Method and device for controlling source array geometry

Patent metadata

Field	Value
Publication number	US-9784872-B2
Application number	US-201615378523-A
Country	US
Kind code	B2
Filing date	Dec 14, 2016
Priority date	Jan 23, 2013
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

Methods related to controlling a source array while performing a seismic survey to achieve an intended source signature. A current three dimensional arrangement of the individual seismic sources is compared with a target 3D arrangement. In view of the comparison, position of at least one of the individual seismic sources is adjusted so that the adjusted 3D arrangement of the individual seismic sources to substantially match the target 3D arrangement.

First claim

What is claimed is:

1. A method for evaluating changes of an underground structure explored using seismic surveys, the method comprising:
towing a source array including seismic sub-arrays, substantially along sail-lines of a previously-conducted seismic survey;
steering one of the seismic sub-arrays to make a current value of a parameter characterizing a geometry of the one of the sub-arrays and another one of the seismic sub-arrays to substantially match a corresponding value of the parameter observed during the previously-conducted seismic survey;
activating the source array at shot locations where the source array was fired during the previously-conducted seismic survey;
acquiring monitor seismic data; and
comparing the monitor seismic data with seismic data acquired during the previously-conducted seismic survey to evaluate the changes of the underground structure,
wherein a change of the parameter affects a signature of the source array, and
wherein the parameter is one of (1) a distance between the one of the sub-arrays and another one of the seismic sub-arrays, wherein the distance is perpendicular on a sail-line, (2) a depth of the one of the sub-arrays, and (3) an angle of the one of the sub-arrays and the sail-line.

2. The method of claim 1 , wherein the monitor seismic data and the seismic data acquired during the previously-conducted seismic survey are wide-azimuth seismic data.

3. The method of claim 1 , wherein a time interval between the previously-conducted seismic survey and acquiring monitor seismic data is substantially longer than duration of the previously-conducted seismic survey of a target area.

4. The method of claim 1 , further comprising:
monitoring the parameter of the one of the sub-arrays and the other one of the seismic sub-arrays over plural locations;
comparing the current value with the corresponding value for the plural locations; and
steering the one of the seismic sub-arrays only if the comparing indicates a difference between the current value and the corresponding value exceeding a predetermined threshold.

5. The method of claim 1 , further comprising:
retrieving plural values of the parameter observed at plural locations along a sail-line during the previously-conducted seismic survey; and
steering the one of the seismic sub-arrays such that the current value to match an evolution of the parameter inferred based on the plural values.

6. A controller for evaluating changes of an underground structure explored using seismic surveys, the controller comprising:
a processor for executing instructions; and
a storage device for storing the instructions, wherein the instructions include,
towing a source array including seismic sub-arrays, substantially along sail-lines of a previously-conducted seismic survey,
steering one of the seismic sub-arrays to make a current value of a parameter characterizing a geometry of the one of the sub-arrays and another one of the seismic sub-arrays to substantially match a corresponding value of the parameter observed during the previously-conducted seismic survey,
activating the source array at shot locations where the source array was fired during the previously-conducted seismic survey,
acquiring monitor seismic data, and
comparing the monitor seismic data with seismic data acquired during the previously-conducted seismic survey to evaluate the changes of the underground structure,
wherein a change of the parameter affects a signature of the source array, and
wherein the parameter is one of (1) a distance between the one of the sub-arrays and another one of the seismic sub-arrays, wherein the distance is perpendicular on a sail-line, (2) a depth of the one of the sub-arrays, and (3) an angle of the one of the sub-arrays and the sail-line.

7. The controller of claim 6 , wherein the monitor seismic data and the seismic data acquired during the previously-conducted seismic survey are wide-azimuth seismic data.

8. The controller of claim 6 , wherein a time interval between the previously-conducted seismic survey and acquiring monitor seismic data is substantially longer than duration of the previously-conducted seismic survey of a target area.

9. The controller of claim 6 , the instructions further comprising:
monitoring the parameter of the one of the sub-arrays and the other one of the seismic sub-arrays over plural locations;
comparing the current value with the corresponding value for the plural locations; and
steering the one of the seismic sub-arrays only if the comparing indicates a difference between the current value and the corresponding value exceeding a predetermined threshold.

10. The controller of claim 6 , further comprising:
retrieving plural values of the parameter observed at plural locations along a sail-line during the previously-conducted seismic survey; and
steering the one of the seismic sub-arrays such that the current value to match an evolution of the parameter inferred based on the plural values.

Assignees

• Cgg Services Sas

Inventors

• Tonchia Helene

Classifications

• G01V1/308

  Time lapse or 4D effects, e.g. production related effects to the formation (fluid flow per se E21B47/00) · CPC title

• G01V1/3808 Primary

  Seismic data acquisition, e.g. survey design · CPC title

• G01V2210/612

  Previously recorded data, e.g. time-lapse or 4D · CPC title

• G01V1/3861

  control of source arrays, e.g. for far field control · CPC title

• G01V2210/1293

  Sea · CPC title