A Review of Monitoring and Inspection Techniques for CO₂ & H₂S Corrosion in Oil & Gas Production Facilities: Location, Location, Location!

Oil and gas production facilities around the globe extract, process and transport an incredibly wide range of fluids. The fluids can contain a variety of species including water, Carbon Dioxide (CO₂) and Hydrogen Sulphide (H₂S) which can combine to form a corrosive medium. The majority of facilities are constructed from mild steel which, depending on the exact composition of the fluid, can corrode at rates exceeding 25 mm/y (1,000 mpy). In order to minimize safety and environmental risks, it is essential the fluids remain contained inside the equipment. To do this, as well as maximize the uptime and lifetime (and hence profit) of the facilities, they must be maintained in a fit-for-service condition. To keep facilities fit-for-service it is important to know the condition of the equipment at all times.

This paper provides an overview of the range of inspection and corrosion monitoring methods available to oil and gas facilities in CO₂ and/or H₂S corrosive environments. Every technique has benefits and limitations and it is the role of corrosion and inspection engineers to determine which technique(s) provide the most cost effective value. It is suggested that any credible mechanical integrity program will use a mixture of monitoring and inspection techniques to provide both tactical (short term) and strategic (long term) information.