Since some supermajors predict unconventional gas like shale gas is expected to meet more than 50 percent of gas demand by 2030, understanding the pros and cons related to shale gas exploitation will be crucial for decision makers and stakeholders. Here’s 3 simple questions and answers:
What is shale gas?
It’s mainly methane gas like the one we use for cooking or heating. However, this gas is tightly trapped in rock formations hundreds of meters down the earth.
There are plenty of shale gas formations in Europe, mostly in France, Poland and Denmark (see map below). The recent Montelimar exploration permit in southern France is covering Initial Gas In Place reserves of up to 85 TCF equivalent to about 650 billion dollars at today’s European gas prices. Snøhvit gas field offshore Norway holds about 4 TCF as a comparison. Shale formations existence and location in Europe were known for decades but only recently, following the increase of energy prices, has exploration started again. Moreover the technology and equipment to extract them are now commercially available and new well stimulation technology could improve gas production by 50%.
What are the advantages of exploiting shale gas?
When burned, methane emits less pollutants than coal or oil. CO2 emissions are lower than today’s global electricity mix based principally on coal. So exploiting shale gas seems to improve the energy status-quo and transition us towards a more environmentally friendly energy mix. Natural gas reserves are mostly in Iran, Qatar and Russia. Being less dependent on imports from this triumvirate could also be an argument for exploiting shale gas at its full potential.
What are the challenges related to shale gas production?
- If the local energy mix is not dominated by coal or oil, the advantage of exploiting shale gas are less obvious. Hydropower, biomass, geothermal, wind, solar and sometimes nuclear are considered much cleaner.
- A lot of water is needed for shale gas production: The 18 million liters of water needed to drill and fracture a typical deep shale gas well is equivalent to the amount of water consumed by New York City in approximately seven minutes . In addition, when the water is used to fracture the rock several hundred meters below the surface, it is blended with sand and chemicals. Therefore the monitoring of any potential leakages is crucial. After it is used, the water has to be treated and disposed off properly adding pollution issues to the surroundings
- The emissions of gas during operations could add an additional environmental burden to the shale gas sector since the emissions of methane for the moment are not well monitored.
- The operations to extract shale gas are very intensive and thousands of drillings and fracturing of the rock have to be performed. The regulations covering these operations are unfortunately not very clear (cf. video below) in some parts of the world new to unconventional gas. This could create unregulated and undesired disturbances, including induced seismicity, in the concerned neighborhoods.
Read more about the viewpoints from DNV’s Research and Innovation unit on this subject in the soon-to-be launched Technology Outlook 2020