There are three important networks of pipeline transportation in the country. From Salaya in Gujarat to Jalandhar in Punjab, via Viramgam, Mathura, Delhi and Sonipat. It has branches to connect Koyali (near Vadodara, Gujarat) Chakshu and other places.

A petroleum refinery is a place where crude oil dug out from earth is processed and refined to produce final useful products like petrol, diesel, heating oil, kerosene and LPG etc.

Petrochemical industries are located close to refineries because transportation of petroleum and its products are always dangerous hence the distance is always kept minimised.

• The famous Digboi, Naharkatiya petroleum deposits are in the state of Assam.
  
• First oil refinery in India was set up in Digboi a town in Tinsukia district of assam state. Digboi is also known as oil city. Oil refinery here was started in and around 1901
  
• Naharkatiya is a town in Dibrugarh district in Assam. It is well-known for petroleum and gas reserves.
  

Kochi oil refinery is located in the Kochi district of Kerala state. It has a production capacity of 9.5 million tonnes per annum. It is a public sector owned organisation. Petrochemical products are obtained from here.

The only oil field of India is called Mumbai high which is located 176 kilometres off the coast of Mumbai. Operations are done by Oil and Natural Gas Corporation of India.

This was discovered by Russian and Indian oil exploration team. It is located in gulf of Kambat. Bombay High crude has more than 60% paraffinic content while light Arabian crude has only 25% paraffin.

The three largest producers of mineral oil or crude oil in India are Rajasthan (23.7%), Gujarat (12.5%), Assam (12.1%).

The largest oil field of India is Bombay high. It is situated about 161 km north of Bombay coast in Mumbai, Maharashtra. It is off shore field. It produces near about 38% of our domestic production or 14% of India requirement. It is discovered by Russia & India oil exploration team in 1965.

About 63 per cent of India’s petroleum production is from Mumbai High, 18 per cent from Gujarat and 16 per cent from Assam.

Gas and Oil fields are located in Naharkatiya, Assam. Oil from these fields is sent to Nunmati for refining and gas is made into electricity at Namrup.

All the oil and gas fields discovered till date in the Upper Assam shelf, are situated mostly on the southeastern slope of the Brahmaputra arch. Some of the major oil fields are Nahorkatiya, Lakwa, Lakhmani, Geleki, Dikom Kathaloni, etc.

Ankleshwar, also famous as Gujarat's “City of Oil” is known for its industrial township called Gujarat Industrial Development Corporation (GIDC).

Digboi is known as the Oil City of Assam where the first oil well in Asia was drilled. The first refinery was started here as early as 1901.

Naharkatia (also spelled as Naharkatia or Nahorkatiya) is a town and a town area committee in Dibrugarh district in the Indian state of Assam. It is well known for its petroleum and gas reserves. Earlier, Duliajan, the head office town of Oil India Limited was in its circle.

Kohima was originally known as Kewhira, It is called after the wild flowering plant Kewhi, found in the mountains.

So cities other than Kohima are associated with oil/petroleum.

Petroleum refinery is located in Barauni in the state of Bihar. It was built in collaboration with Soviet Union. It was started in July 1964.

• First oil refinery in India was set up in Digboi, a town in Tinsukia district of Assam. Digboi is also known as oil city. Oil refinery here was started in and around 1901.
  
• Present day, though the crude production is not high, Digboi has the distinction of being India's oldest oilfield. Digboi refinery which is now a division of Indian Oil Corporation, has a capacity of about 0.65 MMTPA as of 2003.