Employing Nano-sized Additives as Filtration Control Agent in Water-based Drilling Fluids: Study on Barium Sulfate, Bentonite, Surface-modified Bentonite, Titanium Oxide, and Silicon Oxide

Abstract

ABSTRACT A vast number of Nanoparticles (NPs) can enhance the properties of water-based drilling fluids. The performance of NPs in drilling fluids depends on the host fluid’s formulation, temperature, and pressure. Therefore, comparing different NPs’ performance on the filtration properties of water-based fluids at exactly similar conditions is the main objective of the present study. For this purpose, five NPs, including barite (barium sulfate), bentonite nanolayers, a surface-modified bentonite, namely CLOISITE5, TiO2, and SiO2, are selected. Four concentrations of each of the NPs (1–4 wt%) were separately added into a base fluid formulation. Since all the NPs did not decrease the base fluid’s rheological parameters, API filtration test was implemented for all the nanofluids to support the idea of this study. The optimum concentration of all the NPs was selected by analyzing the cumulative filtrations after 30 minutes, the spurt losses at the initial seconds of the test, and also the cakes’ thickness. Also, the permeability of the obtained cakes is compared with the base cake. Then, the filtration test was performed for the optimal nanofluids under 500 psi pressure and 200 ℉ temperature to investigate the NPs’ efficiency at HPHT formations. As it has been assessed with details along with the paper, all the NPs can reduce total fluid loss and spurt loss of the base fluid due to increasing the solid content and forming thicker cakes. Moreover, TiO2 at all the concentrations provides a cake less-permeable than the NP-free cake. 4 wt% barite, 2 wt% bentonite nanolayers, 1 wt% CLOISITE5, 4 wt% TiO2, and 4 wt% SiO2 show the best performances among the nanofluids containing the same NP. In a sentence, the NPs’ potential arrangement to reduce the fluid loss overall is as follows: TiO2, bentonite, barite, CLOISITE5, and SiO2.