Control devices for controlling the position of a marine seismic streamer

• US 20020126575A1
• Filed: 06/26/2001
• Published: 09/12/2002
• Est. Priority Date: 12/20/1996
• Status: Active Grant

• Current Assignee: WesternGeco LLC
• Original Assignee: WesternGeco LLC
• Inventors: Bittleston, Simon Hastings
• Granted Patent: US 6,671,223 B2
• Time in Patent Office: Days
• US Class Current: 367/19
• CPC Class Codes: G01V 1/3808 Seismic data acquisition, e.g. survey design
• CPC Class Codes: G01V 1/3826 dynamic steering, e.g. by paravanes or birds

Abstract

A control device or “bird” for controlling the position of a marine seismic streamer is provided with an elongate, partly flexible body which is designed to be electrically and mechanically connected in series with a streamer. In its preferred form, the bird has two opposed wings which are independently controllable in order to control the streamer'"'"'s lateral position as well as its depth.

Claims

1. A control device for controlling the position of a marine seismic streamer, the device comprising a body mechanically connected in series between two adjacent sections of the streamer, sensor means in the body for determining its angular position in a plane perpendicular to the longitudinal axis of the streamer, two opposed control surfaces projecting outwardly from the body, each control surface being rotatable about an axis which in use extends transversely of the streamer, and control means responsive to control signals and the sensor means for independently adjusting the respective angular positions of said two control surfaces so as to control the lateral position of the streamer as well as its depth.

2. A control device as claimed in claim 1, for use with a multi-section streamer which includes an electric power line, wherein the control means is at least partly electrical and arranged in use to receive electric power from said electric power line.

3. A control device as claimed in claim 1 or claim 2, for use with a streamer which also includes a control line, wherein the control means is arranged in use to receive control signals from the control line.

4. A control device as claimed in any one of claims 1 to 3, wherein said two control surfaces are releasably secured to the body.

5. A control device as claimed in claim 4, wherein the body is adapted to be wound onto a streamer drum while still connected in the streamer.

6. A control device as claimed in claim 5, wherein the body is at least partly flexible.

7. A control device as claimed in claim 5 or claim 6, wherein the body is of approximately the same diameter as the streamer.

8. A control device as claimed in any preceding claim, wherein said control means includes at least one electrical motor.

9. A control device as claimed in any preceding claim, wherein the control means includes means for sensing the angular position of each of the two control surfaces.

10. A control device as claimed in any preceding claim, wherein the two control surfaces rotate about a common axis.

11. A control device as claimed in any preceding claim, wherein each of the two control surfaces comprises a respective wing-like member which is swept back with respect to the direction of tow of the streamer.

12. A control device as claimed in any preceding claim, wherein the body is adapted to be non-rotatably coupled in the streamer.

13. A control device for controlling the position of a streamer, the device being substantially as herein described with respect of FIGS. 1 to 5 of the accompanying drawings.