One of the most essential parts of a geothermal well is the casing, string of pipes which ensure the structural integrity of a well and seal the well from unwanted fluids from the geothermal reservoir.
Á meðal mikilvægustu þátta í byggingu borholu eru fóðringar, rör sem meðal annars halda holunni heilli og skerma af vökva frá kaldari svæðum jarðhitageymis.