Effect of Xanthan Gum Polymer on Corrosion Resistance of Flowline Material in Saline Environments

Abstract

Corrosion of flowline materials in saline environments poses a critical challenge to the oil and gas industry, leading to structural failures, environmental hazards, and high maintenance costs. Conventional inhibitors, though effective, are often costly and environmentally harmful, underscoring the need for sustainable alternatives. Investigation of xanthan gum, a natural polysaccharide widely used in enhanced oil recovery (EOR), as a green corrosion inhibitor for mild steel in saline conditions. Mild steel coupons were exposed to synthetic brine containing varied concentrations of xanthan gum, under controlled temperature and immersion durations. Weight loss analysis, supported by statistical tools including Analysis of Variance (ANOVA) and Response Surface Methodology (RSM), was used to evaluate inhibition efficiency and optimize operating parameters. Results showed that xanthan gum exhibited moderate protective capacity, with maximum inhibition efficiency of 17.28% at optimized conditions (0.74 g/L concentration, 34.8 °C, 12 days). Adsorption onto steel surfaces occurred via hydroxyl and carboxyl functional groups, forming a temporary barrier against chloride ion penetration. However, efficiency decreased at higher temperatures due to reduced film stability, indicating physic-sorption as the dominant mechanism. While xanthan gum cannot yet replace conventional inhibitors, its biodegradability, eco-friendliness, and dual functionality as a rheology modifier in EOR make it a promising candidate for inclusion in hybrid green corrosion management strategies. The findings highlight its potential to extend pipeline lifespan, reduce operational costs, and support the industry’s shift toward sustainable corrosion control.