Revolutionizing Drilling Fluids: Granite Waste as a Cost-Effective Bridging Material

Abstract The ongoing demand for sustainable and economically viable drilling fluid additives is reshaping material selection in the oil and gas sector. This study investigates the potential of repurposing industrial granite waste as a bridging material in water-based drilling fluids, offering a cost-effective and environmentally responsible alternative to conventional barite. Four distinct mud formulations were systematically evaluated: baseline control without bridging material, a conventional fluid with 100% barite, a hybrid blend with 50% barite and 50% granite waste by weight, and a formulation employing 100% granite waste as the sole bridging agent. The granite waste was extensively characterized using particle size distribution analysis, X-ray fluorescence (XRF), X-ray diffraction (XRD), and scanning electron microscopy (SEM), confirming its suitable mineralogy, chemical composition, and particle structure for drilling fluid applications. Laboratory measurements assessed fluid density, pH, and viscosity at 120°F, while filtration performance was initially screened using API tests at room temperature and 100 psi. The most promising formulations underwent rigorous high-temperature, high-pressure (HTHP) filtration tests at 230°F and 300 psi with a 20 μm ceramic disk to simulate challenging downhole conditions. The results revealed that the drilling fluid containing 100% granite waste achieved outstanding fluid loss control, reducing filtrate volume to only 5 mL after 30 minutes outperforming both the traditional barite and hybrid systems. These findings demonstrate that granite waste is not only a technically effective bridging material but also a sustainable solution that promotes resource circularity and reduces environmental impact in drilling operations. The research paves the way for future optimization of waste-derived additives in advanced drilling fluid design.