Fecha de publicación: -- Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE A cellulose nanofiber-reinforced filtrate reducer (HASF) was synthesized by grafting AM, ACMO, and SSS onto an HPMC backbone, followed by incorporation of carboxylated CNF. At 1 wt% concentration, HASF reduced API filtration loss to 8.1 mL after aging at 160°C for 16 h, demonstrating excellent filtration-control performance.

ABSTRACT
To improve the filtration-control performance and stability of cellulose ether-based additives under high-temperature and high-salinity conditions, a cellulose-based composite filtrate reducer (HASF) was developed for water-based drilling fluids. HASF was synthesized by free-radical graft polymerization of hydroxypropyl methylcellulose (HPMC) with acrylamide, 4-acryloylmorpholine, and sodium p-styrene sulfonate, followed by incorporation of carboxylated cellulose nanofibers (CNF). Synthesis parameters were screened by an L16(45) orthogonal experimental design with the high-temperature high-pressure (HTHP) filtration loss as the response. FT-IR and 1H NMR results were consistent with the expected functional groups, and thermogravimetric analysis showed the main mass-loss process above approximately 200°C. After aging at 160°C for 16 h, the HASF-containing mud (1 wt% HASF) exhibited an API filtration loss of 8.1 mL versus 92 mL for the base mud, a reduction of approximately 91%, and an HTHP filtration loss of 22 mL. Within the tested ranges (up to 15 wt% NaCl, 1.5 wt% CaCl2, or 3 wt% KCl), FLAPI remained at or below 11 mL. Sand-disk plugging tests showed reduced filtrate volumes, and SEM revealed a more compact filter cake, indicating the potential of HASF within the temperature, salinity, and formulation ranges investigated.