<p>Calcium carbonate scaling poses a significant challenge in oil and gas production, hindering recovery and impacting economic viability. This study utilizes microfluidic "reservoir-on-chip" platforms to visualize, quantify, and characterize CaCO₃ precipitation in hydrophobic and hydrophilic porous media to elucidate scaling mechanisms. Traditional methods face limitations in observing the intricacies of scale formation at the pore scale. Microfluidic platforms, however, offer real-time, high-resolution visualization of flow dynamics and scale deposition, enabling the study of key parameters like temperature, solution concentration, and surface wettability. This research investigates the impact of these parameters on CaCO₃ scaling, with a particular focus on wettability's influence on the nucleation process. By elucidating the interplay of different factors, this study aims to provide insights into mitigating and controlling scale formation in oil and gas production. Our findings demonstrate that the covered area by precipitates increased with increasing temperature and concentration for both hydrophobic and hydrophilic surfaces, with more substantial coverage observed on hydrophilic surfaces. Scanning electron microscopy and X-ray diffraction analysis confirmed the presence of calcite, vaterite, and aragonite polymorphs. Furthermore, the findings hold implications for advancing carbon capture, utilization, and storage (CCUS) technologies, particularly mineral carbonation, by providing a deeper understanding of carbonate formation dynamics at the pore scale.</p> Graphical abstract <p></p>