The kind of pipeline corrosion caused by microbes in the soil is a serious threat to onshore oil and natural gas systems and needs to be addressed by a global joint industry project, according to DNV GL, a global maritime and oil/gas safety consulting and accreditation organization.
European-based DNV GL, a merger of Norway-based Det Norske Veritas and Germany-based Germanischer Lloyd, is calling for industry partners to form a joint industry project (JIP) aimed at what it has classified as a “serious threat” to transmission pipelines from “microbiologically influenced corrosion (MIC).” MIC is estimated to account for at least 20% of the pipe corrosion problems in the United States, according to DNV GL.
So far only European companies have joined the JIP; there are none from North America, but DNV GL has just begun to solicit partners from outside of Europe, a spokesperson for the organization told NGI on Thursday. “Pipeline operators joining the JIP will be at the forefront of exploring new means for managing MIC related risk and will be assisted in getting more control over external MIC,” she said.
The JIP’s task would be to develop a global recommended practice for the detection and mitigation of MIC. Pipeline integrity programs deal with both internal and external corrosion of pipelines, and the MIC is all external. Internal corrosion was the cause of a major El Paso transmission pipeline failure that killed a dozen people near Carlsbad, NM, in 2000, according to federal investigators (see Daily GPI, June 24, 2002).
“Tiny microorganisms can cause big headaches for onshore pipeline operators since MIC leads to high corrosion rates at unpredictable locations along a pipeline,” said DNV GL’s Mirjam van Burgel, JIP project manager, who said MIC occurs even with good cathodic protection systems in place.
Separately in California on Wednesday, Pacific Gas and Electric Co. (PG&E) introduced a new NASA space program-inspired methane detection device using technology originally developed for identifying the existence of methane on Mars by the rover space craft. PG&E said it is testing a hand-held prototype it hopes eventually will help its field crews locate and deal with ongoing pipeline leaks, many of which are the result of corrosion.
In the proposed global investigation, DNV GL wants to bring a focus on finding ways to prevent or alleviate MIC by exploring the role of pipeline coating conditions and cathodic protection in the eventual occurrence and prevention of MIC. The effort would “identify practical means to support pipeline operators in detecting possible MIC sites by testing and selecting the best measurement techniques,” DNV GL officials said.
External MIC is caused or promoted by microorganisms on the outside of a pipeline system, and DNV GL calls it “one of the leading causes” of corrosion failures. The microorganisms may adhere to metal surfaces and form biofilms (complex microbial ecosystems) that can alter electrochemical conditions on the metal surface to induce corrosion locally. MIC is the most severe anaerobic corrosion scenario
“MIC is a problem of global proportions since many factors affect corrosion rates, like soil type, soil moisture, temperature and microbiological communities present,” the spokesperson said. “Next to buried pipelines, MIC is affecting a wide range of industries and services and is thought to be responsible for at least 20% of the annual corrosion costs experienced in the United States.”
The most common occurrence is pipeline “pitting.” It is difficult to prevent this type of rapid corrosion since it is not possible to prove MIC’s presence without excavating the suspected site, DNV GL said.
“Indications of MIC can be found through detecting either coating degradation using a direct current voltage gradient or the pipeline’s metal loss using in-line inspections,” DNV GL said.
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