The exploitation of shale gas, which is trapped in compact and impermeable clay, would greatly increase global energy supplies.
When used, this fuel would also have less impact on the climate than coal. However, its extraction would pose several environmental problems that would justify the challenges.
Disadvantages of Shale Gas Mining
Deep boreholes of 1,000 to 3,000 m and then injection of a fluid composed of water, sand and detergents under pressure (600 bar) are required to fracture the rock and release the gas. These operations have already caused contamination of groundwater in the United States, in particular following oil leaks along the pipes. In addition, between 2% and 8% of the extracted fuel would be released to the atmosphere at the well level.
However, the majority of it consists of methane (CH4), a greenhouse gas that is considerably more powerful than CO2.
Surface installations must rest on concrete or asphalt floors connected to the road network. A pipeline is also required to evacuate production. In total, each farm would occupy an average area of 3.6 ha. Gas deposits are relatively small.
About 50 wells would be needed to produce as much fuel as a single well in the North Sea! The exploitation of shale gas could, therefore, lead to fragmentation of the landscape. Finally, a borehole requires about 20 million litres of water, which is the daily consumption of about 100,000 inhabitants! This list is not exhaustive…
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