Zirconium oxide nanoparticle as an effective additive for non-damaging drilling fluid: A study through rheology and computational fluid dynamics investigation

The upsurge of drilling in shale and inaccessible reservoirs led to the emergence of Non Damaging Drilling Fluid (NDDF). Although this drilling fluid is non-invasive, the loss of rheological properties at high temperature poses a serious concern. In this study, we have investigated and quantified the enhancement in the performance of NDDF with the addition of zirconium oxide (ZrO2) nanoparticles (NPs) at 30, 60 and 80 °C. The synthesized ZrO2 NPs were of average 27 nm in size and were further characterized by Scanning Electron Microscope (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET) adsorption methods. Varying concentrations, viz., 0.5, 0.8 and 1 wt% of ZrO2 NPs have been used to investigate their effect on various properties of NDDF. From the steady state rotational tests and viscoelastic measurements, it was observed that 1 wt% of ZrO2 NP NDDF had higher thermal stability in terms of viscosity and elasticity with a minimum filtrate loss. The ability to regain structural strength was also enhanced with the addition of ZrO2 NPs. Herschel Bulkley (HB) parameters from rheological measurements were calculated and optimized using genetic algorithm (GA) and were used to further carry out computational fluid dynamics (CFD) analysis. From CFD simulation results, it was observed that 1 wt% ZrO2 NP NDDF exhibited highest cutting carrying capacity as compared to 0 wt% (the base), 0.5 wt% and 0.8 wt% ZrO2 NP NDDF. Additionally, higher skewness in cutting deposition was observed for 1 wt% ZrO2 NP NDDF, limiting the possibility of bottom hole complications while drilling. This study is an important precursor for the oilfield application of nanoparticle based NDDF.