JP_Chapter 03

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Hydraulic Jet Pumps Mohamed ewidar

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Chapter 03

Hydraulic Jet Pumps

TROUBLESHOOTING

1.0 Normal SPM, Pressure down, and Low or Zero Production

This condition usually indicates that the pump plunger has become

disconnected from the middle rod. The cause can be a broken middle rod or an

unscrewed plunger.

The loss of pressure is the key to this situation. In hydraulic-pumping there aretwo areas exposed to pressure: the pump plunger being exposed to discharge

hydrostatic pressure, and the engine piston being exposed to power fluid

pressures. If the plunger area is lost, the power fluid pressure loss will be

equivalent to the plunger area.

This condition can also indicate a leaking traveling valve ball and seat, a leaking

standing valve ball and seat, worn plunger rings, a split pump barrel, ruptured

seating cups, or a leaking tubing standing valve.

In each case, some (or all) of the pump fluid load is lost and less pressure is

required to run the engine.

2.0 Not Stroking, Pressure up

This condition usually indicates an engine malfunction, such as foreign material

getting in the engine valve, or excessive wear. It can be a stuck pump plunger,

however. In a jet pump, pressure build up indicates a plugged nozzle.

Sometimes it is possible to correct this condition by "bouncing" the pump. To

bounce the pump, reverse the four-way valve to "pump-out". As soon as the

pump unseats, quickly switch to "pump-in" so the force of the fluid will make the

pump hit bottom with some force.If it is necessary to hit the pump harder, unseat as before and pump the pump

up the hole for one minute. Reverse to pump-in and close the casing valve.

After pressure builds to about 700 psi, open the casing valve quickly.

If this does not help, there is no alternative except to surface the pump.

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hydrostatic load off the packer rubber. It will also reduce the total

string weight.

3.2 Pump Unseats but Won't Surface

If the pump shows a visible unseat, but will not surface after a proper

length of time, chances are that the swab cups on the retriever are blownout, the standing valve is not holding, or there is some obstruction in the

tubing such as parrafin. This can be checked out, but may get involved.

3.2.1 Standing Valve, Packer or Casing Failure

If it can be determined, by gauging the power fluid tank or a loss

of fluid in the conditioning vessel, that power fluid is being lost in

the hole. If that is the case, the standing valve, packer, or casing

is not holding.

In this circumstance, it will be necessary to fish both the pump andthe standing valve. Visual inspection of the standing valve will

show fluid cuts if the valve is leaking.

3.2.2 Retrieval

The pump can possibly still be retrieved without a rig.

Make up a fishing tool, using a pump retrieving tool and a solid-

type nose, 2-cup swab nose. Pump this into the tubing for the

required amount of time, and it will probably bring the pump back

with it.

The pump can be surfaced without swab cups at a pumping rate

of 3 BPM down the casing annulus if the standing valve is OK.

3.3 Pump Doesn't Unseat/No Pressure Buildup

In pump out operations where there is no indication of pump unseat and

pressure cannot be developed, there can be several reasons, all of them

bad.

3.3.1 Hole in Tubing

A hole in the tubing string is probably the easiest to detect. Thereshould be no returns back through the tubing string until the pump

unseats. Therefore, if the pump doesn't unseat and there are

returns on the tubing side, then fluid is going from the casing to

the tubing at some point above the pump. This would not involve

any loss of power fluid in the hole.

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3.3.2 Power Fluid Loss

If loss of power fluid loss is detected, it could be caused by:

a packer leak,

a hole in the casing, or

damage to the outside diameter of the standingvalve seat

3.4 Increased Power Fluid/No increase in Speed

If the pump will not increase speed no matter how much power fluid is

put in the hole:

First make sure that the multiplex, by-pass, four-way valve,

and suction pressure are OK.

If they are OK, the cause can be a worn out engine on the

pump, a damaged cavity seal collar, pump seals blown, or

a high pressure tubing leak.

To correct the situation, change out the pump. If this doesn't improve the

situation, then it's a tubing job to correct either of the other two

possibilities.

