INVESTIGATION OF RHEOLOGICAL AND FILTRATION CHARACTERISTICS OF NIO NANOPARTICLES WATER-BASED DRILLING FLUID FOR HPHT DRILLING

The demand for drilling deeper wellbores to extract energy resources from deep reservoirs is growing rapidly. Drilling in formations where high temperatures and pressures are encountered is a challenging task. One important aspect of this challenge is to develop drilling fluids, which can function well in such harsh conditions. Use of nanoparticles (NPs) in various areas in petroleum engineering research has gained popularity in recent years. This is partly because of their favorable properties such as strong heat conductivity, large surface area that can significantly improve characteristics of the drilling fluid. The key benefits of using NPs in drilling fluids include a decrease in formation damage, improved heat transmission and lubrication, better control over fluid loss, and enhanced rheological properties. The main objective of this research work was to investigate the effect of using NiO NPs on rheological and fluid filtration characteristics of a water based drilling fluid prepared with this NPs under a wide range of pressure and temperature. NiO NPs were selected because they have already exhibited excellent results in EOR and asphaltene adsorption tests. The NiO NPs were characterization by using transmission electron microscope (TEM) and scanning electron microscopy (SEM). The rheological properties of the drilling fluid samples containing 0, 0.25, 0.5, and 1 wt.% of NiO NPs were measured at temperatures ranging from 25°C to 100°C. Regarding the filtration properties, the drilling fluid samples containing 0, 0.25, 0.5, and 1 wt.% of NiO NPs were tested at 130°C and 500 psi differential pressure. The results obtained from this research work showed that, the filtrate volume and filter cake thickness were lower in the test samples with NiO NPs than in the control sample. The SEM analyses of filter cake demonstrated positive effect of NiO NPs on morphology. The Herschel-Bulkley model fitted best to the experimental shear stress and shear rate data for the smart drilling fluid. The optimum concentration of NiO NPs for both rheological and rheological properties was found to be 0.25 wt%. Overall, adding NiO NPs to a water based drilling fluid enhanced its properties for HPHT condition