Why do we need elastomer in downhole motors?

An episode from the series "Fun with Drilling Engineering" with Prof. Dr. Matthias Reich.
Camera and cut : Susann Klein
Made at the Institute of Drilling Engineering and Fluid Mining of the Technical University Bergakademie Freiberg, Germany.
The education of Petroleum Engineers belongs to the program "Geotechnics, Mining and Geo Energy Systems".
Please feel free to visit our homepage on tu-freiberg.de.... or send feedback, enquiries or suggestions to [e-mail].
Voiceover Artist: Bamisebi Joseph Adetiloye