Synthesis and Characterization of SiO ₂ NPs/MWCNTs Nanocomposite and Effect on the Properties of Na-Bentonite Water Based Drilling Fluids: Experimental Investigation

Drilling fluid is an essential element of the drilling operations and has many functions. Some of these are wellbore cleaning, checking high formation pressures and corrosion protection, etc. This study aimed to determine the effects of multi-walled carbon nanotubes containing silisyum dioxide nanoparticles (SiO ₂ NPsMWCNTs) were investigated on the rheological and filtration loss properties of Na-Bentonite water based drilling fluids (Na-WBDF).In this context SiO ₂ NPs/MWCNTs was produced by chemical vapor deposition (CVD) method, characterized by X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy (SEM), and then added to Na-WBDF in different ratios (0.001 to 0.01% w/v). The rheological properties of the prepared drilling fluids such as plastic viscosity (PV), apparent viscosity (AV), yield point (YP), gel strength (10 s and 10 min) were performed by FANN viscometer, filtration loss and cake thickness were performed by American Petroleum Institute (API) liquid loss test equipment. Compared with spud drilling fluid; SiO ₂ NPs/MWCNTs increased the PV value of Na-WBDF by 71.4%, AV value by 51.9%, YP value by 44%, 10 s and 10 min by 25% and 33.3% respectively, and decreased filtration loss value by 13.8%; At the same time, the value of cake thickness increased by 11%.