Lesser-known Indian basins contain a substantial volume of unexplored oil and gas reserves

In a major revolution in the Indian hydrocarbon (oil and gas) industry, both public and private sector explorers have started focusing on the domestic availability of natural energy resources to reduce the overall import bill and improve long-term sustainability. The shift came with an increasing focus on domestic assets, as lesser-known and unexplored Indian basins are found to contain more hydrocarbon reserves than some of the prominent locations in the world.

Reports indicate that some of the lesser-known and unexplored resources in the Category II and Category III Indian basins possess more oil and gas reserves than the Permian Basin in the United States. These unexplored Indian basins include the Andaman Sea, Bengal, Ganga, Kerala-Konkan, and Mahanadi, among others. The Permian Basin in the United States has already produced 14 billion barrels of crude oil out of its total recoverable reserves of 34 billion barrels.

Currently, crude oil and natural gas production in the country is primarily confined to the Krishna-Godavari (KG basin), Mumbai offshore, Assam Belt, and Carvery, among others. Both the government and private-owned explorers have identified seven sedimentary basins under Category I for exploration. Additionally, there are five basins in Category II that have established petroleum resources but are yet to produce commercially. This accounts for the distribution of total Indian sedimentary area of 3.36 million square kilometres under different categories.

Hardeep Singh Puri, Petroleum Minister, Government of India, stated, “India’s exploration area is likely to increase to 16 percent in 2024, compared to 10 percent previously following the award of blocks under the Open Acreage Licensing Policy (OLAP) rounds. Under OLAP, the government has awarded 144 blocks covering a cumulative area of 244,007 square kilometres. India allows companies under the Open Acreage Licensing Policy to carve out areas for oil and gas exploration and put in an expression of interest for any area throughout the year. Following accumulation of expression of interests thrice a year, these blocks are put on auction. India’s exploration and production (E&P) activities in the oil and gas sector offer investment opportunities valued at US$100 billion by 2030.”

Categories of Indian sedimentary basin
Type of basins (No of basins)	Area (square kilometres)	Hydrocarbon prosperity	Basins/region	Sedimentary area (%)
Category I (7 basins)	998,325	Established commercial production	Cambay, Assam Shelf, Mumbai offshore, Krishna-Godavari, Cauvery, Assam Arakan Fold Belt and Rajasthan	23.21
Category II (5 basins)	780,974	Known accumulation of hydrocarbons but no commercial production as yet	Kutch, Mahanadi-NEC & Andaman-Nicobar, Vindhyan, Saurashtra	29.66
Category III (14 basins)	1,586,150	Indicated hydrocarbon shows that are considered geologically prospectivity	Himalayan Foreland, Ganga, Kerala-Konkan-Lakshadweep, Bengal, Karewa, Spiti-Zanskar, Satpura-South RewaDamodar, Narmada, DecanSyneclise, Bhima-Kaladgi, Cuddapah, Pranhita-Godavari, Bastar, Chhattisgarh	47.13
Total	33,65,449

Sources: Ministry of Petroleum and Natural Gas, Government of India, and Polymerupdate Research

Accelerating exploration
India has 26 sedimentary basins covering an area of 3.36 million square kilometres. The sedimentary basins of India, onland and offshore up to the 400m isobath, have an aerial extent of about 2.04 million square kilometres. In the deepwater beyond the 400m isobath, the sedimentary area has been estimated to be about 1.32 million square kilometres. The Indian sedimentary basins have been broadly divided into three categories (Categories I, II, and III) based on their degree of prospectivity.

Currently, only 10 percent of India's 3.36 million square kilometres wide sedimentary basin is under exploration. India boasts significant discoveries in the Krishna-Godavari, Barmer, and Assam basins, but exploration in other areas has been slower to develop. Of India's 3.36 million square kilometres of sedimentary basins, 1.3 million square kilometres are in deep waters. India had its first foray into deepwater exploration in the Bay of Bengal earlier in the Krishna-Godavari Basin, courtesy of India's state run Oil and Natural Gas Corporation (ONGC).

ONGC was planning to spend over US$10 billion for developing multiple deepwater projects in its KG-DWN-98/2 block in that basin. Oil India recently unveiled that it was targeting a 100 percent increase in its exploration acreage in the coming years, and was looking for partners to help it explore offshore areas.

