Synthesis and characterization of a novel functionalized silica/polyacrylamide composite for advanced water‐based drilling design

Abstract Polyacrylamide (PAM) has become a potential additive in drilling, but it has limitations in terms of viscosity, fluid loss, and bored pile stability concerns. Previous rheological studies have reported silica (SiO2) usage in PAM modification. However, there is insufficient rheological information such as plastic viscosity, apparent viscosity, yield point, and gel strength. Herein, this research investigates the effects of SiO2 in PAM with comprehensive rheological data. The morphological properties of SiO2 were analyzed. Compared with bare PAM, modified PAM demonstrated distinct chemical structures, but both were hydrophilic fluids. Moreover, an undulated trend was observed in the rheological results of all modified PAM for all concentrations of SiO2 and all the selected temperatures. However, all modified PAM showed better rheological performance than bare PAM. Consequently, 0.5 wt% SiO2 is a promising formulation for PAM modification, which can even be simulated in the performance of the bored pile drilling. For thermal stability, the rheological performance of bare PAM and modified PAM performed better at 60 and 40°C, respectively.