RESEARCH OF LOADS ON DRIVE OF ROD INSTALLATIONS IN LOW SPEED MODE AT HIGH-VISCOUS OIL PRODUCTION

Abstract

Reliability and power consumption of the rod installations are largely determined by the drive balancing rate. Today, due to the increasing share of hard-to-recover reserves, issues of balance during the extraction of high viscous and paraffinic products, characterized by increased loads on the rod string due to increasing forces of hydrodynamic friction, paraffin deposition on the walls of sucker rods and pipes, are becoming urgent. The effect of the viscosity of the pumped liquid and the degree of paraffinization of the bore of the elevator pipes on the magnitude of the loads on the drive and power consumption of the rod systems, as well as on the optimal position of balancing crank loads, is studied. As a balance criterion, the minimization of the maximum torque on the crank shaft is taken. A mathematical model of the rod installation based on the analytical model of the balancing drive, taking into account the specified kinematics of the four-link mechanism of the rocking machine is developed. When calculating the hydrodynamic friction loads, the Navier-Stokes equations are used for the steady-state fluid flow in the annular space between the rods and tubing. A study of the loads on the drive at various viscosities and degrees of overlap of the cross section of the elevator pipes showed that an increase in the product viscosity (up to 200 mPa ∙ s) and intensive paraffin deposition on the walls of the rods and elevator pipes (overlapping up to 50 % of the cross section of the elevator lift) leads to an increase in the required torque up to 50 % on the crank shaft of the gearbox (the torque applied to the crank and created by the electric motor) and an increase in the consumed electricity and power up to 100 %, i.e. 2 times.