To tackle the issue of pipeline corrosion caused by microbial activity and improve the understanding of microbiologically influenced corrosion (MIC), its detection, and its control, a collaborative four-year research project led by researchers with three Canadian universities—with support from Canadian government research laboratories, Canadian and U.S. oil and gas facility operators, industry suppliers, and several U.S. and European universities—will study microorganisms found in both onshore and offshore oil and gas environments. Using the latest in genomics techniques, the interdisciplinary team will look for trends related to specific microbes and chemistries that lead to MIC. Ultimately, the project will lead to better predictions of whether microbial corrosion will occur in a given oil and gas operation. The project, “Managing Microbial Corrosion in Canadian Offshore and Onshore Oil Production,” received $7.9 million in funding through the Genome Canada 2015 Large-Scale Applied Research Project Competition.
According to the researchers, MIC is reported to be responsible for at least 20% of the cost of steel infrastructure corrosion in the oil and gas industry, which is estimated to range between $3 billion to $7 billion annually in maintenance, repairs, and replacement. They note, however, that failures are often attributed to MIC when non-biological corrosion phenomena cannot explain a failure. The goals of the research project are to identify the microbes, chemical reactions, and MIC mechanisms that lead to facility failures; develop enhanced methods and tools for detecting and measuring MIC; devise better predictive modeling and risk assessment tools to help improve materials design, and operating and maintenance practices; and improve MIC management and control strategies to reduce potential failures.
Microorganisms don’t cause corrosion directly; the corrosion usually stems from some sort of metabolic activity or process that produces a byproduct that leads to corrosion, explains project lead Lisa Gieg, associate professor in the Department of Biological Sciences at the University of Calgary (Calgary, Alberta, Canada) and NACE International member. She notes that several MIC mechanisms have been identified and mentions sulfate-reducing bacteria (SRB) as a well-known example. The metabolism of these microorganisms reduces sulfate into hydrogen sulfate (H2S), a corrosive product for carbon steel. Additionally, the sulfide resulting from SRB activity reacts with soluble iron released by corrosion to form iron sulfide (FeS), which is an insoluble, highly corrosive product.
Although scientists have learned much about MIC through decades of research, it is still a poorly understood and complicated corrosion mechanism under most operating conditions in the oil and gas industry for several reasons, says NACE member John Wolodko, project lead, associate professor, and Alberta Innovates Strategic Chair in Bio and Industrial Materials at the University of Alberta (Edmonton, Alberta, Canada). For one thing, he explains, MIC mainly has been monitored using growth-based approaches (cultures) that can only target a small fraction of select microbial groups. “We still don’t know all the microbial communities that may or may not cause MIC,” he says. Another reason for a lack of knowledge is that corrosion processes have typically been studied by researchers in isolated disciplines with minimal collaboration between the fields of study. A major gap in understanding MIC and how to effectively predict, monitor for, and mitigate MIC has been due to a disconnect between disciplines.
What this project aims to do, Wolodko continues, is study MIC in a comprehensive manner using advanced genomics. “It’s the tool we will use to dig deeper into the vast population that we don’t have an understanding of yet,” he says. This is expected to lead to the development of better MIC management practices for the study’s targeted oil and gas environments through improved mitigation strategies and standards that can be used by operators to routinely assess MIC so early action can be taken to prevent failures.
The work will be carried out by a multidisciplinary alliance of researchers who have experience in microbiology, genomics, chemistry, corrosion, and engineering. The research team will collect samples from different products in multiple geographic regions, including both offshore infrastructure and upstream pipelines and transmission pipelines, so they can study the various physical characteristics and different fluid chemistries associated with MIC in oil and gas infrastructure. By using the latest in genomics techniques, the interdisciplinary team will be able to look for trends related to specific microbes and chemistries that lead to microbial corrosion. Ultimately, the project will lead to better predictions of whether microbial corrosion will occur in a given oil and gas operation.
As a first step, genomic techniques will be used to identify all the microbe populations that exist in a sample, and then determine the organisms’ specific traits to better understand their metabolic activity. A genome is the genetic material of an organism and includes both genes and DNA, which determine the traits that the organism possesses. Using specific genomic laboratory techniques, the genes and DNA from all organisms in a sample can be extracted and analyzed based on what the researchers want to know. This approach provides a better opportunity to understand which microorganisms typically comprise the entire microbial community found in oil and gas infrastructure environments.
“A genome allows us to determine what kinds of genes these microbes have. If we know that, we can figure out what they can do,” Gieg says. She comments that only 1% of all microorganisms in the world can actually be cultured, so when a sample is cultured in a typical growth-based test, the results are based on an extremely limited microbial community. Very little is known about the other 99%. “We can take bacteria from the field (e.g. from a sludge or process water sample) and try to grow them in a medium, but it doesn’t account for all the genetic potential in that microbial community,” Gieg adds.
Part of work will be discovering the behavior of microbes in the oil and gas infrastructure environments, and how their activities may lead to corrosion processes. "We know that microbes cause corrosion, but we are examining how they cause corrosion," says Faisal Khan, project lead, head of the Department of Process Engineering, and director of C-RISE at Memorial University (St. John's, Newfoundland and Labrador, Canada).
“We will design experiments to address various corrosion questions, and see how the genes present may be responsible,” says Gieg. For example, a reaction may be observed during a laboratory experiment, but the information on why this effect is being seen is not known. When this occurs, the researchers will look to see if there is a gene present in the genome that has the ability to cause the observed reaction. “Basically we’re linking the two approaches—we’re looking at what is happening and what is present that can potentially make it happen,” she explains.
The researchers will analyze samples from different pipelines and infrastructure at various oil fields in multiple geographic regions. “One challenge we have is that standard sampling procedures are not in place by industry,” says NACE member Tesfaalem Haile, a senior corrosion specialist at InnoTech Alberta (Devon, Alberta, Canada). He notes that, as part of the project, a process will be developed early on for collecting samples from the field. “We will target sludge sampling for both microbiological and non-microbiological characterization, along with the development of optimal conditions for storage and transportation.”
The researchers anticipate three major outcomes from the research—knowledge, devices, and predictive models. “Once we have a better understanding from that first experimental stage, then the project has phases that will focus on developing new tools for industry to detect and assess MIC, develop models for end users and integrity engineers to better predict where they might have a problem, as well as find solutions for corrosion mitigation,” says Wolodko.
One outcome, Wolodko notes, is a database that compiles the microbial genetic information about the samples collected from participating operators and end users, and ties the information to field operating conditions, corrosion rates, etc. Gieg notes that another outcome is the development of new devices—such as rapid detection sensors for the field that look for the genes that indicate the presence of corrosion-causing microbes or online tools that detect biofilm formation—that will assist in detecting precursors for MIC. Development of MIC predictive models, the third outcome, will help operators to better manage and mitigate MIC under a variety of pipeline environmental conditions, says Haile. The models, with validation through benchtop and flow-loop studies before they are adopted, are expected to predict MIC-related issues beforehand, and can be used by operators as well as service providers to manage the integrity of oil and gas assets. This will enable the end users to be proactive about predicting and identifying MIC issues before they become a problem.
Ultimately, the project deliverables will allow corrosion managers in the oil and gas industry to better predict when, where, and why failures occur due to MIC and how to best mitigate MIC.
Contact Lisa Gieg, University of Calgary—email: firstname.lastname@example.org; John Wolodko, University of Alberta—email: email@example.com; or Tesfaalem Haile, InnoTech Alberta— email: Tesfa.Haile@innotechalberta.ca.