INTERNAL CORROSION DIRECT ASSESSMENT FOR OFFSHORE PIPELINES

摘要

Inspection of offshore pipelines is essential to provide vital information required for integrity assessment, to allow data driven engineering decisions to be made and prevent costly failures. To identify and quantify anomalous features and defects including internal corrosion damage, it is common to use inline inspection (ILI) pigs. Conventional ILI requires deployment of a tool which has a combination of characteristics that allow the passage of a free-swimming assembly through the pipeline without disruption to normal operation. However, some pipelines deviate from conventionally "piggable" pipelines, so inspection for internal corrosion could be complex and/or unfeasible. To establish the integrity of these difficult to pig pipelines, Internal Corrosion Direct Assessments have been performed to ascertain the condition of these pipelines with considerable success. This paper presents experience from applying Internal Corrosion Direct Assessment (ICDA) for offshore pipelines in the North Sea. The paper focuses on how these assessments have been performed, challenges experienced, results and lessons learnt.