In early years, when pipeline industry and HT transmission system were not so developed in India, AC interference for underground pipelines did not receive adequate attention. In recent years, due to paucity of land and lack of clear policy on utility corridors, have led a situation, wherein cross country Oil & Gas pipelines are running parallel to HT transmission lines. AC interference on pipelines is a real and serious problem, which can place both operator safety and pipeline integrity at risk.
When a long-term induced AC voltage exists on a pipeline, it can be dangerous and potentially life-threatening for operations personnel to touch the pipeline or appurtenances as well as it can lead to pipe corrosion resulting from discharge of current.
Indian Oil Corporation Limited is India’s largest company by sales with a turnover of over $76,250 million for year 2013-14. Indian Oil is also the highest ranked Indian company in Fortune ‘Global 500’ listing, ranked at 96th position. Indian Oil is an integrated energy company, with significant presence in refining, transportation, marketing and petrochemicals business. It also operates about 12000 km of petroleum pipelines, crude oil pipeline, multi product pipelines, dedicated LPG pipelines, Naphtha pipelines, Gas pipelines etc.
The paper presents a case study of about 100% metal loss in a 24” dia crude oil pipeline, having 6.4 mm wall thickness, apparent due to interference from HT AC transmission line is presented in the context of pipeline industry in India and also brought out the constraints pipeline industry face while mitigating different type of interference.