DANVA Tech-dage 11. juni 2013 Ultrasonic Water Well Cleaning Regenering af boringer med highpower ultralyd VandCenter Syd Mads Clausen Institute, SDU

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1 DANVA Tech-dage 11. juni 2013 Ultrasonic Water Well Cleaning Regenering af boringer med highpower ultralyd VandCenter Syd Mads Clausen Institute, SDU Funded by Vandsektorens Teknologiudviklingsfond (Project: 7300) Robert Brehm, Mads Clausen Instituttet, Syddansk Universitet Peer Locher, VandCenter Syd, Project manager Johan Linderberg, VandCenter Syd, Hydrogeologist

2 Ultrasonic Water Well Cleaning Regenering af boringer med highpower ultralyd 1. Project Introduction 2. Involved Technology and Equipment 3. Experimental Setups, Models and Results 4. Improvements 5. Current Progress and Summary

3 Project Introduction Project partner: VandCenter Syd, Mads Clausen Institute (SDU), InFlux Funded by: Vandsektorens Teknologiudviklingsfond Timeframe: Jan Sept Budget: ~1.7 Million DKK Projektpartnerne udvikler et ultralydsbaseret, miljøvenligt og energieffektivt værktøj til rensning og regenerering af grundvandsboringer. Boringen bliver dermed mere effektiv og regenerering foretages i én, tidsbesparende arbejdsgang. This work investigates the usage of high power ultrasonic push-pull transducer to rehabilitate water wells in contrast to conservative well rehabilitation methods. We compare the effectiveness of the ultrasonic cleaning method with state-of-art conventional cleaning methods such as brushes and chemical acids. In addition the task is to study the effectiveness and level of cleaning for different filter gravel granularities and geology compounds around water wells.

4 Water Well Aging Wells get clogged during time and the productivity of the well declines. Physical and chemical processes cause the hydraulic conductivity of the wells filter pipe and gravel pack to decline which results in a higher draw-down at an specific rate or as a loss in the discharge rate. - Gravel coatings consists of oxidised iron and manganese - Particle clogging by silt and fine sands - Precipitation hydroxides forming incrustations between particles.

5 An aged Well Before and After mechanical cleaning using brushing

6 Use known Ultrasonic Cleaning Technology

7 Push-Pull Transducer Resonator rod induce longitudinal pulses in the resonator at the points of attachment. Transducers inside each end cap produce cyclic positive and negative pressure waves The positive pressure wave acts as a pushing force and the negative pressure wave acts as a pulling force (hence "Push-pull"). The pushing and pulling action causes the rod to resonate at the frequency of operation. As a result, near perfect, omni-directional radiation of sound waves is achieved.

8 Ultrasonic Cleaning Effects Micromotion: Micromotion at resonance causes rubbing of the filter gravel stones at each other. Coatings will be rubbed off if not completely hardened. Oscillation: The gravel stones will start volume oscillating and coatings are broken off by spalling. Fluidify thixotropics: The ultrasonic energy is used to fluidify thixotropic cements, cut and break molecular lattice of gels, slime, colloidal substances

9 The test well setup

10 Determination of cleaning efficiency Measurement of the time (flow rate) it takes for a fixed volume of water to flow through a fixed volume of gravel sample. Different samples and a reference clean sample have been tested. DARCY-test. Water reservoir Valve (slider) Tube to be filled with gravel Fine mesh ~400mm Ø ~50mm

11 Proof-of-Concept Experiments Results

12 Recent results in water well model Dirty Gravel Sieved CLEAN Cleaned TOP Cleaned BOT Cleaned TOP Cleaned BOT REFERENCE (15-20cm away) (15-20cm away) (10cm away) (10cm away) 67,62 50,6 53,28 53,97 51,34 48,71 64,1 66,43 51,81 45,03 47,16 51,12 55,15 68,18 55,19 58,57 46,6 44,29 57,69 67,47 68,91 48,66 58,81 40,87 54,03 52,28 65,97 65,09 50,32 54,28 53,47 54,5 56,35 66,5 69,35 51, ,28 52,18 44,65 67,91 68,09 52,72 50,6 44,25 44,29 55,09 70,75 59,94 50,19 56,59 43,19 50,78 54,06 Mean 67, , ,335 54,02 47, , , Std. 2, , , , , , , Flow l/min 0,89 0,90 1,17 1,11 1,25 1,19 1, Flow rate in l/min Dirty Batch 1 Dirty Batch 2 Clean TOP 25cm Clean Bottom 25cm Clean Top 10cm Claen BOT 10cm CLEAN REF

13 Verification of results with real core samples from a polluted well inside a tank. (75cm core sample cleaned by the ultrasonic push-pull transducer) Time in seconds Clean Dirty Sample Number Time in seconds for 1l to pass through fixed volume of gravel.

14 In-Situ testing and verification at a real well in Odense. Quantitative verification through high range turbidity sensor + Qualitative visual verification of cleaning effect using an underwater camera Camera Ultrasonic Probe Inner well tube Gravel pack

15 Turbidity and Video inspection results. 20 data 1 15 relative Turbidity in Tu units Time in minutes

16 Kerneboring til dokumentation af tilklogning af boring Grundvandets strømningsretning Indv. boring Test boringer

17 Sonic Drill Core sampling

18 Kerne prøver fra V3e Testsite Okkerforurenet grus i formationen begynder 7 m.u.vsp.

19 Mathematical modeling of sound propagation inside the well. Filter tube barrierer (signal loss ~70%)

20 Measurement of sound propagation inside water well (tank model) using Hydrophones: Compare to model wave maxima/minima every: / / 0.029

21 RESULTATER INDTIL VIDERE 1. Push-Pull sonden er ikke så egnet som hidtil antaget. 2. Energitabet fra sonde til-vand-til PVCrør til gruskastning er for stor > % 3. Behov for at skabe kontakt mellem sonde og boringsrør 4. Derved minskes tabet betydeligt 5. En prototype er udviklet 6. Målinger er foretaget med betydeligt forbedret resultat. 7. En fuldt opbygget prototype er ved at blive bygget og skal testes snarest.

22 Transducer Kontakt flade (stempel)

23 Improvements for intensity loss compensation Bevægelse af transducere mod foringsrør. Improved Accoustic bridge Transducer in direct connection to filter tube Advantage: Reduction of losses (no loss of intermediate layers between transducer and tube)

24 Stacking af enheder Planen er at placere en række lag med transducere monteret med 120 graders vinkel. Der skal minimum være 6 stk. eller multipler af 6. Dvs. 6, 12, 18 osv.

25 Currently ongoing Consisting of: - Pump test, before and after treatment - Turbidity measurement of pumped water - Hydrophone intensity measurement in different distances - Camera inspection during treatment

26 Special thanks to: For providing the most accurate in-situ MultiSense TuX High-Range Turbidity Sensor for the In-Situ turbidity measurements.

27 For further information or discussions please contact: Peer Locher, tlf.: , mobil VandCenter Syd as Johan Linderberg tlf , mobil Vandværksvej 7, 5000 Odense C Robert Brehm MCI, Mads Clausen Instituttet, 6400 Sønderborg, tlf.: , brehm@mci.sdu.dk Or visit: Project: >