The oldest oil field in India is the _____ field, in _____.

The correct answer is Digboi, Assam. Key Points Digboi, located in Assam, is known as the site of the oldest oil field in India. The first oil well in Digboi was drilled in 1889, making it one of the earliest sites of oil discovery in Asia. Digboi is often referred to as the "Oil City of Assam." The Digboi Refinery, commissioned in 1901, is the oldest operating refinery in the world and continues to function today. Additional Information Anleshwar, Gujarat: Anleshwar (or Ankleshwar) is one of India's major oil fields and is located in Gujarat. It is part of the Western Onshore Basin and is managed by the Oil and Natural Gas Corporation (ONGC). Discovered in the 1960s, it is a significant source of crude oil production in India but is not the oldest oil field. Nawagam, Gujarat: Nawagam is another oil field located in Gujarat. It is part of the Cambay Basin, which is a major oil and gas-producing region in India. Like Ankleshwar, Nawagam is managed by ONGC and contributes significantly to India's hydrocarbon output. Bombay High, Maharashtra: Bombay High, an offshore oil field located in the Arabian Sea, is one of the largest oil fields in India. Discovered in 1974, it plays a crucial role in India's crude oil production. However, it is relatively newer compared to Digboi and is an offshore field rather than an onshore one. Assam: Assam has been a significant region for oil exploration in India. In addition to Digboi, other oil fields in Assam include Naharkatiya and Moran. The region's importance in India's oil production history cannot be overstated. Oil Refining in India: Oil refining in India began with the establishment of the Digboi Refinery in Assam in 1901. This marked the beginning of India's journey in the energy sector, and today, India is a significant player in global oil production and refining.