones and geophones in ocean bottom seismic processing. In this method, each recorded hydrophone and geophone signal, or trace, is decomposed into a series of narrow band-pass filtered traces. For each of the filtered traces, a measurement of the energy level is made upon which normalization factors are computed and applied. The resulting filtered, normalized traces are summed. Optionally, prior to application, the normalization factors can be organized by common shot, common group, common offset, and surface consistent normalization factors derived and applied for each pass-band.
    Type: Grant
    Filed: April 7, 1995
    Date of Patent: June 30, 1998
    Assignee: PGS, Tensor, Inc.
    Inventors: Selwa Sadek, Jack Kinkead, Bill Cafarelli, Joe Sanders
  • Patent number: 5754492
    Abstract: A method for eliminating the influence of multiple reflections in seismic data by determining an up going and down going vector wave-field from the vector wave-field, determining a product of the free surface reflection coefficient and the down going vector wavefield, and adding the product to the up going vector wave-field. Also provided is a method for eliminating the effects of receiver coupling from seismic data taken in a survey by describing a first cross-equalization filter as a function of the reverberation period, describing a second cross-equalization filter as a function of the seismic data, describing an inverse coupling filter as a function of the first cross-equalization filter and the second-equalization filter, and applying the coupling filter to the seismic data.
    Type: Grant
    Filed: February 12, 1996
    Date of Patent: May 19, 1998
    Assignee: PGS Tensor, Inc.
    Inventor: Joel G. Starr