Digboi is a town in Tinsukia district in the north-easternpart of the state of Assam, India. Crude oil wasdiscovered here in late 19th century. Guwahati Refinerywas set up at Noonmati in Guwahati on January 1, 1962.Barauni Refinery was established in July 1964 inBarauni istrict of Bihar.