The tubing can be tested using a dummy pump.

4.0 System Shut-Down

First, it is necessary to determine cause of shut-down. If the system is equipped

with a tattletale panel (which the Econodraulichas) then the problem can be

readily determined. If this equipment is not available, then all possible reasons

must be checked out individually.

4.1 Visual Check

Some faults are obvious and may be detected with a visual inspection.

Check all lines for breaks. Spillage will be noticeable. Line

breaks between the multiplex pump and the well can cause

a low-discharge shut down.

Check power fluid level in tank. Loss of fluid between the

tank and multiplex will cause low-suction shut down.

Check multiplex oil level, engine oil level, and engine

temperature switch. If it is the temperature switch, it may

take a while after start-up to detect it.

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Check the manifold by-pass after start up. If manifold by-

pass is involved it could cause a low discharge shut-down.

4.2 High Pressure Check

After all these points have been cleared up, start the engine, or motor,

being sure high shutdown is set and operable.

Open the by-pass valve fully and kick the clutch in.

Close the by-pass valve slowly while watching the high-pressure switch.

If the pressure goes up past normal operating range and the pump is not

stroking, be sure there is no valve closed in the line.

Go to the manifold and compare gauge readings with the safety switch.

Then go to the well head and check the gauge against the other two.

If all three gauge references are approximately the same, it is likely that

the sub-surface pump is stuck. This would result in a high-pressure shut-

down.

4.3 Multiplex Pump

A common cause of low suction or low discharge shut-down lies in

multiplexes themselves. Be sure that all three plungers are operable.

Often a plunger will stick and shear. Displacement suffers and low

discharge shut-down is the result. Abnormal suction cavitation (fluid

starvation) will cause low shut-down.

4.4 Valve Check

If these checks do not reveal the reasons for low volumes, it is necessary

to check the valves. In checking volumetric efficiency of multiplex

pumps, the following procedure is used:

Check multiplex RPM's

Check plunger size

Calculate rated displacement, from above

Check actual displacement through the power fluid meter.

If actual displacement is under 85 percent of rated

displacement, then appropriate action should be taken.

4.5 Power Fluid Tank Check

In checking lease facilities, one of the most common occurrences is loss

of power fluid from the tank.

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Be sure the power fluid tank by-pass line is closed.

Some power fluid tanks are equipped with what is called a "siphon" line,

which is actually only an emergency overflow line to the stock tanks to

prevent the power fluid tank from running over. It is situated just above

normal power fluid tank level, but usually has a down-comer inside. Ifthis line is not vented, it can become a true siphon and steal fluid from

the power fluid tank to the stock tanks.

If you are involved in construction of new power fluid tanks, always be sure there is a small hole

drilled in the top of the elbow, inside the tank, where the down-comer screws in. This will

sometimes avoid refilling the power fluid tank.

4.6 Down-Hole Problems

4.6.1 Low Discharge Shut Down

A low discharge shut down can also be caused by: a broken middle rod in the down-hole pump,

a bad four-way valve,

a hole in the tubing,

blown or leaking seating cups, or

a bad down-hole pump.

4.6.2 High Discharge Shut DownA high discharge shut down can be caused by:

blockage in the four-way valve.

a plugged nozzle in the jet pump.

paraffin build up in the tubing.

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Hydraulic Pumping Systems

Troubleshooting Guide

Indication Cause Remedy

1. Increased operating

pressure

a. Valves closed a. Check valves for proper open

position.

b. Line crimped at unit or at

well

b. Check lines for swabbing.

