A Novel View of Cement Failure with Application to Geothermal Well Construction

ABSTRACT Geothermal wells are designed following oil and gas practice but have a longer expected life span, and thus their integrity evaluation is based on the same standards and requirements of hydrocarbon wells. Thermal cement degradation is known to occur at temperatures higher than 110°C and many researchers have focused their efforts to develop new recipes that will withstand the high temperatures encountered in these wells. Although other scholars have focused on cement compression and tension strength and its evolution with time and temperature, a closer look at geothermal wells will show that the major load on the cement is generated by the inevitable casing expansion and its effects at the cement-casing contact.