Indradhanush Gas Grid Limited (IGGL), a joint venture of five major oil PSUs, has completed the construction of Asia’s largest hydrocarbon pipeline running beneath the Brahmaputra River, linking Jorhat and Majuli in Assam. The 4,080-meter pipeline is the longest river crossing by any hydrocarbon pipeline of size 24-inch diameter and above in Asia and the second-longest in the world. The HDD river crossing was executed by the intersection method, where two HDD rigs simultaneously started drilling from the two sides of Brahmaputra with intersection of the two drilling heads in the middle at 30 meters beneath the river bed.

CEO Ajit Kumar Thakur announced the completion of the pipeline on April 22, marking a major milestone in the construction of the North East Gas Grid (NEGG) connecting North East India to the National Gas Grid. The pipeline was laid in three separate HDD sections of length 1000 M, 4080 M, and 700 M, with the first and the third sections completed earlier. The next step will be the tie-in of the three sections at two points, which will be located at 15 M and 8 M below Natural Ground Level (NGL).