Advanced Leakage Detection using Helium Gas

Transcription

1 Advanced Leakage Detection using Helium Gas SWIG Conference, Daresbury 8th July 2015 Steve George, Water Europe Business Development, Suez Environnement

2 WHO ARE WE?WHO WE ARE...

3 PRESENT IN 70 COUNTRIES

4 LEAKAGE DETECTION

5 FACTORS AFFECTING LEAKAGE DETECTION Water pressure in the pipe Pipe material and pipe diameter Soil type and soil compaction Depth of soil over the pipe Surface cover: grass, loose soil, asphalt, concrete slab, etc. Environmental conditions Serviceability of the pipe Locational data accuracy Local infrastructure such as valves Policy on strategic and distribution pipes

6 PINPOINTING LEAKS Accoustics: 30% of the leaks cannot be detected In insulated pipes up to 90% Old leaks can generate water caves, softening and absorbing the sound waves

7 WHEN ALL ELSE FAILS DOWSE!!!

8 PINPOINTING LEAKS WITH HELIUM Acoustic systems are a great way for first run over, fast implementation - high percentage of leak detection. Gas tracer systems can perform better as it has no physical propagation issues it goes where the water goes. Needs to be able to applied to in-service, live mains - requires DWI approval Capable of detecting, very small leaks at depth Pipe material independent just don t use too much!

9 THE SCIENTIFIC PART

10 THE CANDIDATES FOR GAS INSERTION Sulfur hexafluoride (SF6) Carbon Dioxide (CO2) Hydrogen Nitrogen Helium Argon Oxygen Xenon Radon

11 KEY REQUIREMENTS OF ANY SOLUTION Live pipes are in service - containing clean drinking water Substance must not be toxic Cannot change the taste / smell that would lead to customer complaints Cannot affects the constitution of the water Must be small enough to escape ground Must be consistently detectable at the surface

12 PHYSICAL ENVIRONMENT

13 CRUNCHING THE NUMBERS

14 THE CANDIDATES FOR GAS INSERTION Sulfur hexafluoride (SF6) heavier than air, will sink Carbon Dioxide (CO2) affects constitution of water, bubbles Nitrogen too abundant in atmosphere, diificult to detect low level Oxygen affects constitution, difficult to detect Argon Expensive, not long lasting Xenon Expensive, not long lasting Radon radioactive, toxicity issue Hydrogen possible candidate Helium possible candidate

15 LONGEVITY IN GROUND FOR DETECTION

16 CONCENTRATION VARIES AS TIME PASSES AND VOLUME OF WATER

17 AND THE WINNER IS Helium Up to five days detection period Concentration values make it easily detectable Very light molecule, rises to the surface

18 GETTING THE GAS INTO THE WATER

19 SOLUBILITY OF A GAS The amount of a substance that can be dissolved in a given amount solvent in a established temperature and pressure conditions William Henry, 1803 The solubility value is setting by Henry s equation: Caq = H Pgas Pgas = Helium partial pressure (gas) in contact with H20 Caq = Gas balance concentration in H20 exposed to partial gas pressure Pgas H = Proportional constant, depends on temp and differs for each gas Gas solubility depends on temperature, pressure and water composition.

20 FACTORS WHEN INJECTING THE GAS FLOW PIPE SIZE PRESSURE TEMPERATURE

21 GAS INJECTION EQUIPMENT

22 THE DETECTION PROCESS

23 THE idroloc PROCESS LEAK DETECTED!! Unusual Helium concentration detected Air contained in the soil is aspirated for analysis Gas desorption Helium comes out from the pipe soaking surrounding terrain Tracer gas is dissolved and flows as part of the liquid inside the pipe Helium Injection inside the pipeline 23

24 idroloc PORTABLE EQUIPMENT

25 SAMPLING FOR HELIUM

26 Helium Concentration PIN POINTING LEAKS 26

27 EXAMPLES OF USE

28 NEW AND DISCONNECTED PIPES Advantages Pressure test and leak location can be done in one go Fast to implement, sensitive, very precise No unnecessary water consumption 28 I

29 PHYSICAL ENVIRONMENT Murcia, Spain 10km, 600mm 12 LEAKS total of 15 m3/h lost water ( 0.70/m3 cost of water) 70k savings per year Localización Caudal Carril Torre Camino Albadel Nº 9 1 m3/h Camino Albadel - Tren Carretera El Palmar 7 m3/h Camino SalaBosque Nº 59 1 m3/h Camino SalaBosque Nº 172 Camino SalaBosque - Gruas 0.7 m3/h Calle Barranquete 1.1 m3/h Camino SalaBosque Nº188 2 m3/h Camino Torresalinas 0.05 m3/h Camino SalaBosque Nº 41 Camino SalaBosque Nº 11

30 TRACING THE PIPES Barcelona 30

31 A FEW MORE EXAMPLES

32 SUMMARY

33 Thank You