Marine seismic streamer having acoustic isolation between strength members and sensor mounting

• US 7,298,672 B1
• Filed: 08/22/2006
• Issued: 11/20/2007
• Est. Priority Date: 08/22/2006
• Status: Active Grant

• Current Assignee: PGS Geophysical As (PGS ASA)
• Original Assignee: PGS Geophysical As (PGS ASA)
• Inventors: Stenzel, Andre, Tenghamn, Stig Rune Lennart
• Primary Examiner(s): Hughes; Deandra M
• Application Number:
  US11/507,782
• Time in Patent Office: 455 Days
• Field of Search: 367/173, 367/174, 367/176
• US Class Current: 367/176
• CPC Class Codes: G01V 1/201 Constructional details of seismic cables, e.g. streamers integrated optoseismic systems G01V1/226; line connectors in general H01R, transducer mountings in general G10K11/004

Abstract

A seismic streamer includes a jacket covering an exterior of the streamer. At least one strength member extends along the length of and is disposed inside the jacket. At least one seismic sensor is disposed in a sensor spacer mounted to the at least one strength member. The streamer includes means for retaining the at least one sensor spacer to the at least one strength member. The means for retaining provides substantial acoustic isolation between the at least one spacer and the at least one strength member.

Claims

1. A seismic streamer, comprising:

a jacket covering an exterior of the streamer;

at least one strength member extending along the length of and disposed inside the jacket;

at least one seismic sensor disposed in a sensor spacer mounted to the at least one strength member; and

means for retaining the at least one sensor spacer to the at least one strength member, the means for retaining providing substantial acoustic isolation between the at least one spacer and the at least one strength member.

2. The streamer of claim 1 wherein the means for retaining comprises a substantially rigid tube surrounding the at least one strength member, and at least one resilient ring disposed between an exterior of the tube and an opening in the respective spacer.

3. The streamer of claim 2 wherein the opening comprises a groove for cooperatively receiving the resilient ring.

4. The streamer of claim 2 wherein the tube comprises a flange on an external surface thereof to longitudinally retain the resilient ring.

5. The streamer of claim 1 wherein the jacket comprises polyurethane.

6. The streamer of claim 1 wherein the at least one strength member comprises fiber rope.

7. The streamer of claim 6 further comprising two strength members.

8. The streamer of claim 1 further comprising buoyancy spacers disposed along the strength member and inside the jacket at spaced apart locations, the spacers having a density selected to provide the streamer with a selected overall density.

9. The streamer of claim 8 wherein the buoyancy spacers comprise foamed polyurethane.

10. The streamer of claim 1 further comprising a cable disposed inside the jacket, the cable having at least one of electrical conductors and an optical fiber, the cable adapted to carry signals from the at least one seismic sensor to a recording system.

11. The streamer of claim 1 wherein the at least one sensor comprises a hydrophone.

12. The streamer of claim 1 further comprising a termination plate coupled to each axial end of the jacket, the termination plates each coupled to the strength member at an axial end thereof, the termination plates adapted to couple to a corresponding termination plate in another segment of the streamer so as to transmit axial force therethrough.

13. The streamer of claim 1 further comprising a curable, synthetic urethane-based polymer introduced into the jacket in liquid form and curing thereafter.

14. A method for making a seismic streamer, comprising:

inserting a seismic sensor into an opening therefor in a sensor spacer;

affixing a substantially rigid tube to at least one strength member at a location therealong corresponding to a position of the sensor spacer;

applying at least one resilient ring to an exterior of the tube, the ring having a diameter selected to cooperate with a receiving feature therefor in the sensor spacer and to substantially prevent contact between the spacer and the tube;

inserting the at least one strength member and the at least one sensor spacer affixed thereto into an acoustically transparent jacket; and

filling the jacket with an acoustically transparent filler material.

15. The method of claim 14 further comprising affixing at least one buoyancy spacer to the at least one strength member prior to the inserting into the jacket.

16. The method of claim 14 wherein the material filling the jacket is introduced in liquid form and undergoes state change thereafter.

17. The method of claim 14 wherein the tube comprises a flange to longitudinally retrain the resilient ring.

18. The method of claim 14 further comprising connecting a cable to the seismic sensor prior to the inserting into the jacket.

