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AE School Pump Sizing Rev. 4.0

5/12/00

Pump Sizing

Pump Sizing Exercise By the end of this section, you should be able to: • Demonstrate how to read a typical pump performance curve. • Demonstrate how to calculate the number of stages required to meet the desired lift • Demonstrate how to calculate the Brakehorsepower required

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AE School Pump Sizing Rev. 4.0

5/12/00

Basic Pump Sizing Example • The first step to sizing a pump is to gather all the data to understand the objectives of the application and to perform the necessary studies and calculations to achieve the desired flow rate.

2000 bpd Pump Sizing • As an example, let's say we have a 9-5/8" casing well with which we want to produce 2000 BPD. We are told that we will need a pump with a total lift of 1850 feet. We will have 60 Hz power available. What do we need to do?

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AE School Pump Sizing Rev. 4.0

5/12/00

2000 bpd Pump Sizing • We must review the curves in the catalog within the desired flow rate. • Look in the catalog to see what pumps are available which will produce 2000 bpd. For 60 Hz power, we will use the 3500 RPM curves. Note: If the power were 50 Hz, we would use the 2917 RPM curves.

2000 bpd Pump Sizing Series - O.D.

Pump Type

Monel Shaft Max BHP

Shaft Size

Recommended Capacity @ 60 Hz 3 ( BPD) (M /D)

DN280 D400 DN440 DN525 DN675 D950 DN1000 DN1100 DN1300 D1400 DN1750 DN1800 DN2150 DN3000 DN3100 DN4000

44 94 94 94 94 125 125 125 125 125 125 125 125 256 256 256

0.50 0.625 0.625 0.625 0.625 0.687 0.687 0.687 0.687 0.687 0.687 0.687 0.687 0.875 0.875 0.875

100 200 100 300 325 600 700 600 800 900 1200 1200 1400 2000 2400 3400

-

450 550 550 625 850 1150 1250 1350 1600 1850 2050 2400 2600 3700 4000 5200

16 32 16 48 52 95 111 95 127 143 191 191 223 318 382 541

-

72 87 87 99 135 183 199 215 254 294 326 382 413 588 636 827

GN1600 GN2100 GN2500 G2700 GN3200 GN4000 GN5200 GN5600 GN7000 GN10000

256 256 256 256 256 375 375 375 375 637

0.875 0.875 0.875 0.875 0.875 0.995 1.00 1.00 1.00 1.187

1200 1650 1800 2000 2200 2500 3900 4000 5000 7000

-

2000 2500 3100 3400 4150 5000 6600 7500 9000 12000

191 262 286 318 350 398 620 636 795 1113

-

318 398 493 541 660 795 1049 1193 1431 1908

"G" series pump is 5.13 inches in diameter 400 Series - O.D. 4.00

513 Series O.D. 5.13

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AE School Pump Sizing Rev. 4.0

5/12/00

2000 bpd Pump Sizing DN1750 - 60 Hz

Head in Feet 35

DN2150 - 60 Hz

Head in Feet 40

30 30

25 20

20

15 10

10

5 0

0

500

1000

1500 Flow Rate - BPD

2000

2500

3000

GN1600 - 60 Hz

Head in Feet

0

60

50

50

40

40

30

30

20

20

10

10 0

500

1000

1500 Flow Rate - BPD

2000

500

2500

3000

0

0

1000

1500 2000 Flow Rate - BPD

2500

3000

GN2100 - 60 Hz

Head in Feet

60

0

0

500

1000

1500 2000 Flow Rate - BPD

2500

3000

3500

General Sizing Tips: • What do we do with that many choices? We could size all and compare them but that might take more time than we have. Consider ways to cull them before going too far.

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AE School Pump Sizing Rev. 4.0

5/12/00

Bigger Diameter is almost always better: Advantages: • Usually More Efficient

Disadvantages: • Lower Maximum Pressure

• Usually Less Expensive

• Can Interfere w/ Y-Tool

• Better in Gas & Viscosity

• More Downthrust

• Handles Higher HP

General Sizing Tips: • Based on this, let's eliminate the "D" series pumps since they are smaller diameter.

Now compare the GN1600, GN2100 and GN2500.

