Crude oil is a mixture of hydrocarbons formed from animal and vegetable material that is collected at the bottom of ancient seas. Crude oil exists in liquid phase in the natural underground reservoirs. These oil-bearing reservoirs are porous, permeable sedimentary rock formation containing oil and/or natural gas enclosed or surrounded by layers of less permeable or impervious rock. (Bahadori et al. 2014)
Petroleum refineries are the large installations that are used to separate various components of crude oil and convert it into usable fuel products or feedstock for other processes. Refinery is, thus, considered as an essential part of the downstream side of the petroleum industry.
The crude oil is subjected to various physical and chemical methods during the refining processes. Initially, the crude is boiled as part of distillation process leading to separation of various fractions. The streams of these separated fractions are further subjected to cracking, reforming, and other conversion processes to induce changes in size and structure of molecules. This is followed by removal of undesirable constituents from the converted products with the application of various treatment and separation processes. (Gary et al. 2007)
The crude oil is thus transformed into useful petroleum products such as Liquefied Petroleum Gas (LPG), Petrol (MS), Naptha, Aviation Fuel (ATF), SKO (Kerosene), HSD (Diesel), Light Diesel Oil (LDO), Lubes, Furnace Oil (FO), Bitumen, Pet cokes and others.
India has 26 sedimentary basins covering an area of 3.14 million sq. km. The sedimentary basins of India, on-land and offshore up to the 400m isobaths (an imaginary line that connect all points having same depth below a water surface such as ocean), have an aerial extent of about 1.84 million sq. km. In the deep water beyond the 400m isobath, the sedimentary area has been estimated to be about 1.30 million sq. km. (MPNG 2019)
The estimated reserves of crude oil in India as on 31.03.2018 stood at 594.49 million tonnes (MT), where as that of Natural Gas is 1339.57 Billion Cubic Meters (BCM) (MOSPI, 2019).
The total refining capacity of 23 refineries in India is 248 MMTPA. The two refineries at Motikhavdi, Jamnagar, both operated by the Reliance Industries Ltd. (RIL), are the largest refineries in India with capacity of 35.2 MMTPA and 33 MMPTA respectively. Indian Oil Corporation (IOC), the state owned corporation, has the highest refining capacity of 69.2 MMTPA in India (MOSPI, 2019). Illustration 1 shows Bina Petroleum Refinery in Madhya Pradesh. Illustration 2 shows Reliance Petroleum Refinery in Gujarat.
Illustration 1: Bina Petroleum Refinery, Madhya Pradesh
Illustration 2: Reliance Petroleum Refinery, Gujarat
Bahadori, A., Nwaoha, C. and Clark, M. W., 2014, Dictionary of Oil, Gas, and Petrochemical Processing, Taylor & Francis Group, Boca Raton.
Gary, J. H., Handwerk, G. E. and Kaiser, M.J. 2007, Petroleum refining : technology and economics. -- 5th ed., Taylor & Francis Group, Boca Raton.
MPNG, Annual Report : 2016-2017, Government of India, Ministry of Petroleum and Natural Gases (MPNG), New Delhi.
MOSPI. 2019, Energy Statistics 2019. New Delhi: Ministry of Statistics and Programme Implementation (MOSPI).