Abstract
Oil drilling fluids require additives to control and regulate their rheological properties. For water-based mud, many components such as polymers are introduced to respond to specific functions. In this work, starches extracted from potatoes and corn, were proposed as a filtration controller and their effects on the rheological properties of Algerian Na-Bentonite are examined. The potato and corn starches were fabricated by adopting an easy, eco-friendly, and cost-effective route (peeling, mixing, filtration and drying) for potatoes and (soaking, crushing, filtration and drying) for corn kernels. A comparative study of the rheological properties included apparent viscosity, plastic viscosity, yield point and gel strength. The measurements were performed in the presence of caustic soda and potassium chloride while varying the concentration for both starches (0.6, 1.2, and 2.0%) and potassium chloride (1.5, 3.0, and 4.5%). From the obtained results, both potato and corn starches enhanced the rheological properties meanwhile reduced the fluid loss and the filter cake thickness by an average of (20.66% and 26.66%) and (6.33% and 17.77%), respectively in basic/saline media drilling fluid formulations. This research demonstrates that bio-starches stand as a potential alternative additives for the enhancement of rheological and filtration properties in water-based drilling fluids.