Simulation of the operating characteristics of an all-metal conical screw pump

The all-metal conical screw pump can achieve efficient lifting of fluids with different viscosities by adjusting the stator-rotor clearance fit. To investigate the operational characteristics of the all-metal conical screw pump under various fluid viscosities, this study builds upon outdoor experiments and employs numerical simulation for further analysis. The effects of stator-rotor clearance fit and rotor speed on pump displacement, energy efficiency, torque, and volumetric efficiency under different fluid viscosities are obtained. Reasonable operating parameters are recommended for heavy-oil reservoirs under different lifting conditions. The results indicate that the all-metal conical screw pump overcomes the limitations of traditional elastomer pumps and equal-diameter metal pumps, enabling efficient lifting across a wide viscosity range. Fluids of different viscosities correspond to different operating conditions: for high-viscosity fluids, the pump's energy efficiency increases first and then decreases with larger clearances, while it decreases with increasing rotor speed. Under thermal recovery of heavy oil, the pump should operate with small clearance and high speed, whereas under cold production, large clearance and low speed are preferable.