Combating Subsea Pipeline Corrosion Using Papaya Leaves

Abstract Over the past two decades, numerous pipeline networks within Nigeria's oil and gas industry have experienced severe failures. This is largely attributed to the corrosive nature of the operating environment and the transportation of corrosive fluids through these oil pipelines. In this research, the Papaya leaf extract (PLE) was prepared and utilized to slow down the corrosion of Subsea Pipelines (SP) in harsh offshore environments. The experiment was conducted using the gravimetric (weight loss) method, using 12 specimens (coupons) comprising three metal coupons in the proportion of four Aluminum, four Mild steel and four Galvanized Steel. The coupons were kept in a workable state to prevent them from any preferential attack. The coupons were rinsed in distilled water, dried, and weighed to obtain the initial weights. Each coupon was immersed into a beaker containing 200 ml of seawater polluted with 1M H2SO4 solution and varying PLE concentrations. Through a five-day exposure period and varying PLE concentrations (8 ml, 12 ml, and 16 ml), the experiment utilizes a control group (0 ml PLE) to gauge inhibitor effectiveness. Quantitative analysis of weight loss (WL) and corrosion rates (CR) provided critical insights into the inhibitory potential of PLE for subsea pipeline corrosion prevention. Notably, the efficiency of the 16 ml inhibitor demonstrated superior performance, showcasing overall efficiencies of 19.44%, 79.82%, and 86.03% for AL, MS, and GS samples, respectively. Also, the MS had the least weight loss at 13.4% proving to be a better material choice for subsea pipelines. This research contributes essential quantitative data, emphasizing the impact of PLE concentration on corrosion resistance and positioning PLE as a promising eco-friendly inhibitor for subsea pipeline protection.