Diagnostics of downhole dynamometer data for control and troubleshooting of reciprocating rod lift systems

A reciprocating rod lift system, comprising:

• a pump comprising:
• a pump barrel;
• a plunger;
• a standing valve;
• and
• a traveling valve;
• and
• a control unit for controlling the pump, wherein the control unit has computer-executable code stored thereon that, when executed by the control unit, causes the control unit to:
• measure downhole data during a pump cycle, wherein the downhole data comprises a first plurality of data points associated with an upstroke of the pump cycle and a second plurality of data points associated with a downstroke of the pump cycle, each data point comprising a rod position value and an associated rod load value;
• convert the data points to non-dimensional data points;
• calculate non-dimensional slope values between non-dimensional data points;
• determine pump fillage based, at least in part, on the calculated non-dimensional slope values;
• and
• control the reciprocating rod lift system based on the determined pump fillage.