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 Counter Balance Weights Crank Beam Horse Head Up Stroke Electrical Enclosure Gearbox Down Stroke Polished Rod Stuffing Box Motor Sucker Rod Pump Assembly Position Sensor Alternative Position Sensor Location Rod String Travelling Valve Plunger Standing Valve Reservoir 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 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. Zero torque limit Regeneration occurs during stroke direction transition
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 ENA System 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
Decrease the network consumption 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 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 Low Pump Fill - Energy Waste: 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 Position High Position 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 Pump Fill Controller Block. Block Diagram: Span Motor Torque Prox Switch Motor Speed Pump Energy Consumption Rod Position Calculator Zero Adjust Rate/Stroke Minimum Speed Pump Fill Calculator Span & Zero setup via RMO Pump Fill Comparator Speed Adjust Algorithm Speed Reference High Level + Low Level 1 0 Low Level 2 - --
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 Dynamometer Display Used to calibrate the Pump Fill Controller. Start / stop plot Display / hide up stroke Pump Information
Use of standard motors 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 Advantages of ENA system with Altivar 71 Cost cutting : no motor inductances, braking resistors no
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