Numaligarh Refinery Limited achieves milestone with longest HDD for crude oil pipeline in Assam's Subansiri River
Assam based Numaligarh Refinery Limited (NRL) is executing its mega project of laying of a cross country pipeline of 1635 km from Paradip Port in Odisha to Numaligarh along with expansion of its refinery from 3.0 MMTPA to 9.0 MMTPA, as part of ‘Numaligarh Refinery Expansion Project (NREP)’.
The prestigious NREP Project is the single largest Investment in Northeast India as part of Government of India’s ‘Hydrocarbon Vision 2030 for North East India’. The pipeline passes through five States traversing numerous enroute crossings including all major rivers of East India, namely Ganga, Jia Bharali, Subansiri, Brahmaputra through a technique called Horizontal Directional Drilling (HDD) with intersection.
Subansiri River, which connects Lakhimpur in the North and Majuli in the South side, is one of the of the most challenging HDD sites due to its complex 3510-meter-long profile length for a 26-inch diameter pipe.
The remote site made it more challenging due to non-accessibility of the area which remains flooded most of the year leaving a working window of 4-5 months during November to March. The executing agency had to construct a temporary bridge over Lohit River enroute for movement of the heavy equipment and project accessories. Two giant rigs of capacity 500 MT were positioned on both side of the river and are used for drillings, reaming and pulling activities.
The pulling of the 26-inch dia pipe started on 12th February 2024 and continued non-stop for around 60 hours till entire 3.51 km long pipe string was pulled
