In recent years, effective techniques have been developed for conducting integrity assessments along cross-country pipelines. In order to provide similar confidence in facility integrity, it was proposed to apply a modified external corrosion direct assessment process to a small station. Until now, congested facility environments have not generally been considered suitable for this approach because of the added complexity associated with electrically-continuous grounding and the large number of pipes and structures in close proximity.
This paper describes the technical approach which was developed in order to overcome the expected challenges. The conventional close-interval potential and direct current voltage gradient surveys were also enhanced to allow effective application in a facility. These enhancements are described as they relate to a variety of common conditions, and guidelines for properly interpreting survey results in a station are given.