Abstract
This study presents a numerical investigation into the mechanical behavior of foam cements used in geothermal wells, particularly focusing on their
performance under high-temperature (HT) conditions. Conventional cementing solutions in geothermal wells, such as Portland-based cement, often struggle with maintaining well integrity due to high thermal stresses and casing expansion during well heating. Foam cement, characterized by its lower Young’s modulus, hardening modules, and compaction yield pressure, is proposed as an alternative due to its enhanced flexibility and compressibility. This research develops and implements an advanced well-cement model within the CASINTEG software to simulate the response of foam cement in geothermal wells. The model incorporates key factors such as plasticity, temperature dependent material properties, and the compaction behavior of the cement under HT conditions. The results indicate that foam cement significantly reduces contact pressure at the casing/cement interface, thereby potentially reducing the risk of casing collapse during thermal cycling. Moreover, foam cement facilitates more homogeneous compaction, enhancing the cement's ability to accommodate radial expansion and contributing to overall well integrity. This study highlights the potential of foam cement to improve the long-term performance and safety of geothermal wells, enabling more efficient energy extraction from super hot geothermal reservoirs.