Rheological investigations of water based drilling fluid system developed using synthesized nanocomposite

In the present study, polyacrylamide grafted xanthan gum/multiwalled carbon nanotubes (PA-g-XG/MWCNT) nanocomposite was synthesized by free radical polymerization technique using potassium persulfate as an initiator. The polyacrylamide was grafted on xanthan gum backbone in the presence of MWCNT. The synthesized nanocomposite was characterized by X-ray diffraction technique (XRD), and Fourier transform infrared spectroscopy analysis (FT-IR). The morphological characteristics of the nanocomposite were analyzed by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) analyses. Also, its temperature resistance property was observed with Thermogravimetric analysis (TGA). The effect of nanocomposite on the rheological properties of the developed drilling fluid system was analyzed with a strain controlled rheometer and Fann viscometer. Flow curves were drawn for the developed water based drilling fluid system at elevated temperatures. The experimental data were fitted to Bingham, power-law, and Herschel Bulkley flow models. It was observed that the Herschel Bulkley flow model predict the flow behavior of the developed system more accurately. Further, nanocomposite exhibited non-Newtonian shear thinning flow behavior in the developed drilling fluid system. Nanocomposite showed high temperature stability and had a significant effect on the rheological properties of the developed drilling fluid system as compared to conventionally used partially hydrolyzed polyacrylamide (PHPA) polymer.