TRIBOTECHNICAL CHARACTERISTICS OF THE SCREW PAIR OF THE PROGRESSING CAVITY PUMP

Abstract

The relevance of the study is caused by the necessity in increasing the precision of calculating the torsional loads, which will provide conditions for refining the diagnostic algorithms and predicting the resource of progressing cavity pumps. They are used in downhole conditions characterized by high viscosity of the pumped fluid (more than 30 mPa·s) and a high content of mechanical impurities in it (the concentration of particles is more than 500 mg/l). The operating experience of the progressing cavity pumps shows that the reliability of pumping units depends on the state of the working bodies. During operation, the stator elastomer swells, which leads to increase in friction losses. To improve the efficiency of selection, calculation and diagnostics of the progressing cavity pumps, it is important to have a deep understanding of the processes occurring during the friction of a metal rotor against the stator elastomer under conditions of formation fluid lubrication. The purpose of the study is to determine the dependence of the friction coefficient of a pair of working bodies of the progressing cavity pump on the Sommerfeld number for the elastomeric material of the progressing cavity pump stator and to plot a section of the Stribeck curve typical for the operating conditions of the progressing cavity pumps. Methods: experimental studies on tribotechnical installation II-5018 metal-elastomer pairs. Results. The authors have determined the friction coefficient dependence on the Sommerfeld number for the rotor–stator friction pair, according to which the Stribeck curve was constructed.

Keywords

• oil production
• progressing cavity pump
• friction
• elastomer
• tribotechnics
• sommerfeld number
• striebeck curve