JP_Chapter 02

8/12/2019 JP_Chapter 02

1/11

Hydraulic Jet Pumps Mohamed ewidar

1

Chapter 02

Hydraulic Jet Pumps

Surface equipment package for hydraulic pumpingapplications.

It provides complete fluid conditioning as well as a surface pump to providepressurized power fluid to the down-hole pump.

It is designed for continuous operation and will perform satisfactorily when properlyset, adjusted and maintained. Periodic inspections and repairs will be required.The end-user of the equipment must determine the intervals of inspections.

System Description

The fluid and gas Check Valve received from the producing well are fluids from theformation and fluids that have been used to power the down-hole hydraulic pumpwhich have been co-mingled down hole.

Check valve

The fluids first enter the package through a check valve normally furnished bythe user of the equipment.

Accumulator Surge Vessel

The first entrance of fluids into the unit itself will be at the accumulator surgevessel (25) (vertical separator). See the drawing below.

The purpose of the accumulator surge vessel (25) is to prevent excess gasfrom entering the cyclone desander (9) causing cyclone desander inefficiency.The vertical separator also serves as a surge chamber should the vessel besubjected to a high-pressure kick from the well. It prevents the surge frombeing transmitted to the cyclone desander and the conditioning vessel.

Surge Control Valve

The surge control valve (13) is set to open whenever a high-pressure surge issensed at the valve inlet (i.e. at the accumulation surge vessel). The valve isnormally set to open at a differential pressure of 40 psi. It can be adjusted tosense other differentials if required.

If too much fluid is being by-passed in front of the cyclone desander (9) withthe surge valve (13) set to open at 40 psi differential, the surge valve (13) may

8/12/2019 JP_Chapter 02

2/11


2

be set for a higher differential pressure ( up to 45 psi ). This will by-pass lessfluid through valve (13) and direct more fluid through the cyclone desander (9).

If no fluid or gas is being by-passed with the surge valve (13) is set to open ata differential of 40 psi, the surge valve (13) may be set to open at a lower

differential pressure ( 35 psi minimu m ) so that gas and some liquid will by-pass the cyclone desander.

The surge control valve can be converted to a back-pressure regulator byisolating the pressure source to the top of the valve diaphragm and looseningthe adjusting screw sealing nut. When a back pressure greater than 60 psi isrequired, a stronger spring must be installed.

Cyclone Desander

The cyclone desander is considered to be the very heart of the 9Unit. Withoutexcellent solids separation, unnecessarily short pump runs and excessivemultiplex maintenance will result.

The cyclone desander(s) (9) must be sized to effect maximum solid particleseparation and furnish essentially clean fluid for the surface power fluid pump(29) and the down-hole hydraulic pump.

The solids separated by cyclone desander (9) are discharged downwardthrough the cyclone desander underflow and can be viewed through visualsight glass (22).

The clean power fluid passes from the top (overflow) of the cyclone desander

(9), through the cyclone desander outlet valve (20) and on into the fluidconditioning vessel (24) for further separation of gas, oil, and water.

Fluid Conditioning Vessel

The retention time of the power fluid in the conditioning vessel is not reallylong enough for any appreciable settling of solids particles from the fluids, somost solids separation must be done by the cyclone desander. This is whatmakes proper installation, sizing, monitoring and operation of the cyclonedesander so important to the entire system operation.

Once the hydraulic system is operating, fluid in excess of that required by thesurface and subsurface pumps is discharged from fluid conditioning vessel(24) through manual selector valve (3) (high outlet) for oil discharge, orthrough valve (4) (low outlet) for primarily water discharge.

The amount of fluid discharge from conditioning vessel (24) is controlled bythe pressure differential between conditioning vessel (24) and flow linepressure.

8/12/2019 JP_Chapter 02

3/11


3

The level of liquids in the conditioning vessel is maintained at a high enoughlevel to supply the multiplex with adequate clean fluid.

Safety Valves

The Unit is equipped with two safety valves. There is a conditioning vesselsafety valve (10) and an accumulator safety valve (14). Each valve is set toprovide over-pressure protection for the vessels.

