Enhancing High-Performance Water-Based Mud (HPWBM) Stability and Performance Using Low Viscosity Polyanionic Cellulose (PAC-LV) at 200°F

Abstract This study discusses the contribution of low viscosity polyanionic cellulose (PAC-LV) to the thermal stability and performance improvement of high-performance water-based mud (HPWBM) at 200°F. Mud samples with varying PAC-LV concentrations (0-2 ppb) were subjected to hot rolling at 200°F and analyzed for rheological and filtration properties. The results showed a significant reduction in fluid loss, from 4.2 to 2.6 mL/30 minutes, demonstrating improved filtration control. Rheological properties also improved, with plastic viscosity increasing from 18 to 44 cP, yield point from 31 to 47 lb/100ft 2 , and gel strength from 11 to 16 lb/100ft 2 (10 seconds). Importantly, the mud exhibited high thermal stability, as indicated by consistent mud weight (1.55 g/cm 3 ), stable pH, and unchanged K + and Cl − concentrations after aging. These findings confirm that PAC-LV enhances both the stability and functional performance of HPWBM, making it a reliable additive for drilling operations in high-temperature environments.