Pipeline leak detection eLearning Part 1 of 2 Please turn on your - PowerPoint PPT Presentation

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Historical development Leak detection system requirements Causes of leaks Leak detection options Non-continuous leak detection Continuous external leak detection Continuous internal leak detection Title here again in Arial 24 max. one line Pipeline leak detection Agenda

Leak localization Human Machine Interface Additional functions in leak detection Typical applications of leak detection systems Title here again in Arial 24 max. one line Pipeline leak detection Agenda

Introduction Historical development Copper pipes for First transport of Supplying Peking with natural water transport hydrocarbons gas 3000 BC 500 BC 400 BC 3 | Pipeline leak detection

Introduction Historical development Factors influencing the construction of pipelines: � Discovery of crude oil � Development of refineries � Dependency of oil transport � Invention of the automobile 19th century 4 | Pipeline leak detection

Introduction Current situation Oil, crude oil, refined products, natural gases, condensate, process gases, water and salt water 5 | Pipeline leak detection

Leak detection system requirements Official requirements Title Contents of requirement TRFL Technical Rules for Pipelines API 1130 Computational Pipeline Monitoring for Liquids Pipeline variable uncertainties and their effects API 1149 on leak detection API 1155 (replaced by API 1130) Performance criteria for leak detection systems 49 CFR 195 Transport of hazardous liquids via pipeline CSA Z662 Oil and gas pipelines 7 | Pipeline leak detection

Leak detection system requirements Performance criteria Label Description • Minimum detectable leak rate Sensitivity • Detection time • Avoid false alarms Reliability • Reliably detect leaks Accuracy • Accurate localisation of leaks • Detect failing sensors Robustness • Fall-back strategies in the event of sensor failure PipePatrol E-RTTM 8 | Pipeline leak detection 8

Causes of leaks � Fatigue cracks � Stress corrosion � Hydrogen indexing � Material manufacturing errors � External influence In Out F 9 | Pipeline leak detection

Leak detection options Leak detection systems Continuous Non-continuous • Inspection by helicopter External systems Internal systems • Smart pigging • Fibre optic cable • Pressure point analysis • Tracking dogs • Acoustic systems • Mass balance method • Sensor hoses • Statistical systems • Video monitoring • RTTM-based systems • E-RTTM 10 | Pipeline leak detection

Non-continuous leak detection Inspection by helicopter Leak detection methods: � Laser � Infrared camera � Leak sniffer Usage conditions: � Detecting small gas leaks � Accuracy depends on weather conditions � Poor weather conditions make helicopter flight difficult 11 | Pipeline leak detection

Non-continuous leak detection Smart pigging Types of pigging: Smart pigs • Cleaning pigs • Magnetic flux leakage method • Batching pigs • Testing using the principle of ultrasonic 12 | Pipeline leak detection

Non-continuous leak detection Smart pigging 1 - 5 m/s Usage conditions: � Detecting existing and potential leaks � Zero or baseline pigging � Pipeline must be piggable � Accuracy of measurement depends on the pig velocity 13 | Pipeline leak detection

Non-continuous leak detection Tracking dogs Trained to smell certain odorant Usage conditions: � Short pipelines, segments � Containment of leak sites � Certification difficult 14 | Pipeline leak detection

External leak detection Fiber optic cable Gas Laser ° C Liquids s L 0 Usage conditions: � Accurate localisation of leaks � Many reflections required � Limited length possible � Cable position must be selected according to the medium 15 | Pipeline leak detection

External leak detection Acoustic systems A A A A A A A dB L s 0 • Large number of sensors for Usage conditions: longer pipelines Acoustic sensors directly on the pipeline or with steel rods for � Difficult to detect small leaks underground pipelines 16 | Pipeline leak detection

External leak detection Video monitoring Usage conditions: � Short distances � Continuous leak detection may be possible 17 | Pipeline leak detection

External leak detection Sensor hoses Gas detector Pump ∆ Gas concentration Pump time Usage conditions: � Monitoring short pipelines � Small leaks detectable � Cable position must be selected according to the medium 18 | Pipeline leak detection

