Improvement in Geothermal Well Integrity: A Review of New Advanced Cementing Technologies

Geothermal wells, with downhole conditions surpassing 350°C temperature, over 200 MPa pressure, and an extremely aggressive chemical environment, raise demands on conventional cementing systems for durability. This paper reviews the advanced cementing technologies developed to meet these challenges: improved thermal resistance, mechanical flexibility, and chemical stability. There is a discussion on novel formulation containing nano-silica, fibers, superplasticizers, and self-healing additives, improving thermal degradation resistance, flexing, and resistance against chemical attacks. New material geometries such as geopolymers, calcium aluminate cement, and chemical expanding agents have been identified that would provide superior performance for wellbore zonal isolation and long-term integrity of the well. Operational efficiency will be further enhanced with well reliability through the integration of digital technologies, including AI-driven slurry optimization and real-time monitoring. The abovementioned developments are considered effective in reducing microcracking, debonding, and fluid migration to extend the lifespan of the geothermal wells by confirmation through field applications and studies in the laboratory. Finally, the environmental benefits accrue as reduced CO₂ emission and minimal groundwater contamination to the global goals of sustainability. This review highlights the key deficiencies within the existing practices and presented guidelines for future research concerning materials development and advanced placement techniques. These advances would now allow access to more reliable, long-lasting, environmentally friendly operations of geothermal wells, which will enhance the adoption of geothermal energy as a clean resource.