Subsea Measurement System And Method Of Determining A Subsea Location-Related Parameter

• US 20120134236A1
• Filed: 01/12/2010
• Published: 05/31/2012
• Est. Priority Date: 01/12/2009
• Status: Active Grant

• Current Assignee: Sonardyne International Limited (Sonardyne Group Ltd.)
• Original Assignee: Sonardyne International Limited (Sonardyne Group Ltd.)
• Inventors: Pearce, Christopher, Larsen, Mikael, Lawes, David
• Granted Patent: US 9,939,527 B2
• Time in Patent Office: Days
• US Class Current: 367/118
• CPC Class Codes: G01S 15/872 Combination of several systems for attitude determination using inertial means G01C9/00, control of attitude G05D1/49
• CPC Class Codes: G01S 15/874 Combination of several spaced transponders or reflectors of known location for determining the position of a receiver G01S15/872 takes precedence
• CPC Class Codes: G01S 2015/465 by Trilateration, i.e. two transducers determine separately the distance to a target, whereby with the knowledge of the baseline length, i.e. the distance between the transducers, the position data of the target is determined

Abstract

A subsea measurement system (400) comprises a first reference beacon (110) disposed at a first known location, a second reference beacon (112) disposed at a second known location, and an acoustic communications module (302) for coupling to a subsea element to be monitored. The acoustic communications module (302) is capable of moving, when in use, relative to the first reference beacon (110) and the second reference beacon (112). The acoustic communications module (302) also comprises a processing resource and is arranged to determine first range-related data to the first reference beacon (110) in response to receipt of a first signal by the acoustic communications module (302) from the first reference beacon (110) and second range-related data to the second reference beacon (112) in response to receipt by the acoustic communication module (302) of a second signal from the second reference beacon (112).

Claims

1. A subsea measurement system comprising:

a first reference beacon disposed at a first known location;

a second reference beacon disposed at a second known location; and

an acoustic communications module for coupling to a subsea element to be monitored, the acoustic communications module being capable of moving, when in use, relative to the first reference beacon and the second reference beacon;

wherein

the acoustic communications module comprises a processing resource and is arranged to determine first range-related data to the first reference beacon in response to receipt of a first signal by the acoustic communications module from the first reference beacon and second range-related data to the second reference beacon in response to receipt by the acoustic communication module of a second signal from the second reference beacon.

2. The system as claimed in claim 1, wherein the acoustic communications module is further arranged to determine first angle data to the first reference beacon in response to receipt of the first signal by the acoustic communications module from the first reference beacon and second angle data to the second reference beacon in response to receipt by the acoustic communication module of the second signal from the second reference beacon.

3. The system as claimed in claim 2, wherein the first angle data comprises a first direction cosine angle and a second direction cosine angle and/or the second angle data comprises a third direction cosine angle and a fourth direction cosine angle.

4. The system as claimed in claim 1, further comprising:

another acoustic communications module for coupling to the subsea element to be monitored, the another acoustic communications module being capable of moving, when in use, relative to the first reference beacon and the second reference beacon;

wherein

the another acoustic communications module comprises another processing resource and is arranged to determine third range-related data to the first reference beacon in response to receipt of the first signal by the another acoustic communications module from the first reference beacon and fourth range-related data to the second reference beacon in response to receipt by the another acoustic communication module of the second signal from the second reference beacon.

5. The system as claimed in claim 4, wherein the another acoustic communications module is further arranged to determine third angle data to the first reference beacon in response to receipt of the first signal by the acoustic communications module from the first reference beacon and fourth angle data to the second reference beacon in response to receipt by the acoustic communication module of the second signal from the second reference beacon.

6. The system as claimed in claim 5, wherein the third angle data comprises a fifth direction cosine angle and a sixth direction cosine angle and/or the fourth angle data comprises a seventh direction cosine angle and a eighth direction cosine angle.

7. The system as claimed in claim 1, further comprising:

a further processing resource arranged to calculate at least one location-related parameter for the subsea element to be monitored.

8. The system as claimed in claim 2, wherein the location-related parameter is a position associated with the acoustic communications module.

9. The system as claimed in claim 7, wherein the location-related parameter is a heading associated with the acoustic communications module.

10. The system as claimed in claim 7, wherein the location-related parameter is a roll and/or pitch associated with the acoustic communications module.

11. The system as claimed in claim 7, wherein the location-related parameter is an attitude associated with the acoustic communications module.

13. The system as claimed in claim 1, further comprising:

a third reference beacon disposed at a third known location.

14. The system as claimed in claim 13, wherein the acoustic communications module is arranged to determine fifth range-related data from the acoustic communications module to the third beacon in response to receipt of a third signal by the acoustic communications module from the third reference beacon.

15. The system as claimed in claim 13, wherein the acoustic communications module is arranged to determine fifth angle data to the third reference beacon in response to receipt of the third signal by the acoustic communications module from the third reference beacon.

20. The system as claimed in claim 1, wherein the first beacon and the second beacon are respectively fixed at the first known location and the second known location.

24. The system as claimed in claim 1, wherein the first beacon is a first transponder and the second beacon is a second transponder.

25. The system as claim in claim 1, wherein the first beacon is removably mounted in a first mount and/or the second beacon is removably mounted in a second mount.

28. A free standing hybrid riser (FSHR) apparatus comprising the subsea measurement system as claimed in claim 1.

29. A constellation of free standing hybrid riser apparatus for coupling to a floating production storage and offloading (FPSO) vessel comprising the free standing hybrid riser apparatus as claimed in claim 28.

12. (canceled)

16. (canceled)

17. (canceled)

18. (canceled)

19. (canceled)

21. (canceled)

22. (canceled)

23. (canceled)

26. (canceled)

27. (canceled)

30. A method of determining a subsea location-related parameter, the method comprising:

disposing a first reference beacon at a first known location; and

disposing a second reference beacon at a second known location;

providing an acoustic communications module for coupling to a subsea element to be monitored, the acoustic communications module being capable of moving relative to the first reference beacon and the second reference beacon; and

determining first range-related data from the acoustic communications module to the first reference beacon in response to receipt of a first signal by the acoustic communications module from the first beacon and second range-related data from the acoustic communications module to the second reference beacon in response to receipt by the acoustic communications module of a second signal from the second reference beacon.