Category-wise Indian basin development
Basin category	Basin name	Prognotisticated resource (million metric tonnes oil equivalent or MMTOe)
		Estimate 1995-96	Estimate (2017)
Category I (Basins with reserves being produced and exploited)	Assam Arakan Fold Belt	1,860	1,632.8
	Assam Belt	3,180	6,001.2
	Cambay	2,050	2,585.6
	Cauvery	700	1,964.4
	Krishna Godavari	1,130	9,554.5
	Mumbai Offshore	9,190	9,646
	Rajasthan	380	4,126
Sub-total (Category I)		18,490	35,510.5
Category II (Basins with contingent resources to be developed and monetized)	Andaman	180	371.4
	Kutch	760	898.4
	Mahanadi	145	865.6
	Saurashtra	280	1,325.2
	Vindhyan	Not studied	632.5
Sub-total  (Category II)		1,365	3,878.1
Category III (Basins with only prospective resources to be explored and discovered)	Bastar	Not studied	1.3
	Bengal	190	828.3
	Bhima-Kaladgi	Not studied	3.2
	Chhattisgarh	Not studied	25
	Cuddapah	Not studied	5.1
	Deccan	Not studied	11
	Ganga	230	128.4
	Himalayan Foreland	150	44.4
	Karewa	Not studied	4
	Kerala-Konkan	660	1,244.6
	Narmada	Not studied	18
	Pranhita Godavari	Not studied	95.4
	Satpura-S Rewa-Damodar	Not studied	63
	Spiti-Zanskar	Not studied	11.1
Sub-total  (Category III)		1,230	2,482.8
Deep water areas		7,000	Deep water area estimated basin-wise and resources added to respective basins
Grand total (MMTOe)		28,085	41,871.4

Sources: Ministry of Petroleum and Natural Gas, Government of India, and Polymerupdate Research

Hydrocarbon resources assessment
The previous hydrocarbon resources assessment exercise was carried out approximately two decades ago (1995-96). During the course of implementation of pre-NELP (New Exploration Licensing Policy) and NELP rounds and other exploration and production activities, substantial geoscientific data have been generated. New oil and gas fields have also been discovered by utilizing improved geological understanding and new technology.

With the increase in exploration spread and quantum jump in availability of geo-scientific data generated under NELP, there was a need to revisit the hydrocarbon resource assessment of all sedimentary basins of India. A Multi Organization Team (MOT) composed of representatives of ONGC, OIL, and Directorate General of Hydrocarbon (DGH) has carried out estimation of hydrocarbon resource potential in the country.

The exercise of re-assessment of hydrocarbon resources for all the sedimentary basins in the country was completed, based on the current assessment. The conventional hydrocarbon resources in 26 sedimentary basins of the country are of the order of 41.87 billion tonnes (oil and oil equivalent of gas), which is about 49 percent increase as compared to earlier estimates of 28.08 billion tonnes.

Marginal increase in production
A recent report from the Petroleum Planning & Analysis Cell (PPAC), under the Ministry of Petroleum and Natural Gas, showed India’s crude oil production from indigenous sources rose by 1.6 percent to 2.4 million metric tonnes (MMT) in April 2024. This indicates a modest growth from the comparable month of the previous year. Of this, government-owned Oil and Natural Gas Corporation (ONGC) produced 1.6 MMT, contributing a significant volume to this rise.

However, the processing volume rose by 0.8 percent to 21.6 MMT, with public sector undertakings (PSUs) and joint ventures processing 14.5 MMT, and private sector refiners processed 7.1 MMT. Of the total, indigenous crude oil accounted for 2.2 MMT, and imported goods made up 19.4 MMT. Further bolstering the energy sector, production and petroleum products surged by 3.9 percent to 23.4 MMT, mainly high-speed diesel (HSD), which accounted for 42 percent of total petroleum products, followed by motor spirit (MS) at 15.7 percent, and naphtha at 6.7 percent.

Significance of the Permian Basin
The global oil demand has been on the rise after the Covid-19 pandemic. Moreover, the Russia-Ukraine conflict caused major alterations in energy supply routes, which went in favor of the US shale drillers, including those in the Permian Basin. Spanning Texas and New Mexico, Permian Basin remains the largest oil-producing shale play in the United States. Strong global demand and geopolitical shifts continue to support growth and competitiveness of this critical energy region, says GlobalData, a leading data and analytics company.

The latest report titled ‘Permian Basin in the US, 2024,’ reveals that benefiting from a dense pipeline network and Gulf Coast infrastructure, Permian Basin’s crude oil production averaged 5.6 million barrels per day (mmbd) during the January-March 2024 quarter.

Ravindra Puranik, Oil and Gas Analyst at GlobalData, comments, “Europe’s strategic shift away from Russian energy exports has resulted in key changes to the global energy supplies. This is anticipated to benefit the United States shale oil and gas drillers as well as liquefied natural gas (LNG) producers that are positioned to reap from these evolving supply chain dynamics. The United States shale oil production might also benefit from the Red Sea crisis that has added a risk premium to ship-based exports from the Middle East to Europe.”

The Permian Basin remains the largest oil-producing shale play in the United States, with global demand and geopolitical shifts continuing to support growth and competitiveness in the region. The region’s crude oil production averaged 5.6 million barrels per day (mbpd) during the January-March quarter of 2024.


DILIP KUMAR JHA
Editor
dilip.jha@polymerupdate.com