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PD15 EN REVA 2007

Rod pump control improves reliability and extends the lifetime of pumpsRod pump control is an optional application program for ABB industrial drives, covering the power range from 0.55 to 5600 kW.

The program is suitable for artifi cial oil lifting applications where a sucker rod pump (don-key pump) is used. The program improves the rod pump reliability, increases the life expectancy and minimizes the overall mainte-nance cost. It also reduces overall stress of the mechanical equipment.

Minimizing the number of load cycles within each stroke reduces the wear on the rods. This reduction in load cycles reduces the number of impacts between the rod and the tubing. The reduction of rod stress gives the user the option of increasing the strokes per minute; increasing the stroke length; lowering of the pump; or changing to a higher capacity pump.

Rod pump control offers four ready-made mac-ros that can be selected to use depending on the properties of the oil well.

Using the “pump off control” function, the pump continuously operates under normal conditions. As the infl ow to the well changes, the speed of the pump automatically changes.

Oil industry terminology is used in the signal and parameter units.

What is artifi cial lifting? Additional pumping equipment is needed when crude oil does not fl ow by natural pres-sure. This occurs when there is high viscosity, low pressure in the well or heavy or extra heavy crude oil. In such cases the oil is extract-ed by injection of water, steam, gases etc. The oil is pumped up to ground level by using rod pumps, progressive cavity pumps or electro-submersible pumps. Surface movement to fl ow stations is handled by multiphase pumps.

“Pump off control” (POC)POC is used to maintain a constant fl uid level in the well. The pump speed is adjusted au-tomatically upon the varying infl ow rate. This prevents “pump off”, reduces mechanical stress and ensures optimized production. The unit maintains a predetermined fl uid level above the pump, ensuring a constant and optimized bottom hole pressure.

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PD15 EN REVA 2007

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ABB OyDrivesP. O. Box 184FI - 00381 HelsinkiFinlandTelephone +358 10 2211Telefax +358 10 222 2287Internet www.abb.com/drives

POC measures the energy per stroke and com-pares it to a full well bore measurement that is determined during start up. The drive increases or decreases the speed to maintain the energy set point.

A proximity switch to determine the upstroke position is normally the only sensor that is needed.

On/off timerThis function allows the pump to run and stop for a specifi ed period in a continuous cycle. This on/off cycle is designed for a well that is known to “pump off” where automatic “pump off control” is not desired or possible.

Signals telling the remaining operation time and remaining fi lling time are available.

Inverse load controlInverse load control allows the pump to re-spond inversely to an input. Typically the input to inverse load control is current or torque seen by the motor. The motor reference speed is then trimmed by the ratio of the nominal load setting divided by the load input.

Dual speed controlThe dual speed control function allows the pump operator to make a total of two speed adjustments, one upstroke and one down stroke, during each stroke of the pumping unit. The user can defi ne the stroke position where speed adjustment will happen.

Protection functionsThe rod pump control program offers various protection functions that are common to all ABB industrial drives. In addition, the follow-ing protection functions are designed for rod pump applications:

Rod-string fl otation protectionFlotation protection will reduce the pump speed reference when a rod-string fl otation condition is detected. The fl otation condition is detected by comparing minimum running ten-sion to the fl otation limit.

Thermal protectionA total of three separately confi gurable tem-perature functions are provided for the thermal protection of the motor and pumping unit.

Pressure protectionA total of three separately confi gurable pres-sure transducer signals can be confi gured to provide an alarm or fault events for the follow-ing signals: casing pressure, tubing pressure, intake pressure.

All pressure signals are scaled to oil industry standard units.

Torque limit protectionProvides protection against high torque condi-tions, which may cause damage, or low torque conditions, which indicate a problem with the motor/pump unit.

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