The difference between corrosion engineering and corrosion management

Corrosion management is a relatively new term and not fully understood. Consultant Corrosion Engineer, NACE International member, and author Ali Morshed discussed the concept of corrosion management in a Materials Performance Interview Series. In excerpts from the podcast’s transcript (below), he defines the concept of corrosion management, breaks down its various components, and highlights the many benefits asset owners can realize through its implementation.

The origins and concept of corrosion management

Corrosion engineering has three components, which are design, material selection, and controlling the environment, like chemical treatment. This was what I refer to as the traditional or classical integrative management view. That if there is a corrosion problem, the root cause is corrosion engineering related, so the solution has to also be corrosion engineering related. Through the years, I found out that there were many non-corrosion engineering related factors that played a very important part in our corrosion problems and in resolving of corrosion problems. That helped me to formulate a model, which I later called corrosion management, which is being used these days, for the past eight years, as a means to mitigate and control corrosion initially in the hydrocarbon industry and later in the non-hydrocarbon industry.

When we deal with corrosion, we have to take into consideration both corrosion engineering-based and non-corrosion engineering-based factors. By the latter I mean factors or parameters like communication, competency, procedures, strategies, team structures, plant integrity windows. These are all non-corrosion-based parameters, but they play a very significant role in mitigating corrosion in our assets.

Some background as to where the concept of corrosion management concept came from…the corrosion management term came from the U.K. North Sea oil and gas industry in the late ’90s and early 2000s. U.K. is the birthplace for the concept. What I have to highlight here is that, unfortunately, still today there are many individuals, both in the hydrocarbon industry and in the non-hydrocarbon industry, who regard the term “corrosion management” as a mere synonym for corrosion engineering. When they talk about corrosion management, they are actually talking about corrosion engineering, because to them these two terms are synonyms, and this is, I believe, a wrong approach. Because corrosion management is a rather new and fresh term, there is still a great deal of confusion about its definition and its application.

In all the books and articles that I’ve written, I have used another definition which I believe is much more useful and practical. Based on this definition, corrosion management is the process of reviewing the required integrity management measures, regularly monitoring of their performance, and assessment of their effectiveness post-commissioning. So, when you look at this definition, corrosion management comprises three components, or three smaller processes.

I’ll give an example. In the oil and gas industry, we inject corrosion inhibitors into the system in order to control or mitigate the internal corrosion of our piping vessels or pipelines. A corrosion inhibitor is a chemical, most of the time a film-forming chemical, which produces a thin film on the inner surface of our equipment, thus separating them from the corrosive environment. If I want to apply the corrosion management concept to corrosion inhibitor injection, we mentioned that the corrosion management concept has got three smaller processes.

Definition of corrosion management

All in all, the corrosion management process is defined as a process comprising three smaller processes. This is my offered and preferred definition for the corrosion management concept.

The Integrity Review Process The first one was the integrity review process. So if I want to select and then inject a corrosion inhibitor, I have to review all the parameters which affect and influence the successfulness or the efficiency of a corrosion injection project. Such parameters include the location at which I inject the corrosion inhibitor, the concentration at which I inject a corrosion inhibitor, the type of the chemical which is going to be injected, the chemical compatibility of the system of course if you’re injecting a few different chemicals (beforehand you have to ensure that all these chemicals are compatible, i.e., they do not neutralize each other). Another parameter is the order at which we inject these chemicals. Another one is the process conditions, the flowrate, the temperature is too high, it might degrade the corrosion inhibitor chemical you are going to inject. These are the parameters which have to be taken into consideration, and you do that during your integrity review process.

The Monitoring Review Process Once you have started injecting your corrosion inhibitor, we go to the second process within the corrosion management concept, which is monitoring the performance. Of course, if you're injecting the corrosion inhibitor, your main target is to reduce the internal corrosion rate, so you have to monitor the inhibited corrosion rate, that is, you have to monitor the corrosion rate downstream of the location you are injecting your corrosion inhibitor. You have to have a measure of the corrosion rate after the injection of your chemical.

Assessing of Effectiveness Process The third process within the corrosion management concept was the assessing of the effectiveness. Once you have measured your inhibited corrosion rate, then you have to compare it with an acceptable inhibited corrosion rate to make sure that the rate you have measured, the rate you have recorded is equal to or less than that acceptable corrosion rate. Thus, you are assessing the effectiveness of your chemical treatment. If your measured corrosion rate is equal to or lower than your acceptable corrosion rate, then you're doing fine. If not, then you go back to the integrity review process. You have again to review all the parameters to make sure that your corrosion inhibitor is meeting its target, that’s the accepted corrosion rate.