CAUTIONS

Never pipe the safety relief outlets backinto the flow line. If a downstream valve isclosed or the flow line plugs the wholesystem will be over pressured, possiblyresulting in a ruptured vessel.

The safety valves are factory set to meetvessel specifications and are sealed. Theyare not to be adjusted in the field.

Power Fluid Pump

Fluid from the conditioning vessel is supplied to the surface power fluid pump(29) (multiplex pump) which provides pressurized liquid to operate thesubsurface hydraulic pump. The power fluid pump is powered by an electricmotor, diesel, or gas engine.

Pulsation Dampener

A pulsation dampener (32) is installed near the multiplex discharge todissipate "fluid hammer" in the system which can develop due to the pulsatingmultiplex output.

If the pressure fluctuations from the multiplex are not damped out, the fluidhammer can become severe enough to actually break the wellheadconnections.

As the pulsating shock waves travel farther from the pump, the reflecting

shock wave becomes amplified. These amplified pulsations, if not dampedout, will also reflect back into the fluid power pump destroying the pump. Forthis reason the pulsation dampener must be located as close as possible tothe multiplex discharge.

8/12/2019 JP_Chapter 02

4/11


4

Manual By-pass Valve

The power fluid manual by-pass valve (15) regulates the volume of power fluidwhich is diverted from the down-hole pump and circulated back into the Unitas excess power fluid.Since the multiplex displacement is greater than the volume required tooperate the subsurface hydraulic pump, some fluid must be by-passed. Theamount by-passed fluid must be adjustable so that the volume of injectedpower fluid can be varied to regulate the hydraulic pumping speed.

Control Panel

The control panel is a standard oil-field type Murphy panel with indicators andlimit controls for safety, start up, operation, and shut down.

Component Description

Accumulator Surge Vessel

The accumulator surge vessel (25) provides ample storage capacity in the eventthe well "heads-up" with gas. It separates the gas and cushions abnormallyhigh pressure surges.

Surge Control Valve

The surge control valve (13) will open when the valve inlet receives a high surgeof pressure.

When the volume of fluid processed is great enough to cause a 40 psi pressureloss across the cyclone desander (9) the surge valve (13) will open and excessgas and fluid will be removed from the accumulator surge vessel (25). Thisresults in a fluid level near the vessel top.

The valve may also be set for other differential pressures.

Cyclone Desander

The cyclone desander (9) cleans the fluid so it can be used in the pumps. Thefluid must be cleaned sufficiently to prevent excessive wear to the surfacemultiplex pump and the sub-surface hydraulic pump.

Fluid Conditioning Vessel

The fluid conditioning vessel is a storage container which separates the oil,water and gas.

Fluid in excess of that required by the surface and sub-surface pumps isdischarged from the vessel through valve (3) for oil discharge or valve (4) forwater discharge.

8/12/2019 JP_Chapter 02

5/11


5

When the pre-set fluid level reaches approximately 5 inches from top of the fluidconditioning vessel, the fluid is passed into an over-flow line outside the vessel.The overflow is routed to a pipe leading to the flow line and lease tank battery.

Vessel Safety Valves

The fluid conditioning vessel safety valves (10 & 14) prevent excessive pressureinside each of the vessels.

Throttle Valve

The manual throttle valve (21) beneath the cyclone desander underflow willcontrol the fluid flow when properly adjusted. If the underflow fluid is very dirty ittends to plug the opening, therefore the valve must be opened as fully aspossible.

If too much fluid is lost from the system the valve must be partly closed.Caution must be exercised to prevent complete plugging which will cause thedirty fluid to go into the remainder of the system and contaminate the system.

By-pass Valve

Manual by-pass valve (15) allows high-pressure fluid to be bypassed andreturned to the low-pressure system. This valve controls the volume of fluidfrom the multiplex pump to the subsurface hydraulic pump.

