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US 4,992,992 AGranted
Processing for seismic data from slanted cable
AssigneeWestern Atlas International, Inc.
InventorWilliam H. Dragoset, Jr.
Life of this patent
Estimating the term…
Abstract
Marine seismic data is gathered using a cable towed behind a cable having a slanted orientation in the water. The recorded data is processed to remove the time offset in the recorded data of seismic signals arriving at the cable at varying plane wave angles. In a preferred embodiment of the invention, the recorded data is then processed to align the primary signals, thereby misaligning the ghost signals. The data is also processed to align the ghost signals, thereby misaligning the primary signals. The two resulting data sets may then be summed.
Claims18
A method of marine seismic exploration comprising:
- recording seismic data utilizing detectors positioned on a cable towed behind a vessel at substantially a determinable angle;
- processing said seismic data to substantially remove the time offset in the recorded data resulting from the cable slant for seismic signals arriving at said slanted cable at varying plane wave angles, wherein said processing comprises:
- transforming shot gather data from time-offset domain data to horizontal wavenumber-frequency domain data;
- mapping horizontal wave numbers of events in the transformed data to new horizontal wavenumbers so that events appear as if recorded by a horizontal cable thereby generating remapped data;
- and
- transforming said remapped data back to the time-offset domain.
3 more elements
A method of marine seismic exploration comprising:
- recording seismic data utilizing detectors positioned on a cable towed behind a vessel at substantially a determinable angle;
- processing said seismic data to substantially remove the time offset in the recorded data resulting from the cable slant for seismic signals arriving at said slanted cable at varying plane wave angles, wherein said processing comprises:
- transforming shot gather data from time-offset domain to horizontal wavenumber-frequency domain data;
- mapping horizontal wavenumbers of events in the transformed data to new horizontal wavenumbers so that the upwardly traveling events appear as if recorded by a horizontal cable, thereby generating Data Set A;
- mapping horizontal wavenumbers of events in the transformed data to new horizontal wavenumbers so that the downwardly traveling events appear as if recorded by a horizontal cable, thereby generating Data Set B;
- processing Data Set B so as to make the downwardly traveling events align with upgoing events in Data Set A, thereby generating Data Set C;
- summing Data Sets A and C;
- inverse transforming the summation of data sets A and C from the horizontal wavenumber-frequency domain to the time-offset domain.
5 more elements
A method of marine seismic exploration comprising:
- recording seismic data utilizing detectors positioned on a cable towed behind a vessel at substantially a determinable angle;
- processing said seismic data to substantially remove the time offset in the recorded data resulting from the cable slant for seismic signals arriving at said slanted cable at varying plane wave angles, wherein said processing comprises:
- transforming shot gather data from time-offset domain to horizontal wavenumber-frequency domain data.
- mapping horizontal wavenumbers of events in the transformed data to new horizontal wavenumbers so that upwardly traveling events appear as if recorded by a horizontal cable, thereby generating Data Set A;
- mapping horizontal wavenumbers of events in the transformed data to new horizontal wavenumbers so that downwardly traveling events appear as if recorded by a horizontal cable, thereby generating Data Set B;
- processing Data Set B so as to make the downwardly traveling events align with upgoing events in Data Set A, thereby generating Data Set C;
- inverse transforming Data Sets A and C separately from the horizontal wavenumber-frequency domain to the time-offset domain;
- and
- summing Data Sets A and C.
6 more elements
A method of marine seismic exploration, comprising:
- processing seismic data recorded utilizing detectors positioned on a cable towed behind a vessel at substantially a determinable angle so as to substantially remove the time offset in the recorded data resulting from the cable slant for seismic signals arriving at said slanted cable from varying directions, wherein said processing comprises:
- transforming shot gather data from time-offset domain data to horizontal wavenumber-frequency domain data;
- mapping horizontal wave numbers of events in the transformed data to new horizontal wavenumbers so that events appear as if recorded by a horizontal cable, thereby generating remapped data;
- and
- transforming said remapped data back to the time-offset domain.
2 more elements
A method of marine seismic exploration, comprising:
- processing seismic data recorded utilizing detectors positioned on a cable towed behind a vessel at substantially a determinable angle so as to substantially remove the time offset in the recorded data resulting from the cable slant for seismic signals arriving at said slanted cable from varying directions, wherein said processing comprises:
- transforming shot gather data from time-offset domain data to horizontal wavenumber-frequency domain data;
- mapping horizontal wavenumbers of events in the transformed data to new horizontal wavenumbers so that upwardly traveling events appear as if recorded by a horizontal cable, thereby generating Data Set A;
- mapping horizontal wavenumbers of events in the transformed data to new horizontal wavenumbers so that the downwardly traveling events appear as if recorded by a horizontal cable, thereby generating Data Set B;
- processing Data Set B so as to make the downwardly traveling events align with upgoing events in Data Set A, thereby generating Data Set C;
- summing data sets A and C;
- inverse transforming the summation of data sets A and C from the horizontal wavenumber-frequency domain to the time-offset domain.
4 more elements
A method of marine seismic exploration, comprising:
- processing seismic data recorded utilizing detectors positioned on a cable towed behind a vessel at substantially a determinable angle so as to substantially remove the time offset in the recorded data resulting from the cable slant for seismic signals arriving at said slanted cable from varying directions, wherein said processing comprises:
- transforming shot gather data from time-offset domain to horizontal wavenumber-frequency domain data.
- mapping horizontal wavenumbers of events in the transformed data to new horizontal wavenumbers so that upwardly traveling events appear as if recorded by a horizontal cable, thereby generating Data Set A;
- mapping horizontal wavenumbers of events in the transformed data to new horizontal wavenumbers so that downwardly traveling events appear as if recorded by a horizontal cable, thereby generating Data Set B;
- processing Data Set B so as to make the downwardly traveling events align with upgoing events in Data Set A, thereby generating Data Set C;
- inverse transforming Data Sets A and C separately from the horizontal wavenumber-frequency domain to the time-offset domain;
- and
- summing Data Sets A and C.
5 more elements
Dependencies are inferred from the claim text.