Pump Basics

Centrifugal Pump

Schlumberger Private

Centrifugal Pumps Schlumberger Private

The term “centrifugal pump” has been used to describe a wide variety of pumping applications and designs throughout the years.

Centrifugal Pump

Schlumberger Private

The REDA centrifugal pump is a multistage pump, containing a selected number (application dependent) of impellers equipped with vanes, inside a closely fitted diffuser, located in series an axial shaft, driven by the electrical motor.

Centrifugal Pump

The impeller’s job is to transfer energy by rotation to the liquid passing through it, thus raising the kinetic energy.

Schlumberger Private

A centrifugal pump creates pressure by the rotation of a series of vanes in an impeller.

Centrifugal Pump

Schlumberger Private

The diffuser section then converts this energy to potential energy, raising the discharge pressure.

Centrifugal Pump

Schlumberger Private

From there, the rotation of the high-speed impeller throws the liquid into the diffuser.

Centrifugal Pumps

Upthrust Washer Impeller Down Thrust Washer Diffuser

Schlumberger Private

Each "stage" consists of an impeller and a diffuser. The impeller takes the fluid and imparts kinetic energy to it. The diffuser converts this kinetic energy into potential energy (head or pressure).

HEAD Head: The height to which the pump will "lift" the fluid

Schlumberger Private

• Curves for centrifugal pumps are normally shown as flow versus head in feet, meters, or some other consistent unit.

Maximum Head-Capacity 4.5" Casing 5.5" Casing 7" Casing

15000

10000

5000

0 0

10000

20000

Flow Rate - BPD (60 Hz)

30000

Schlumberger Private

Total Dynamic Head -Feet

20000

SN2600 60 HZ / 3500 RPM

REDA

Optimum Operating Range Nominal Housing Diameter Shaft Diameter Shaft Cross Sectional Area Minimum Casing Size

Rev. B

Pump Performance Curve

1600 - 3200 5.38 0.875 0.601 7.000

bpd inches inches in2 inches

538 Series - 1 Stage(s) - Sp. Gr. 1.00

Shaft Brake Horsepower Limit: Housing Burst Pressure Limit:

Standard High Strength Standard Buttress Welded

Feet

B.E.P. Q = 2581 H = 46.75 P = 1.31 E = 68.09

60

Hp Hp psi psi psi

Hp Eff 3.00 60%

2.50 50%

40

2.00 40%

30

1.50 30%

20

1.00 20%

10

0.50 10%

500

1,000

1,500

2,000

2,500

3,000

3,500

Capacity - Barrels per Day

From this curve we can determine the head produced, brake horsepower required and hydraulic efficiency at any flow rate.

4,000

Schlumberger Private

50

0

•

256 410 N/A 6000 6000

Impeller Thrust An Impeller has three forces acting on it.

Cross-Section of a Typical Impeller

Schlumberger Private

The sum of these three forces is the total thrust.

Impeller Thrust Gravity:

F=mA

Pressure:

F = Press x Area

Momentum: F = d(mass) x velocity + d(velocity) x mass

High Pressure

Low Pressure

d(time)

Schlumberger Private

d(time)

Impeller Thrust Pressure:

Low Pressure

High Pressure

Low Pressure Fluid

Balance Hole

Schlumberger Private

Balance Ring

By using a "balance ring" between the impeller and diffuser and drilling "balance holes" in the upper impeller skirt, we can recirculate lower pressure fluid over the majority of the upper surface.

