Method and device for dynamic control of delays in gun controller

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.