Nanoparticles Patterned Ceramsites Showing Super-Hydrophobicity and Low Crushing Rate: The Promising Proppant for Gas and Oil Well Fracturing.

Abstract

An ideal proppant showing super-hydrophobicity and enough strength to bear high closure stress is revolutionary for the effective exploration of gas or oil in shale. Here, the ideal proppants were obtained by wrapping specially treated phenol formaldehyde resins around the cover of the traditional ceramsites. The resin coating is patterned with innumerable fluorine-modified silica nanoparticles, whose thickness is controllable. Benefitting from the low surface energy of fluorine, nano-roughness structures from nano-silica, and the adhesive action of the resin, the modified proppant exhibits awesome properties. The nanoparticle-patterned resin gives the ceramic proppants a water contact angle of 157.8° that has been proved to be stable after being treated in strong acid, thus dramatically accelerating the fracture conductivity for oil by 150% whereas totally preventing water passing through. Besides, it is the resin that reduces the crushing rate of the proppants by 52% and decreases the density of the proppants to 1.63 g/cm³.