Rheological and filtration properties of water-based drilling fluids as influenced by cellulose nanomaterials: different aspect ratios and modified groups

In this work, the application potential of three kinds of cellulose nanomaterials (CNMs) with different aspect ratios and surface modified groups in water-based drilling fluids (WBMs) was studied. The surface modification groups and thermogravimetric analysis of CNMs were measured and compared. The effects of CNMs on the rheology and filtration of WBMs were investigated and compared with those of xanthan gum. The rheological analysis showed that the viscosity building and shear thinning behaviors were more pronounced for fluids containing cellulose nanofibrils modified with carboxymethyl (CNF-C), while the filtration was optimized by increasing the concentration of cellulose nanocrystals containing carboxymethyl (C-CNC) in the fluid while concurrently improving the rheology. At the same time, the WBMs added with C-CNC showed better gel strength, thermal stability, and salt resistance than the WBMs prepared by CNF-C and cellulose nanocrystals containing the sulfonic acid group (CNC-C). The Herschel-Bulkely rheological model was selected to be well-suited for the measured shear stress and shear rate data of WBMs before and after aging with correlation coefficients larger than 0.99. Compared with xanthan gum, the WBMs prepared by C-CNC have significantly improved rheology, gel strength, filtration performance, and thermal stability. CNMs provide a new choice for more environmentally friendly drilling fluid materials in the energy industry. Graphical abstract The relationship between the Aspect Ratios and Modified Groups of CNMs drilling fluid rheological properties was studied. This research provides a new choice for more environmentally drilling fluid materials in the energy industry.