Performance evaluation of chemically modified starch-based additives for enhanced water-based mud formulations in high-temperature and salinity drilling operations
摘要
This study investigates the rheological and filtration properties of water-based mud systems formulated with cassava-based polymer additives, including untreated cassava starch flour (CF), sulfonated cassava starch flour (CFAS), untreated cassava peel (CP), and sulfonated cassava peel (CPAS), compared against carboxymethyl cellulose (CMC) as the standard. The effect of temperature, aging, salinity, and pressure on the performance of these polymer systems was evaluated, focusing on parameters such as apparent viscosity (AV), plastic viscosity (PV), yield point (YP), gel strength, filtration volume, and filter cake thickness. At ambient conditions, CMC exhibited superior performance with the highest AV (38 cP), PV (25 cP), and YP (35 lbf/100 ft2). However, CFAS and CPAS demonstrated comparable rheological properties, with AV and YP values approaching those of CMC. Under elevated temperatures (170°F), CFAS and CPAS retained significant thermal stability, outperforming untreated cassava-based materials (CF and CP). Filtration tests showed that CFAS and CPAS had lower fluid loss volumes and thinner filter cakes than CF and CP, aligning closely with API standards. Salinity tolerance tests revealed that sulfonated derivatives (CFAS and CPAS) exhibited enhanced stability in KCl concentrations up to 4%, maintaining AV, PV, and YP values closer to those of CMC. The novelty of this study lies in the sulfonation of cassava-based polymers, which significantly improved their rheological and filtration performance under saline and elevated-temperature conditions, positioning CFAS and CPAS as viable, cost-effective alternatives to CMC for WBM formulations. These findings highlight the potential of chemically modified cassava-based additives for sustainable and high-performance drilling fluid applications.