Benefits of Applying Corrosion Management

According to traditional ways of education and training, when we were dealing with corrosion issues in the industry, we always looked into corrosion engineering-based parameters, like design, material selection, and controlling the environment. But the corrosion management concept teaches us that there are also non-corrosion engineering-based parameters which control corrosion mitigation as well.

When we take into consideration both the corrosion engineering-based and the non-corrosion engineering-based parameters, we can see the whole picture more clearly. As you can see the picture more clearly, you see your corrosion problems better. And when you see your corrosion problems better, you can offer and implement better solutions. This corrosion management application provides a great deal of benefits. I will just mention a few of them.

Identification of Deterioration Mechanisms

One benefit is that through the corrosion management process, you can identify your existing and future deterioration mechanisms. Once you know what your deterioration mechanism is, then you can come up with a solution to stop it or mitigate it. So identification of the existing or future deterioration mechanisms is one great benefit of corrosion management. 

Reduced Deterioration Rates The other benefit is reduced deterioration rates. Through the corrosion management concept, you have a better understanding, more clear understanding of the system, your operational parameters, process parameters, and corrosion problems. You do better inspections, you use your corrosion rate monitoring and sampling systems more efficiently, and that helps you to have a better mitigation program in place, and that means you can more successfully and more efficiently reduce your corrosion rates or your deterioration rates. It stands to reason once you have managed to reduce your corrosion rates, you will have less corrosion leaks.

Increased Asset Uptime Another benefit which I can list here is the increased asset uptime. If you can manage to reduce the number of your corrosion accidents and corrosion leaks, you will be operating and producing for a longer time. So increased asset uptime is another great benefit. 

Extended Asset Lifespan Another benefit that we see is extending asset operational life beyond the design considerations. If you have designed your asset for 30 years and you manage to keep your deterioration or corrosion rates low, maybe you can operate your asset for 35 years instead of 30 years, or even 40 or 50 years.

Safety and Environment Protection Other benefits include improved personnel safety and environmental protection. Of course, if you're having lesser leaks (for example in the oil and gas industry), then the safety on site and the environmental protection are increased.

Risk-based Inspections Another very important benefit of corrosion management implementation is that our inspections become risk based. You know we have got different types of inspections, which are the consequence-based inspections, time-based inspections, and the risk-based inspection. In an asset where we are implementing corrosion management, the inspections become risk based. When they are risk-based, they have a greater capability to find corrosion failures before they happen. In other words, when you're implementing corrosion management, you are actually enhancing your corrosion failure preemption capability. That’s very important, so I have to reiterate it here again. Through corrosion management applications, our inspections become risk based. When we are carrying out risk-based inspections, we enhance the corrosion failure preemption capability of our team or of our asset. We have a greater ability to identify corrosion leaks before they actually become a leak or an issue.

Cost Benefits Another important benefit of corrosion management application are cost benefits. Through corrosion management application, you optimize your corrosion and integrity costs. It’s very obvious. If through corrosion management applications you're reducing the number of your leaks, you're reducing the costs. Because after each leak, you have to pay for repair and maintenance. You have to pay for extra labor. You have to pay for the transfer of spare parts to the location. Sometimes there are legal fees, there are fines. So if you manage to reduce the number of leaks, you are reducing your corrosion costs.

Corrosion management’s greatest benefit

Of course, as I mentioned earlier, because in the corrosion management process we mentioned the first small process is the integrity review, you will review all the mitigation measures you have got in place. If you are injecting a chemical, you review the parameters which influence it. If you have got a coating, you will review the parameters which affect the successful performance of the coating. If you have got a cathodic protection system, you do the same. You are already spending money on your chemical treatment, on your inspection, on your coating, on your cathodic protection system. But through corrosion management, all this spending will become very wise spending because you're improving the effectiveness of all these different programs. Through improving them, you are actually making them more efficient. Cost optimization is one of the greatest benefits of corrosion management applications.

Fight and mitigate corrosion in the hydrocarbon industry or your own industry with An Introduction to Asset Corrosion Management in the Oil and Gas Industry, Third Edition by Ali Morshed.

Source: Materials Performance podcast Interview Series, fall 2020.

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