It is well known that the oil and Gas industry is suffering from the effects of corrosion. ‘Corrosion is seen lining the oil plants that occur during hydrocarbon refining process. It is the breakdown of a metal into its atomic form due to chemical reactions with its surroundings. The effect of corrosion in the oil industry leads to the failure of parts which in turn leads to shut down. According to ZerustOil-Gas ‘The amount spent in the cleaning and adverse effects of corrosion on a year amounts to US$ 3.7 billion.’
In a lecture delivered by Udoka Obi, a University of Aberdeen PhD student and supervised by Dr Alfred Akisanya on the ‘Effect of ageing on phase evolution, mechanical and corrosion properties of a high tungsten super-duplex stainless steel’ she presented a study on the influence of ageing parameters on the microstructure of a duplex stainless steel 2507. Her argument is that ‘Alloy 2507 (UNS S32750)’ which is a super duplex stainless steel with 25% chromium, 4% molybdenum, and 7% nickel designed for demanding applications which require exceptional strength and corrosion resistance, are also not suitable to prevent corrosion completely, according to Udoka, ‘Although, the steel has excellent resistance to chloride stress corrosion cracking, high thermal conductivity, and a low coefficient of thermal expansion. The high chromium, molybdenum, and nitrogen levels provide excellent resistance to pitting, crevice, and general corrosion; but under intense monitoring and when super duplex stainless steels are exposed to temperatures below the solution annealing temperature, the metastable thermodynamic balance is disturbed, causing the material to seek a more stable thermodynamic state through the precipitation of intermetallic phases and a microstructural imbalance between ferrite and austenite.’The results of her study confirm that the relationship between microstructure and mechanical properties require further logical research and the effect of change in microstructure evolution on the mechanical properties was not conclusive.
A company known as Permasense Limited in April at the world’s foremost event for the development of offshore resources in the fields of drilling, exploration, production and environmental protection – the continuous corrosion monitoring system, provided an insight into the benefits of continuous monitoring for upstream applications, and demonstrating how its corrosion monitoring system works, but they also claim that understanding the levels and rates at which damage may be occurring is also an ongoing challenge. The company provided a permanent installed solution that can operate in extreme temperature environments and inaccessible locations. The structure combines ultrasonic sensor technology with wireless communication to deliver data of the highest integrity to the end user. They showcased its new long-range corrosion monitoring system which allows retrieval of data from monitoring locations up to 40km (25 miles) from the gateway location. Building on the proven technology of their short-range system, the long-range system has been developed to allow for easy deployment on pipeline and feeder lines upstream and midstream. Again, the system offers an efficient and safe way to monitor the integrity of pipework enabling better informed decision making and improving operator flexibility. According to the CEO Dr Peter Collins, “Continuous measurement presents a step change in the levels of corrosion rates that can be determined and the accuracy of that determination. We are pleased by the rapid acceptance of our breakthrough technologies by the industry, with more than 4000 sensors already in operation in over 40 facilities in 11 countries.” The system has been deployed in refineries and upstream facilities, including offshore platforms, worldwide. Their application will go a long way to encourage wireless sensor network experts in using their skills to tackle other problems in the oil and Gas industry.