Which is the oldest oil producing state of India?

The Correct Answer is Assam. Key Points Assam is the oldest oil (petroleum) producing state of India. India's oldest oil refinery Digboi is located in Assam. Assam, Gujarat and Rajasthan, together account for more than 96% of oil from onshore fields. Assam is the oldest oil-producing state in India and has major oil fields in India located. India's first oil well was dug in 1866. The first commercial discovery of crude oil in India was made in 1889 at Digboi. The first refinery was started in Digboi in 1901. Digboi is the oldest oil well still in use. Other oil refineries in Assam are: Numaligarh Refinery. Bongaigaon Refinery. Guwahati Refinery. The locations of Refineries in India are as follows Additional Information The list of Refineries in India is as follows- S. No. Refinery location Name of company Capacity MMTPA 1 Guwahati Indian Oil Corporation Limited 1.00 2 Barauni 6.00 3 Koyali 13.70 4 Haldia 7.50 5 Mathura 8.00 6 Digboi 0.65 7 Panipat 15.00 8 Bongaigaon 2.35 9 Mumbai Hindustan Petroleum Corporation Limited 6.50 10 Visakhapatnam 8.30 11 Mumbai Bharat Petroleum Corporation Limited 12.00 12 Kochi 9.50 13 Manali Chennai Petroleum Corporation Limited 10.50 14 Nagapattinam 1.00 15 Numaligarh Numaligarh Refinery Ltd. 3.00 16 Mangalore MRPL 15.00 17 Tatipaka ONGC 0.66 Total 120.66 JV Refineries 18 Bina Bharat Oman Refinery Ltd. 6.00 19 Bathinda HPCL Mittal Energy Ltd. 9.00 Total 15.00 Private sector refineries 20 Jamnagar Reliance Industries Limited 33.00 21 SEZ, Jamnagar 27.00 22 Vadinar Essar Oil Limited 20.00 Total 80.00 Grand Total 215.66