Sustainable cement blends for oil well steam injection using rice husk ash

This study involves applying Rice Husk Ash (RHA), a sustainable source of silica, as an alternative to the use of Silica Flour (SF) in well cementing prior to steam injection. Slurries were prepared containing 20% and 30% BWOC of RHA along with standard slurries without additives and with 40% BWOC of SF. Behavior of the slurries was investigated using X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and uniaxial compressive strength assays. The results indicate that adding 30% of RHA and silica flour makes it possible to maintain compressive strength in the cement, and presents C-S-H crystalline phases rich in silica (Xonotlite and Tobermorite), as demonstrated by XRD, TGA and SEM. That makes it more attractive than standard slurry with 20% of RHA. That substitution makes slurry RHA competitive with SF and interesting for industry, due to its high content of renewable silica along with a low production cost.