| Abstract |
China possesses abundant hydrothermal geothermal resources with significant development potential. However, the presence of corrosive components (e.g., oxygen, carbon dioxide, hydrogen sulfide, chloride ions) and scaling issues in geothermal fluids severely impacts both surface pipelines and downhole equipment, leading to reduced efficiency and operational risks. Current scale inhibitors and conventional dosing methods struggle to provide long-term protection, particularly in harsh downhole environments where high temperatures, pressures, and fluid dynamics accelerate corrosion and scaling.To address these challenges, this study innovatively developed melamine-formaldehyde (MF) resin-coated microcapsules for sustained-release anti-corrosion and scale inhibition. Through in-situ polymerization, polyepoxysuccinic acid (PESA, scale inhibitor) and octadecylamine (ODA, corrosion inhibitor) were encapsulated within MF microcapsules, forming MF/PESA-ODA composite microcapsules. The microcapsules were characterized via scanning electron microscopy (SEM), and their encapsulation efficiency, stability, and release performance were systematically evaluated. Results demonstrated that the microcapsules exhibit a smooth surface, uniform particle size, high stability, and an encapsulation rate of up to 92%. Sustained-release tests under both static and dynamic conditions showed release rates of 80% and 86.2%, respectively, confirming excellent controlled-release properties.This technology not only ensures long-term protection for long-distance pipelines but also significantly enhances downhole application effectiveness. By maintaining consistent inhibitor release under extreme conditions, it improves the utilization efficiency of anti-corrosion and scale inhibitors, reduces maintenance frequency, and extends the service life of geothermal wells and associated infrastructure. |