Crude Oil and Natural Gas Conduit Corrosion Durability (CCD) in Coastal Mangrove Swamp Environments of Niger Delta Regions-Nigeria (Published)
Pipeline network among other means of crude oil and natural gas transportation have been long identified as one of the most essential and effective oil production midstream unit that ensures availability of crude oil as industrial feedstock and its distillates as products for man daily consumption as fuel/energy and petrochemicals precursors. This system is highly attacked by corrosion agents which affects its durability over time as a function of the pipeline type. In this work, crude oil and natural gas conduit corrosion durability (CCD) in coastal mangrove swamps environments of Niger Delta regions-Nigeria is been assessed correspondently with the degree of the environmental physiochemical response to the corroding system with 77 days exposure period. Using three pipelines of same material properties; 45 inches (3.75 ft or 114.3 cm) long, 3.1 inch (0.258333 ft or 7.874cm) internal diameter, making the volume of 377.38 cubic inches (0.2184 ft3) and 59.8424 g/cm density, subterranean as conduits in Okrika, Kalabari and Bonny coastal mangrove environments of the Niger Delta regions -Nigeria, the LCS non-coated pipelines corrosion response were determined as a function of the exposure period, as well the soil physiochemical properties behavior with the studied period, using physical and non-destructive testing methods. The result was able to identify that the LCS non-coated pipelines of 8.46kg individual weights depleted to 7.032kg, 7.109kg and 6.934kg over 77 days’ exposure period in Okrika, Kalabari and Bonny coastal regions respectively, leading to the increase in the metal cumulative weight loss. It was also identified that Bonny coastal mangrove regions (S3) tends more corrosion enhancing compared to other two, with a cumulative weight loss of 1.526kg attained within the 77 days studied period, which is greater than that attained by Okrika (S1) and Kalabari (S2) as 1.428kg and 1.351kg respectively. Also, corrosion rate of mm/yr was recorded for the Bonny coastal mangrove environment, while mm/yr for Okrika mangrove and mm/yr for Kalabari mangrove. It was also noticed the mangrove environmental DO and pH reduces with increase in the exposure time, while EC increases slowly. The internal corrosion assessment of the pipelines was also carried out using Long Range Ultrasonic Testing (LRUT) equipment which was able to identify a small depletion of the pipeline over time of study. Conclusively, LCS metal used as conduit in mangrove region experience a fast and spontaneous degradation in a coastal mangrove region of Niger Delta, especially that of Bonny, and the rate of corroding affects the environmental physiochemical properties. Hence, it’s recommended that proper assessment of the pipeline should always be carried out to safe guide the transported fluid from been spilled over time, also, efficient coating/inhibition should be applied on the pipelines running through the mangrove regions as they gets corroded fasted than expected.
Keywords: Bonny and Kalabari regions, Long Range Ultrasonic Testing (LRUT) equipment, Oil-spillage, Okrika, River state, Weight Loss, barges and tankers, pipeline, transportation measures durability