Preparation of Nano-silica Fume Coating Rubber Composite Particle and Its Application in Toughening the Oil Well Cement Stone

A kind of nano-silica fume coating rubber composite particles was prepared by the Particle Composite System (PCS), and the adhesion performance of composite particles was tested by the high-speed agitating test, the composite particles were filled into the oil well cement slurry to toughen the oil well cement stone. The results indicated that the surface of the rubber particles is coated with nano-silica layer, and the composite particles are grey; the adhesion between the silica fume and the rubber particles is good; the elastic modulus of oil well cement stone reduces by 20% and the Possion ratio increases by 5.1% as the filler fraction is 4 wt.%. Therefore, the nano-silica fume coating rubber composite particles can improve the toughness of oil well cement stone.