The Kharsang oil Field is located in the state of Arunachal Pradesh about 50 Km east of Digboi Refinery and is part of the Assam-Arakan Basin. The field was discovered in 1975 by M/s Oil India Ltd. (OIL) and was put into regular production in 1983. Other significant producing fields in the Upper Assam Basin include Moran, Naharkatiya, Dikom-Kathaloni-Hatiala, Rudrasagar, Lakwa-Lakhmani, Geleki and Borholla-Changpang. The upper Assam fields, once India's sole producing basin, now produce approximately 15% of India's oil and 9% of gas production. The Kharsang field is spread over 11 Square Km area, in a partly hilly jungle region with an elevation of approximately 200m above sea level.

In the year 1995, the field was taken over by a consortium comprising Oil India Ltd(40%), Enpro India Ltd.(25%)(now assigned to Jubilant Energy (Kharsang) Pvt Ltd.), Geopetrol International Inc.(25%) and GeoEnpro Petroleum Ltd (10%) under a Production Sharing Contract dated 16th June, 1995 with the Government of India (GoI). Geo Enpro was nominated as Operator of Kharsang oil field. At the time of take-over, the field had a total of 36 legacy wells drilled by Oil India to depths ranging from 700 m to 3400 m and production was around 42 KLOPD (265 BOPD). After taking over the field, the Operator had carried out various work-over and drilling operations to gradually increase the production from Kharsang Oil Field.

The consortium has drilled a total of 34 wells under different drilling campaigns. Phase-I for 5 wells in the year 2005-06, Phase-II for 15 wells in 2008-09 & 2009-10, Phase-III for 8 wells in 2011-12 & 2012-13 and Phase-III Extension for 6 wells in 2012-13 & 2013-14. Presently, the total well count in Kharsang field is 70 wells and the production from the field is around 1800 BOPD from upper Girujan reservoirs.