JP_Chapter 01

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Hydraulic Jet Pumps Mohamed ewidar

Chapter 01

Hydraulic Jet Pumps

1.0 General

Jet Pumps are very important members in family of hydraulic pumps.

Production and power fluid rates in Jet Pumps are controlled by a nozzle/venturi

arrangement. Different geometry configurations are used for controlling the

clearance between the nozzle and mixing tube orifices, as specified by a

computer, to attain proper production rates.

2.0 Advantages

Jet Pumps have no moving parts, they are especially attractive because of

low maintenance costs, long runs, and either high or low volumes. Usually,

the main point of failure will be either a nozzle or mixing tube, either of which

may be easily replaced, even at the well site.

Jet Pumps are available in 2-inch, 2.5-inch, 3-inch and 4-inch sizes, in

standard materials or premium materials to fit almost every competitive

bottom-hole assembly.

Jet Pumps are of the free-pump concept, which incorporate all the

advantages previously listed for free pumps.

Capable of handling extremely high volumes. Adjustable to varying production rates.

Low maintenance costs.

Pressure and temperature recording devices may be used as an integral

addition to the pump

Suitable for low gravity and high-pour-point crude oils.

Adaptable for use with a sliding sleeve.

Can be run in crooked holes.

Handles gassy production

Handles solids and corrosive fluids

3.0 Limitations

Producing Rate Relative to Bottomhole Pressure

Some Require Specific Bottomhole Assemblies

Lower Horsepower Efficiency

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4.0 How it works

1. Power fluid is pumped at a given rate (QN) to the down-hole jet pump

where it reaches a nozzle with a total pressure, designated as PN. This

high-pressure fluid (high potential energy) is then directed through thenozzle, which converts the fluid stream to a high velocity (high kinetic

energy) and low static pressure.

2. The low pressure (PS) allows well fluids to flow into the well bore and

pump at the desired production rate (QS). The high-momentum power fluid

is then mixed with the low-momentum production in a constant area

mixing tube. It is in this mixing process that energy is transferred from the

power fluid to the production. When the combined fluids reach the end of

the mixing tube, they are at a low pressure and high velocity.

3. The fluid then exits the pump through a diffuser section which converts thefluid to a high-static-pressure, low velocity state. This high discharge

pressure (PD) must be sufficient to lift the combined fluid rate (QD) to the

surface.

4. The key components of the jet pump are the nozzle and mixing tube

(throat). The area of the openings in these parts determines the

performance characteristics of the pump. These areas are designated as

ANand AT.

5. The ratio of these areas, AN/AT, is referred to as the area ratio. Pumps

with the same area ratio have the same performance curve.

6. The volume of power fluid used will be proportional to the size of the

nozzle.

7. The sizes of nozzles and throats determine the flow rate while the ratio of

their flow areas determines tradeoff between produced head and flow rate.

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8. If, for example, a throat is selected such that the area of the nozzle is 60%

of the throat area, a relatively high head, low flow will result. There is a

small area around the jet for well fluids to enter, leading to low production

rates.9.

10. If, on the other hand, a throat is selected such that the area of the nozzle

is 20% of the throat area, more production flow is possible, but, since the

nozzle energy is being transferred to a large amount of production, lower

head will be developed.

11. The cavitation characteristics of the pump must be considered, cavitation

will occur when the velocity of the produced fluids entering the throat

around the power fluid jet is high enough that static pressure in the fluid

falls to its vapor pressure. This will choke the flow and damage the throat.

5.0 Selecting a Pump

The Jet Pump selected to produce a well must have a capacity large enough to

obtain the rate of production the well is capable of producing. At the same time,

the required surface horsepower must be kept at a reasonable level.

The task of selecting the proper jet pump involves finding a pump geometry

capable of achieving the production rate, but capable of operating within given

horsepower requirements, or at an optimum horsepower.

The calculations on the following pages will provide the information necessary

to select the correct pump for any application.