Internal leak detection P 0 T 0 T L P L 19 | Pipeline leak detection

Internal leak detection Overview of the systems Volume comparison Statistical Pressure point analysis RTTM-based method systems P T P T Extended-RTTM 20 | Pipeline leak detection

Internal leak detection Pressure point analysis dp/dt Upper threshold Lower threshold 0 t P In Out 21 | Pipeline leak detection

Internal leak detection Mass balance method In/Out Difference 30 30 25 25 20 20 Uncompensated mass balance 15 15 In 10 10 Out 5 5 0 0 In Out 22 | Pipeline leak detection

Internal leak detection Statistical systems Probability No leak Leak Alarm Statistical variable In Out 23 | Pipeline leak detection

Internal leak detection Real-Time Transient Model RTTM Conservation of Mass In Out Conservation of Momentum L Conservation of Energy

Internal leak detection RTTM P 0 T 0 T L P L F 0 F L ∆ = compensated leak rate Change in pipe contents Change in pipe contents RTTM-compensated mass balance t 25 | Pipeline leak detection

Internal leak detection E-RTTM P 0 T 0 T L P L F 0 F L ∆ ∆ F 0 F L Residual x ≡ F 0 – F 0 Residual y ≡ F L – F L 26 | Pipeline leak detection

Internal leak detection E-RTTM P 0 T 0 T L P L F 0 F L ∆ ∆ F 0 F L Residuals x and y are used by the system as decision values Residual x ≡ F 0 – F 0 Residual y ≡ FL – FL x s Leak signature 27 | Pipeline leak detection

Internal leak detection Capabilities of internal systems Method Typical min. Time to detect Time to Detectable False Accuracy of detectable leak (liquids) detect leak types of leak alarm leak localisation leak rate (gases) frequency > 5% Short Long Spontaneous High High with Pressure leaks additional point pressure analysis sensors, dependent on > 1% Long Very long Spontaneous High Average with Mass balance sampling rate and creeping additional method leaks pressure sensors > 0.5% Long Very long Spontaneous Slight Average with Statistical and creeping additional methods leaks pressure sensors > 1% Short Short Spontaneous Average High RTTM and creeping leaks > 0.5% Very short Short Spontaneous Slight High E-RTTM and creeping leaks

Leak localization Overview p t t s s s Gradient Intersection Wave Propagation Extended Wave Propagation Method Method Method Possibility of combining methods � Improving accuracy � Reducing problems in localizing 3 | Pipeline leak detection

Leak localisation Gradient Intersection Method Advantages • Localising: spontaneous, creeping leaks p • Good accuracy with stationary operation p 0 Disadvantages • Accuracy depends on length of pipeline • Pipeline geometry must be taken into consideratio p L s Leak 0 L s P P In Out 4 | Pipeline leak detection

Leak localisation Wave Propagation Method t p 0 Δ t pL s Leak t Leak Advantages • Good accuracy 0 L s • Can be used during operation and pauses Disadvantages P P • No localizing of creeping or small leaks • Fast sampling required In Out 5 | Pipeline leak detection

Leak localisation Extended Wave Propagation Method t p 0 pL p 2 p 3 s Leak t Leak 0 L s • Good accuracy P P P P In Out 6 | Pipeline leak detection

HMI (Human Machine Interface) 7 | Pipeline leak detection

HMI (Human Machine Interface) 8 | Pipeline leak detection

Added functions in leak detection Efficiency analysis 100% efficiency 87% efficiency 9 | Pipeline leak detection

Added functions in leak detection � Inventory calculation � Operator training � Theft detection � Hydraulic profiles 10 | Pipeline leak detection

Added functions in leak detection Batch tracking Batch tracking Batch scheduling � Tracking products and � Scheduling arrival times mixing zones and capacities � Scheduling of delivery � Reducing waste 11 | Pipeline leak detection

Typical applications 12 | Pipeline leak detection

Typical applications FPSO to refinery • Long pipelines with large diameters • Substation measurements impossible 13 | Pipeline leak detection

Typical applications Oil field to refinery • Long pipelines with large diameters • Changes in viscosity and density • Elevation and temperature differences 14 | Pipeline leak detection

Typical applications Offshore drilling rig to refinery • Large diameter • Substation measurements impossible • Changes in viscosity and density 15 | Pipeline leak detection