Applicability of Fe3O4 nanoparticles for improving rheological and filtration properties of bentonite-water drilling fluids in the presence of sodium, calcium, and magnesium chlorides

Abstract There are impressive efforts in conjunction with improving rheological and filtration properties of Water-Based Drilling Fluids (WBDFs) employing Nano-Particles (NPs). However, NPs’ performance in the presence of different salts has not been well assessed. This study intends to investigate the effect of Fe3O4 NPs on rheological and filtration properties of bentonite-water drilling fluids exposed to NaCl, CaCl2, and MgCl2 salts. To reach the goal specified for this study, three 0.5, 1 and 2 wt% NP concentrations, separately, were added into a salt-free and three salt-contaminated bentonite-water drilling fluids (four base fluids). So, 16 different drilling fluids were prepared for this research. The rheological models obtained by six shear rates, apparent viscosity, plastic viscosity, yield point, gel strength, and cutting carrying ability of all the drilling fluids are described in the paper. Moreover, API fluid losses (under 100 psi differential pressure), the cakes’ thickness, and the cakes’ permeability compared to the same as the salt-free base fluid, are interpreted to evaluate the NPs’ performance on filtration control ability of all the drilling fluids. The results showed that the salts weaken the rheological and filtration properties of the salt-free base fluid, while Fe3O4 NPs sustain and improve the rheological properties of salt-free and salty drilling fluids, significantly. Nano-sized Fe3O4 weakens the filtration properties of the salt-free WBDF, but it is a suitable filtration control agent for salt-contaminated drilling fluids. In a sentence, nano-Fe3O4 is a suitable additive to enhance salty-WBDFs’ performance