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.