Vibration damping of an ancillary device attached to a marine streamer and method
A low-vibration collar system for vibration mitigation in a device towed in water. The low-vibration collar system includes a clamp attached to a streamer towed underwater by a seismic vessel, the streamer comprising a plurality of sensors to record seismic data; a collar configured to be attached to the clamp; a connecting mechanism located on the collar and configured to attach an ancillary device to the collar; and a vibration mitigation system configured to attenuate an amplitude of a vibration produced by the ancillary device. The vibration interferes with seismic data recorded by seismic sensors located on the streamer.
1. A low-vibration collar system for vibration mitigation comprising:
a clamp attached to a streamer towed underwater by a seismic vessel, the streamer comprising a plurality of sensors to record seismic data;
a collar configured to be attached to the clamp;
a connecting mechanism located on the collar and configured to attach an ancillary device to the collar; and
a suspension mechanism located between the clamp and the collar and configured to attenuate an amplitude of a vibration produced by the ancillary device,
wherein the vibration interferes with seismic data recorded by seismic sensors located on the streamer.
2. The system of claim 1 , further comprising: a series of elastic isolation pads spaced around a circumference of the streamer, the series of elastic isolation pads being attached to the clamp.
3. The system of claim 2 , wherein the series of elastic isolation pads are critically damped.
4. The system of claim 1 , wherein the suspension mechanism includes a series of flexible beams spaced around a circumference of the streamer.
5. The system of claim 4 , wherein the collar moves independent of the clamp due to the suspension mechanism.
6. The system of claim 4 , wherein the suspension mechanism comprises:
a spring leaf body; and
first and second skis, each of the skis being attached to one end of the spring leaf body.
7. The system of claim 6 , wherein the skis spatially filter surface imperfections in the clamp.
8. The system of claim 6 , wherein the first and second skis are in direct contact with the clamp while the leaf spring body is not.
9. The system of claim 1 , wherein the collar fully encircles the streamer.
10. The system of claim 1 , wherein the collar only partially encircles the streamer.
11. The system of claim 10 , further comprising:
a first strut connected to the collar; and
a second strut connected to the collar, opposite to the first strut,
wherein a center of gravity of the first strut and the second strut is below a center of gravity of the streamer.
12. The system of claim 1 , wherein the vibration mitigation system further includes:
an elastic element located between two halves of the collar.
13. A low-vibration collar system for vibration mitigation comprising:
a clamp to be attached to a cable;
a collar located over the clamp and only partially encircling the cable, the collar being configured to receive an ancillary device; and
a vibration mitigation system configured to attenuate an amplitude of vibrations produced by the ancillary device, the vibration mitigation system including a suspension system attached to an inner part of the collar, the suspension system being sandwiched between the clamp and the collar.
14. The system of claim 13 , further comprising:
a connecting mechanism attached to the collar and configured to receive the ancillary device.
15. The system of claim 14 , wherein a center of gravity of the connecting mechanism is lower than a center of gravity of the streamer.
16. The system of claim 14 , wherein the connecting mechanism comprises:
a latching pin that enters through the collar to contact a corresponding groove in the clamp.
17. The system of claim 13 , further comprising:
one or more elastic isolation pads attached to the clamp and riding on the streamer.
18. A method for attaching an ancillary device to a streamer with a low-vibration collar system, the method comprising:
attaching a clamp to the streamer towed underwater;
attaching a collar to the clamp;
attaching the ancillary device to the collar with a connecting mechanism located on the collar; and
attenuating an amplitude of a vibration produced by the ancillary device with a vibration mitigation system, wherein the vibration mitigation system includes plural elastic insulation pads located between the streamer and the clamp and a suspension mechanism located between the clamp and the collar, and
wherein the vibration interferes with seismic data recorded by seismic sensors located on the streamer.