2. Sudden increase in

operating pressure -

piston pump stroking/jet

pump producing

a. Valves partially or fully

closed

a. Check valves for proper open

position. Check lines for

swabbing.

b. Paraffin build-up orobstruction in power line,

flow line, or valve

b. Run soluble plug, scraper,hot oil, or remove obstruction

c. Pumping heavy material,

such as salt water or

mud

c. Keep pump operating. Do

not shut down

3. Gradual increase in



pump producing

a. Valve closed

b. Gradually lowering fluid

level. Standing valve or

formation plugging up

c. Slow build up of paraffin

d. Increase in water

production

a. Check valve for full open

b. Surface pump and inspect

c. Run soluble plug, scraper, or

hot oil

d. Raise SPM on piston

pump/increase pressure on

jet pump

4. Erratic stroking at widely

varying pressure

Failure or plugging of

engine

Surface pump and repair

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5. Sudden increase in


piston pump not pump

stroking/jet inoperable

a. Valve closed

b. Piston pump stuck or

stalled/jet pump plugged

c. Sudden change in well

conditions requiring

operating pressure in

excess of multiplex relief

valve setting

d. Sudden change in

power fluid emulsion

e. Obstruction in

production line

a. Check valve positions.

b. Piston Pump

Alternately increase and

decrease pressure. If

necessary, unseat and

reseat pump. If this fails to

start pump, surface pump

and repair.

Jet Pump

Surface and remove

obstruction from nozzle.c. Gradually raise setting on

relief valve.

d. Check power fluid supply

e. Locate obstruction and

correct

6. Stroke "down-kicking"

instead of "up-kicking"

a. Well pumped off - pump

speeded up.

b. Pump intake or down-

hole equipment plugged

c. Pump failure (balls and

seats)

a. Decrease speed. Consider

changing to smaller pump

end.

b. Surface pump and clean.

Pull standing valve and

thoroughly back flush.

c. Surface pump and repair.

7. Gradual or sudden

increase in power fluid

required to maintain

piston pump speed/jet

pump pressure. Low

engine efficiency.

a. Engine wear

b. Leak in tubulars, power

fluid tubing, bottom hole

assembly, seals, power

fluid line, or four-way

valve

a. Surface pump and repair

b. Locate leak and repair

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8. Sudden decrease in



pump producing

a. Rising fluid level - pump

efficiency up

b. Failure of pump seal

allowing part of power

fluid to be by-passed

c. Gas passing through

pump

d. Tubular failure down

hole or in surface powerfluid line

e. Broken middle rod.

Increased speed

f. Seal sleeve in bottom

hole assembly washed

or failed. Speed

reduced.

g. Four-way valve leaking

a. Speed up piston

pump/increase jet pump

pressure to get desired

production

b. Surface pump and repair

seal

c. Run a gas anchor, check gas

line for obstructions.

d. Check tubulars - run adummy pump to pressure up

tubing string. Loss of

pressure indicates leakage.

e. Surface pump and repair

f. Pull tubing and repair bottom

hole assembly.

g. Repair or replace four-way

valve

9. Well not producing -

pressure increase - pump

stroking

a. Engine plugging

b. Flow line plugged

c. Broken middle rod

d. Suction plugged

a. Surface pump and repair.

b. Locate restriction in flow line

and remove.

c. Surface pump and repair.

d. Pull standing valve

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10. Apparent loss of, or

unable to account for,

system fluid

a. System not full of fluid

when pump was started;

due to water in annulus

U-tubing after

circulating, well flowing,

or standing valve,

casing, or packer

leaking.

b. Inaccurate meters or

measurement

c. Leaking valve, powerfluid, production line, or

packer

d. Effect of gas on

production metering

a. Continue pumping to fill up

system. Pull standing valve

if pump surfacing is slow and

cups look good. Run

isolation sleeve to check

casing and packer.

b. Check meters. Repair if

necessary.

c. Locate leak and repair.

d. Improve gas separation.

11. Sudden decrease in


pump not stroking

a. Pump not on seat

b. Failure of production unitor external seal

c. Bad leak in power fluid

tubing string

d. Bad leak in surface

power fluid line

e. Not enough power fluid

a. Circulate pump back onto

seat

b. Surface pump and repair

c. Check tubing. Pull and

repair if leaking.

d. Locate and repair leak.

e. Check volume of fluiddischarged from multiplex.

Check for valve failure,

plugged supply line, low

power fluid supply, excess

by-passing, etc., all of which

could reduce available volume.

