How can pipeline leaks promote microbiologically influenced corrosion?

Microbiologically influenced corrosion (MIC) is a perennial problem for pipelines used to process and transport petroleum products.

The challenge for the oil and gas industry is the potential for process leaks into the cooling water systems. In the absence of adequate leak detection, leaks can cause rapid and severe problems including pitting corrosion, deposition and microbiological fouling due to the additional carbon food sources upon which the microorganisms feed. (Pitting corrosion is examined more fully in Pitting Corrosion in Oil and Gas Wells and Pipelines.)

Increasingly, MIC is being implicated in midstream and pipeline corrosion failures. While this may not be intuitive, some emulsified water remains with the hydrocarbon being transferred at the oil/water interfaces. The problems are compounded if the sulfur content of the transferred hydrocarbon product is high. Best practices in this industry included pigging the lines and adding biocides after the pigging is completed.