Synergistic effect of nano-silica slurries for cementing oil and gas wells

Abstract

Nanosilica, when combined with cement slurry aids in improving its compressive strength even, reduces the wait-on-cement time for cement plugs. This study focuses on the synergistic effect of nano-silica in oil and gas well cementing. A comparative study is conducted on the performance of cement slurry (conventional 118 pcf (15.8 lbm/gal) with nanosilica and cement slurry without nano-silica. The cement slurry combined with nano-silica has shown an early compressive strength development in cement slurry at different concentration of silica fume at 10% and 20% by weight of cement. This study also focuses on other areas for improvement including slurry stability, free fluid reduction, lower fluid loss value, fine rheology, appropriate thickening time and higher ultimate compressive strength development. The cement slurry with nano-silica has shown improvement in the compressive strength due to the increased rate of hydration, thus thickening time was within 5hrs. Keywords: Nanosilica, Thickening time, Compressive strength, Ultrasonic cement analyzer