The International Energy Agency announced last year(1) that in 2015 the United States would become the world’s largest gas producer, dethroning Russia. They owe this position to the entry into the energy market of shale gas, the exploitation of which has really exploded in recent years.
While in 2000 shale gas represented only 2% of the US natural gas production, in 2012 this proportion reached 37%. The ultra-fast development of this production has impressed the world and challenged experts and politicians on the potential of exploitation.
In fact, shale gas has been known for a long time, as have the techniques for exploiting it. It is the combination of two of these techniques, hydraulic fracturing and horizontal drilling, that has made it possible to greatly improve extraction capacities and to once again make people dream of the energy cornucopia.
Thus, China, which has significant reserves (25,000 billion m³), plans to increase its production from 6.5 billion m³ in 2015 to 100 billion m³ in 2020.
The Europeans who pay the most attention to what is happening across the Atlantic are convinced that shale gas will free them from the spectre of scarcity and dependence:
- Poland, 70% dependent on Russian gas for its supply, has regularly expressed its enthusiasm for a resource that would free it from the grip of its powerful neighbor; the estimated national reserves, even if they are regularly revised, allow one to dream, since the figures announce an underground potential ranging from 300 to 750 billion cubic metres(2)
- On December 13, the British government, under pressure from the business community, which is very mobilized and attentive to developments in the US(3), gave the green light to the exploitation of shale gas.
The European Commission is reserved, while declaring its interest in further investigating the exploitation of unconventional gas and, more specifically, shale gas.
Recently, a group of European researchers under the auspices of the Joint Research Centre(4) published a report aimed at identifying the prospects for shale gas in Europe. Their estimates conclude that there is a significant geological potential in the order of 15,000 billion m³, most of which is located in Western Europe; however, they draw attention to the uncertainty in the recovery rate, which could vary between 15 and 40%.
In addition, they point out a significant difference between the situation in the United States and that in Europe: in the United States, in addition to the existence of very rich deposits, the gas industry benefits from the existence of a large network of pipelines, which is half as dense in Europe, which significantly increases the costs of operation and distribution.
In conclusion, European experts believe that if the best geological, technical, economic and political conditions were met, unconventional gas (i.e. shale gas plus coal seam gas and sandstone gas) could at most compensate for the decline in conventional regional resources!
In short, there is not much to be excited about.
But, there is more serious. If we look at the ecological impact of the techniques used for the extraction of shale gas stored at great depths (1500 to 4500 m), we can only be deeply concerned:
- Hydraulic fracturing involves the injection of water, sand and a cocktail of chemicals at very high pressure. With the gas, water, loaded with heavy metals and radioactive elements, and a large part of the injected chemicals are brought up. This heavily polluted water that ends up on the surface cannot be treated by conventional sewage treatment plants; moreover, contamination of aquifers due to chemical leakage is practically unavoidable;
- water consumption is enormous (15,000 to 22,000 m³ per fracturing) to the detriment of local agricultural activities;
- the land area is impressive; each drilling zone (about ten wells per zone) occupies 3 to 4 hectares, twice as much as a conventional drilling;
- the seismic risk is real. Initial drilling in the UK in April and May 2011 in the North West (near Blackpool) caused two earthquakes, albeit small, but sufficient to cause the experiment to be suspended. In addition, wastewater re-injection, as practiced, can also cause an earthquake when it reaches a geological fault;
- the health effects, observed in the United States, have been widely documented by the federal Environmental Protection Agency: asthma problems in 25% of young children in the six Texas counties concerned, i.e. three times the average rate; air quality in Wyoming is below the standards in force because of benzene and toluene pollution from the wells(5);
These impacts, lightly conceded by shale gas enthusiasts, are in line with the environmental destruction caused by the exploitation of fossil resources, but more serious given the specific aggressiveness of the extraction techniques and the difficult accessibility of the resource.
In addition to these direct and localized impacts in the vicinity of the extraction sites, which rightly arouse the opposition of local residents, there is the equally worrying impact on global equilibrium, and particularly on the climate. Indeed, if methane gas can be considered as the least polluting of the fossil fuels when used, shale gas, due to the extraction process, becomes one of the dirtiest fuels. A study, the first results of which were presented at the annual meeting of the American Geophysical Union, shows a leakage rate in the wells of around 9%.
Methane is a powerful greenhouse gas (23 times greater than CO2).
As a result, such large leaks lead to a disastrous overall balance. Thus, the main « ecological » argument of the shale gas supporters collapses.
Towards a shale gas bubble
But there is another argument that could be decisive for potential investors. Indeed, there has been a rapid decline in production from drilling wells in the United States. This would decrease by 70% to 80% after 1 year and would only represent 5% to 15% of the initial production at the end of the fourth year of operation. This requires more drilling to compensate for the decline in production from the initial drilling. The consequence is an impressive sprawl of the territory (more than 500,000 wells in the United States in 31 states) and a significant increase in costs(6).
This mechanism, together with the overestimation of the recovery rate and the imperative need to limit negative impacts on the environment, may lead to the fear of a new bubble born of the exaggeration of all the parameters and an underestimation of the constraints(7).
Everything indicates that the only real asset of shale gas is its ability to postpone the inexorable end of fossil fuels by a few years. Its main disadvantage is that it delays the development of renewable energies.
The headlong rush in the United States, with all the drums and trumpets, must be seen as the last gasp of a dying « civilization ». It would be unrealistic and dangerous to follow their lead.
- World energy outlook; special report on unconventional gas; AIEA, 2012.
- Courier international; n° 1153, décembre 2012.
- Le Monde: Londres relance l’extraction du gaz de schiste; 15 décembre 2012.
- Ivan Pearson et al: Unconventional gas: potential energy market impacts in the European Union; JRC Scientific and policy reports; 2012.
- AEA et al; Report for the European Commission; DG environment; 10 août 2012.
- Centre d’analyse stratégique; note d’analyse; n° 215, mars 2011.
- B.Thévard: L’Europe face au pic pétrolier; étude commandée par le groupe des Verts/ALE au Parlement européen.