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AE School Pump Sizing Rev. 4.0

5/12/00

2000 bpd Pump Sizing GN1600 - 60 Hz

GN2100 - 60 Hz

Head in Feet

Head in Feet

GN2500 - 60 Hz

Head in Feet

60

60

50

50

50

40

40

40

30

30

30

20

20

20

10

10

10

60

0

0

500

1000

1500

2000

2500

3000

Flow Rate - BPD

0

0

500 1000 1500 2000 2500 3000 3500

Flow Rate - BPD

0

0

500

1000 1500 2000 2500 3000 3500

Flow Rate - BPD

2000 bpd Pump Sizing • Note that the GN1600 only supplies about 35 feet per stage while the GN2100 supplies 45 feet per stage and the GN2500 supplies 46.1 feet per stage. This means that the GN2100 and GN2500 will take fewer stages to do the job. • Note also that the GN2100 would be operating closer to the middle of the recommended range which means that this pump will be more efficient.

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AE School Pump Sizing Rev. 4.0

5/12/00

2000 bpd Pump Sizing GN1600 - 60 Hz

GN2100 - 60 Hz

Head in Feet

Head in Feet

GN2500 - 60 Hz

Head in Feet

60

60

50

50

50

40

40

40

30

30

30

20

20

20

10

10

10

60

0

0

500

1000

1500

2000

2500

3000

Flow Rate - BPD

0

0

500 1000 1500 2000 2500 3000 3500

Flow Rate - BPD

0

0

500

1000 1500 2000 2500 3000 3500

Flow Rate - BPD

2000 bpd Pump Sizing • The fewer stages and better efficiency will most likely mean that the GN2100 will be less expensive to purchase as well as to operate so let's use it.

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AE School Pump Sizing Rev. 4.0

5/12/00

2000 bpd Pump Sizing • Note the head per stage is about 45 feet.

GN2100 - 60 Hz

Head in Feet 60 50 40 30 20 10 0

0

500

1000

1500 2000 Flow Rate - BPD

2500

3000

3500

• But how does this apply to our example? Remember that we wanted a pump to give 1850 feet of head. We now know the GN2100 we have chosen will provide 45 feet per stage.

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AE School Pump Sizing Rev. 4.0

5/12/00

2000 bpd Pump Sizing 1850 feet -------------- = 41 stages 45 ft/stage This means we will need a 41 stage GN2100 to do the job.

2000 bpd Pump Sizing Note that the BHP/stage is about 1.05 BHP per Stage 1.1

1

0.9

0.8

0.7

0.6

0

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500

1000

All

1500 2000 Flow Rate - BPD

2500

3000

3500

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AE School Pump Sizing Rev. 4.0

5/12/00

2000 bpd Pump Sizing 1.05 BHP/stage * 41 stages = 43 Horsepower This means that the pump will require 43 horsepower to do the job.

2000 bpd Pump Sizing • In Summary: We ended up with a 41 stage GN2100 which will draw 43 horsepower. That's all there is to sizing a pump.

By the way, what is the efficiency?

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AE School Pump Sizing Rev. 4.0

5/12/00

2000 bpd Pump Sizing • In Summary: Remember that Flow * Head * γ η = --------------------BHP * 135,771

For this pump, η = 63.4% compared to 63.4% for the GN2100

Sizing Comparison: • The GN1600 is 56.2% efficient and requires 48.5 Hp • The GN2500 is 59.8% efficient and requires 45.6 Hp • The GN2100 is 63.4% efficient and requires 43 Hp In three cases we have calculated the horsepower necessary to "run" the pump. How much energy (horsepower) is each pump actually supplying to the fluid?

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AE School Pump Sizing Rev. 4.0

5/12/00

Sizing Comparison: η = work out/work in • For the GN1600: 56.2% = work out / 48.5 Hp ⇒ Work Out = 27.3 Hp • For the GN2500: 59.8% = work out / 45.6 Hp ⇒ Work Out = 27.3 Hp • For the GN2100: 63.4% = work out / 43 Hp ⇒ Work Out = 27.3 Hp As you can see, regardless of what type of pump we use, the energy required to pump the fluid is constant

Sizing Comparison: • For the GN1600: 48.5 Hp − 27.3 Hp = 21.2 Hp missing • For the GN2500: 45.6 Hp − 27.3 Hp = 18.3 Hp missing • For the GN2100: 43 Hp − 27.3 Hp = 15.7 Hp missing Where did it go?

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AE School Pump Sizing Rev. 4.0

5/12/00

Sizing Comparison: • We can see that, as predicted, the GN1600 and GN2500 are less efficient so they will require a larger motor to be purchased as well as more electricity to run them. Additionally the GN1600 pump took more stages (52 compared to 41) so will probably be a more expensive pump. • The GN2100 is a better sizing.

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13

Pump Selection  

PUMPS SELECTION