Method to determine the deviation of seismic equipment from a planned curved path
View Patent ↗A group of techniques can be used to determine if components of a seismic spread have deviated from a planned path during a coil or other curved and substantially circular acquisition pattern. In one aspect, and in general, the presently disclosed techniques include a computer-readable program storage medium for determining the deviation of spread array element from a planned curved path during a towed-array marine seismic survey. The method comprises: determining a nominal position of the spread array element at a given point in the planned curved path; determining the actual position of the spread array element; and performing an error analysis predicated on the nominal and actual positions.
1. A computer-implemented method for determining the deviation of spread array element from a planned curved path during a towed-array marine seismic survey, the comprising:
determining a nominal position of the spread array element at a given point in the planned curved path, wherein the planned curved path has a radius that is a function of a width of a marine spread on which the spread array element is disposed;
determining the actual position of the spread array element; and
performing an error analysis predicated on the nominal and actual positions.
2. A computer-implemented method for determining the deviation of spread array element from a planned curved path during a towed-array marine seismic survey, the comprising:
determining a nominal position of the spread array element at a given point in the planned curved path, wherein determining the nominal position of the spread array element comprises determining the nominal position from an equipment nominal offset and a shot number;
determining the actual position of the spread array element; and
performing an error analysis predicated on the nominal and actual positions.
3. The computer-implemented method of claim 1 , wherein determining the nominal position of the spread array element in the method includes determining distance along and distance across.
4. The computer-implemented method of claim 1 , wherein determining the actual position of the spread array element in the method includes acoustic ranging or GPS positioning.
5. The computer-implemented method of claim 1 , wherein performing the error analysis in the method includes performing an error analysis during the survey to correct position errors for survey elements.
6. The computer-implemented method of claim 1 , wherein performing the error analysis in the method includes performing an error analysis after the survey for quality control purposes.
7. The computer-implemented method of claim 1 , wherein performing the error analysis in the method includes any one of, or any combination of:
determining the difference between the desired position and the actual position of steered survey elements to issue a steering command;
determining the difference between the desired position and the actual position of steered survey elements to produce a plot of the deviation from the desired position;
computing statistics establishing whether one or more survey specifications are being met; and
producing a plot for display to the user.
8. A computer-readable program storage medium encoded with instructions that, when executed by a computing device, perform a method for determining the deviation of spread array element from a planned curved path during a towed-array marine seismic survey, comprising:
determining a nominal position of the spread array element at a given point in the planned curved path, wherein the planned curved path has a radius that is a function of a width of a marine spread on which the spread array element is disposed;
determining the actual position of the spread array element; and
performing an error analysis predicated on the nominal and actual positions.
9. The computer-readable program storage medium of claim 8 , wherein determining the nominal position of the spread array element includes determining the nominal position from an equipment nominal offset and a shot number.
10. The computer-readable program storage medium of claim 8 , wherein determining the nominal position of the spread array element includes determining distance along and distance across.
11. The computer-readable program storage medium of claim 8 , wherein determining the actual position of the spread array element includes acoustic ranging or GPS positioning.
12. The computer-readable program storage medium of claim 8 , wherein performing the error analysis includes performing an error analysis during the survey to correct position errors for survey elements.
13. The computer-readable program storage medium of claim 8 , wherein performing the error analysis includes performing an error analysis after the survey for quality control purposes.
14. The computer-readable program storage medium of claim 8 , wherein performing the error analysis includes any one of, or any combination of:
determining the difference between the desired position and the actual position of steered survey elements to issue a steering command;
determining the difference between the desired position and the actual position of steered survey elements to produce a plot of the deviation from the desired position in an across/along reference frame for display to the user in real time;
computing statistics establishing whether one or more survey specifications are being met; and
producing a plot for display to the user.
15. A programmed computing apparatus, comprising:
a processor;
a storage accessible by the processor;
a software component residing on the storage that, when executed by the processor, will perform a method for determining the deviation of spread array element from a planned curved path during a towed-array marine seismic survey, the method including:
determining a nominal position of the spread array element at a given point in the planned curved path, wherein determining the nominal position of the spread array element includes determining the nominal position from an equipment nominal offset and a shot number;
determining the actual position of the spread array element; and
performing an error analysis predicated on the nominal and actual positions.
16. The programmed computing apparatus of claim 15 , wherein determining the nominal position of the spread array element includes determining distance along and distance across.
17. The programmed computing apparatus of claim 15 , wherein determining the actual position of the spread array element includes acoustic ranging or GPS positioning.
18. The programmed computing apparatus of claim 15 , wherein performing the error analysis includes performing an error analysis during the survey to correct position errors for survey elements.
19. The programmed computing apparatus of claim 15 , wherein performing the error analysis includes performing an error analysis after the survey for quality control purposes.
20. The programmed computing apparatus of claim 15 , wherein performing the error analysis includes any one of, or any combination of:
determining the difference between the desired position and the actual position of steered survey elements to issue a steering command;
determining the difference between the desired position and the actual position of steered survey elements to produce a plot of the deviation from the desired position in an across/along reference frame for display to the user in real time;
computing statistics establishing whether one or more survey specifications are being met; and
producing a plot for display to the user.
21. A towed-array, marine seismic survey apparatus, comprising:
means for traversing a seismic survey spread on a coil path; and
means for positioning the elements of the seismic survey spread during the traversal, including:
means for determining a nominal position of the spread array element at a given point in the planned coil path;
means for determining the actual position of the spread array element;
means for performing an error analysis predicated on the nominal and actual positions; and
means for correcting an error in the position of the spread array element obtained from the error analysis.