Cairn India will partner US-based Halliburton to start shale exploration in the Lower Barmer Hill formation, Western Rajasthan.
- 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.
- Unlike conventional hydrocarbons that can be extracted from the permeable rocks easily, shale gas is trapped under low permeable rocks.
- Extraction requires creation of fractures in oil and gas rich shale to release hydrocarbons through a process called hydraulic fracking/fracturing.
- It requires a mixture of ‘pressurised water, chemicals, and sand’ (shale fluid) to break low permeable rocks and have access to the shale gas reserves.
- Russia and the US are among the largest shale oil producers in the world, with a surge in shale oil production in the US having played a key role in turning the country from an importer of crude to a net exporter in 2019.
- Shale oil and gas exploration faces several challenges other than environmental concerns around massive water requirements for fracking and potential for groundwater contamination.
- Shale rocks are usually found adjacent to rocks containing usable/ drinking water known as ‘aquifers’.
- While fracking, the shale fluid could possibly penetrate aquifers leading to methane poisoning of groundwater used for drinking and irrigation purposes.
Conventional and Unconventional Resources
- Conventional oil or gas comes from formations that are straightforward to extract product from.
- Extracting fossil fuels from these geological formations can be done with standard methods that can be used to economically remove the fuel from the deposit.
- Conventional resources tend to be easier and less expensive to produce simply because they require no specialized technologies and can utilize common methods.
- Unconventional oil or gas resources are much more difficult to extract.
SOURCE: THE HINDU,THE ECONOMIC TIMES,MINT