The manual by-pass valve (flow control valve) is a manually-variable, orifice-

type valve. The orifice consists of slots formed in a tungsten carbide sleeve withopenings controlled by moving an integral carbide plug inside the sleeve to thedesired position. The integral plug uncovers or covers the orifice slots allowinga greater or lesser volume of fluid to exit the by-pass valve (15) into the by-passline.

As more power fluid is by-passed, less fluid is injected down hole, slowing thepump strokes on a piston pump and reducing the operating pressure on a jetpump.

The flow control valve (15) is a simple device which gives few problems in

actual operation. The volume of by-passed fluid will remain very stable as longas there are no great pressure fluctuations in the system.

Safety Valve

The safety valve (11) prevents excessive pressure in the power fluid lineconnected to the well head and protects the pump and motor from excessiveoverload.

8/12/2019 JP_Chapter 02

6/11


6

Motor

The motor (gas, diesel, or electric powered) provides power to the multiplexpump. Operation and maintenance manuals for the motor are provided by themotor manufacturer.

Multiplex Pump

The surface power fluid multiplex pump (29) provides pressurized fluid to thesubsurface hydraulic pump.

The pump shaft is properly aligned with the motor shaft and connected througha flexible coupling at the factory. However, it is necessary to check the gap andangular alignment after final installation on the job site.

Control Panel

The control panel (12) is a standard oil-field type Murphy indicating and limitcontrol for safe start-up, operation and shut-down.

The control panel is mounted off of the unit skid to prevent vibrations fromcausing control panel malfunctions.

The limit controls must be properly set, adjusted and maintained to assureadequate protection of personnel, equipment, and property.

8/12/2019 JP_Chapter 02

7/11


7

Major Component Identification

1. Multiplex pump high level suction valve.2. Multiplex pump low level suction valve.3. Conditioning vessel high level outlet valve.

4. Conditioning vessel low level outlet valve.9. Cyclone desander.10. Conditioning vessel safety relief valve.11. Multiplex pump discharge safety relief valve.12. Control panel.13. Well surge control valve.14. Accumulator surge vessel safety relief valve.15. Power fluid manual by-pass control valve.16. Manual valve.18. Manual valve.

19. Desander inlet manual valve.20. Desander outlet manual valve.21. Desander underflow manual valve.22. Desander underflow visual flow sight glass.23. Conditioning vessel drain manual valve.24. Conditioning vessel.25. Accumulator surge vessel.26. Accumulator surge vessel pressure gauge.27. Conditioning vessel pressure gauge.29. Power fluid pump (multiplex).30. Electric motor, diesel, or gas engine.31. Chemical injection pump.32. Multiplex pump discharge pulsation dampener

5.0 Power oil Tank and Accessories.

A typical power oil treating system which has proven adequate for most openpower oil systems when "stock tank" quality oil is supplied, is illustrated in Figurebelow.

The following paragraphs cover the functions of important components and

recommended piping instructions for the power oil treating system.

9.1 Tank Construction

The power oil settling tank in this system is usually a 24-foot high, three-ring, bolted steel tank. A tank of this height generally will provide adequatehead for gravity flow of oil from the tank to the intake of the charge pump.

8/12/2019 JP_Chapter 02

8/11


8

If more than one plunger pump is required for this system, individual poweroil tanks can be set for each pump, or a single large tank can be used;whichever is most economical and best meets the operating requirements.

Ideal tank size would be large enough to allow for 24 hours settling time.

This means that oil entering the tank would arrive at the suction or themultiplex pump 24 hours later.The tank should be positioned between the heater treater and the stocktanks, so that total lease production comes across the power oil tank,ensuring that the power oil tank is full at all times.

There should be two suction connections in the tank, one high and one low.High suction, the cleanest oil in the tank, is for normal operation. Lowsuction is for emergency.

At the time of construction, a bypass line should be installed directly

between the treater and the stock tanks by-passing the power oil tank foruse in emergencies.

Standard Power Oil Facility Always check sizes and capacities of lease treaters. Over-loaded treaterswill not do a thorough job of separating oil from water. This condition willshow up in the power oil tank.

