High-Performance Oil Well Cement with Modified Calcium Carbonate Whiskers: Enhancing Durability Under HTHP Conditions

This study investigates the effect of incorporating modified calcium carbonate whiskers, treated with tetraethyl orthosilicate (TEOS), to enhance the mechanical properties and sealing integrity of oil well cement under high-temperature and high-pressure (HTHP) conditions. Traditional cement systems are prone to brittleness and cracking under dynamic loads, leading to compromised wellbore sealing performance. Our findings demonstrate that fiber-toughened cement slurry improves the toughness and sealing performance of the cement annulus, maintaining gas tightness and mechanical integrity under cyclic alternating pressures at 150 °C. Specifically, the inclusion of 5% modified whisker fibers improves compressive strength by 24.5% and flexural strength by 43.3% while maintaining stable rheological and thickening properties. These results support the hypothesis that modified whisker fibers enhance the durability and sealing integrity of cement wellbores under extreme conditions, providing a practical solution for challenging cementing applications.