Dual Functionality of Biobased Bacterial Nanocellulose as Polymer Additive for Drilling Operations and Post-Drilling Filter Cake Removal.

This work explores bacterial nanocellulose (BNC) as a biobased and sustainable polymeric additive for water-based drilling fluids (WBMs). BNC was isolated from the cellulosic byproduct of kombucha tea production, yielding highly pure cellulose with high crystallinity and mechanical stability. WBMs prepared with BNC exhibited higher viscosities and similar pseudoplastic behavior compared with those formulated using xanthan gum (XGD). Thermal aging at 90 °C showed that BNC-based fluids retained around 80% of their initial viscosity, confirming superior thermal stability and longer service life. Although slightly higher filtrate volumes were recorded, the overall rheological performance was enhanced. Additionally, enzymatic treatment of BNC enables controlled viscosity reduction, which may facilitate fluid management during cementing operations. This dual functionalityhigh performance during drilling coupled with controlled postuse degradabilitysupports a circular materials strategy by reducing polymer consumption and minimizing waste generation. In this context, the proposed approach contributes to sustainable development goal (SDG) 12: Responsible Consumption and Production and SDG 9: Industry, Innovation and Infrastructure, through the development of sustainable materials for industrial applications. Overall, these results highlight BNC as a promising multifunctional polymer and provide initial insights for the development of alternative sustainable drilling fluid formulations.