Hydrocarbon pipelines are one of the key elements of the energy security system of a country, especially in a large country like India. Hydrocarbon pipelines are the backbone of the energy distribution system. While operational reliability of such a system is important to ensure a sustained supply of hydrocarbon energy across the country, continued structural integrity of the network is vital for public safety. Generally, pipelines are the safest mode of transportation of bulk hydrocarbon energy, but pipeline failure is not uncommon.
In India due to growth in large HVAC (High Voltage Alternating Current) power line and pipeline network, the HVAC interference with the pipeline has increased. This interference increases the risk of external corrosion in the pipeline. The paper discusses the development of a semi-quantitative risk assessment-based approach. The developed model considers all the relevant threats, however, in the context of this paper the external corrosion risk model is discussed extensively. After evaluation of the external corrosion, a Direct Assessment based approach was carried out using a structural reliability algorithm with a Bayesian approach. The paper highlight however direct assessment methodology can be enhanced using a semi-quantitative approach coupled with Bayesian Statistics. A pipeline of 528 km was evaluated with a semi-quantitative risk approach which was filtered to 40 km of direct assessment to implement an effective strategy for mitigation of HVAC related threat.