Comparative study of reciprocating sliding wear of HNBR on the effects of temperature

The wear of the sealing rubber of packers, which are widely used in the field of oil production, has drawn more and more attention nowadays. This research conducted the reciprocating sliding wear tests of hydrogenated nitrile rubber (HNBR) at 20 degrees C, 60 degrees C, 100 degrees C and 140 degrees Cin different downhole mediums (dry, water, crude oil). The results show that the coefficient of friction (COF) curves fluctuate greatly under dry sliding and water medium condition, but keep a stable state in crude oil medium. In dry sliding condition, the average COFs and wear volume increase firstly, then diminish and reach the minimum at 140 degrees C due to the reduced hardness and matrix binding force. Schallamach waves, little debris and pits feather the worn surface of HNBR at lower test temperature (20 degrees Cand 60 degrees C). Plastic deformation and cracks occur at 100 degrees C and 140 degrees C, indicating the combined mechanism of abrasive wear and fatigue wear at this condition. Both the average COF and wear volume increase slightly with temperature in water and crude oil medium. This paper has guiding significance to improve the sealing performance of packer.