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1
ASR Well Systems andFactory Pump Injection Testing:
Is This Necessary?Nathan Nutter, P.E.
Carollo Engineers, Phoenix, Arizona, USA
Gary M. Gin, R.G.City of Phoenix
City of Phoenix
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Vadose ZoneVadose Zone
Injection/StorageDuring
Off-PeakMonths
Injection/StorageDuring
Off-PeakMonths
AquiferAquifer
Aquifer Storage and Recovery (ASR) WellSummary: Dual Purpose Well System
Injection/Storage
3
RecoveryDuringPeak
Months
RecoveryDuringPeak
Months Vadose ZoneVadose Zone
AquiferAquifer
Aquifer Storage and Recovery (ASR) WellSummary: Dual Purpose Well System
Recovery
4
What is a Factory Pump Test?
• Measures PumpPerformance
– Flow vs. Friction Loss Pump Curve
– Flow at Design PressureHead (TDH)
– Pump Efficiency– Motor Horsepower– Shows Limits of
Operational Range andBest Operating Point
Efficiency
Pressure Head (TDH)
Horsepower
5
What is a Factory Injection Test?
• Measures PumpAssembly Losses
– Flow vs. FrictionLoss through BowlAssembly Injection Curve
PressureGauge (P1)
PressureGauge (P2)
6
Why Are Factory Injection Tests Critical forASR Wells?
• Accurately calculate injection hydraulics, ie, injectionrate at various pressures during recharge operation.
• Verify correct size of bowl assembly for injectionhydraulics.
• Advances programming by already knowing howvalve automation will work.
• Provides verification that air entrainment will notoccur during reverse-siphon start up upon first startup.
The Reverse Siphon Concept EliminatesAir Entrainment
To Distribution System
The Reverse Siphon Concept EliminatesAir Entrainment
To Distribution System
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Case Study – City of Phoenix, Arizona, USACave Creek ASR Well
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Line-shaft Turbine Pump
- 440ft (135 m) Static Water Level
Filter Pack
Well Statistics• 1,500 gpm Production
(8,200 m3/day)• 1,200 gpm Recharge
(6,500 m3/day)• 500 ft (150 m) TDH
Case Study – Cave Creek ASR Well
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Injection Testing Took Place at American-Turbine in Lubbock, TX
12
Our Team Identified Three Main Goals forthis Trip
1. Verify production hydraulics of the specified bowlassembly.
2. Verify injection hydraulics of the specified bowlassembly.
3. Test and determine viability of energy recovery byremoving backspin ratchet during injection testing…
….which I will cover if there’s enough time!
13
Our Team Identified Three Main Goals forthis Trip
1. Verify production hydraulics of the specified bowlassembly.
2. Verify injection hydraulics of the specified bowlassembly.
3. Test and determine viability of energy recovery byremoving backspin ratchet during injection testing.
14
Our Team Identified Three Main Goals forthis Trip
1. Verify production hydraulics of the specified bowlassembly.
2. Verify injection hydraulics of the specified bowlassembly.
3. Test and determine viability of energy recovery byremoving backspin ratchet during injection testing.
15
Static Water Level
The Original Bowl Assembly Proved to beOversized for Injection Operation
Injection Rate>Production Rate
180 ft (55 m) Air Gap
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Line-shaft Turbine Pump
- 440 ft (135 m) StaticWater Level
The Original Bowl Assembly Proved to beOversized for Injection Operation
- 260 ft (80 m) of Bowl Losses @1,200 gpm (6,500 m3/day)
- 180 ft (55 m) Air Gap @1,200 gpm (6,500 m3/day)
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A New Bowl Assembly Was Selected toMeet Production Requirements
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Static Water Level
New Bowl Assembly Provided AdequateBackpressure for Recharge Operation
160 ft (50 m) ofAdd’l Pressure
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0
100
200
300
400
500
600
700
800
0 200 400 600 800 1000 1200 1400 1600 1800 2000
Fric
tion
Loss
(ft)
Flow (gpm)
15" vs 12" Bowl Assembly (Ratchet Engaged)Injection Test
12-inch- 9 Stage 15-inch- 5 stage
Static Water Level
Comparison of Bowl Assemblies ShowsVariations in Injection Rates vs Pressure
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Three Main Goals for this Trip
1. Verify production hydraulics of the specified bowlassembly.
2. Verify injection hydraulics of the specified bowlassembly.
3. Test and determine viability of energy recovery byremoving backspin ratchet during injection testing.
21
Three Main Goals for this Trip
1. Verify production hydraulics of the specified bowlassembly.
2. Verify injection hydraulics of the specified bowlassembly.
3. Test and determine viability of energy recovery byremoving backspin ratchet during injection testing.
22
The Backspin Ratchet was Removed toDetermine the Efficacy of Energy Recovery
• Removed Ratchet.• Conducted injection bowl performance testing to determine
if flow through bowls was adequate for operation.
23
Static Water Level
The Unratcheted Bowl Assembly Did NotAllow Adequate Flow
Enough Headloss;Adequate Flow
Never ReachesDesired Flow Rate!
24
Static Water Level
The Original Bowl Assembly Would HaveWorked for Energy Recovery
Not EnoughHeadloss
Enough Headloss
25
Does Energy Recovery Make Sense for theCave Creek ASR Well?
• There was too much headloss through the final bowlassembly, and it was determined that water in theground was more important than energy savings thatcould be had.
• Payback was calculated to be between 15-25 years,based on duty cycle of well.
• Running shaft backwards for long periods of time mayadversely affect or shorten the life of the well pump.
26
Three Main Goals for this Trip
1. Verify production hydraulics of the specified bowlassembly.
2. Verify injection hydraulics of the specified bowlassembly.
3. Test and determine viability of energy recovery byremoving backspin ratchet during injection testing.
27
Injection Test Conclusions• Provides great accuracy of injection hydraulics, which gives a high
level of confidence to the client about how their system will work.
• Cost is reasonable ($5,000 - $7,000).
• The manufacturer is already doing the production test, so it’sreasonable to run it the other way.
• Verifies the elimination of air entrainment prior to first injection startup.
• Verifies the correct size of bowl assembly for injection hydraulics.
• Advances programming by already knowing how valve automationwill work.
• Has proven that reverse-siphon is viable for very deep pump settingsand deep water tables.
28
Contact Information
Nathan Nutter, P.E.Carollo Engineers, Inc.
4600 E. Washington St, Suite 500Phoenix, AZ 85034
Gary M. Gin, R.G.City of Phoenix
Water Services Department200 West Washington St. 8th Floor
Phoenix, AZ [email protected]
602-495-5654