Thrust Bearing LowerSeals and Upper Seals and · centrifugal pumps; i.e, 100-200 BPD. Again without...
Transcript of Thrust Bearing LowerSeals and Upper Seals and · centrifugal pumps; i.e, 100-200 BPD. Again without...
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Rod String Drive
Transmission
Upper Seals and
Compensator
TransmissionLower Seals and
Thrust Bearing
Pump
Rod String Drive
Pay ZoneGas Anchor
Drive Head
Drive Rod String
Receiver Section
Upper Seals and
Compensator
LowerSeals and
Thrust Bearing
Transmission
Pump
Intake Stinger
Pay Zone
Drive Head
The Geared Centrifugal Pump
• A mechanically driven centrifugal pumping system.
• Rod string drives an ESP pump via a 7:1 gearbox increasing speed from 500 to 3500 RPM.
• No electrical components down hole.
• ESP capacity with better efficiency.
What is the GCP?
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Rod String Drive
Transmission
Upper Seals and
Compensator
TransmissionLower Seals and
Thrust Bearing
Pump
Rod String Drive
Pay ZoneGas Anchor
Drive Head
Drive Rod String
Receiver Section
Upper Seals and
Compensator
LowerSeals and
Thrust Bearing
Transmission
Pump
Intake Stinger
Pay Zone
Drive Head The Geared Centrifugal Pump
GCP Components from the Bottom up
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1
2
2
3
3
4
4
5
5
6
6
7
7
• Pump intake stinger
• Centrifugal pump
• Lower seal section with thrust bearing
• Transmission
• Upper seal, compensator
• Receiver
• Tubing with a guided rod string
• Drive head8
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Rod String Drive
Transmission
Upper Seals and
Compensator
TransmissionLower Seals and
Thrust Bearing
Pump
Rod String Drive
Pay ZoneGas Anchor
Drive Head
Drive Rod String
Receiver Section
Upper Seals and
Compensator
LowerSeals and
Thrust Bearing
Transmission
Pump
Intake Stinger
Pay Zone
Drive Head
The Geared Centrifugal Pump
• A bottom intake pump – better gas handling
• Fluid load is carried by the tubing.– Axial rod load is the buoyant rod
weight so side loads are small.
– Load on drive head thrust bearing reduced
– Issue: rod rotational instability at bottom due to low string tension.
• Transmission – Multi-stage parallel shaft transmission
– Unique PHG gearing provides high power in a small diameter.
Unique Traits of the GCP
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The Geared Centrifugal Pump Transmission
Before and after load is imposed
Before
After
Paired Helical Gearing - Operation
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The Geared Centrifugal Pump Transmission
GCP Single-Stage prototype input spline shaft strain gauge torque – four gear-pair first stage.
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0
100
200
300
400
500
600
700
800
900
1000
10 11 12 13 14 15 16 17 18 19
Time, seconds
Bridge 2
Bridge 3
Bridge 4
Bridge 5
`
Torq
ue, ft-lbs
4321
1 Input, 920 ft-lbs
2
3
4 220 ft-lbs
680 ft-lbs
440 ft-lbs
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Geared Centrifugal PumpTransmission Gear Train Layout
1st Stage (PHG)
3rd Stage5th Stage
4th Stage
2nd Stage
Input
Output
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The Geared Centrifugal Pump
Transmission - large D-channels for fluid flow
Rod String Drive
Transmission
Upper Seals and
Compensator
TransmissionLower Seals and
Thrust Bearing
Pump
Rod String Drive
Pay ZoneGas Anchor
Drive Head
Drive Rod String
Receiver Section
Upper Seals and
Compensator
LowerSeals and
Thrust Bearing
Transmission
Pump
Intake Stinger
Pay Zone
Drive Head
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Rod String Drive
Transmission
Upper Seals and
Compensator
TransmissionLower Seals and
Thrust Bearing
Pump
Rod String Drive
Pay ZoneGas Anchor
Drive Head
Drive Rod String
Receiver Section
Upper Seals and
Compensator
LowerSeals and
Thrust Bearing
Transmission
Pump
Intake Stinger
Pay Zone
Drive Head
The Geared Centrifugal Pump
• D-tube flow channels provide
excellent cooling of gears and
bearings
• Forced lube oil circulation reduces
oil degradation due to stagnation
• Forced oil circulation prevents
overheating during gas lock or
pump-off.
