The recent partnership between Cairn India and US-based Halliburton has brought shale exploration in the Lower Barmer Hill formation, Western Rajasthan into the limelight. This collaboration aims at exploiting the shale oil and gas reserves located in the region. The article unpacks and explores the different aspects of shale oil and gas, their extraction process, top producers, associated concerns, conventional and unconventional resources, as well as the potential prospects of shale oil exploration in India.
Understanding Shale Oil and Gas
Shale oil, commonly known as ‘tight oil’, differs from conventional crude in that it is found in smaller quantities and at greater depths than conventional crude deposits. On the other hand, shale gas, unlike conventional hydrocarbons that can easily be extracted from permeable rocks, is locked beneath rocks with low permeability. The extraction process involves creating fractures in the oil and gas-rich shale to release hydrocarbons, a procedure known as hydraulic fracking or fracturing. This requires a mixture of pressurized water, chemicals, and sand (shale fluid) to break low permeable rocks and access the shale gas reserves.
Top Producers of Shale Oil
Russia and the United States are considered the world’s largest shale oil producers. A surge in shale oil production in the US was instrumental in transforming the country from an importer of crude to a net exporter in 2019.
Concerns Associated with Shale Oil and Gas Exploration
Exploring shale oil and gas presents several challenges, including environmental issues linked to high water requirements for fracking and potential groundwater contamination. Shale rocks are often located near aquifers, which contain usable/drinking water. During the fracking process, there’s a risk that the shale fluid could penetrate these aquifers, leading to potential methane poisoning of groundwater used for drinking and irrigation purposes.
Conventional Vs. Unconventional Resources
The extraction of conventional oil or gas from formations is straightforward and can be achieved using standard methods. These conventional resources tend to be easier and less expensive to produce, mainly because they require no specialized technologies. In contrast, unconventional resources like shale oil or gas require specialized techniques for extraction due to their poor permeability and porosity.
Shale Oil Exploration Prospects in India
At present, India does not have any large-scale commercial production of shale oil and gas. In 2013, the state-owned ONGC discovered prospects of shale oil at the Cambay basin in Gujarat and the Krishna Godavari basin in Andhra Pradesh. Yet, it concluded that the oil flow observed in these basins was not commercially viable, and Indian shales’ general characteristics differ considerably from North American ones. The collaboration between Cairn India and Halliburton is a step toward exploring the untapped potential of shale oil and gas in India.