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12. Drop in production -

piston pump speed

constant/jet pump

pressure constant

a. Failure of pump end of

production unit

b. Leak in gas vent tubing

string

c. Well pumped off- pump

speeded up

d. Leak in production

return line

e. Change in wellconditions

f. Pump or standing valve

plugging

g. Pump handling free gas

h. Jet pump mixing tube

cavitated

a. Surface pump and repair

b. Check gas vent system

c. Decrease pump speed

d. Locate leak and repair

e. Adjust SPM, check systemand well.

f. Surface pump and check.

g. Test to determine best

operating speed

h. Surface pump and repair

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Power Fluid Plunger Pumps

Troubleshooting Guide


1. Knocking or pounding influid end and piping

a. Suction line restricted by:

1) Trash, scale build-

up, etc.

2) Partially closed

valve in suction line

3) Meters, filters, not

fully opening check

valves, cut-offvalves or other

restrictions

4) Sharp 90-degree

bends or 90-degree

blind tees

1) Locate and remove.

2) Locate and correct

3) Rework suction line to

eliminate

4) Rework suction line to

eliminate

b. Air entering suction line

through valve stem

packing

b. Tighten or repack valve

stem packing

c. Air entering suction line

through loose connection

or faulty pipe

c. Locate and correct

d. Air or vapor trapped in

suction line

d. Locate rise or trap and

correct by straightening

line. Provide enough

slope to permit escape of

air and prevent build up.

e. Low fluid level e. Increase supply and install

automatic low-level shut-

down switch

f. Suction Damper not

working

f. Inspect and repair as

required.

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1. (continued) g. Worn pump valves or

broken spring

g. Provide gas boot or

scrubber for fluid

h. Inadequately sized

suction line

h. Replace with individual

suction line of next size

larger than inlet of pump.

i. Leaking pressure relief

valve that has been piped

back into pump suction

i. Repair valve and rework

piping to return to supply

tank, not to suction line

j. Bypass piped back to

suction

j. Rework to return by-

passed fluid to supply

tank, not to supply line.

k. Broken plunger k. Inspect when rotating

pump by hand and replace

as required.

l. Worn cross head pin or

connecting rod

l. Locate and replace as

required.

2. Knock in power end a. Worn cross head pin or

connecting rod

a. Locate and replace as

required. Check oil quality

and level.

b. Worn main bearings b. Replace as required.

Check oil quality and level.

c. Loose plunger,

intermediate rod, or cross

head connection

c. Inspect for damage.

Replace as required and

tighten.

3. Rapid valve wear or failure a. Cavitation is a

predominant cause of

short valve life. Usually

the result of poor suction

conditions.

a. Improve suction conditions

b. Corrosion b. Treat fluid as required

c. Abrasives in fluid c. Treat to remove harmful

solids.

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4. Fluid seal plunger wear,

leakage or failure1

a. Solids in power fluid are

likely to cause the greatest

amount of wear.

a. Analyze power fluid for

amount and type of solids

content. Treat to removesolids

b. Improper installation

c. Poor lubrication

b. Follow written instructions

and use proper tools.

Remember plunger and liner

are matched sets. Assure

proper lubrication at start up.

(Be sure air is bled out of

fluid before starting up.)

c. Check lubrication.

5. Reduced volume or pressure a. Bypassing fluid a. Locate and correct.

b. Air in fluid end of multiplex b. Bleed off air.

c. Inaccurate meter or

pressure gauge

c. Check and correct.

d. Pump suction cavitation due

to improper hook up, suction

restriction or entrained gas

d. Locate and correct.

e. Valves worn or broken e. Test and replace

f. Plungers and liners worn f. Replace

g. Reduced prime mover

speed due to increased

load, fuel or other

conditions2

g. Determine cause and

correct.

1The plunger sleeve is secured to the mandrel by a self-locking set screw, which is a safety device against

unexpected over loading from galling, seizing, or misalignment. The set screw is designed to break under theseconditions to prevent serious overloads on the power end of the triples. Screw breakage is usually an indicationof solids in the power fluid or of inadequate lubrication.

2May be increased pressure due to paraffin, temperature change, etc.

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