Schneider elelc Chenai CII EE -Hemant
Transcript of Schneider elelc Chenai CII EE -Hemant
Energy Efficiency in On shore Exploration- Oil Pumping Application
Beam pump Controller
Contents• Beam pump general
• Regeneration control
• ENA System
• Speed control for Beam Pumps and
related problems
• Speed control algorithm
• HMI and messaging
Beam pump – Lay-out
Plunger
Up Stroke
Down Stroke
Polished RodStuffing Box
Rod String
Beam
Alternative Position
Sensor Location
Position SensorMotor
Crank
Counter Balance Weights
Gearbox
Electrical Enclosure
Travelling Valve
Horse Head
Standing Valve
Reservoir
Sucker Rod Pump Assembly
Beam Pump Controller
Challenges• Regenerative energy during parts of the pumping
cycle
• Ever changing well conditions require complex speed regulation algorithm.
• Extreme climatic conditions.
• High starting torque, due to eccentric load
• Retro fit applications make extensive equipment modifications difficult and application specific
Beam Pump Issues/Problems
Changing Well conditions• Pumps are installed and geared up to
match the well conditions, ensuring 100% pump fill per stroke
• Well capcatity reduces over time resulting in incomplete filling.
• This results in ineficency and severe mechanical deteriation.
• Fluid Pound
•Gas Lock
ATV71 – ENA SYSTEM
Regeneration occurs during stroke direction transition
Zero torque limit
Regeneration• During direction transition the motor
will regenerate energy for a short period of time.
• In a Direct On Line system, this energy is fed back into the mains.
• Standard Drives, as standard, can not handle this energy and IGBT’s will be turned off to protect the drive. This will result in loss of control.
ATV71 ENA System
Regeneration: Common Solutions:1. Dynamic Brake Resistors
• Energy waste because the regenerative energy is transformed to heat
• Additional equipment
2. Active Front End
• No energy waste
• Expensive
Regeneration: ATV71 ENA feature.
• The pump speed is adjusted to absorb the regen energy as kinetic energy in the moving mechanism
• No additional equipment, no energy waste
• Economical
§ A special Algorythm for Oil pumps
§ Easy to adjust (3 parameters only)
§ No external or additional device to brake the counter weight
§ Energy saving
§ Preserve the mechanics of the system
§ Display with customer unit : hits / minute
§ No motor inductances : shot distance to the pump
ENA SystemENA System
Energy consumed in the network is reduced because of the ENA algorythm. This make a huge energy saving that can reach 50%.
Line current with a standard system Line current with Ena System
Decrease the network consumption Decrease the network consumption
Beam Pump Issues/Problems
Optimum Operation - 100% Pump fill – No Fluid Pound
Beam Pump Issues/Problems
Non Optimum Operation 50% pump Fill – Fluid Pound and Low Efficiency
Beam Pump Issues/Problems
100% pump fill
• Torque profile on the up stroke is the same for 100% and 50% pump fill (Energy required in both cases is N)
• Torque on the down stroke is different, because the travelling valve is closed as the plunger travells through gas. (Energy required for the 100% pump fill is N, Energy required for the 50% pump fill is N/2)
• The total energy required for one stroke is N+N=2N for 100% pump fill and N+N/2=1.5N for 50% pump fill
The total Energy consumed in one stroke is NOT proportional to pump fill level!
Over 30% Energy waste can occur!
Low Pump Fill - Energy Waste:
Beam Pump Issues/Problems
Gas Lock• Gas Lock results from very low pump fill.
• On the down stroke the standing valve is closed. The travelling valve also remains closed. The gas is compressed,.. On the way up, the gas expands and again both valves remain closed.
• The plunger travels up and down without pumping oil. The result is energy waste, production loss and mechanical wear as the plunger is now un-lubricated
ATV71 RodMax – Pump Fill Controller
Hig
h Pos
ition
Zero
Low Level 1
High Level
Low Level 2
+
-
0
--
Low
Posi
tion
Span
Rod Position Calculator
Motor Torque Prox Switch Motor Speed
Pump Energy Consumption
Pump Fill CalculatorSpan & Zero setup via RMO
Pump Fill Comparator
Speed Adjust Algorithm
Speed Reference
Adjust Rate/Stroke
Minimum Speed
Pump Fill Controller Block. Block Diagram:
ATV71 – messaging
Messaging. providing full system operation feedback
• Stroke Length Monitoring. Monitors belt slippage, switch failure. (the PFC is disabled and an alarm is generated)
•System status (starting, pumping, direction, short or long cycle, wait)
•Energy Meter displays the estimated KWh consumed by the drive.
•Minimum and maximum achieved pump fill level.
• Hours run counter for maintenance purposes.
•Balance display indicates the balance of the counter weights.
•Motor and Drive thermal state
•Crank position in degrees or %
•Pump Torque and Speed
•Real date and time
RodMax Optimiser
Start / stop plot
Display / hide up stroke
Dynamometer Display Used to calibrate the Pump Fill Controller.
Pump Information
ENA permit the utilization of standard 4 poles motors instead of highly isolated motors like Nema B that are more expensive.
4 Polos
1450 RPM
Use of standard motors Use of standard motors
§ Cost cutting : no motor inductances, no braking resistors
Advantages of ENA system with Advantages of ENA system with AltivarAltivar 71 71