Apparatus and methods for optimizing control of artificial lifting systems

An artificial lift system producing fluid from a wellbore to surface, comprising:

• a linear actuator comprising a movable component moveable between a lower position and an upper position and driveably coupled to a downhole pump via a rod string;
• a power unit coupled to said linear actuator for driving said movable component to reciprocate;
• the reciprocating of the movable component driving the downhole rod pump to pump fluid to the surface;
• a position sensor for detecting a position of the movable component;
• an axial load sensor for detecting an axial load on the rod string;
• and
• a controller coupled to the position sensor, the axial load sensor, and the power unit, the controller configured to:
• control the power unit for reciprocating said movable component between the lower position and the upper position at a pump speed;
• and
• automatically adjust the pump speed in response to the detected position and axial load to avoid fluid pounding by decreasing the pump speed if the measured axial load at a first reference position is equal to or greater than a first threshold axial load at the first reference position, and increasing the pump speed if the measured axial load at the first reference position is less than the first threshold axial load at the first reference position;
• and
• maintain the pump speed if increasing the pump speed would result in the actuator exceeding an upper spm operational limit, and maintain the pump speed if decreasing the pump speed would result in the actuator exceeding a lower spm operational limit.