• Modular construction – allows easy
modification of transmission
Other Transmission Features
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The Geared Centrifugal Pump
GCP Rate Potential
• Same rate potential as an ESP with
equal HP rating
• Nominal depth limit is 10,000 feetGeared Centrifugal Pump
Fluid Rate vs. Depth
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1000
2000
3000
4000
5000
6000
7000
8000
9000
0 1 2 3 4 5 6 7 8 9
Pump Depth, '000 feet
Flu
id R
ate
, B
FP
D
150 HP
100 HP
75 HP
200 HP
Rod String Drive
Transmission
Upper Seals and
Compensator
TransmissionLower Seals and
Thrust Bearing
Pump
Rod String Drive
Pay ZoneGas Anchor
Drive Head
Drive Rod String
Receiver Section
Upper Seals and
Compensator
LowerSeals and
Thrust Bearing
Transmission
Pump
Intake Stinger
Pay Zone
Drive Head
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Geared Centrifugal PumpField Installation and Testing
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Rod String Drive
Transmission
Upper Seals and
Compensator
TransmissionLower Seals and
Thrust Bearing
Pump
Rod String Drive
Pay ZoneGas Anchor
Drive Head
Drive Rod String
Receiver Section
Upper Seals and
Compensator
LowerSeals and
Thrust Bearing
Transmission
Pump
Intake Stinger
Pay Zone
Drive Head
The Geared Centrifugal Pump
• Installed May 19, 2010 in West Texas waterflood producer. Replaced ESP.
• ESP
– 450 series 60 HP, 156 stage FC1200
– 1150 BFPD, 98% WC
– 100% motor load
– ESP overall efficiency = 45 %
• GCP
– 575-100, 87 stage G17 pump
– 1550 BFPD, 98% WC
– GCP overall efficiency > 50%
– Mechanical efficiency = 79.5%
GCP Field Installation
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Geared Centrifugal Pump - Downhole Test
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Rod String Drive
Transmission
Upper Seals and
Compensator
TransmissionLower Seals and
Thrust Bearing
Pump
Rod String Drive
Pay ZoneGas Anchor
Drive Head
Drive Rod String
Receiver Section
Upper Seals and
Compensator
LowerSeals and
Thrust Bearing
Transmission
Pump
Intake Stinger
Pay Zone
Drive Head
The Geared Centrifugal Pump
GCP Field Trial Results
• Performance – GCP efficiency was
higher that expected.
• No problems installing or operating
the GCP.
• Unit has run 18 months at time of
writing
Second 575-100 GCP run in a well in
New Mexico, January 18, 2011. 14
GCP Rod String Test Apparatus
• Test the effect of RPM, rod tension, well inclination and stabilizer spacing on rod stability
• Single 25 foot 1” drive rod inside 3-1/2” water-filled tubing
• Hydraulic drive 0 to 1100 RPM, variable tension up to 12,000 lbs
• Rod stability monitored via lasers and multiple view ports in tubing
• Rig inclination variable from 0 deg. (vertical) and 85 deg.
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GCP Rod String Test Apparatus
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• Over 1000 test measurements
• At 0 tension and 500 RPM, rods require three stabilizers per rod for stable rotation
• Only one stabilizer per 25’ rod is required above 650 feet from bottom at 500 RPM
• Rods stable with one stabilizer per rod at 800 RPM above 850 feet from bottom.
