Quality-based steering methods and systems for 4D geophysical surveys
First Claim
1. A survey method that comprises:
- towing one or more sources and one or more streamers behind a vessel to acquire geophysical survey data; and
determining a steering signal for at least one of;
the one or more sources, the one or more streamers, and the vessel,wherein the steering signal minimizes an error function having parameters that include a measure of a cross-line position error and a measure of data quality.
1 Assignment
0 Petitions
Accused Products
Abstract
A survey method includes towing one or more sources and one or more streamers behind a vessel to acquire geophysical survey data. Steering signals are determined for at least one of: the one or more sources, the one or more streamers, and the vessel. The steering signals minimize an error function having parameters that include a measure of a cross-line position error and a measure of data quality. The cross-line position error may be measured as an offset of the sources or the receivers from their desired paths, or in some embodiments as an offset between midpoints for base survey traces and subsequent survey traces. Some embodiments may employ a maximum spatial cross-correlation coefficient between a newly acquired trace and one or more base survey traces as a data quality measure, while others may employ a time shift, a phase rotation, or a normalized root mean square error. Data quality may indicate sensor noise levels.
32 Citations
23 Claims
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1. A survey method that comprises:
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towing one or more sources and one or more streamers behind a vessel to acquire geophysical survey data; and determining a steering signal for at least one of;
the one or more sources, the one or more streamers, and the vessel,wherein the steering signal minimizes an error function having parameters that include a measure of a cross-line position error and a measure of data quality. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A survey system that comprises:
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one or more sources; one or more streamers; and a vessel that tows the one or more sources and the one or more streamers, the vessel including a data acquisition and control system configured to record source and streamer position information and further configured to record trace signals newly acquired by the one or more streamers, wherein the data acquisition and control system is configured to generate a steering signal for at least one of;
the one or more sources, the one or more streamers, and the vessel, wherein the steering signal minimizes an error function having parameters that include a cross-line position error measure and a data quality measure. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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20. A survey system that comprises:
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a first vessel towing one or more sources; a second vessel towing one or more streamers, the second vessel including a data acquisition and control system configured to record streamer position information and further configured to record trace signals newly acquired by the one or more streamers, wherein the data acquisition and control system is configured to generate a steering signal for at least one of;
the one or more streamers, and the second vessel,wherein the steering signal minimizes an error function having parameters that include a cross-line position error measure and a data quality measure. - View Dependent Claims (21, 22, 23)
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Specification