6.0 Jet pump design step by step

1. From well data for production, QS, and pump intake pressure, PSand GOR,

calculate the minimum annular area to avoid cavitations.

2. From the table of annular area, select nozzle and throat combination which

has an annular area greater than A SM

3. Calculate the pressure at the nozzle, PN, which is the sum of the operatingpressure (known from the available Pump [triplex or horizontal pump]) plus

the hydrostatic pressure in the tubing minus friction losses in the tubing.

4. The friction in the annular or tubing can be determined from.

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Annular flow Tubing flowD1 Casing I.D Tubing I.D

D2 Tubing O.D 0

5. Determine the power fluidrate, QNfrom,

6. Determine the returned flowrate, QD,

7. Determine the production gradient (pump suction),

8. Determine the returned flow fluid gradient, GD,from,

9. Calculate the returned flow WC, WCD

10. Calculate the returned flow gas liquid ratio, GLR,

11. Determine the returned flow liquid viscosity for calculating friction loss, D

from,

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12. Calculate the pump discharge pressur PD pressur which is the sum of

hydrostatic pressure in the reurn conduit, the friction losses, and the well

head back pressure,

13. Calculate N(dimensionless pressure recover ratio) from,

14. Calculate M(dimensionless mass flow ratio) from,

15. Calculate N (dimensionless pressure recover ratio), for the value of R

selected, using of Mfrom step 11

16. Compare the current value of N with the N value from step 13. if the

difference is less than 0.5%,iteration is completed go to step 19otherwise

go to step 17.17. If the required is power fluid pressure, calculate new nozzle pressure from

equation,

Then go to step 5

18. If the required is PIP, calculate it from the equation,

Then go to step 3

19. Determine the new surface operating pressure (triples) from equation,

20. Calculate the maximum non-cavitating flow from equation,

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21. Calculate triplex HP assuming 90% efficiency from the equation,

7.0 Glossary

AN= Nozzle flow area in2

AS= Throat annulus area (AT-AN) in2

ASM= Minimum throat annulus area to avoid cavitation in2

AT= Throat flow area in2

D = Vertical depth of well ft

D1= ID of tubing or casing in

D2= OD of inner tubing in annular flow in

GD= Gradient of returned mixed power fluid and producing fluid psi/ft

GLR = Returned flow gas liquid ratio scf/bbl

GN= Power fluid gradient at nozzle psi/ft

GO= Produced oil gradient psi/ft

GOR = Gas oil ratio scf/bbl

GS= Water gradient psi/ft

KN = Nozzle loss coefficient

KTD = Throat-diffuser loss coefficient

L = Tubing length ft

M = Dimensionless mass flow rateN = Dimensionless pressure recovery ratio

PD= Pump discharge pressure psi

PF= Friction loss in tubing psi/ft

PFN= friction loss in power fluid tubing psi/ft

PFD= Friction loss in returned conduit psi/ft

PN= pressure at nozzle interance psi

PS= pump suction pressure (Pwf) psi

PT= Surface operating pressure (triplex pressure) psi

PWH= Well head pressure psi

QD= Flow rate from pump discharge bpd

QG= Flow rate of gas through pump bpd

QN= Flow rate through the nozzle bpd

QS= Producing flow rate bpd

QSC= Minimum non-cavitating pump suction flow rate bpd

R = Nozzle throat areas ration (AN/AT)

WC = Water cut (decimal)

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WCD= Returned flow water cut

D= Returned fluid viscosity cp

O= Viscosity of oil cp

W= Viscosity of water cp

Guiberson AN, AT, AS, and R as Example:

