CAIRN OIL & Gas has announced that it is partnering US-based Halliburton to start shale exploration in the Lower Barmer Hill formation, Western Rajasthan.
What is shale oil?
- Shale oil also refers to crude oil produced from shales of very low permeability formations, called “tight oil”.
- Shale oil is unconventional oil produced from oil shale rock fragments by pyrolysis, hydrogenation, or thermal dissolution. These processes produce synthetic oil and gas which can be used as a fuel or upgraded refinery feedstock.
- Shale oil is formed by accumulation of mud, silt and organic wastes and heat & pressure being applied on these biological wastes for millions of years.
How does it differ from conventional crude oil?
- The key difference between shale oil and conventional crude is that the former, also called ‘tight oil, is found in smaller batches, and deeper than conventional crude deposits.
- Its extraction requires creation of fractures in oil and gas rich shale to release hydrocarbons via hydraulic fracking.
What are the prospects of shale oil exploration in India?
Russia and the US are among the largest shale oil producers, with a surge in shale oil output in the US having played a key role in turning the country from an importer of crude to a net exporter in 2019.
Currently, there is no large-scale commercial production of shale oil and gas in India.
State owned ONGC had, in 2013, started exploration and, by the end of FY21, assessed shale oil and gas potential in 25 nomination blocks, but has reduced investments over the past few years after only getting limited success in shale exploration efforts.
While ONGC’s assessment found prospects of shale oil at the Cambay basin in Gujarat and the Krishna Godavari basin in Andhra Pradesh, the company concluded that the quantity of oil flow observed in these basins” did not indicate “commerciality” and that the general characteristics of Indian shales are quite different from North American ones.
According to experts, India currently does not have adequate seismic data and the ecosystem required for large scale production of commercial shale oil and gas. Shale exploration faces challenges besides environmental concerns of huge water requirements and potential for contamination.