Critique Of Corrosion Monitoring Methods Used In Oil And Gas Production And Transportation Facilities

In oil and gas production, carbon steel is widely used as the material of construction for downhole tubing, vessels and piping. Although it is inexpensive compared to stainless steel, carbon steel is susceptible to corrosion attack from CO2 and/or H2S present in the produced water. Therefore, the corrosion risks of this material have to be proactively managed. To this end we have to develop and to implement corrosion control strategies which integrate risk assessment and corrosion control with corrosion monitoring and inspection. The application of corrosion monitoring as part of a corrosion control strategy is complex and often becomes the responsibility of engineers who are not experts in the field. The aim of corrosion monitoring is primarily to ensure that the design life is not being adversely affected or compromised and also to maximise the safe and economic operational life of a facility. When undertaking corrosion monitoring it is important not to rely on just one method. The best results are obtained by using a range of techniques. Some corrosion measurement techniques can be used on-line, constantly exposed to the process stream, while others provide off-line measurement, such as that determined in a laboratory analysis. Some techniques give a direct measure of metal loss or corrosion rate, while others are used to infer that a corrosive environment may exist. The aim of this work is to provide an aid to the operator in the choice of the corrosion monitoring technique