Nozzle

A

Throat 1 2 3

1R 0.38 0.29 0.23

AS 0.0088 0.0134 0.0186

A+

Throat 1 2 3 4 5

2R 0.52 0.4 0.31 0.24 0.2

AS 0.0068 0.0114 0.0166 0.0239 0.0305

B

Throat 1 2 3 4 5 6

3R 0.66 0.5 0.39 0.3 0.25 0.21

AS 0.0048 0.0094 0.0146 0.0219 0.0285 0.0357

B+

Throat 1 2 3 4 5 6 7

0.04R 0.76 0.58 0.45 0.35 0.29 0.24 0.21

AS 0.0034 0.008 0.0132 0.0205 0.0271 0.0343 0.0422

C

Throat 1 2 3 4 5 6 7

5R 0.86 0.65 0.51 0.39 0.32 0.27 0.23

AS 0.002 0.0066 0.0118 0.0191 0.0257 0.0329 0.0408

C+

Throat 2 3 4 0.05 6 7 8

6R 0.79 0.62 0.48 0.39 0.33 0.28 0.23

AS 0.0039 0.0091 0.0164 0.023 0.0302 0.0381 0.0511

D

Throat 3 4 5 6 7 8 9

7R 0.73 0.56 0.47 0.39 0.33 0.27 0.22

AS 0.0064 0.0137 0.0203 0.0275 0.0354 0.0484 0.0627

E

Throat 4 5 6 7 8 9 10 11

8R 0.77 0.63 0.53 0.45 0.36 0.3 0.25 0.2

AS 0.0073 0.0139 0.0211 0.029 0.042 0.0563 0.0721 0.0954

F

Throat 6 7 8 9 10 11 12

9R 0.69 0.59 0.48 0.39 0.33 0.26 0.22

AS 0.0138 0.0217 0.0347 0.049 0.0648 0.0881 0.1138

G

Throat 8 9 10 11 12 13 14

10R 0.68 0.56 0.47 0.38 0.31 0.26 0.21

AS 0.0209 0.0352 0.051 0.0743 0.1 0.132 0.1713

H

Throat 10 11 12 13 14 15 16

11R 0.69 0.55 0.46 0.37 0.31 0.25 0.21

AS 0.0301 0.0534 0.0791 0.1111 0.1504 0.1945 0.2466

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I

Throat 11 12 13 14 15 16 17

12R 0.72 0.59 0.48 0.39 0.33 0.27 0.23

AS 0.034 0.0597 0.0917 0.131 0.1751 0.2272 0.2895

J

Throat 13 14 15 16 17 18 19

13R 0.71 0.58 0.48 0.4 0.34 0.28 0.23

AS 0.0515 0.0908 0.1349 0.187 0.2493 0.3256 0.4167

K

Throat 15 16 17 18 19 20

14R 0.61 0.51 0.42 0.35 0.29 0.24

AS 0.1016 0.1537 0.216 0.2923 0.3834 0.4928

L

Throat 16 17 18 19 20

15R 0.63 0.52 0.43 0.36 0.3

AS 0.1164 0.1787 0.255 0.3461 0.4555

M

Throat 17 18 19 20

16R 0.66 0.55 0.45 0.38

AS 0.1287 0.205 0.2961 0.4055

N

Throat 18 19 20

17R 0.69 0.57 0.48

AS 0.1396 0.2307 0.3401

P

Throat 19 20

18R 0.71 0.59

AS 0.1576 0.267

Throat Nozzle

No. Area Nom. Area1 0.0143 A 0.0055

2 0.0189 A+ 0.0075

3 0.0241 B 0.0095

4 0.0314 B+ 0.0109

5 0.038 C 0.0123

6 0.0452 C+ 0.015

7 0.0531 D 0.0177

8 0.0661 E 0.0241

9 0.0804 F 0.0314

10 0.0962 G 0.0452

11 0.1195 H 0.0661

12 0.1452 I 0.0855

13 0.1772 J 0.1257

14 0.2165 K 0.159

15 0.2606 L 0.1963

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16 0.3127 M 0.2463

17 0.375 N 0.3117

18 0.4513 P 0.3848

19 0.5424

20 0.6518

JP_Chapter 01

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