Waste Manag. 2025 Jul 8;205:114982. doi: 10.1016/j.wasman.2025.114982. Online ahead of print.
ABSTRACT
This study investigates the combined effect of blast furnace slag (BFS) and rice husk ash (RHA) as supplementary cementitious materials (SCMs) for oil well cementing applications across a wide temperature range. A simplex-centroid mixture design was used to formulate slurries with 0-50 % BFS and RHA replacement by weight of cement. Mechanical and microstructural properties were evaluated after curing at 47 °C (low-temperature) and 300 °C (high-temperature). At 47 °C, BFS-rich formulations showed superior performance, with the 50 % BFS slurry achieving a compressive strength of 48.89 MPa, significantly higher than the 39.64 MPa of the control slurry. Conversely, at 300 °C, RHA was crucial for mitigating strength retrogression. The 50 % RHA formulation reached 16.79 MPa, while the control sample’s strength dropped to 4.65 MPa. Formulations combining both wastes, such as 10 %BFS-40 %RHA, also demonstrated robust performance (11.87 MPa), exceeding the industry benchmark for high-temperature wells. Analysis of Variance (ANOVA) confirmed the statistical significance of these effects, and response surface models quantified the distinct contributions of each SCM. The novel contribution of this work is the systematic evaluation of the synergistic interaction between industrial (BFS) and agricultural (RHA) waste streams to create a versatile cement system. This study demonstrates the potential to develop a single, waste-derived cement formulation viable for both low and high-temperature well conditions, offering a sustainable alternative to conventional practices. While results are based on laboratory conditions, they provide a strong basis for future field-scale validation.
PMID:40633131 | DOI:10.1016/j.wasman.2025.114982
