Strip away the scientific, textbook descriptions, and a sulfate-reducing bacterium is a street fighter not easily moved from its turf.
Not to stereotype, but when found in a pipeline, these bacteria are bad actors – bugs that attach themselves to the inside walls and brazenly corrupt their surroundings. Sulfate-reducing bacteria, or SRB, are naturally occurring microorganisms. They never ask for permission, and only dig deeper when they find a neighborhood they like.
So, why are these microorganisms such a big deal in oilfield operations and delivering energy around the globe? SRB are some of the main culprits in pipeline corrosion and, left untreated, would eat their way through the walls of hundreds of thousands of miles of pipelines.
Keeping them from loitering is an exercise in persistence, because they can grow in remote sections of a pipeline, miles away from access points. The pipeline provides SRB an anaerobic, or oxygen-free, living space that also hosts organics and other nutrients they need to thrive.
Much like a doctor addressing a clogged artery, researchers tackling SRB in pipelines must find innovative ways to reach the actual problem area. When sending physical and chemical tools through the pipeline, they sometimes must travel dozens of miles before reaching the intended target.
“You’ve got miles of pipeline, and our tools have to go the entire length,” said Ramsey Smith, a team leader for the materials and corrosion laboratory at ExxonMobil’s Friendswood, Texas, facility.
ExxonMobil’s petroleum microbiology laboratory at Friendswood is where the company studies these and other microorganisms. It’s one of the few laboratories dedicated to the study of microbial corrosion where researchers can replicate pipeline environments from Nigeria to Russia to Canada.
Success is plodding, and victory is achieved through attrition, but Smith and his colleagues continue to test, evaluate and retest how to best take down, or at least reduce, this pipeline enemy number one.