Nano SiO2/Welan gum nanocomposite—microbial polysaccharide thickener used for 220 ℃ water-based drilling fluid, high-temperature sedimentation control stability

Temperature-Responsive Nano-SiO2 Composite for Improving Shale Stability in Oil-Based Drilling Fluids

“…Organic/inorganic composite materials composed of an inorganic rigid material as the core and an organic deformable material as the shell could be plugged by synergistic actions. ,− Inorganic core materials could bridge and plug shale nanopores, while organic materials fill the pores formed by rigid bridged nanocomposite through their excellent deformation properties. The two materials may work synergistically to form a tight plugging layer on the rock surface to prevent loss of drilling fluid, thereby protecting the well wall. − Zhong et al prepared a hyperbranched polyethylenimine modified nano-SiO 2 with dual effects of chemical inhibition and physical plugging . Nano-SiO 2 plugged the micropores of the shale formation, while the hyperbranched polyethylenimine adsorbed onto the clay surface through electrostatic and hydrogen bonding, thereby reducing fluid loss.…”