In geothermal wells, the use of glass reinforced epoxy (GRE) casing has increased significantly during the last decade. Corrosion resistance, even under harsh borehole conditions is this material’s main advantage when compared to steel. Reduced thermal conductivity resulting in less heat losses of thermal water to the formation and extremely smooth inner-pipe surfaces leading to an optimized flow profile are further characteristics which are ideal for geothermal projects. However, the reduced collapse resistance in contrast to steel tubular demands specially customized cement slurries. ...