Comparative study on wear properties for rubber elastomers under different downhole condition

As the critical component of the solid expandable tubular (SET), the wear problem of rubber elastomer has been an increasing concern during operation in downhole working condition. Therefore, this research conducted the reciprocating sliding wear tests of nitrile rubber and fluoro rubber against N80 casing steel at 20 °C and 110 °C in different downhole mediums (dry, water, crude oil). The results showed that the coefficient of friction decreases dramatically at 110 °C in dry condition but increases slightly in water and crude oil condition compared to 20 °C condition. Due to the sharp decline on mechanical properties of rubber elastomer at 110 °C, the falling off of particle and generation of cracks, pits resulted in a larger wear rate ultimately. Abrasive wear and oxidative wear are the main wear mechanism at 20 °C, while the rubber is under the combined action of abrasive wear, oxidative wear and fatigue wear at 110 °C. The rubber showed more excellent wear resistance in crude oil medium, and the adverse effect of high temperature is slight. The experimental results gave profound guidance for SET technology in the petroleum industry and enriched the rubber tribological theory at high temperature.