Abstract
Metallurgical investigations of three internally initiated in-service piping leaks and one pipe section containing internal pits, associated with interconnected crude oil piping from multiple facilities, concluded that the likely failure and pitting mechanisms were predominately microbiologically influenced corrosion (MIC). The ubiquitous nature of the failures to the exclusion of other possible failure mechanisms and, in most cases, rapid corrosion rates highlight a need for continued industry awareness of the threat of MIC in crude oil facility piping. Four independent metallurgical analyses were performed on pipe samples from different facilities and included photography, microscopy, deposit analyses, microbiological testing, X-ray diffraction (XRD) scanning electron microscopy energy dispersive spectroscopy (SEM-EDS), and metallography. The objectives of this paper are to present the generalized failure analysis approach, including key factors for sample preservation, and a comparison of similarities and differences in the results from the metallurgical analyses, as well as high-level corrosion monitoring strategies for MIC in crude oil facility piping.
