Here are some common issues maintenance crews may encounter with POCs in rod-pumped oil wells.

1. Problem: False Pump-Off Detection or Missed Events

Cause: False pump-off detection or missed shut-in events typically result from sensor drift or outright failure—particularly in load cells and position sensors—which leads to inaccurate data. Misconfigured thresholds or poorly tuned control logic can also trigger incorrect responses.  In some cases, the system misinterprets dynamometer or torque curve data, failing to shut down during fluid pound or gas lock. Additionally, electrical supply disturbances, such as transient overvoltage, can lead to corrupted signals or unstable microprocessor behavior.
Solution: To address these issues, operators should calibrate sensors regularly, verify fillage and shutdown parameters, and utilize real-time diagnostics like torque analysis to improve detection accuracy. It’s also important to protect the controller from electrical disturbances with Transient Voltage Surge Suppressors (TVSS) at the panel level and to ensure clean power delivery using filtering or conditioning equipment. These measures help maintain logic stability and prevent erratic sensor readings.

2. Problem: Unplanned Shutdowns or Idle Time

Cause: Unexpected shutdowns or excessive idle periods often result from power quality issues, firmware glitches, or improper runtime/downtime configurations. Even extremely brief power interruptions (as is the case with transient overvoltage) can trip sensitive pump-off controllers or cause them to freeze and/or reset unexpectedly.
Solution: Crews should routinely inspect power sources, ensure all firmware is up to date and validated, and configure appropriate timing values. Install necessary transient overvoltage mitigation, and add reset mechanisms to help the POC recover gracefully from minor electrical faults.

3. Problem: Mechanical Wear from Inefficient Pumping

Cause: Mechanical wear may result from the POC’s failure to detect abnormal operating conditions such as gas lock, fluid pound, or insufficient inflow. This can occur due to logic misinterpretation or data corruption from unstable input signals.
Solution: Control logic should be reviewed and tuned to current production conditions, supported by regular testing to verify surface indicators against individual well behavior. Shielding and protecting sensor inputs from electrical noise and other power anomalies can also improve system reliability and reduce logic misfires that lead to premature wear.