Active steering for marine seismic sources
View Patent ↗A seismic survey system having a source array ( 11 ) coupled to a deflector device ( 15 ) that controls the position of the source array. A positioning system unit ( 16 ) is mounted on the source array to provide a signal to a controller, informing the controller of the current position of the source array so that the controller can control the position of the deflector device ( 15 ) and the coupled source array. A seismic source ( 14 ) on the source array may be triggered when the source array is at a desired location as measured by the positioning system unit. The deflector device ( 15 ) comprises one or more wings ( 18 ) in a generally vertical or, alternatively, in a generally horizontal arrangement disposed adjacent to a central body ( 19 ). The streamlined central body has connection points that allow the deflector device ( 15 ) to be connected to a tow cable ( 13 ) from the tow vessel ( 12 ) and to the source array ( 11 ).
1. A method of positioning a source array in tow behind a vessel, comprising:
determining the position of the source array; and
independently steering a deflector device coupled to the source array to move the source array to a desired position, wherein the deflector device has a body and one or more wings that are positioned at a lateral distance from the body in a crossline direction.
2. The method of claim 1 , further comprising:
controlling the deflector device to steer the source array to the desired position.
3. The method of claim 2 , further comprising:
determining the position of the source array, and
providing the position to the controller.
4. The method of claim 3 , further comprising:
triggering a seismic source on the source array when the source array is at a desired position.
5. The method of claim 2 , wherein the deflector device further comprises:
an actuator disposed within the body.
6. The method of claim 5 , further comprising:
transmitting a control signal to the actuator; and
moving the one or more wings with the actuator, wherein the movement of the one or more wings steers the source array.
7. The method of claim 1 , further comprising:
coupling a second independently steerable deflector device to a second source array for controlling a second position of the second source array.
8. The method of claim 1 , further comprising:
detecting acoustic signals indicating obstructions in the path of the source array; and
adjusting the deflector device to steer clear of the detected obstructions.
9. The method of claim 8 , further comprising:
operating an acoustical transducer and receiver in a range typical for sonar devices.
10. The method of claim 9 , further comprising:
sweeping the acoustic transducer and receiver in many directions.
11. A seismic survey system for use in water, comprising:
a source array towed by a first tow cable;
a deflector deflecting a second tow cable, wherein the deflector comprises a body and one or more wings;
a distance rope coupling the first tow cable to the second tow cable; and
a winch attached to the distance rope, wherein the winch adjusts a length of the distance rope to modify a position of the source array.
12. The seismic survey system of claim 11 , further comprising:
a controller for controlling the position of the source array.
13. The seismic survey system of claim 12 , further comprising:
a positioning system unit attached to the source array, wherein the positioning system unit provides a signal to inform the controller of the position of the source array.
14. The seismic survey system of claim 13 , wherein a seismic source on the source array is triggered when the source array is at a desired location.
15. The seismic survey system of claim 12 , wherein the controller is positioned at a location selected from a towing vessel, the winch, and combinations thereof.
16. The seismic survey system of claim 11 , wherein the winch comprises:
a reel for winding the distance rope onto the winch;
an actuator for rotating the reel; and
a housing adjacent to the reel.
17. The seismic survey system of claim 11 , further comprising:
an acoustical transducer and receiver coupled to the source array; and
a controller, wherein the controller adjusts the winch to steer clear of an obstruction located by the acoustical transducer and receiver.
18. A seismic survey system for use in water, comprising:
a source array;
a steerable deflector device coupled to the source array, wherein the deflector device comprises a body and a wing that is positioned at a lateral distance from the body in a crossline direction, wherein the wing controls the position of the source array and is adjustably attached to the body; and
a positioning system to determine a location of the source array.
19. The seismic survey system of claim 18 , wherein the positioning system comprises a positioning unit mounted on the source array, and the positioning unit provides a controller with the location of the source array.
20. The seismic survey system of claim 19 , wherein the positioning system is selected from a global positioning system, a satellite positioning system, an acoustic network, and a laser system.