Thermomechanical Stresses of Multilayered Wellbore Structure of Underground Hydrogen Storage - A Simplified Solution Based on Recursive Algorithm

Large scale of hydrogen storage is needed to balance the energy supply-demand fluctuation issues. Among few of the large scale storage systems, depleted oil and gas wells are widely employed. The construction of wellbore is normally in cylindrical shape and formed by layers of cement, casing and formation. As failure of wellbore is costly, proper structural integrity assessment is essential. In this article, an analytical solution derived based on recursive algorithm for estimating the thermomechanical stresses across the wellbore structure was proposed and verified. The temperature and stresses distribution results obtained from proposed analytical solution were compared with numerical results and they were found in good agreement. The percentage of difference was observed to be less than 0.1%. Besides that, a comparison study was performed on two, four and six layers wellbore structure. It was observed that four and six layers structure can produce much lower tangential tensile stress on the steel casing of the wellbore.