Influence of carbon nanotubes, nanosilica and nanometakaolin on some morphological-mechanical properties of oil well cement pastes subjected to elevated water curing temperature and regular room air curing temperature

•Enhancing mechanical properties of oil well cement (OWC) pastes using different nanomaterials.•Increasing curing temperature causes a notable increase in the compressive strength.•0.1% CNTs causes a good enhancement in the mechanical properties of the hardened OWC pastes.•Optimum addition of NS to hardened OWC pastes is 1% at 25 and 90°C. Nanotechnology has shown great potential in different applications and presents solutions to some of the upstream and downstream challenges in the oil and gas industry. This research work aimed to improve the mechanical properties of oil well cement (OWC) pastes using multiwall carbon nanotubes (CNTs), nano-silica (NS) and nano-metakaolin (NMK). The effect of different curing temperatures, namely; room temperature and elevated temperature (90°C) on the hydration reaction of OWC pastes admixed with different nano materials was investigated. XRD, TG/DTG, and SEM techniques were used to investigate the phase composition and the microstructure of some selected hardened specimens. The obtained results indicated that all of the nano materials used in this study cause a notable improvement in the mechanical properties of hardened OWC pastes at both curing temperatures. In addition, NMK – OWC hardened pastes present the highest improvement in the mechanical properties among all of other tested mixes.