Marine seismic surveying with towed components below water's surface

Patent metadata

Field	Value
Publication number	US-9766360-B2
Application number	US-201414339726-A
Country	US
Kind code	B2
Filing date	Jul 24, 2014
Priority date	Mar 9, 2009
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A skeg mounts from the stern of a towing vessel and extends below the waterline. A channel in the skeg protects cables for steamers and a source (e.g., air gun array) of a seismic system deployed from the vessel. Tow points on the skeg lie below the water's surface and connect to towlines to support the steamers and the source. A floatation device supports the source and tows below the water's surface to avoid ice floes or other issues encountered at the water's surface. Seismic streamers have head floats supporting the streamers. Each of the floats has adjustable buoyancy preconfigured to counterbalance the weight in water of the towed component that the float supports. Acoustic signals from a transceiver at the vessel find locations of the towed components. A towed fish at a lower level than the towed components also uses acoustic signals with a transceiver to further refine the locations of the towed components.

First claim

What is claimed is:

1. A marine seismic surveying apparatus for a vessel, the apparatus comprising:
a plurality of towed components obtaining seismic data, the towed components towed in a horizontal spread by the vessel and submerged at first levels below the surface of the water;
at least one first transceiver disposed at the vessel, the at least one first transceiver emitting a first signal and detecting first location information of the towed components in the horizontal spread with the first signal;
at least one second transceiver towed from the vessel and submerged at a second level below the surface of the water, the at least one second transceiver emitting a second signal and detecting second location information of the towed components with the second signal; and
a processor processing the first and second location information and producing location data of the towed components in the horizontal spread for association with the seismic data obtained, the produced location data accounting for a non-planar network of the towed components submerged at the first levels in the horizontal spread.

2. The apparatus of claim 1 , comprising a deployed device towed from the vessel and having the at least one second transceiver.

3. The apparatus of claim 1 , wherein the first location information comprises distances of at least some of the towed components from the at least one first transceiver.

4. The apparatus of claim 1 , wherein the first location information further comprises bearings of at least some of the towed components relative to the at least one first transceiver.

5. The apparatus of claim 1 , wherein the second level is beneath the first levels.

6. The apparatus of claim 1 , wherein the towed components comprise streamers towed submerged at the first levels in the horizontal spread, and wherein the apparatus further comprises cross-bracing equipment disposed along the streamers, the cross-bracing equipment emitting a third signal and detecting third location information of the streamers with the third signal.

7. The apparatus of claim 1 , wherein the at least one first and second transceivers each comprise an acoustic transceiver.

8. The apparatus of claim 1 , wherein the first and second signals each comprise at least one of an acoustic positioning signal, an ultra short base line signal, a short base line signal, and a long base line signal.

9. The apparatus of claim 1 , comprising at least one transponder associated with the at least one second transceiver and responding to the first signal.

10. The apparatus of claim 1 , wherein the towed components are selected from the group consisting of a seismic source, an air gun array, an electromagnetic source, a magnetic source, a sonar device, a sound generating device, a paravane, an acoustic device, an imaging device, and a streamer.

11. The apparatus of claim 1 , wherein towed components comprise a seismic source having at least one transponder responding to the first signal.

12. The apparatus of claim 11 , wherein the at least one first transceiver disposed at the vessel comprises:
one of the at least one first transceiver disposed on the vessel and paired with the at least one transponder of the seismic source; and
another of the at least one first transceiver disposed on the source and emitting the first signal to additional ones of the towed components.

13. The apparatus of claim 1 , wherein at least one of the towed components comprises a float submerged below the surface of the water and supporting the at least one towed component, the float having a configured buoyancy.

14. The apparatus of claim 13 , wherein the at least one towed component comprises a streamer towed by the vessel and supported by the float, the streamer having one or more sensors for sensing a seismic signal.

15. The apparatus of claim 13 , wherein the at least one towed component comprises a paravane towed by the vessel and supported by the float, the paravane coupled to one or more additional of the towed components.

16. A marine seismic surveying apparatus for a vessel, the apparatus comprising:
a plurality of towed components obtaining seismic data, the towed components towed by the vessel and submerged at a first level below the surface of the water;
at least one first transceiver disposed at the vessel, the at least one first transceiver emitting a first signal and detecting first location information of the towed components with the first signal; and
at least one second transceiver towed from the vessel and submerged at a second level below the surface of the water, the at least one second transceiver emitting a second signal and detecting second location information of the towed components with the second signal,
wherein at least one of the towed components comprises a float submerged below the surface of the water and supporting the at least one towed component, wherein the float has a configured buoyancy and comprises: a body defining a hollow; and one or more buoyant inserts disposed in the hollow and configuring the buoyancy of the float.

17. The apparatus of claim 16 , further comprising one or more spacers being neutral and disposed in the hollow.

18. The apparatus of claim 16 , wherein the body comprises:
a housing having the hollow defined therein; and
at least one end cap affixed to one end of the housing and enclosing the hollow.

19. The apparatus of claim 16 , wherein the at least one towed component comprises a streamer towed by the vessel and supported by the float, the streamer having one or more sensors for sensing a seismic signal.

20. The apparatus of claim 16 , wherein the at least one towed component comprises a paravane towed by the vessel and supported by the float, the paravane coupled to one or more additional of the towed components.

21. A method of marine seismic surveying with a vessel, the method comprising:
towing, with the vessel, a plurality of towed components in a horizontal spread submerged at first levels below the surface of the water;
obtaining seismic data with the towed components;
detecting first location information of the towed components in the horizontal spread with a first signal emitted by at least one first transceiver disposed at the vessel;
detecting second location information of the towed components in the horizontal spread with a second signal emitted by at least one second transceiver towed behind the vessel and submerged at a second level below the surface of the water; and
rectifying locations of the towed components in a non-planar network submerged at the first levels in the horizontal spread by processing the first and second location information.

22. The method of claim 21 , wherein detecting the first location information comprises detecting at least distances of at least some of the towed components from the at least one first transceiver.

23. The method of claim 22 , wherein detecting the first location information further comprises detecting bearings of at least some of the towed components relative to the at least one first transceiver.

24. The method of claim 23 , wherein detecting the second location information comprises detecting distances and bearings of at least some of the towed components from the at least one second transceiver.

25. The method of claim 21 , wherein detecting the first location information comprises detecting at least one transponder associated with the at least one second t

Assignees

• Ion Geophysical Corp

Inventors

• Schneider Curt
• Dudley Timothy A

Classifications

• B63B3/38

  Keels (movable keels B63B41/00) · CPC title

• G01V1/3843 Primary

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

• B63B2211/06

  Operation in ice-infested waters · 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

• G01V1/3826 Primary

  dynamic steering, e.g. by paravanes or birds · CPC title