Efficiency 100% Mechanical

Recirculation from Impeller Shape

Pump Output

Hydraulic Loss

Schlumberger Private

% Horse Power

Natural Leakage

0% 0%

Flow Rate

100%

Schlumberger Private

Schlumberger Private

Pump Descriptions and Names The series designations are defined as: Type

P

Outside Diameter

338 400 540 538 562 675 738 862 950 950 1125

DN 1300

3.38” 4.00” 5.13” 5.38” 5.63” 6.75” 7.25” 8.63” 9.5” 10.00” 11.25”

Minimum Casing Size 4 ½” 5 ½” 6 5/8” 7” 7” 8 5/8” 9 5/8” 10 ¾” 11 ¾” 11 ¾” 13 3/8”

Schlumberger Private

A D G S H J L M N

Series

Pump Descriptions and Names: • N = NiResist • V = Type 4 • Many other letters will be used to discribe the pump…

Schlumberger Private

• R = 5530

Pump Nomenclature: Frequently Used Terms Definition Abrasion Resistant: Zirconia bushings and sleeves Abrasion Resistant: Silicon Carbide sleeves Abrasion Resistant: Silicon Carbide bushing and sleeves Abrasion Resistant: Tungsten-Carbide sleeves Abrasion Resistant: Tungsten-Carbide bushings and sleeves Abrasion Resistant: Zirconia bushing bushings and Silicon sleeves Abrasion Resistant: Zirconia bushing bushings and Tungsten sleeves Compression Center Tandem Compression-Center Tandem Compression-Lower Tandem Compression Ring Compression Ring-Center Tandem Compression Ring-Lower Tandem Enhanced Stability Floater Floater-Center Tandem Floater-Lower Tandem Floater-Single section Hydraulic Balance Housing Single Stainless Steel Stainless Steel Head and Base Carbon Steel Monel Trim Redaloy Self Lubricating bearings (Graphalloy) High Strength Shaft

Schlumberger Private

Abbreviation ARZ ARZ-S ARZ-SS ARZ-T ARZ-TT ARZ-ZS ARZ-ZT C CT C-CT C-LT CR CR-CT CR-LT ES FL FL-CT FL-LT FL-S HB HSG S SS SS H and B CS M-Trim Rloy SLB HSS

Pump naming conventions DN1400 indicates: = 400 series, therefore, 4.0” in diameter

N = the material of the stage, in this case niresist. 1400 = the best efficiency flow rate (60 Hz : 3500 RPM) in barrels per day.

Schlumberger Private

D

Pump Construction

Floater - Type Compression - Type

Schlumberger Private

There are two types of pump stage construction for ESP oil field applications:

2 Types of Stage Construction Impeller Thrust

Floater

Protector Thrust Bearing Motor Thrust Bearing

Schlumberger Private

Compression

Pump Down Thrust Carried here

"Compression" Pumps In a compression pump, all the impellers are rigidly fixed to the shaft so that if an impeller wants to move up or down, it will take the shaft with it. Schlumberger Private

The impeller is normally sitting down on its lower diffuser during assembly due to gravity. Because of this, the pump shaft is "raised" with shims in the coupling so that the impeller is not allowed to touch the diffuser after final assembly. This allows all thrust developed in the pump shaft to be transferred to the protector shaft directly.

Pump Shimming

There is a small amount of free play in the coupling such that the pump shaft can fall down to where the impellers ride directly on the lower diffusers or on the downthrust washers if available.

Schlumberger Private

Impeller is in full down position

Pump Shimming Add shims so the impeller is

Shims placed in coupling to raise the shaft

Schlumberger Private

lifted slightly off diffuser.

Why use Compression Pumps? •

• •

•

washer in the stage. Some fluids (e.g. liquid propane) do not have enough lubricity to properly lubricate a thrust washer. If abrasives or corrosives are present, it may be beneficial to handle the thrust in an area lubricated by motor oil rather than well fluid. Occasionally in very gassy wells, the flow volume changes so drastically within the pump that parts of a floater pump could be in very severe thrust while others are not so a compression pump could be one alternative. Since all the thrust is handled in the protector, as long as the protector has a great enough capacity, the pump operating range can be extended over a much wider area without any increased wear or reduced life.

Schlumberger Private

•

Some stages generate too much thrust to be handled by a thrust

Centrifugal Pumps

Schlumberger Private

A radial flow (pancake) impeller has vane angels at close to 90 degree, and therefore, are usually found in pump ranges for lower flow rates.

Centrifugal Pumps Schlumberger Private

A mixed flow impeller has vane angels at close to 45 degree, and therefore, are usually found in pump ranges for higher flow rates.