Abstract
In the oil and gas industry, internal corrosion of metallic components and piping is caused by the associated water flow onto the surface along with the crude oil. Once established, the corrosion characteristics of the produced water changes due to corresponding change in the fluid properties. By continuously monitoring the corrosion rates and type of corrosion attack on the standard corrosion coupons it is possible to get an indication of the corrosion mechanism operating within different water streams. The corrosion mitigation measures also can be selected and applied based on the predominant corrosion mechanism operating in the system and optimized accordingly.
In this study internal corrosion monitoring data from effluent water treatment plants and seawater treatment plant is evaluated with respect to its dissolved H2S and bacterial activity respectively especially the oilfield bacterial counts (General Aerobic, General Anaerobic and Sulfate Reducing Bacteria). Distinct features have been observed on the corrosion coupons retrieved from sour and non-sour water systems and seawater service. Significantly lower corrosion rates and surface adherent FeS scale found on the coupons retrieved from the sour service were compared to that from non-sour waters and subsequent corrosion mitigation measures applied has also been presented here.
