Reciprocating Rod Lift
Rotaflex Long-Stroke Pumping Unit
®
The Rotaflex unit is Weatherford’s long-stroke
pumping unit for sucker-rod pumps. Using proven
technology and design innovations, the unit
provides greater efficiency and cost effectiveness
for pumping deep, troublesome, and high-volume
wells; and with the Rotaflex unit, sucker-rod
pumps can be used for applications where electric
submersible or hydraulic subsurface pumps were
once required.
Long pump stroke (up to 366 in., or 9.3 m)
and virtually no minimum speed provide more
complete pump fillage and lower dynamic loading.
Dynamometer cards run on Rotaflex applications
are similar to a theoretically perfect card. Pumping
with the Rotaflex unit reduces stress on equipment
because the rod string is operated at relatively
constant velocities. Constant velocity and fewer
strokes per barrel increase the life span of the
pumping unit, downhole pump, and rod string.
Servicing a well with the Rotaflex unit is safe
and simple. After the bridle and carrier bar are
disconnected from the polished rod, the Rotaflex
unit rolls away from the wellhead without any
disassembly. After a workover is completed, the
unit is rolled back into place, and the carrier bar
is reconnected to the polished rod.
Applications
• High-volume and high-load wells
• Deviated and horizontal wells
• Wells that experience frequent downhole
equipment failures
• Operations requiring energy savings
Weatherford International Ltd.
515 Post Oak Blvd., Suite 600
Houston, Texas 77027 USA
Tel: 713-693-4000
www.weatherford.com
© 2007 Weatherford. All rights reserved.
843.02
Reciprocating Rod Lift
Rotaflex Long-Stroke Pumping Unit
®
Features, Advantages and Benefits
• Extended stroke length and unique design make the Rotaflex
unit significantly more efficient than other pumping units.
Savings in energy costs typically range from 15 to 25 percent.
• Constant velocity and fewer strokes per barrel increase the
life span of the pumping unit, downhole pump, and rod string.
• Extended stroke length allows for fewer cycles and reversals,
resulting in increased system efficiency and reliability.
• Long pump stroke and virtually no minimum speed provide
more complete pump fillage and lower dynamic loading.
• The Rotaflex unit is shipped in one piece for ease of service
and installation.
• Longer downhole stroke provides better pump compression
ratio to help eliminate gas-lock problems.
• The unique mechanical reversing mechanism is proven in the
field for over 20 years.
• Long-life, heavy-duty load belt, used to link the power train to
the rod string, acts as a shock absorber, effectively reducing
stress on the entire system.
Downstroke Position
• The short radius of the torque arm markedly reduces required
torque demand and allows the use of a smaller prime mover
and gear reducer, which are less expensive to buy and operate.
Upstroke Position
Weatherford International Ltd.
515 Post Oak Blvd., Suite 600
Houston, Texas 77027 USA
Tel: 713-693-4000
www.weatherford.com
© 2007 Weatherford. All rights reserved.
843.02
Reciprocating Rod Lift
Rotaflex Long-Stroke Pumping Unit
®
Specifications
Model
900
Reducer torque (in.-lbf, kN•m)
Stroke length (in./m)
Maximum polished rod weight (lb/kg)
Maximum speed* (spm)
1100
1150
1151
320,000
36.16
288
7.3
420,000
47.45
306
7.8
366
9.3
36,000
16,329
4.50
Minimum speed (spm)
50,000
22,680
4.30
3.64
3.75
No absolute minimum
Weight of counterweight assembly
(lb/kg)
9,400
4,264
9,800
4,445
Auxiliary counterweight (lb/kg)
21,980
9,969
30,200
13,698
Total weight (lb/kg)
31,380
14,234
40,000
18,144
Unit dimensions, L × W × H, (ft/m)
21.8 × 7.8 × 40.5
6.64 × 2.38 × 12.34
23.8 × 8.5 × 44.5
7.25 × 2.59 × 13.56
23.8 × 8.5 × 49.5
7.25 × 2.59 × 15.09
23.8 × 8.5 × 49.5
7.25 × 2.59 × 15.09
Unit shipping size, L × W × H, (ft/m)
40.5 × 7.8 × 9.0
12.34 × 2.38 × 2.74
44.5 × 8.5 × 10.5
13.56 × 2.59 × 3.20
49.5 × 8.5 × 10.5
15.09 × 2.59 × 3.20
49.5 × 8.5 × 10.5
15.09 × 2.59 × 3.20
42,900
19,459
52,300
23,723
53,880
24,440
55,000
24,948
466.0 × 50.0
11.84 × 1.27
466.0 × 50.0
11.84 × 1.27
Unit shipping weight (lb/kg)
24.0 × 8.5
7.32 × 2.62
Base dimensions, L × W (ft/m)
29,000
13,154
Base weight (lb/kg)
–40° to +140°
–40° to +60°
Working temperature (°F/°C)
Load belt dimensions, L × W (in./m)
Load belt tensile strength, PIW (lb/kg)
Automatic brake system
390.0 × 42.0
9.91 × 1.07
406.0 × 50.0
10.3 × 1.27
10,000
4,536
Yes
*Higher speeds are attainable with variable frequency drive, increasing production by as much as 25%.
Weatherford International Ltd.
515 Post Oak Blvd., Suite 600
Houston, Texas 77027 USA
Tel: 713-693-4000
www.weatherford.com
© 2007 Weatherford. All rights reserved.
843.02
Reciprocating Rod Lift
Rotaflex Long-Stroke Pumping Unit
®
Options
• Weatherford’s hydraulically powered Rotaflex rollback system for moving and repositioning the Rotaflex
long-stroke pumping unit is available for new installations of Rotaflex long-stroke pumping units and can
also be retrofitted to previously installed pumping units.
• Gas-engine extensions.
• Wire-mesh safety fences.
• Variable frequency drive.
Weatherford International Ltd.
515 Post Oak Blvd., Suite 600
Houston, Texas 77027 USA
Tel: 713-693-4000
www.weatherford.com
Weatherford products and services are subject to the Company’s standard terms and conditions, available on request
or at www.weatherford.com. For more information contact an authorized Weatherford representative. Unless noted
otherwise, trademarks and service marks herein are the property of Weatherford. Specifications are subject to change
without notice. Weatherford sells its products and services in accordance with the terms and conditions set forth in the
applicable contract between Weatherford and the client.
© 2007 Weatherford. All rights reserved.
843.02