SubSea Leak Detection using LeakFusion TM An OptaSense Pipeline Assurance Product Dr Chris Minto MTS Subsea Leak 2014 chris.minto@optasense.com +44 7500 782508 Skype: chris.minto.optasense UK, USA, Canada, UAE, Australia, www.optasense.com
OptaSense is owned by QinetiQ Group, a UK based multinational R&D organisation employing 7,000 people worldwide, with revenues of roughly $2 billion per year. OptaSense uses Distributed Acoustic Sensing (DAS) to enable customers to prevent intrusion, monitor assets and protect people. In four years OptaSense has grown to over 180 people, has filed about 120 patents and has opened offices in Houston, San Francisco, Calgary and Dubai.
About OptaSense 120 km Pipeline, Tunisia >1000km Pipeline, Kazakhstan 1090 km Pipeline, Turkey San Francisco Calgary Houston The UK Dubai 180 km Pipeline, Iraq 800 km Pipeline, India 160km Railway 200 km Pipeline, India Application Areas Oil & Gas Transport Defence & Security Telecommunications OptaSense Offices 230 km Pipeline Columbia 250km of Pipeline 250km Pipeline, Yemen OptaSense has a worldwide presence, with four major offices, serving operations in 40 countries.
Incident Prevention vs. Incident Detection Incident equals Damage, damage equals Cost! Pipeline TPI / Integrity Monitoring 4Mode TM & LeakFusion TM
Introducing OptaSense 4 Mode Leak Detection Multiple approaches, one fibre. Integrated. Computational.
Leak Detection: time Ground Heave Fibre Pipeline Fibre Orifice Noise Negative Pressure Pulse Pipeline Pipeline DTGS Fibre Pipeline
The benefits of 4 mode leak Alert fusion to cope with multiple scenarios In our proprietary fusion engine, the detector output can be prioritised and weighted in accordance with product, geometry and environmental conditions A solution can come from one detector or from all four Detection can be optimised for Liquid, Gas or mixed phase one solution can cover all products Combines some of the best aspects of individual discrete solutions All the economic benefits of fibre sensing, resolution, cost, simplicity Designed to be compatible with API standards, RP s & procedures Highly sensitive leak detection: below noise floor of mass balance Tolerant of ducting / non ducting Future potential for Leak Size based measurements
Compliance with API practices OptaSense are corporate members of the American Petroleum Institute and our system and GUI are designed around integration with the nearest compatible standards (where relevant): API 1130 RP Computational Monitoring API 1149 PUBL Pipeline Variable Uncertainties API 1164 STND Pipeline SCADA Security API 1165 RP Pipeline SCADA Displays API 1167 RP Pipeline SCADA Alarm Management API 1160 RP Managing System Integrity A detailed statement of API compliance is available on request. OptaSense Leak Prevention can also assist with achieving compliance with API 1172 RP Construction Parallel to Existing Pipelines
Subsea leak available signal
Available Signals for subsea leak IPC2014 33725, 2014, Shane Siebenaler et al
Available Signals for subsea leak RJ Urick, Principles of Underwater Sound (aka the bible ) Deep water spectra illustrates plenty useable signal above wind noise
Subsea Leak mode application
4 Mode optimisation: Subsea Liquid Pipelines LOW Some application in large leak events Some seducing by environment HIGH Immediate on Leak Low nuisance alarm rate Less dependent on fibre offset HIGH Immediate on Leak Fibre clamped to pipe NA Little application subsea (unless heated line)
4 Mode optimisation: Subsea Gas Pipelines LOW Some application in large leak events Some seducing by environment HIGH Immediate on Leak Low nuisance alarm rate Less dependent on fibre offset HIGH Immediate on Leak Fibre clamped to pipe LOW Little application subsea Requires direct cooling will be co-registered with strain
Mode 1: Negative Pressure Pulse Example: Valve induced pressure wave in a flowing branch tap P c 0 v Joukowsky equation limit for an instantaneous closure / leak
Mode 1: Negative Pressure Pulse Example: Pressure pulse caused by motion of pig The interaction of a cleaning pig / scraper with the side walls and butt welds creates a moving series of pressure pulses long used for very precise PIG location ID
Mode 1: Negative Pressure Pulse Detector Window