19. The method of claim 14 further comprising affixing a termination plate to each end of the at least one strength member and coupling each termination plate to an interior surface of the jacket at the ends thereof.

20. A seismic streamer, comprising:

a jacket covering an exterior of the streamer;

at least two strength members extending along the length of and disposed inside the jacket;

at least one seismic sensor disposed in each of a plurality of sensor spacers mounted at longitudinally spaced apart positions along the strength member; and

means for retaining the sensor spacers to the strength members, the means for retaining providing substantial acoustic isolation between the sensor spacers and the strength members.

21. The streamer of claim 20 wherein the means for retaining comprises a substantially rigid tube surrounding each strength member at a longitudinal position of each sensor spacer, and at least one resilient ring at each longitudinal end of each tube disposed between an exterior of each tube and an opening in the respective spacer.

22. The streamer of claim 21 wherein the opening comprises groove for cooperatively receiving each resilient ring.

23. The streamer of claim 21 wherein each tube comprises a flange on an external surface at each longitudinal end thereof to longitudinally retain the corresponding resilient ring.

24. The streamer of claim 20 wherein the jacket comprises polyurethane.

25. The streamer of claim 20 wherein the strength members comprise fiber rope.

26. The streamer of claim 20 further comprising buoyancy spacers disposed along the strength members and inside the jacket at spaced apart locations, the spacers having a density selected to provide the streamer with a selected overall density.

27. The streamer of claim 26 wherein the buoyancy spacers comprise foamed polyurethane.

28. The streamer of claim 20 further comprising a cable disposed inside the jacket, the cable having at least one of electrical conductors and an optical fiber, the cable adapted to carry signals from the seismic sensors to a recording system.

29. The streamer of claim 20 wherein the seismic sensors comprises hydrophones.

30. The streamer of claim 20 further comprising a termination plate coupled to each axial end of the jacket, the termination plates each coupled to the strength member at an axial end thereof, the termination plates adapted to couple to a corresponding termination plate in another segment of the streamer so as to transmit axial force therethrough.

31. The streamer of claim 20 further comprising a curable, synthetic urethane-based polymer introduced into the jacket in liquid form and curing thereafter.

32. A seismic streamer, comprising:

a jacket covering an exterior of the streamer;

at least one strength member extending along the length of and disposed inside the jacket;

at least one seismic sensor disposed in a sensor spacer mounted to the at least one strength member; and

an acoustic isolator disposed between the at least one seismic sensor spacer and the at least one strength member.

33. The streamer of claim 32 wherein the acoustic isolator comprises a substantially rigid tube surrounding the at least one strength member, and at least one resilient ring disposed between an exterior of the tube and an opening in the respective spacer.

34. The streamer of claim 33 wherein the opening comprises a groove for cooperatively receiving the resilient ring.

35. The streamer of claim 33 wherein the tube comprises a flange on an external surface thereof to longitudinally retain the resilient ring.

36. The streamer of claim 32 wherein the jacket comprises polyurethane.

37. The streamer of claim 32 wherein the at least one strength member comprises fiber rope.

38. The streamer of claim 37 further comprising two strength members.

39. The streamer of claim 32 further comprising buoyancy spacers disposed along the strength member and inside the jacket at spaced apart locations, the spacers having a density selected to provide the streamer with a selected overall density.

40. The streamer of claim 39 wherein the buoyancy spacers comprise foamed polyurethane.

41. The streamer of claim 32 further comprising a cable disposed inside the jacket, the cable having at least one of electrical conductors and an optical fiber, the cable adapted to carry signals from the at least one seismic sensor to a recording system.

42. The streamer of claim 32 wherein the at least one sensor comprises a hydrophone.

43. The streamer of claim 32 further comprising a termination plate coupled to each axial end of the jacket, the termination plates each coupled to the strength member at an axial end thereof, the termination plates adapted to couple to a corresponding termination plate in another segment of the streamer so as to transmit axial force therethrough.

44. The streamer of claim 32 further comprising a curable, synthetic urethane-based polymer introduced into the jacket in liquid form and curing thereafter.