Micronized calcium carbonate to enhance water-based drilling fluid properties

Advanced drilling technique requires competent drilling fluids. This study tests micronized calcium carbonate (CaCO₃) as a water-based drilling fluid (WBDF) additive. CaCO₃ microparticles were extracted from Aruma formation outcrop and studied for structural, colloidal stability, morphology, and particle size distribution. WBDF systems were prepared with varying quantities of CaCO₃ microparticles, including 0, 15, 30, and 45 lb/bbl, respectively. The addition of CaCO₃ microparticles was investigated in terms of the rheological, high pressure-high temperature (HPHT) filtration, barite sagging, density, and pH. The results showed that CaCO₃ microparticles are stable at a pH greater than 8. Moreover, fluid containing CaCO₃ microparticles exhibited an enhancement in rheological properties. The yield point increased by 29%, 34%, and 37% for 15, 30, and 45 lb/bbl of CaCO₃ respectively. In addition, the HPHT filtration also showed that CaCO₃ has a significant improvement in both filtration loss and filter cake thickness. The filter cake thickness decreased by 17%, 40%, and 65% at 15, 30, and 45 lb/bbl of CaCO₃ respectively. Static and dynamic sag maintained in a safe range at 30 lb/bbl of CaCO₃ microparticles. This study showed that using CaCO₃ microparticles along with conventional fluid additives improved the thermal stability and rheological properties of drilling fluid.