Insights into Editorial: The shale gas challenge
Many scholars believe that fossil fuel energy will decline markedly by 2050. Such conclusions have been challenged by others who say that the earth has enough resources to quench humankind’s thirst for development for many centuries to come.
Among other energy supplies, shale gas and oil are likely to be abundant and available.
Shale Gas and Oil Salient Features:
Shale gas and oil are unconventional natural resources. They are found at 2,500-5,000 metres below the earth’s surface.
They are deeper in comparison to conventional crude oil found at 1,500 metres.
The process of extracting shale oil and gas requires deep vertical drilling followed by horizontal drilling.
The most common way to extract shale gas is ‘hydraulic fracturing’ (fracking), this is nothing but sending high volumes of water mixed with certain chemicals to break the rocks and release the trapped energy minerals.
On August 2018, the Central government approved a far-reaching policy that allows private and government players to explore and exploit unconventional hydrocarbons (including shale gas) in contract areas that were primarily allocated for extracting conventional hydrocarbons.
Unlike conventional hydrocarbons that can be sponged out of permeable rocks easily, shale gas is trapped under low permeable rocks.
Therefore, a mixture of ‘pressurised water, chemicals, and sand’ (shale fluid) is required to break low permeable rocks in order to unlock the shale gas reserves.
The process requires around 5 to 9 million litres of water per extraction activity, posing a daunting challenge to India’s fresh water resources.
Hydraulic Fracturing: Most Common way to extract Shale Gas:
Hydraulic well fracturing (“fracking”) is the process of pumping fluid into a wellbore to create enough pressure to crack or fracture the rock layer.
Fractures are created by pumping large quantities of fluids at high pressure down a wellbore and into the target rock formation.
The fluid usually contains a “proppant,” like sand, that helps keep the fractures open to allow oil and gas to be produced to the well.
Guidelines Issued on Environmental Management:
The Directorate General of Hydrocarbons (DGH) issued the guidelines on environmental precautions during shale gas extraction. It stated that “overall volume of fracture fluid is 5 to 10 times that of conventional methods”.
The DGH notification states that these issues will be dealt with while granting environmental clearances as per the Environmental Impact Assessment (EIA) process.
The EIA process, however, does not differentiate between conventional and unconventional hydrocarbons.
Therefore, the fracturing activities are likely to deplete water sources and cause pollution due to the disposal of flow-back water.
Negative Consequences by using the Shale Gas:
- It requires large amounts of water, on an average, it requires 15,000 m3/well.
- It also requires relatively larger surface area.
- It is bound to impact irrigation and other local requirements.
- In the US, experience out of 260 chemical substances shows that, 58 have been identified to pose a risk to human life and environment, out of them eight are carcinogens and 17 are toxic to freshwater organisms.
- Fracking can cause tremors on the deeper areas of earth which results in
- 25-90% of the fluid is not retrieved and cracks in the shaft are possible, hence there will be a risk of pollution to nearby underground water.
- The instances of underground pollution are reported in US and Canada.
- Fracking has other impacts such as increase in air emissions, including greenhouse gases and seismic activity.
The Government introduced a policy on shale gas and oil in 2013. It permitted National Oil Companies to engage in fracking.
Under the first phase, shale gas blocks were identified in Andhra Pradesh, Arunachal Pradesh, Assam, Gujarat, Rajasthan and Tamil Nadu.
The environmental groups say that they have adverse environmental effects. Even the well-developed western countries like Germany and France and sub-national Governments like Scotland have banned fracking.
Indian households and irrigation thrive on groundwater. Implementation of the fracking processes without a consultative thought through process, especially on ‘water usage policy’, may result in larger issues including water stress, contamination of groundwater, and related health hazards.
But as the process stands today, we are missing an opportunity to comprehensively regulate the fracking process for a sustainable shale gas exploration in India.
As a first step, a sector-specific EIA manual on exploration and production of unconventional hydrocarbon resources may be a good idea.