• Well inclination has only a minor effect on rod stability
• Stable, smooth rod string drive for the GCP is easily achievable
GCP Rod String TestingResults
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High Temperature GCP
• Initial reason for developing the GCP was for Conoco-Phillips’ Alberta, Canada SAGD project.
• SAGD project requires 2500 - 4000 BFPD at 250 deg. C.
• Current 575-100 GCP has high temperature transmission, thrust bearing, and pressure compensator design.
• Conversion to high temperature service requires only changing materials (steel, elastomers, lubricant)
• Full assembly high temperature testing beginning in March. First field installation expected in 3rd quarter of this year.
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• Full GCP assembly testing, including
short rod string
• 3000 B/D rate at 3000 psi and 250º C.
• 125 HP drive motor with VSD
• Monitor input torque, RPM, inlet and
discharge pump pressures and
temperatures, and flow rate
• All principal controls and data
collection in remote location
High Temperature GCP
Test Loop
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Rod String Drive
Transmission
Upper Seals and
Compensator
TransmissionLower Seals and
Thrust Bearing
Pump
Rod String Drive
Pay ZoneGas Anchor
Drive Head
Drive Rod String
Receiver Section
Upper Seals and
Compensator
LowerSeals and
Thrust Bearing
Transmission
Pump
Intake Stinger
Pay Zone
Drive Head
• Bottom intake pump provides better gas handling than ESP.
• ESP rates at lower cost and better efficiency (especially in 5-1/2” casing).
• Estimated power cost savings of 10-15% over an equivalent ESP system
• Utilizes the best part of an ESP – the pump; eliminates the worst –the down-hole electric motor and cable.
• Utilizes the best part of a PCP system eliminates the worst – the elastomer PCP stator exposed to wellbore fluids and varying conditions.
Advantages of the GCP
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Rod String Drive
Transmission
Upper Seals and
Compensator
TransmissionLower Seals and
Thrust Bearing
Pump
Rod String Drive
Pay ZoneGas Anchor
Drive Head
Drive Rod String
Receiver Section
Upper Seals and
Compensator
LowerSeals and
Thrust Bearing
Transmission
Pump
Intake Stinger
Pay Zone
Drive Head
• High temperature application -currently testing a 575-100 for 250º C (482º F).
• Surface drive – electric, IC, or hydraulic motor. Simple, inexpensive ‘speed change, just change the sheave .
• If a VSD is required, it is a less expensive VSD than an ESP VSD, no sine wave filter and the surface package requires no step-up transformer.
• No downhole electrical components
Advantages of the GCP
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Rod String Drive
Transmission
Upper Seals and
Compensator
TransmissionLower Seals and
Thrust Bearing
Pump
Rod String Drive
Pay ZoneGas Anchor
Drive Head
Drive Rod String
Receiver Section
Upper Seals and
Compensator
LowerSeals and
Thrust Bearing
Transmission
Pump
Intake Stinger
Pay Zone
Drive Head
• The system can ride through a gas-lock condition no concerns with burning up a motor.
• The system can deploy low flow rate centrifugal pumps; i.e, 100-200 BPD. Again without the concern of cooling a downhole electric motor.
• Can be operated on single phase power.
• Less expensive installation; no cable spooling, no banding.
• Fewer pump changes in a dewatering cycle.
Advantages of the GCP
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Rod String Drive
Transmission
Upper Seals and
Compensator
TransmissionLower Seals and
Thrust Bearing
Pump
Rod String Drive
Pay ZoneGas Anchor
Drive Head
Drive Rod String
Receiver Section
Upper Seals and
Compensator
LowerSeals and
Thrust Bearing
Transmission
Pump
Intake Stinger
Pay Zone
Drive Head
• Can be deployed with a standard PCP type downhole pressure/temperature gauge.
• A cost effective alternative to large mechanical pumping systems: i.e., 640/912/1280 pumping units, tubing pumps .
Advantages of the GCP
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