Pipeline Integrity Assessment: Methodology

With ever increasing energy demands, approximately 90 million barrels of oil per day and 3314 billion cubic meters of gas per year are consumed around the world [1]. To meet such huge energy demands a complicated and vast network of offshore and onshore production and distribution pipelines is necessary. Pipelines connect areas that are relatively rich in resources with areas that are demand-hungry but poor in resources. They play a central role in providing to the energy needs of businesses and public, forming the veins and arteries of the Oil and Gas industry. These pipelines are susceptible to damage, both internal and external based on the type of product in the pipeline and the environment in the vicinity of the pipeline i.e. offshore or onshore. The damage to the pipeline needs to be identified and the significance of the damage clearly defined. The inline inspection (ILI) tools help to identify the damage and record the extent and type of damage. Inability to prioritize the damaged areas and carry out necessary intervention to at least curtail the damage may occasionally lead to calamitous consequences. One such example is of a 30-inch Liquid pipeline failure that occurred in Michigan on July 25, 2010. The National Transportation Safety Board (NTSB) reported that the corrosion fatigue cracks that grew and coalesced from corrosion defects resulted in the rupture and prolonged release from the 30-inch oil pipeline [2]. This failure resulted in a revenue loss of approximately $16 million and estimated costs of $767 million for regulatory and professional support in connection with the clean-up operations. Condition assessment of the pipelines as part of the pipeline integrity management system is the primary means through which such catastrophic pipeline system failures could be prevented. This paper presents the methodology that is adopted for “Integrity Assessment” of the pipelines.