Oil India Limited was formed by the Burmah Oil Company Limited as its subsidiary in in what is now India 1887 to explore in the Assam Basin, India ( Corley, T A B ,1983, The History of the Burmah Oil Company, 1886-1983). Staff at he Burmah Oil Company Limited had heard from a geologist with the colonial British Indian Geological Survey, Thomas Oldham, that oil was found on the feet of elephants that were being used as beasts of burden in the vicinity of the Digboi village (Arun Metrie, pers. comm., former Burmah Oil economist, 1988). The oil on the elephants' feet was traced to the Digboi area, where a surface fold (anticline in geological parlance) had formed a broad hill. A successful technique for exploration for hydrocarbons at the time was drilling beneath seeps on anticlines (Thornton, S E, 2015, The history of Oil Exploration in the Union of Myanmar, Paper No. 10807), so Oil India drilled beneath the Digboi seeps and found a giant oil field oil field. Several other oil fields were subsequently found by Oil India Limited in what became India's first oil production.