Mode 1: Negative Pressure Pulse Example: Pressure pulse caused by gravity induced slack lines
Mode 2: Leak Orifice Noise Tuneable to leak size / Nuisance Alarm Rate Single Phase Liquid Single Phase, Gas Leak Mixed Phase, Slug Mixed Phase, Bubbles in Liquid 19
Mode 2: Leak Orifice Noise Single Phase Liquid Single Phase, Gas Leak Mixed Phase, Bubbles in Liquid Mixed Phase, Slug ~30 bar gas leak at orifice, 1x12mm slot (c.4mm equiv hole), sandy soil, 300mm offset from fibre, 12,000 dropping to 1,500 SLPM 20
Subsea Leak Case Study Umbilical Rupture
Subsea Leak Detection Case Study Subsea umbilical with catastrophic failure in ethylene glycol line Client had tried DTS techniques to locate leak and been unsuccessful. DAS was able to first localise the leak using a liquid fill and pump within 30mins on site. Located to a ±10m accuracy 30km optical
Subsea Leak Detection Case Study Liquid Fill Client had tried DTS techniques to locate leak and been unsuccessful. DAS was able to first localise the leak using a liquid fill and pump within 30mins on site. Located to a ±10m accuracy Continuous leak orifice noise Noise from parallel operating pipeline flow data Time Umbilical filling No more filling leak location Distance along umbilical
Subsea Leak Detection Case Study Gas Fill The test was repeated with a Nitrogen filling Pressure on sea water out flow Pressurised Orifice Noise Time Pressurised Orifice Noise Location verified with visual check Pressure off sea water in flow Distance along umbilical
Subsea Leak Detection Case Study Looking at the interface in more detail Pressurised Orifice Noise Flow Rate: c. 300 scfm Time Pressure on sea water out flow Two distinct acoustic events with flow / against flow Distance along umbilical Peak Pressure: c. 270 psi
Subsea Leak Detection Case Study Looking closer Pressurised Orifice Noise Too slow for acoustic mechanical? gas propagation in umbilical? Fast but acoustic, multiple pulses, not continuous Time Leak Location & Point where gas fill balances pressure head Gas Filled Still filled with water Distance along umbilical
Subsea Leak Detection Case Study Closer still Orifice Noise Continuous / pulsing Negative Pressure Pulses / turbulent flow ~ 1434 ms 1 close to speed of sound in water Time Line pressure balances sea water head Gas filled Sea water filled Distance along umbilical
Subsea Leak Detection Case Study Undersea Gas Leak NPP Detection
Subsea Performance Tests
Subsea Mode 2 - OFN Orifice Noise Acoustic Noise from Water Leak: 50psi, (3.5bar), 1/8, 45deg, 10km Zone 0 Zone 1 Zone 2 Zone 3 30
Subsea Mode 2 - OFN Orifice Noise Acoustic Noise from Gas Leak: 12psi, (0.8bar), 1/32, 0deg, 10km Zone 0 Zone 1 Zone 2 Zone 3 31
Subsea Mode 2 - OFN Orifice Noise Verified Test Results - Positive Detections for the following ranges. Detection Variable Liquid Pressure Liquid Orifice Size Liquid Offset Distance Gas Pressure Gas Orifice Size Detection Range 0.07 Mpa 0.69 Mpa 10psi 100psi 0.7bar 7bar 0.79mm 4.76mm 0m 0.5m 0.07 Mpa 1.38 Mpa 10psi 200psi 0.7bar 13.8bar 0.79mm 4.76mm Gas Offset Distance 0m 1.15m System optimised for multiple rapid detections not maximum sensitivity 32
4Mode TM leak with LeakFusion TM is a new technology development aimed at expanding the range of current leak detection systems towards more sensitive, more accurate and more robust leak detection and prevention Follow OptaSense: UK, USA, Canada, Dubai, Australia, www.optasense.com
Additional Slides
Operations Optimization Inline Inspection Toolkit V 3.0 Tool speed plotted over distance Alerts for tool arrival time / speed alerts Indicators of wax build up in liquid pipe Indicator for pipeline damage issues Monitor gas pressure profile Locate stuck devices
System Marinisation Marinisation project underway available early 2015 Current DAS interrogation system Integrated into a subsea assembly (2015) Repackaged into a pressure vessel and fully qualified (2014)
Vibration monitoring Problem Axial and radial vibration measurements in subsea pumps Axial motion more critical than radial motion Can lead to damage of pump and flow lines
DTGS Detection Detection rate determined by environment and product properties 150 lpm 15 lpm 24 min 110 min 3.4 min 13 min 0.9min 3.5min Void fraction = 0.43, includes larger T at greater standoff due to steady-state heat flow 38
