Which of the following states is the oldest producer of oil?

Assam is correct answer. Key Points Assam is India's first state to produce petroleum. The country's first oil resources were discovered near the town of Digboi in the state of Assam. The state's major oil fields include Digboi, Naharkatiya, and Moran-Hugrijan. Digboi is regarded as Assam's Oil City, as it was here that the first oil well in Asia was drilled. The first refinery was established here in 1901. Digboi has the oldest operating oil well. Additional Information Rajasthan is India's greatest petroleum production, followed by Gujarat and Assam. Rajasthan accounts for around 23.29% of the country's crude oil production. Oil can be discovered in Assam, Gujarat, Mumbai High, and the Godavari and Krishna river basins in India. ONGC is a government-owned Maharatna enterprise headquartered in New Delhi that was created in 1956. The activities of ONGC, India's largest oil corporation, are based on crude oil extraction, and it consistently contributes to 70% of India's overall oil production.