S09 ORME 2 2021 Endress & Hauser_Layout 1 09/03/2021 14:44 Page 34
Corrosion Protection
Addressing corrosion challenges
with digital solutions Image Credit: Emerson Automation Solutions
Pankaj Lahoti, MEA Corrosion & Erosion subject matter expert, Emerson Automation Solutions, discusses how digital solutions can be leveraged to improve and facilitate internal corrosion monitoring and inspection. IL AND GAS operators across the Middle East face tremendous pressure to improve their production margins to stay competitive. Production facilities – refinery, gas plant or gas-oil separation units – are expected to reduce their operational expenditure, delay shutdowns, improve the HSE index of their facility – and achieve all of this with limited access to CAPEX budgets. Restricted personnel movement due to COVID is further restraining plant corrosion and inspection teams to conduct even the regular maintenance and inspection activities. With infrequent or reduced data collection, the threat of loss of primary containment is imminent. Advancements in technology around connectivity and analytics provide operators with an opportunity to navigate these difficulties by digitalising their corrosion monitoring and inspection methods.
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Continuous corrosion monitoring solutions
The traditional method Oil and gas operators have been using several types of instrumentation for corrosion monitoring, and two of the most common are corrosion probes and manual ultrasonic inspection. Intrusive corrosion (or Electrical Resistance, ER) probes have been in use for more than 60 years. They are considered a very well-established technology that often consists of an intrusive element with a sacrificial tip sitting in the fluid. It is typically made of the same material as the surrounding equipment. Data collection happens via offline dataloggers or wired connection to the control system. On the other hand, manual ultrasonic inspection has been used for half a century
Online corrosion monitoring is only as good as the software used to analyse the data.” 34
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NDE technician. Also, the equipment used and the NDE technician's skill level can vary between measurements, introducing high variability to the measurements. High temperatures above 100°C (212°F) can, at times, permanently damage the NDT (Non-Destructive Testing) equipment. There are also safety risks to the NDT technician at higher temperature locations. Physical access – the NDT technician requires access to the equipment at the measurement location of interest, which involves scaffolding (possibly permanently installed) and stripping insulation to expose the metalwork to make the manual measurements, involving high costs. At times, it also delays measurement until shutdown.
Pankaj Lahoti, MEA Corrosion & Erosion subject matter expert, Emerson Automation Solutions.
and is considered a conventional technique for measuring metal wall thickness. This involves the generation of ultrasound from a transducer placed directly onto the metal surface or back wall. The reflected ultrasound or A-scan is then recorded, and the time difference or “time-of-flight” between the sending and reflected signals provides the measurement of the wall thickness. Although the technique is reliable, completing a full set of measurements for a typical production plant with thousands of corrosion measurement locations (CMLs) tends to be very time-consuming and labour-intensive. Other disadvantages associated with this technique are: Poor repeatability – It is highly unlikely that consecutive measurements will be taken in precisely the same location by the same
The best practices now consist of using permanently mounted ultrasonic sensors that measure wall thickness and employ wireless data retrieval. Once deployed on critical TMLs, these sensors provide good quality and frequent data otherwise unavailable, and are cost-effective and straightforward to deploy at a scale. The information supports a wide range of operational decisions due to its sensitivity to small changes in wall thickness, robustness to extreme plant conditions (up to 600ºC), and extended battery life enabling reliable operation over the entire cycle between turnarounds. Data is transferred using industry standard Wireless HART communications to the multiple end users’ desk, allowing frequent, reliable, and safe wall thickness monitoring. Online corrosion monitoring is only as good as the software used to analyse the data. Independent market research shows corrosion monitoring software and software services growing faster than any corrosion monitoring hardware over the next five years. Operators may gain access to an abundance of data, but knowing how to use it to produce actionable insights is the key. Emerson Automation Solutions identified
