Effectiveness of natural inhibitors against oil pipeline corrosion under corrosive conditions in the Berkaoui Region

Abstract

Microbiologically Influenced Corrosion (MIC) represents a major challenge to the integrity of oilfield infrastructure, particularly in the Haoud Berkaoui oil field, where chemical factors such as carbon monoxide (CO) and hydrogen sulfide (H₂S), together with corrosive bacterial species such as Sulfate-Reducing Bacteria (SRB), accelerate equipment degradation. This study investigates the corrosion inhibition properties of oregano, rosemary, and neem extracts as natural and environmentally friendly alternatives to conventional chemical inhibitors. The extracts, rich in bioactive compounds such as thymol, carvacrol, and flavonoids, were tested at different concentrations on X52 steel specimens under simulated oilfield conditions. Weight-loss measurements and microscopic analysis revealed that the addition of oregano, rosemary, and neem extracts significantly reduced the corrosion rate and shifted corrosion potentials toward more negative values, indicating a cathodic inhibition behavior. These extracts formed a protective barrier against corrosive species and inhibited the activity of sulfate-reducing bacteria (SRB). The results indicate that oregano, rosemary, and neem extracts provide effective corrosion protection while contributing to sustainable and environmentally responsible corrosion management practices in the hydrocarbon sector. Further optimization and field testing are recommended to validate their industrial applicability and long-term performance