Application of Low-Density Oil Well Cement Slurries Containing Ceramic Microspheres Associated with Sodium Silicate: An Eco-Friendly Alternative

The cement industry is a significant contributor to global pollution, accounting for approximately 7% of the carbon dioxide emissions. This has led to the development of sustainable, high-performance materials for sensitive applications such as oil well cementing. This study developed and characterized a cementitious composite, in which part of the cement was replaced by hollow ceramic microspheres (MS) combined with sodium silicate. This innovative approach resulted in a more environmentally friendly product by reusing low-value industrial waste. Mechanical and chemical characterizations, such as compressive strength, shear stress, pressure analysis, X-ray fluorescence (XRF), X-ray diffraction (XRD), and scanning electron microscopy (SEM), were conducted to evaluate performance. The optimized paste was further analyzed through high-pressure rheology, providing key experimental data for reservoir simulations. The material showed Bingham-type rheological behavior and achieved a compressive strength of 9.35 MPa, which is significantly higher than that of conventional pastes (4 MPa). Additionally, it met the stability standards of the Brazilian oil industry, confirming its suitability for oil wells with low fracture gradients.