Toward Improvement of Water-Based Drilling Mud via Zirconia Nanoparticle/API Bentonite Material

Abstract

Enhanced rheological and mud-filtrate loss characteristics of drilling muds are key to a successful drilling operation. Zirconium dioxide (ZrO2)/clay material (ZCNC) was synthesized using ultrasonication and characterized via scanning electron microscopy (SEM), X-ray diffraction, and Fourier-transform infrared spectroscopy. Moreover, the zeta potential of pristine zirconia and ZCNC was evaluated in distilled water to examine the stability of the colloidal material. Zeta potential measurements revealed that adding ZCNC to conventional water-based mud (WBM) exhibited a zeta potential similar to bentonite with very minute changes. Moreover, SEM revealed that zirconia nanoparticles formed a uniform layer on the bentonite surface. For the WBM, rheology and American Petroleum Institute (API) mud-filtrate loss are generally controlled using polymers, and these properties could also be improved by adding a minute concentration of synthesized ZCNC. Incorporating nanoparticles into the bentonite layer might augment the colloidal behavior of drilling mud and improve the rheological properties. The yield point was enhanced after adding 0.3 wt % of ZCNC. The gel strength improved by 60% after adding 0.6 wt % of ZCNC to a conventional WBM. A gradual increase in the ZCNC concentration to 0.6 wt % reduced the API mud-filtrate loss volume and minimized the mud-cake thickness. These characteristics could be attributed to coating bentonite layers with zirconia nanoparticles and plugging interparticle pore spaces in the mud system.