Post on 04-Apr-2018
transcript
www.cfertech.com
Liquid Pipeline Leak Detection -Ongoing Research to Evaluate Selected External Leak Detection Technologies
Mark Stephens, C-FER TechnologiesPipeline Safety Trust Conference, New Orleans LA
October 20, 2016
12016 Pipeline Safety Trust Conference
www.cfertech.com
Rationale
• Conventional Computational Pipeline Monitoring (CPM) methods have very limited ability to detect small leaks– Small leaks if undetected can lead to significant spill volumes
• Interest in alternative External Leak Detection (ELD) methods– In conjunction with existing internal methods can provide system
redundancy and thereby enhance overall leak detection capability– Have potential to address blind spot associated with detection of
small leaks
• Many ELD technologies are new and capabilities are evolving– Performance capabilities have yet to be verified– Difficult to verify through field trials and/or pilot projects
• Actual pipeline leak events are rare• Realistic simulation of leak events problematic
2016 Pipeline Safety Trust Conference 2
www.cfertech.com
External Leak Detection Methods
• Continuous monitoring (in-ground systems)– Acoustic, temperature or displacement sensing (fibre optic cable)– Hydrocarbon sensing (electrical cable)– Vapour sensing (permeable tube)
• Periodic inspection (airborne and/or satellite systems)– Visual inspection
• Manual or automated image interpretation– Vapour sensing
• Laser or ambient light absorption sensing• Flame ionization detection
– Temperature sensing• Thermal imaging
– Displacement sensing• Laser light detection and ranging (LIDAR)
32016 Pipeline Safety Trust Conference
C-FER AirborneLeak Detection JIP
C-FER Ground BasedLeak Detection JIP
www.cfertech.com
Ground Based Leak Detection Joint industry Project
• Program objective– Experimentally valuate selected commercially available cable or tube
based systems for leak detection on buried liquid pipelines
• Technology focus– Fibre optic cables for
distributed acoustic sensing (DAS) and/ordistributed temperature sensing (DTS)
– Vapour sensing tubes (VST)– Hydrocarbon sensing cables (HSC)
• Deliverables– Independently verified data on system performance capabilities– Information to help vendors benchmark and improve their systems
• Research partners– Enbridge Pipelines, TransCanada Pipelines, Kinder Morgan Canada
2016 Pipeline Safety Trust Conference 4
DAS and DTS
VST
HSC
www.cfertech.com
Experimental Design Considerations
• Simulate leaks under real world operating conditions– Realistic soil conditions and sensor placement configurations– Realistic temperature differentials between oil and soil– Realistic release events
• Representative driving pressures, hole sizes and flow rates• Range of release orientations (i.e. different clock positions)
• Facilitate unbiased evaluation of ELD technologies– Matching conditions for competing technologies– Provisions to ensure ‘blind testing’ from vendor perspective
• Ensure safe handling and disposal of hydrocarbons– Apparatus to accommodate full range of LVP hydrocarbon liquids– Near-term focus on diluted bitumen (dilbit)
2016 Pipeline Safety Trust Conference 5
www.cfertech.com
Test Apparatus
2016 Pipeline Safety Trust Conference 6
Soil Containment Tank
Retractable Enclosure
Product Storage Vessel
Test Pipe with Release Ports
Spill Containment Berm
Pump Skid with Acoustic Enclosure and Base Isolation System
Catalytic Oxidizer
High Pressure Product Discharge Vessel
Product Filter and Circulation Piping, Discharge Piping,
Vessel Pressurization Systems, Control Valves, Pressure Regulators and Flow Meter Not Shown
External Leak Detection Experimental Research (ELDER) Apparatus
www.cfertech.com
Test Apparatus –Commissioning Trials
2016 Pipeline Safety Trust Conference 7
www.cfertech.com
Candidate ELD sensor cable/tubeplacement locations
Light compaction:backfill
Heavy compaction:undisturbed soil
← Trench boundary
Soil and Sensor Placement
Soil placement considerations:• In lifts to maximize consistency• Lift compaction varied to simulate
undisturbed soil and consolidated backfill
82016 Pipeline Safety Trust Conference
Sensor placement considerations:• Sensing mechanism and vendor
recommendations• Pipeline construction and cable
installation feasibility• Insight from previous tests
www.cfertech.com
Test Preparation
2016 Pipeline Safety Trust Conference 9
www.cfertech.com
Apparatus Ready for Testing
2016 Pipeline Safety Trust Conference 10
Release parameters and timing of release events not known by vendors
Testing involves the staging of multiple release events over a one-week period
www.cfertech.com
Ground Based Leak Detection JIP - Directional Findings
• Leak detection capabilities varies between technology types and between vendors of a given technology typein terms of both detection threshold and time to detect
• Detection capability can be significantly influence by sensor placement location and release orientation
• Detection of small leaks (leak rates < 1% flow rate)is possible
2016 Pipeline Safety Trust Conference 11
www.cfertech.com
Airborne Leak DetectionJoint industry Project
• Program objective– Evaluate selected technologies conveyed on airborne platforms for detecting
hydrocarbon liquid leaks from buried pipelines
• Technology focus– Laser absorption– Flame ionization– Thermal imaging
• Deliverables– Models for volatile liquid vapour migration through soils, vapour dispersion in
the atmosphere and thermal effects of leaks at ground surface– Evaluation of sensitivity of selected technologies for hydrocarbon liquid
vapour detection in the atmosphere and temperature differential detectionat ground surface
• Research partners– Enbridge Pipelines, TransCanada Pipelines, Kinder Morgan Canada
2016 Pipeline Safety Trust Conference 12
hydrocarbon vapour sensing hydrocarbon vapour sensing ground temperature sensing
www.cfertech.com
Release Modeling – In Ground
Temperature change Vapour flux
• Determine magnitude of “signal” reaching surface• Determine species of gases generated by liquid leaks
www.cfertech.com
Release Modeling – In Atmosphere
• Determine hydrocarbon vapour plume concentration above ground surface
0
50
100
150
200
250
300
350
1.0E-08 1.0E-06 1.0E-04 1.0E-02 1.0E+00
Heig
ht A
bove
Gro
und
(m)
Pentane Concentraion (ppmV)
Class 1Class 2Class 3
Hei
ght a
bove
gro
und
Concentration
www.cfertech.com
Model Verification
Example• Confirm vapour flux model by
collecting volatile compoundsproduced by liquid leaks inELDER tests
PID
www.cfertech.com
Technology Evaluation
Example• Conduct controlled outdoor gas releases with vendor
sensors mounted on boom-lift• Evaluate detection capabilities
Mobile boom-lift(up to 125 ft)
Central weatherstation
Release points & weather stations
C-FER DataAcquisition Trailer
AITF mobilerelease lab
www.cfertech.com
Airborne Leak Detection JIP -Current Status
• Evaluation of technologies for detecting liquid leaks by sensing hydrocarbon vapours in the atmosphere is on going
• Evaluation of technologies for detecting liquid leaks by sensing ground surface temperature changes is soon to start
2016 Pipeline Safety Trust Conference 17