Enhancing the properties of water based drilling fluid using bismuth ferrite nanoparticles

Drilling fluids are characterized by rheological and filtration characteristics and control of these properties is critical to the success of drilling operation. Among the popular additives for the control of these properties, nanoparticles are emerging to be one of the best additives for drilling fluids. For water based muds, rheology and filtration loss is generally controlled by polymers and it can also be improved by addition of small amounts of nanoparticles. In this paper, we have synthesized a BiFeO3 (BFO) nanoparticle by non-aqueous wet chemical techniques and used as additive for water based mud along with bentonite and other polymeric additives. BFO nanoparticles showed good compatibility with clay resulting in improved mud properties. Interaction of nanoparticles with clay and polymers resulted in enhanced apparent viscosity (AV), plastic viscosity (PV), yield point (YP), and API fluid loss. It was found that increasing the nanoparticle concentration from zero to 0.30 w/v % resulted in 25% increase in AV, PV and YP whereas a 35% decrease in API filtrate loss was observed at 20 degrees C before hot rolling. Even after hot rolling at 110 degrees C, these properties were not degraded significantly as was the case with mud without nanoparticles. Nanoparticles combined with bentonite platelets imparted good thermal stability to the drilling fluid.