Structural modeling of the casings in high temperature geothermal wells

•Wellhead displacement data was gathered during discharge of 5 wells in Iceland.•For the initially cold wells, the displacement was very fast in the beginning.•For the initially warm wells, the fast initial displacement was missing.•Wellhead displacement slows down with time and shows signs of exponential decay.•Numerical results show good agreement with the wellhead displacement data. High temperature geothermal wells are constructed of several concentric steel casings that are fully cemented up to the surface. The structural integrity of such casings is essential for the utilization of wells. The casing is subjected to multiple thermo-mechanical loads that can cause casing failures. Thermal expansion generates thermal stresses in the casings and causes the wellhead to rise slightly during discharge. In this paper, a nonlinear structural finite-element model of the cased section of a geothermal well is presented and validated. The numerical results show good agreement with wellhead displacement measurements of 5 different wells in Iceland.