Rigid-stem lead-in method and system

Patent metadata

Field	Value
Publication number	US-9244184-B2
Application number	US-201213729248-A
Country	US
Kind code	B2
Filing date	Dec 28, 2012
Priority date	Dec 28, 2012
Publication date	Jan 26, 2016
Grant date	Jan 26, 2016

Abstract

Disclosed are methods and systems for using a rigid-stem lead-in assembly comprising a plurality of interconnected rigid stems in a marine geophysical survey. An embodiment discloses a method of towing a survey device from a survey vessel, comprising: coupling the survey device to the survey vessel with a lead-in comprising a rigid-stem lead-in assembly, the rigid-stem lead-in assembly comprising a plurality of rigid stems that are interconnected and each comprise a stem both defining one or more interior chambers; and towing the survey device through a body of water. Also disclosed are marine geophysical survey methods and marine survey systems.

First claim

What is claimed is:

1. A method of towing a survey device from a survey vessel, comprising:
coupling the survey device to the survey vessel with a lead-in comprising a rigid-stem lead-in assembly, the rigid-stem lead-in assembly comprising a plurality of rigid stems that are interconnected and each comprise a stem body defining one or more interior chambers; and
towing the survey device through a body of water.

2. The method of claim 1 , further comprising coupling stem joints between the plurality of the rigid stems to form a rigid connection between adjacent stem joints, wherein one or more flexible cables extend between the plurality of rigid stems.

3. The method of claim 2 , further comprising coupling the rigid-stem lead-in assembly to a second rigid-stem lead-in assembly, the second rigid-stem lead-in assembly comprising a plurality of interconnected rigid stems each comprising a stem bodying defining one or more interior chambers.

4. The method of claim 1 , further comprising generating signals with sensors located on the sensor streamer in response to energy emitted from one or more energy sources.

5. The method of claim 1 , further comprising expelling seawater from at least one ballast tank disposed in the stem body of at least one of the rigid stems.

6. The method of claim 1 , further comprising adjusting an angle of an aileron attached to an edge of the stem body of at least one of the rigid stems to control rotation of the rigid stem.

7. The method of claim 1 , wherein at least one of the rigid stems comprises a wing mounted to the stem body, and wherein the method further comprising deploying the wing into an open position.

8. The method of claim 7 , wherein the deploying comprises sliding a sleeve on the stem body to release the wing.

9. The method of claim 1 , wherein each of the rigid stems has a length in a range of from about 1 meter to about 50 meters.

10. The method of claim 1 , wherein the stem body for at least one of the rigid stems has a wing-shaped cross-section.

11. A marine geophysical survey method, comprising:
towing at least one sensor streamer through a body of water, the sensor streamer coupled to a survey vessel with one or more rigid-stem lead-in assemblies each comprising a plurality of rigidly interconnected rigid stems, the rigid stems each comprising a stem body defining one or more interior chambers; and
generating signals with geophysical sensors located on the sensor streamer in response to energy emitted from one or more energy sources.

12. The method of claim 11 , further comprising coupling stem joints between the plurality of the rigid stems on one of the rigid-stem lead-in assemblies to form a rigid connection between adjacent stem joints, wherein one or more flexible cables extend between the plurality of rigid stems.

13. A marine survey system, comprising:
a survey vessel;
a lead-in coupled to the survey vessel, wherein the lead-in comprises a rigid-stem assembly the rigid-stem lead-in assembly comprising a plurality of rigid stems that are interconnected, each of the rigid stems comprising a stem body defining one or more interior chambers; and
a survey device coupled to the survey vessel by the lead-in.

14. The system of claim 13 , wherein each of the rigid stems has a length in a range of about 3 meters to about 12.5 meters.

15. The system of claim 13 , wherein the rigid-stem lead-in assembly is characterized as having a bending stiffness of 700 Nm 2 over a length of at least about 25 meters.

16. The system of claim 13 , wherein the rigid-stem lead-in assembly is rigid for a length of at least about 25 meters, the rigid-stem lead-in assembly having a length in a range of from about 50 meters to about 1000 meters and having a smallest width or height of about 1 meter or less.

17. The system of claim 13 , wherein the rigid-stem lead-in assembly further comprises a plurality of stem joints that rigidly interconnect at least a portion of the rigid stems.

18. The system of claim 13 , wherein the stem body for at least one of the rigid stems has a wing-shaped cross-section.

19. The system of claim 13 , wherein at least of the rigid stems comprises a wing mounted to the corresponding stem body.

20. The system of claim 13 , wherein at least one of the rigid stems comprises an aileron attached to an edge of the corresponding stem body.

21. The system of claim 13 , wherein the survey device comprises a sensor streamer, wherein the sensor streamer comprises at least one sensor selected from the group consisting of: seismic sensors, electromagnetic field sensors, and any combination thereof.

22. The system of claim 13 , wherein the survey device comprises at least one device selected from the group consisting of a sensor streamer, an energy source, a sensor assembly, a transducer, and any combination thereof.

Assignees

• Pgs Geophysical As

Inventors

• Voldsbekk Rune Sindre

Classifications

• G01V1/201 Primary

  Constructional details of seismic cables, e.g. streamers (integrated optoseismic systems G01V1/226; line connectors in general H01R, transducer mountings in general G10K11/004) · CPC title

• G01V1/38 Primary

  specially adapted for water-covered areas (G01V1/28 takes precedence) · CPC title

• B63B21/66

  Equipment specially adapted for towing underwater objects or vessels, e.g. fairings for tow-cables ({paravanes for dragging fishing nets A01K73/02; } salvaging underwater vessels or objects B63C7/00; towed underwater vessels B63G8/42) · CPC title

• G01V1/3843

  Deployment of seismic devices, e.g. of streamers (equipment for marine deployment in general B63B) · CPC title

• B63B21/56

  Towing or pushing equipment (tugs B63B35/66; towing arrangements for water sports use B63B34/60) · CPC title