▎ 摘　　要

Hybrid effects of nano-silica and graphene oxide on mechanical properties and hydration products of oil well cement have been investigated by means of TEM, TGA, XRD, SEM, MIP and mechanical testing. The results showed the designed hybrid structure was beneficial for SiO2 particles and GO nanosheets to disperse well in alkaline cement. The compressive and flexural strength of cement with hybrid nano materials of 1.5% NS and 0.03% GO was increased by 43.2% and 42% with 28 days of curing respectively, which was far better than cement with single NS or GO. Graphene oxide and nano-silica have a hybrid effect including better dispersion of nano-materials, higher degree of hydration and pozzolanic reaction, and network structure formation of hydration products, all of which were beneficial to reinforcing the mechanical properties of cement. (C) 2018 Elsevier Ltd. All rights reserved.