Abstract:

Conventional low-density cement slurry has low compressive strength, and sphereliter low-density slurry’s density will increase rapidly under high pressure in deep wells. Based on optimization of granular dry blends, this work has developed ultrahigh-performance light cement made with vermiculite as a lightweight material and other silica materials. Laboratory experiments show that this light cement, with densities ranging from 1.35-1.50 g/cm3, exhibits high compressive strength, good rheology, low fluid loss and high slurry stability under high pressures. As such, the cement can be used for wells with low fracture pressure. SEM and XRD techniques have been used to investigate the effect of vermiculite on cement hydrating and hardening processes.

Key words: low-density drilling fluid, light cement, vermiculite, laboratory test, well cementing