Investigation of Particle Size on Drilling Fluid Properties in Water-Based Drilling Fluid

This study examines the influence of particle size on the properties of water-based drilling fluids, which are commonly utilized in oil and gas drilling operations. Drilling fluids, or muds, play a crucial role in lubricating the drill bit, controlling downhole pressure, and transporting cuttings to the surface. The performance of these fluids is primarily determined by their rheological properties, which are influenced by the composition and size distribution of the solid particles within the fluid. This research investigates how varying the particle size distribution of fine, medium, and coarse calcium carbonate impacts key properties, including plastic viscosity (PV), yield point (YP), and gel strength, at temperatures of 80°F, 120°F, and 150°F. A total of 1.67 grams of each particle size, fine, medium, and coarse calcium carbonate, was used to prepare a 5-gram mixture for each size. The effects of both individual and composite mixtures on the rheological properties of water-based drilling fluids were evaluated under the specified temperature conditions. The results indicated that variations in particle size did not significantly alter the PV, YP, or the flow curves obtained from shear stress versus shear rate plots. The fluid flow curves followed the typical behavior of drilling fluid models, with shear stress increasing proportionally to shear rate as temperature rose. Coarse carbonate particles exhibited the most significant improvement in viscosity as temperature increased. The composite mixture displayed optimal performance, with high YP suggesting that the drilling fluid may lose its rheological properties due to temperature fluctuations downhole. The medium particle size also performed well in terms of YP at elevated temperatures. Gel strength was maximized when a mixture of fine, medium, and coarse particles was incorporated into the drilling fluid. Overall, this work highlights the impact of carbonate particle size on the rheological properties of water-based drilling fluids and demonstrates that altering particle size can significantly influence gel strength, PV, and YP.