Mathematical model of controllers for progressive cavity pumps

Abstract

Progressive Cavity Pumps (PCP) is an artificial fluid lift method widely used in oil wells of Colombia, Canada and Venezuela, where the pump is driven by a rod connected to the motor located at the surface. Efficiency in energy production is critical, and the current control techniques used are based on discrete changes, seeking for an operational point. This approach can be improved, and optimization techniques proposed are presented in this paper. Strategies of control based on continuous adjustments of motor speed and fuzzy logic together with a downhole pressure sensor are simulated for this nonlinear system. Utilization of Kalman filtering, for estimation of the fluid level in wells that are not instrumented, is proposed. Linear Quadratic Regulator (LQR) also is used to optimize production performance. Results show good performance compared with current techniques.

Keywords

• fuzzy logic
• kalman filter
• linear quadratic regulator
• oil production
• progressive cavity pump