Method and device for dynamic control of delays in gun controller

Patent metadata

Field	Value
Publication number	US-9354345-B2
Application number	US-201313923519-A
Country	US
Kind code	B2
Filing date	Jun 21, 2013
Priority date	Aug 2, 2012
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

A method controls a delay of an air-gun in an aquatic seismic source. The method includes a step of receiving an attribute of the air-gun during the aquatic seismic survey; a step of calculating, based on a time-delay algorithm that uses the attribute, the asynchronization time of the air-gun; a step of determining whether the asynchronization time is smaller than a given time threshold; a step of instructing a controller to (1) wait for a predetermined time before calculating again the asynchronization time of the air-gun if the asynchronization time is smaller than the given time threshold, or (2) calculate an updated asynchronization time for the air-gun based on the attribute if the asynchronization time is larger than the given time threshold; and a step of sending the updated asynchronization time to a gun controller of the air-gun for adjusting a delay time for firing the air-gun.

First claim

What is claimed is:

1. A method for controlling a delay of an air-gun in an aquatic seismic source during an aquatic seismic survey, the method comprising:
firing the air-gun with a delay time;
receiving an attribute of the air-gun during the aquatic seismic survey, wherein the attribute is indicative of an asynchronization time of the air-gun;
calculating, based on a time-delay algorithm that uses the attribute, the asynchronization time of the air-gun, wherein the asynchronization time is a time difference between (i) a time when the air-gun is desired to fire according to a nominally designed time and (ii) an actual time when the air-gun actually fires;
determining whether the asynchronization time is within a given range;
instructing a controller to (1) wait for a predetermined time before calculating again the asynchronization time of the air-gun if the asynchronization time is within the range, or (2) calculate an updated asynchronization time for the air-gun based on the attribute if the asynchronization time is not within the range;
sending the updated asynchronization time to a gun controller of the air-gun for adjusting the delay time; and
firing the air-gun using the adjusted delay time.

2. The method of claim 1 , wherein the updated asynchronization time is set as Δ{tilde over (t)} i =sign(ΔT i )*Δt, where sign is the signum function and Δt is a gun controller time resolution.

3. The method of claim 1 , wherein the asynchronization time is calculated with a first time-delay algorithm and the updated asynchronization time is calculated with a second time-delay algorithm.

4. The method of claim 1 , wherein the attribute is a near-field signature.

5. The method of claim 4 , wherein the attribute further includes information about a position of the air-gun and a depth of the air-gun under water.

6. The method of claim 1 , wherein a delay time of each air-gun of the seismic source is dynamically adjusted during the seismic survey.

7. The method of claim 6 , wherein a first delay time of a first air-gun of the seismic source is dynamically adjusted with a different value than a second delay time of a second air-gun of the seismic source.

8. The method of claim 1 , wherein the updated asynchronization time is a minimum adjustable time.

9. A computing device for controlling a delay of an air-gun in an aquatic seismic source during an aquatic seismic survey, the computing device comprising:
an interface for receiving an attribute of the air-gun during the aquatic seismic survey, wherein the attribute is obtained after firing the air-gun with a delay time and the attribute is indicative of an asynchronization time of the air-gun; and
a processor connected to the interface and configured to,
calculate, based on a time-delay algorithm that uses the attribute, the asynchronization time of the air-gun, wherein the asynchronization time is a time difference between (i) a time when the air-gun is desired to fire according to a nominally designed time and (ii) an actual time when the air-gun actually fires;
determine whether the asynchronization time is within a given range;
instruct the computing device to (1) wait for a predetermined time before calculating again the asynchronization time of the air-gun if the asynchronization time is within the given range, or (2) calculate an updated asynchronization time for the air-gun based on the attribute if the asynchronization time is not within the given range; and
send the updated asynchronization time to a gun controller of the air-gun for adjusting the delay time so that the gun controller fires the air-gun using the adjusted delay time.

10. The computing device of claim 9 , wherein the updated asynchronization time is set as Δ{tilde over (t)} i =sign(ΔT i )*Δt, where sign is the signum function and Δt is a gun controller time resolution.

11. The computing device of claim 9 , wherein the asynchronization time is calculated with a first time-delay algorithm and the updated asynchronization time is calculated with a second time-delay algorithm.

12. The computing device of claim 9 , wherein the attribute is a near-field signature.

13. The computing device of claim 12 , wherein the attribute further includes information about a position of the air-gun and a depth of the air-gun under water.

14. The computing device of claim 9 , wherein a delay time of each air-gun of the seismic source is dynamically adjusted during the seismic survey.

15. The computing device of claim 14 , wherein a first delay time of a first air-gun of the seismic source is dynamically adjusted with a different value than a second delay time of a second air-gun of the seismic source.

16. The computing device of claim 9 , wherein the updated asynchronization time is a minimum adjustable time.

17. A computer readable media non-transitorily storing executable codes which when executed on a computer make the computer perform a method for controlling a delay of an air-gun in an aquatic seismic source during an aquatic seismic survey, the method comprising:
firing the air-gun with a delay time;
receiving an attribute of the air-gun during the aquatic seismic survey, wherein the attribute is indicative of an asynchronization time of the air-gun;
calculating, based on a time-delay algorithm that uses the attribute, the asynchronization time of the air-gun, wherein the asynchronization time is a time difference between (i) a time when the air-gun is desired to fire according to a nominally designed time and (ii) an actual time when the air-gun actually fires;
determining whether the asynchronization time is within a given range;
instructing a controller to (1) wait for a predetermined time before calculating again the asynchronization time of the air-gun if the asynchronization time is within the given range, or (2) calculate an updated asynchronization time for the air-gun based on the attribute if the asynchronization time is not within the given range; and
sending the updated asynchronization time to a gun controller of the air-gun for adjusting the delay time so that the gun controller fires the air-gun using the adjusted delay time.

18. The medium of claim 17 , wherein the updated asynchronization time is set as Δ{tilde over (t)} i =sign(ΔT i )*Δt, where sign is the signum function and Δt is a gun controller time resolution.

19. The medium of claim 17 , wherein the asynchronization time is calculated with a first time-delay algorithm and the updated asynchronization time is calculated with a second time-delay algorithm.

20. The medium of claim 19 , wherein the attribute is a near-field signature.

Assignees

• Cgg Services Sa

Inventors

• Ni Yuan
• Siliqi Risto
• Niang Cheikh

Classifications

• G01V1/08

  involving time-delay devices · CPC title

• G01V2200/12

  Clock synchronization-related issues · CPC title

• G01V1/3808 Primary

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

• G01V1/26

  Reference-signal-transmitting devices, e.g. indicating moment of firing of shot · CPC title

• G01V1/3861 Primary

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