ONGC Current Affairs
State-owned Oil and Natural Gas Corp (ONGC) has made oil and gas discoveries in Madhya Pradesh and West Bengal that may potentially open up two new sedimentary basins in country. They are category-III basins, having hydrocarbon and are considered geologically prospective for exploration.
Madhya Pradesh: The gas deposits were discovered in block in Vindhyan basin. This find is at 3,000-plus meters deep and is being now tested. Four wells drilled after discovery and now hydro-frack will be undertaken to test commerciality of this field.
West Bengal: Oil and gas was discovered in well in Ashok Nagar of 24 Parganas district. Around one lakh cubic meters per day of gas has flowed from one object that was tested.
India has 26 sedimentary basins, of which only seven category-I basins have commercial production of oil and gas. Except for Assam shelf, ONGC opened up all the other six basins, including Cambay, Mumbai Offshore, Rajasthan, Krishna Godavari, Cauvery, and Assam-Arakan Fold Belt for commercial production. The seventh basin was opened way back in 1985. It is in the process of adding eighth basin by putting Kutch offshore discovery (it holds about one trillion cubic feet of gas reserves) to production.
26 sedimentary basins (category wise)
Category-I basins: Cambay, Mumbai Offshore, Rajasthan, Krishna Godavari, Cauvery, Assam Shelf and Assam-Arakan Fold Belt. They have been established for commercial production.
Category-II basins: Kutch, Mahanadi-NEC (North East Coast), Andaman-Nicobar, Kerala-Konkan-Lakshadweep. They are known for accumulation of hydrocarbons but no commercial production has been achieved so far.
Category-III basins: Himalayan Foreland Basin, Ganga Basin, Vindhyan basin, Saurashtra Basin, Kerela Konkan Basin, Bengal Basin. They having hydrocarbon and are considered geologically prospective.
Category-IV basins: Karewa, Spiti-Zanskar, Satpura–South Rewa–Damodar, Chhattisgarh, Narmada, Deccan Syneclise, Bhima-Kaladgi, Bastar, Pranhita Godavari and Cuddapah. They have uncertain potential which may be prospective by analogy with similar basins in the world.
State owned Oil and Natural Gas Corporation (ONGC) is planning to introduce carbon dioxide (CO2) injection technology in its Gandhar oil field in Gujarat. It will be first large scale CO2-injected project in Asia.
Its purpose is to recover extra 20 million barrels of crude oil under enhanced oil recovery (EOR) programme. EOR programme aims at recovering up to 20% of residual oil from ageing oil fields to improve India’s energy security.
Gandhar located in Gujarat is one of ONGC’s major brownfields and was discovered in 1983. The field produces approximately 30,000 barrels of oil per day and is on the decline.
Under this project, ONGC plans to invest $75 million in CO2 capture and another $200 million in injector producer network to recover an extra 15% of residual oil currently valued at $1.36 billion. It will be operational in 20 months. ONGC is in talks with National Thermal Power Corporation (NTPC) for utilising nearly 5 million tonnes of emitted gas (CO2) from the latter’s Gandhar plant.
CO2 injection technology
CO2 injection technology is a proven concept in the West specially the US and Canada. Under it, CO2 gas is injected with residual oil in the ageing field in which total oil production has been declining. It reduces its viscosity and makes it easier to displace oil from the rock pores. CO2 gas also swells oil, thereby pushing it towards the producing well for extraction.