Stress and/or tension monitoring systems and methods

• US 7,591,188 B2
• Filed: 11/13/2006
• Issued: 09/22/2009
• Est. Priority Date: 11/15/2005
• Status: Expired due to Fees

• Current Assignee: Shell Oil Company (Shell Plc)
• Original Assignee: Shell Oil Company (Shell Plc)
• Inventors: McMullen, Clay Douglas, Lee, Li, Allen, Donald Wayne
• Primary Examiner(s): NOORI, MAX H
• Application Number:
  US11/559,202
• Publication Number:
  US 20070193363A1
• Time in Patent Office: 1,044 Days
• Field of Search: 73825-826
• US Class Current: 73/825
• CPC Class Codes: B63B 71/00 Designing vessels; Predicting their performance
• CPC Class Codes: E21B 17/01 Risers
• CPC Class Codes: G01M 5/0025 of elongated objects, e.g. pipes, masts, towers or railways G01M5/0058 takes precedence
• CPC Class Codes: G01M 5/0041 by determining deflection or stress
• CPC Class Codes: G01M 5/0066 by exciting or detecting vibration or acceleration vibration testing of structures G01M7/00

Abstract

There is disclosed a system comprising a structure, from 1 to 10 dynamic tension sensors, adapted to monitor a dynamic tension level of at least one point along a length of the structure, and a controller adapted to calculate a dynamic bending stress or strain level at a plurality of points along the length of the structure as a function of time. In some embodiments, the system also includes a vessel connected to the structure, wherein the vessel is floating in a body of water.

Claims

1. A system comprising:

a structure;

from 1 to 10 dynamic tension sensors, adapted to monitor a dynamic tension level of at least a first set of points along a length of the structure; and

a controller adapted to calculate a dynamic bending stress or strain level at a second set of points along the length of the structure as a function of time, wherein the second set of points do not comprise dynamic tension sensors;

wherein the structure comprises one or more strakes and/or fairings adapted to lower the vortex induced vibration value of the structure.

2. The system of claim 1, further comprising a vessel connected to the structure, wherein the vessel is floating in a body of water.

3. The system of claim 1, wherein the structure is selected from the group consisting of risers and mooring lines.

4. The system of claim 1, comprising from 1 to 5 dynamic tension sensors.

5. The system of claim 1, further comprising a vessel connected to the structure, wherein the vessel comprises an oil platform.

6. The system of claim 1, wherein the sensors are located about a circumference of the structure at one point along an axis of the structure.

7. The system of claim 1, consisting essentially of 1 dynamic tension sensor.

8. The system of claim 1, further comprising a means for conveying the dynamic tension level from the sensors to the controller.

9. The system of claim 8, wherein the means for conveying the dynamic tension level comprises an umbilical, a wire, a wireless device, an acoustic device, a radiofrequency device, a laser, or a light.

10. The system of claim 1, wherein the sensors are within a body of water.

11. The system of claim 1, wherein the controller is above a body of water.

12. The system of claim 1, further comprising a power generator located within a body of water selected from the group consisting of a turbine, a nuclear reactor, a buoy, a thermo-electric device, and/or a battery to power the sensors.

13. The system of claim 1, further comprising a power generator located above a body of water selected from the group consisting of a wind turbine, a solar panel, a water current turbine, and/or a battery to power the controller.

14. A method of calculating a dynamic tension level at a plurality of points along a length of a structure, the method comprising:

providing a structure;

attaching from 1 to 10 dynamic tension sensors to the structure;

monitoring a dynamic tension level of at least a first set of points along a length of the structure with the sensors;

transmitting the dynamic tension level of the first set of points to a controller; and

calculating a dynamic bending stress or strain level at a second set of points along the length of the structure as a function of time with the controller, wherein the second set of points do not comprise dynamic tension sensors;

wherein the structure comprises one or more strakes and/or fairings adapted to lower the vortex induced vibration value of the structure.