Acoustic Pipeline Leak Detection Presented by Mark Wood SALDS 2012 Houston TX

1. Acoustic Pipeline Leak Detection Presented by Mark Wood SALDS 2012 Houston TX

2. Ocean Sonics Ltd. Design & Build Smart Hydrophones Used for Data Presentation Software • Ocean Science • Environmental Monitoring • Ocean Noise Measurement • Sea Mammal Detection • Pipeline Leak Detection • Vessel Tracking

3. Underwater Sound Important Tool Working in the Sea Learning about the Ocean Measuring the Health of the Sea Visualization of Sounds Always a Sub-plot! Sounds can tell a story Always a Sub-plot!

4. Ocean Pipelines Safest way to transport energy Pipelines age Content is corrosive Build-up Damage Storms Anchors Avalanche

5. Ocean Pipelines Gulf of Mexico 54,000 km of pipeline in 2007 2700 km of new pipeline/year avg.

6. GOM Pipeline Damage 2005

7. What is a leak? Crack or split in pipe body Stress, Construction, Movement Spot Corrosion Contents damage inside lining Damaged Seal Stress, Construction, Repair Open Valve Operator Error

8. Finding Leaks Do we have a leak? Hydrostatic Test Unexplained pressure dip How small is too small? No agreement on this

9. Leak Sounds Leak produces a ‘hiss’ Ultrasonic Easier to detect visually

10. Leak Detection Leak ‘Location’ Avoid False ‘Detects’

11. Physics of Leaks Leak Types Frequency Increases with pressure & density Decreases with leak cross sectional area Intensity Increases with pressure & density Decreases with distance from the leak source

12. Physics of Leaks Absorption Example Assume a leak sound with average level of 140 dB re.1uPa 120 dB - Easy to detect 85dB - Fine in moderate noise 70 dB - Possible only in quiet environment

13. Pipeline Leak Gulf of Mexico Large Leak from Valve ROV mounted Ship ROV Smart Hydrophone

14. Pipeline Leak ROV Thrusters & leak, no filtering

15. Pipeline Leak ROV Thrusters & Leak - Filtered

16. Pipeline Leak Gulf of Mexico

17. Diver Gulf of Mexico Pipe Repair after Storm 500 feet of water Low visibility Small leak prevented commissioning Spent 5 weeks looking for leak Cause: loose needle valve Soundscape Breathing regulator Warm water circulator

18. Diver Gulf of Mexico Breathing

19. Diver Gulf of Mexico Leak Sound

20. Diver Gulf of Mexico Two Events

21. Large Submerged Pontoon Gulf of Mexico ROV Thrusters & Leak Unfiltered

22. Large Submerged Pontoon Gulf of Mexico Leak Signals

23. Progress • Challenges Addressed • Signal Quality • 80dB to 120dB dynamic range • Lower noise floor to Sea State Zero • Fully Calibrated - units in uPa • Simple Deployment • Very Small, handheld, Single Cable • Tactile Feedback

24. Progress • Challenges Addressed • Increase Reliability • Tolerate ‘dirty power’ • Log all Survey Data Internally • Improve Event Detection • Configurable Events based on frequency band & energy • Sends a message when event triggers • Autonomous Operation

25. Progress • What’s left to do? • Develop Acoustic/Hydrodynamic Models • Currently not well understood • Account for sound channel effects, eg. depth, sea bottom • Develop Feature Extraction Algorithms • Filters that extract features unique to leaks • Question of Funding still needs to be answered

26. Progress • Requirements • Discern False Detects • Find Characteristics Specific to Leaks • Develop Feature Extraction Algorithms

27. Modeling of Leak Hydrodynamics Understand properties of Leaks Better Leak Flow Dynamics

28. Modeling of Leak Hydrodynamics Understand properties of Leaks Better Environment Inside and Outside Pipe Numerical model of pipe flow combined with leak flow

29. Other Leak Challenges Pipe in Pipe Is it possible to detect a leak? Change construction to instrument pipe? Buried Pipe?

30. Pipeline leaks • Passive Acoustics • Proven to be a powerful tool for finding pipeline leaks. • Pipeline surveys using ROV or diver • Deep water, up to 3500m depth • Continuous pipeline health monitoring • Max range function of leak sound intensity • Deeper understanding will improve detection quality

31. Thank You Mark Wood Ocean Sonics Ltd. 14 Nov. 2012 Nova Scotia