Abstract
Water-based muds (WBMs) are increasingly favored over oil-based muds (OBMs) in drilling operations due to their lower environmental impact and cost-effectiveness. WBMs offer better biodegradability and are less environmentally harmful than OBMs. Using biopolymers in WBMs is common as they do not harm crude oil, making modified starches a key area of research. In this study, the behavior of modified starch in WBMs was investigated under the influence of various salt systems such as NaCl, KCl, and CaCl₂, compared to a reference mud system formulated with xanthan gum, modified starch, and CaCO₃, following API standards. All testing was conducted at 150 °F and 300 °F after hot rolling in aging cells at the lab scale. Results show that modified starches improved fluid loss control and enhanced rheological properties by 40% and 30%, respectively, compared to conventional starches. Additionally, modified starches contributed to the slower thermal decomposition of the mud system, improving stability under high-temperature conditions. This study highlights the potential of high-performance WBMs (HPWBMs) in reducing drilling costs and environmental impacts while maintaining drilling efficiency.