Corrosion Behavior in External Surface of API 5L X52 Underground Pipelines in Buzurgan Region/ Missan province

Kadhim F.  Alsultani; Zahraa Qasim Mutasher

doi:10.52716/jprs.v11i1.428

Authors

Kadhim F. Alsultani College of Materials Engineering, University of Babylon –Iraq
Zahraa Qasim Mutasher Missan Oil Company, Ministry of Oil.

DOI:

https://doi.org/10.52716/jprs.v11i1.428

Keywords:

Buried pipe, corrosion, chemical composition for soil, API 5L X52.

Abstract

External corrosion of underground pipeline is one of the most common damage mechanisms
associated with the soil environment particularly in ageing pipelines. This study investigates
the external corrosion phenomenon for exporting crude oil pipeline (28'') in Buzurgan region /
Missan province. Corrosion rate was measured by using weight loss method, and Tafel
extrapolation. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS)
were also used in this work. During the field survey, soil sample was taken from Buzurgan
region (collected as close as possible to buried pipes at 1.2 m) for tests were carried out for soil
that included: pH, moisture content, resistivity and chemical composition (XRF, XRD, and
soluble salts). It was found that the environment of the areahas a low soil resistivity value
(870) ohm.cm. On other hand, the samples that were immersed in Buzurgan soil showed the
that highest damage was by pitting corrosion due to the high soluble salts content particularly
chlorides (7388 )ppm and sulfates (2570) ppm.