Bionic Surface Textured Stator for Deep/Ultra-Deep Well Oil Production Progressing Cavity Pump

Progressing cavity pump (PCP) are characterized by their simple structure, high transmission efficiency, and broad adaptability. They have been used in drilling and oil extraction engineering since the 1980s and have now developed into one of the most important lifting equipment in oil production [1, 2]. Currently, there are more than 11,000 ground-driven screw pump wells in China, with an average pump inspection cycle of about 700 days. PCP is composed of a metal rotor and a rubber stator, during the operation of the PCP, there is continuous contact and friction between the rubber stator and rotor, which causes wear on the rubber stator. According to the failure statistics on the oilfield site, the wear of the stator and rotor is one of the main reasons affecting the performance and service life of screw pumps, accounting for approximately 30% of total failures. At present, there is no effective solution for the wear of the rubber stator, so it is necessary to carry out research on lubrication, wear reduction, and resistance reduction of the stator and rotor of the PCP. In recent years, bionic surface texturing technology, as an effective means to reduce friction, wear, and improve the load-bearing capacity of the friction pair's liquid film, has attracted widespread attention from domestic and foreign tribologists. The excellent characteristics of bionic non-smooth surfaces such as detachment, wear reduction, and resistance reduction have been verified and applied in many engineering fields [3–5].