8/12/2019 JP_Chapter 02

9/11


9

Also check operation of water dump leg on treaters. These have beenknown to malfunction dumping everything to the pit, thereby pumping poweroil tank dry.

9.2 Gas Boot

The gas boot is essentially a part of the power oil tank. The purpose of theboot is to provide final gas-oil separation so that the oil will be stable atatmospheric pressure.

If the gas is not sufficiently separated from the oil, entrained free gas canenter the settling tank and destroy the settling process by causing the fluidin the tank to roll.

The following piping specifications for the gas boot are necessary to insureundisturbed settling.

o The gas boot inlet height should be 4 feet above the top of the settlingtank. This will allow the incoming fluid to fall. The resulting agitation willencourage gas-oil separation.

o The top section of the gas boot should be at least 3 feet in diameter and8 feet higher than the top of the settling tank. These two factors willprovide a reservoir that should absorb the surges.

o The gas line out of the top of the boot should be tied into the settling tankand stock tank vent line. Should the gas boot become overloaded,thereby kicking fluid over through the gas line, this arrangement willprevent the raw or settled fluid from being dumped in the top of thesettling tank. If this occurs, it may contaminate the oil drawn off to themultiplex.

o The line connecting the gas boot to the settling tank should be at least 4inches in diameter. This is necessary to minimize restrictions to flowduring surge loadings of the boot.

9.3 Spreader

Oil entering a large tank at the bottom and rising to be drawn off the toptends to channel from the tank inlet to the outlet. This is true because thechanneling fluid moves more rapidly than the rest of the fluid in the tankwhich remains relatively undisturbed.

The purpose of the spreader is to reduce the velocity of the incoming fluidby distributing the incoming volume over a large area. This allows the fluidto rise upward at a more even rate.

The type of spreader recommended consists of a round flat plate,approximately a half of the diameter of the tank. (See Figure 5-4) It should

8/12/2019 JP_Chapter 02

10/11


10

have a 4-inch skirt, which has 60-degree, triangular "saw-tooth" slots cut init. The slots provide automatic opening adjustment for varying amounts offlow. It is essential that the slots be cut to a uniform depth to obtain an evendistribution of flow.

This type spreader must be installed with the tops of all the slots in a levelplane to prevent fluid from dumping out under a high side.The spreader should be mounted about 2 feet above the bottom rim of thetank.

Although this type spreader is relatively expensive, it will give satisfactoryspreading of flow with a minimum of trouble and maintenance.

9.4 Stock Oil Take-off and Level Control

The location of the stock tank take-off and level control is important in that itestablishes the effective settling interval of the settling tank and controls thefluid level in the power oil tank.

All fluid coming from the spreader rises to the stock tanks. Fluid risingabove this level is only that amount required to replace the fluid withdrawnby the plunger pump.

The stock take-off point should be located within six feet of the spreader.The height to which the stock oil must rise in the piping to overflow into thestock tank determines the fluid level in the settling tank. For this reason, thelevel control should be placed a minimum of 18 inches from the top of thesettling tank. The diameter of piping used should be sufficient to providenegligible resistance for the required volume of flow.

The extension at the top of the level control is connected to the gas line toprovide a vent which keeps oil in the settling tank from being siphoned downto the level of the top of the stock tank.

9.5 Power Oil Outlets

The power oil outlet should be located on the opposite side of the settlingtank from the stock take-off outlet to balance the flow distribution within the

tank.Since the fluid level in the tank is maintained approximately 18 inches fromthe top of the tank, the upper outlet should be located 3 feet below the top ofthe tank. This will ensure the oil level will be above the outlet at all times.

The second, or emergency, power oil outlet should be located below theupper outlet for use in starting up or filling tubing strings. The location of

8/12/2019 JP_Chapter 02

11/11


11

this outlet will depend on estimated emergency requirements and thecapacity per foot of tank. A distance of 7 feet from the top of the tank isusually sufficient.

This lower outlet line contains a shut-off valve which is to be kept closed

during normal operations in order that the full settling interval will be used.

JP_Chapter 02

Documents

Transcript of JP_Chapter 02