Digging into Mic

Corrosion-causing bacteria account for approximately 20 percent of corrosion failures in oil and gas pipelines, and billions of dollars of damage each year. Yet, relatively little is known about how this phenomenon, known as Microbiologically Influenced Corrosion (MIC), occurs.

In 2016, a $7.8 million collaborative research project involving four universities in Alberta and Atlantic Canada was launched with the aim of filling in some of our knowledge gaps about MIC. Managing Microbial Corrosion in Canadian Offshore and Onshore Oil Production (“geno-Mic” for short) uses genomics to better predict how, where and why MIC occurs and how to mitigate it. Ultimately, a better understanding of MIC could improve infrastructure integrity, reduce the potential of oil spills, and improve worker safety – potentially reducing operating costs and saving Canada’s oil and gas industry $300-500 million over 10 to 20 years.

The project is funded by the federal government under Genome Canada’s Large-Scale Applied Research Project Competition (LSARP) with additional support from multiple university and industry partners, and is co-managed by Genome Alberta and Genome Atlantic.

Dr. Lisa Gieg, University of Calgary, is a co-lead on the project. Dr. Gieg was in Halifax recently for a project meeting and to present at ISMOS-7, an international scientific conference on microbiology and molecular biology in the oil and gas industry. We caught up with her for an update on the project three years in and to find out how project scientists are filling some of those knowledge gaps.

An interview with Dr. Lisa Gieg

Genome Atlantic: Why do we know so relatively little about MIC – and how is this project trying to change that?

A:MIC is one of the several ways by which corrosion of materials can occur – and one of the challenges with understanding and diagnosing MIC is that it is not an isolated mechanism. That is, while microorganisms play a key role in the corrosion, their metabolism is affected by the chemical environment surrounding them (e.g., kinds of carbon, such as fatty acids or hydrocarbon; or electron acceptors, like oxygen, nitrate, or sulfate, pH) and the surrounding physical conditions, such as temperature and pressure. MIC is very complicated because many factors can affect whether microorganisms will thrive and metabolize in such a way that leads to corrosion. Thus, it’s difficult to pinpoint that corrosion is solely due to the action of microorganisms. Put another way, microorganisms are everywhere, but whether their activity leads to corrosion can be difficult to sort out because of other corrosion that may occur due to the chemical and physical environment.

Based on studies with pure cultures of microorganisms such as sulfate-reducing microorganisms (SRM), a lot is already known about specific mechanisms of MIC, but less is known about other types of microorganisms, and how communities of microorganisms can work together in a way that leads to corrosion. Also, MIC has often been studied in ‘isolation’ – e.g., by microbiologists, or chemists, or engineers. Rarely have all these disciplines come together to tackle the MIC problem.

The geno-MIC project is unique in that it has researchers in many different disciplines such as these working together towards a better understanding of MIC. We are approaching an understanding of MIC from a holistic point of view. We are using genomics to identify key microorganisms present in different environments for which we know the physical conditions (or operating conditions – temperature, pressure, fluid flow rates, etc.), and the chemical conditions (pH, chemical composition, etc.), and determining corrosion rates under these different conditions. In this way, we start to look for trends as to which kinds of microorganisms are most actively contributing to corrosion under different oil and gas operating conditions (e.g., in different kinds of pipelines, processing facilities, produced waters, etc.). When we identify the key microorganisms and the conditions most conducive to promoting MIC, we will know which organisms to target to better monitor and mitigate MIC.

Does MIC manifest itself differently in onshore and offshore pipelines?

A: Microbial corrosion can occur in both environments, but differences in the mechanisms of MIC are due to the chemical environment surrounding the microbial communities. Offshore, because seawater is used in many of the operations, sulfate is present in relatively high concentrations (20-30 mM) which readily stimulates sulfate-reducing microorganisms (SRM). This microbial metabolic process yields hydrogen sulfide which reacts with iron in carbon steel infrastructure to form FeS (iron sulfide) which is highly corrosive.

Onshore, sulfate may be present in some systems, but not always, so other microorganisms are likely playing more important roles. For example, we recently studied a sample collected from a leaking pipeline, and while all indications strongly pointed to MIC as the major mechanism of corrosion, neither sulfate nor SRM were present in substantial amounts – many other kinds of microorganisms were more abundant and were most likely the key players in the corrosion scenario. We are still in the process of identifying exactly how these other kinds of microorganisms are behaving in order to corrode metal. In almost all cases of MIC, microorganisms attached to pipe surfaces are the most detrimental, but we still have a lot to discover in terms of the many ways and the kinds of microorganisms that may be contributing to metal corrosion.

Three years in, what are some of the main things you’ve found out? And what are the next steps?

A: The major objective of our project is to gain a better understanding of MIC under different conditions in order to better detect and manage this important yet poorly understood mechanism of corrosion. Our project has 4 major activities (1) Knowledge – where we aim to identify the different kinds of microbes and activities associated with MIC and are building a MIC database in order to do this; (2) Devices & Assays – where we aim to develop tools for MIC monitoring/detection; (3) Models – where we aim to better predict MIC; and (4) Translation – where we aim to better understand the gaps between academic research and industry uptake, to incorporate research findings into industry standards, and to help industry consider MIC as part of corrosion management strategies.

To date, the project has developed several predictive and risk-based models and we are in the process of validating these with field data from our industry partners. For the translation piece, our team has been hosting stakeholder workshops and conference forums/workshops on the topic of MIC and are actively involved in either creating new standards (on the topic of using molecular microbiological methods for MIC) or updating industry standards related to MIC (e.g., through NACE International, and DNV-GL).

For the Knowledge and Devices/Assays activities, we have been analyzing many field samples from different kinds of oil and gas operations (offshore and onshore, collected from infrastructure operated under different physical conditions such as temperature/pressure) by characterizing microbial communities, chemistry, and corrosion rates. This data is being entered into a new database also being developed by the project that we will ultimately use to discern trends in the data – again – for the purpose of identifying which microbial players are most corrosive under different conditions so that we can better detect (through devices and assays), monitor for, and mitigate MIC.

When will the project wrap up?

A: We officially wrap up in October 2020 but are applying for a no-cost extension so hope to continue the project until October 2021. We will be looking for opportunities to continue some aspects of the project beyond that date, either through another LSARP, GAPP (Genome Canada’s Large-Scale Applied Research Project and Genomic Applications Partnership Program), or another funding avenue.

How will the project results be integrated into industry practices or operations?

A: Our project team is actively involved in meeting with our industry partners on an ongoing basis. We host workshops and forums on MIC a few times a year, bringing together academic researchers and industry stakeholders (oil and gas operators, service companies, chemical suppliers, consultants) so that we can learn from each other and have an ongoing dialog about the challenges and the tools that can be used/developed to determine whether MIC will be a problem in a given system.

We are also involved in preparing industry standards related to the topic of MIC that a lot of industry stakeholders look to for guidance on dealing with corrosion detection and management. For example, several team members (academic and industry partners) are in the process of developing a new NACE International standard on Molecular Microbiological Methods – essentially outlining the best practices towards using genomics for identifying microorganisms in oil and gas samples. Finally, predictive or risk-based models developed in the geno-MIC project are being reviewed by our industry partners who are also providing field data for their validation. Thus, our geno-MIC team is doing research in close conjunction with industry, which will help immensely with the uptake/use of our research findings by them.