Carbon dioxide (CO2) is found in oil and gas fields in varying concentrations. Dry CO2, be it in gas phase or a supercritical fluid is not corrosive to metals and alloys. However, in presence of water-containing produced fluids, severe corrosion of the infrastructure may result due to the formation of carbonic acid.
Corrosion of materials in contact with CO2-containing fluid is dependent on various factors. These include: (i) Concentration of CO2 (and other components like H2S), (ii) water chemistry, (iii) operating conditions, and (iv) material type.
The economic impact of CO2 corrosion has been known to the oil and gas industry for a long time. Many mitigation methods have been implemented. However, as new fields with ever increasing temperatures, pressures and varied produced fluid composition are explored, the corrosion performances of existing and new materials need to be assessed.
TWI has a dedicated corrosion laboratory, currently with 485m2 of floor space which is soon to be 1000m2. The capability is specifically designed to handle H2S, CO2 and other process fluids. TWI has the capability to carry out testing in large solution volumes and in occluded volumes suitable for flexibles.
TWI has wide ranging expertise in CO2 corrosion damage investigation and remedial recommendations, with particular awareness of the influence of welding and joining technologies upon materials performance.
TWI has the expertise to carry out both industry standard tests and specifically tailored tests to meet the requirements of the clients. We have several facilities to carry out CO2 corrosion tests in gas phase and in supercritical fluid in the presence of water and other impurities (e.g. H2S).
It has been reported that the cost of corrosion in many developed nations is over 4% of their GDP. Mitigation of corrosion and methodology to determine corrosion rates can result in significant cost saving. In addition, this will also result in safe operation and accurate remaining life assessment to avoid the expensive consequences of failure of components during service.
TWI has carried out several confidential works in the area for clients around the globe. Several Joint Industry Programmes have been completed in the past few decades.