Mechanical Strength Improvement of Mud Motor’s Elastomer by Nano Clay and Prediction the Working Life via Strain Energy

In directional drilling, the most important thing that leads to pulling out the drill string is end of mud motor working life. Considering the working conditions of down hole mud motors; increasing the mechanical properties of their stator’s elastomer is crucial. Some attempts were done to increase the motor performance through geometrical changes but lack of material improvement is significant in previous studies. In this study, NBR/nanoclay composite samples were prepared through melt intercalation in an internal mixer and tested with regard to the temperature and drilling mud of down hole. Hardness, tear, fatigue and tensile test results of neat NBR elastomer and nanocomposite of NBR and different loading of nanoclay showed that the mechanical strength of new composites are considerably increased. With the help of strain energy method it was revealed that the life of NBR/nanoclay composite compared to neat NBR was enhanced. Therefore, increasing the working life and performance of the motor is achievable by using this nanocomposite. In the drilling industry, there is a direct relation between time and cost; therefore, increasing the working life of the motor leads to a considerable cost reduction in this expensive industry.