Mode 4: DTGS Distributed Temperature Gradient Sensing leak examples
Leak Alert Integration fuser 3ii Information Verification & Analysis (Clustering) Mode Tracking Same Displays, without processed data only alerting Clear examination of clustering / fuser The alert fuser looks for a range of activities across time and nearby channels for the presence of sufficient corroborating evidence of a leak prior to declaring a leak the distribution of new and continuing alerts can be probed. Different detectors are given different weightings Draft GUI Development for discussion: release OptaSense 3.5
Modes 1 & 2 coupled: In field leak detection Hot Tap Detection via Acoustics
Mode 3: Ground Heave ~30 bar gas leak at orifice, 1x12mm slot (c.4mm equiv hole), sandy soil, 300mm offset from fibre, 12,000 dropping to 1,500 SLPM
Mode 4: DTGS ~30 bar leak at orifice, 2mm hole, clay soil, 300mm offset from fibre, 5,000 SLPM dropping to 1,000 SLPM
Alert Integration & Data Output
Integration with control systems Information integration achieved at multiple levels: Alert Activity DCS / SCADA Alert Detail (Rich) HTTP / OPC Duplex Integration Flexible GUI Control Display Control External Systems (Sparse) SMS Email etc Dry Contacts
Leak Alert Integration 1 Information level 2 Confidence Addition Pre Alerts Illustrates level of activity in each mode Non Alerting Separate Table Right Click GUI clustering Alerts Full Alert TOTE Fused Output May represent single mode Right Click Separate Leak console Draft GUI Development for discussion: release OptaSense 3.5
Leak Alert Integration 3i Information Verification & Analysis (Trending) Leak Channel Mode Tracking Time based analysis Viewpoint controls Monitor Trend Expectation based on geometry and pipeline particulars What tools are required? Draft GUI Development for discussion: release OptaSense 3.5
4 Mode Leak Detection analytics Workflow & toolkit
4 Mode optimisation: Buried Gas Pipelines HIGH Immediate ground heave on substantial leak Orientation not directly an issue HIGH MEDIUM HIGH Immediate on Leak Low nuisance alarm rate Less dependent on fibre offset Some speed variation with gas pressure LOW Immediate on Leak Dependent on fibre offset Less dependent on fibre orientation Environmental noise Follows Leak by time offset Leak paths may not be direct: orientation Joule Thomson cooling only in path of leak Some seducing by environment
4 Mode optimisation: Buried Liquid Pipelines LOW Follows Leak by time offset Co-registers with DTGS (fluid pressure on fibre) Leak paths may not be direct: orientation HIGH Immediate on Leak Low nuisance alarm rate Less dependent on fibre offset Low speed variation MEDIUM HIGH Immediate on Leak Dependent on fibre offset Less dependent on fibre orientation Environmental noise MEDIUM Follows Leak by time offset Leak paths may not be direct: orientation Some seducing by environment
4 Mode optimisation: Mixed Phase Flowlines NA High dynamic strain environment HIGH Immediate on Leak Considerable variation with flow conditions experimental verification required HIGH Immediate on Leak Fibre clamped to pipe Environmental noise MEDIUM Close to leak start Dependent on fabrication conditions may not have application
Standing waves from turbulence Small scale NPP from static locations 53
Multi Phase Flow from a production pipe Differing phase velocities 54
Subsea Mode 2 - OFN Orifice Noise Test Results Liquid Pd Orifice size vs Pressure 6.00 Liquid OFN Pd Orifice Size (mm) vs Pressure (psi) 5.00 4.00 Orrifice Size (mm) 3.00 2.00 SWRI Pond 1.00 0.00 0 50 100 150 200 250 Pressure (psi) 55
Subsea Mode 2 - OFN Orifice Noise Test Results Liquid Pd Distance vs Pressure 0.6 Liquid OFN Pd Distance to Detector (m) vs Pressure (psi) 0.5 Distance to Detector (m) 0.4 0.3 0.2 SWRI Pond 0.1 0 0 50 100 150 200 250 Pressure (psi) 56
Subsea Mode 2 - OFN Orifice Noise Test Results Gas Pd Orifice size vs Pressure 6.00 Gas OFN Pd Orifice Size (mm) vs Pressure (psi) 5.00 4.00 Orrifice Size (mm) 3.00 2.00 SWRI Pond 1.00 0.00 0 50 100 150 200 250 Pressure (psi) 57
Subsea Mode 2 - OFN Orifice Noise Test Results Gas Pd Distance vs Pressure 0.6 Gas OFN Positive Detections Distance to Detector (m) vs Pressure (psi) 0.5 Distance to Detector (m) 0.4 0.3 0.2 SWRI Pond 0.1 0 0 50 100 150 200 250 Pressure (psi) 58