Oil India (OIL) has achieved mechanical completion of its Numaligarh–Siliguri Product Pipeline (NSPL) upgradation project on 12 October, 2025.

The project enhances the pipeline’s capacity from 1.77 million tonne per annum (MTPA) to 5.5 MTPA, significantly improving the transport of refined petroleum products from the Numaligarh Refinery in Assam to Siliguri, West Bengal. The upgrade is expected to ease transportation bottlenecks and boost supply efficiency across India’s northeastern region. The NSPL upgradation supplements the ongoing Numaligarh Refinery Expansion Project (NREP) by Numaligarh Refinery (NRL), a subsidiary of OIL, which aims to increase refining capacity from three MTPA to nine MTPA. 

Oil India said the mechanical completion represents one of the final steps before commissioning and underscores its commitment to strengthening India’s energy infrastructure and ensuring long-term energy security. The company emphasised that this milestone aligns with its goal of supporting regional and national economic growth.