Gas hidden in rock

In this promising shale, gas is not enclosed in an underground reservoir but is more or less spread in the rock, which soaks up gas like a sponge. The challenge is therefore in opening up the pores of the rock so that the trapped gas can “escape” out into horizontal collection wells. This is done through a technique known as fracking. The method is based on filling wells with water and chemicals under high pressure so that the almost impermeable rock breaks. Gas then leaks from microfissures.

However, environmentalists object that the chemicals driven underground can leak from the shale bed into underground water reservoirs, and handling the necessary chemicals is expensive and complicated, and some companies sometimes do not comply with regulations.

The greenhouse effect is also a global consideration in shale gas extraction. Gas is considered to be a cleaner energy source than coal because its combustion produces less CO2. But around 10 percent of the extracted gas escapes into the atmosphere from wells, collecting equipment and gas pipelines. Furthermore, shale gas contains a considerable volume of methane, which is roughly a hundred times more detrimental a greenhouse gas than CO2.

Shale proponents argue that shale gas will lead to energy independence. An MIT study has shown that by 2020 the US will be able to cover at least 40 percent and possibly up to one-half of its extraction of gas from its own deposits -- today the figure is 20 percent.

This wave of euphoria is also expanding to Europe. In Poland, where the largest reserves of any European country have been found, predictions are that if the consumption of gas were stable, shale deposits could cover energy needs for the next 200 years.

These optimistic expectations are to the advantage of extraction companies, as their share values are positively influenced by such predictions. In the US there have been discussions on energy self-sufficiency for 30 years, yet the country is increasingly energy dependent. Similar Polish hopes may also be a mere reflection of anger at being jilted, in a case of “Russia has bypassed us with the Nord Stream gas pipeline, so we will show them now.”

Each shale formation is different, in age and in the composition of gas. In the early stages of extraction most of the gas can be light methane, with slower-flowing ethane towards the end, for which the majority of current devices are not adapted (e.g., gas boilers), meaning that wells can become less efficient over time.

Preparing a territory for extraction requires significant investment, as there is no single “lucky” well but rather an area with several hundred boreholes. The whole system is interconnected through a network of intake pipes and must be linked to a regional gas pipeline. In short, this extraction is neither easy nor cheap.

These are some of the reasons why not much money has yet been made from shale gas. In spite of practically unbounded optimism in the media, a majority of small American shareholders are routinely losing part of their investments in the shale gas industry. The risk is that shale extraction could generate enormous returns initially but then deposits could be exhausted within a few years, resulting in the rapid closure of expensively opened deposit areas.

In rough terms we can thus speak about shale as a raw material with enormous, but still perhaps overestimated, potential and risks that are difficult to assess. One might go as far as speaking of the danger of a pyramid scheme in which falling yields from old bores are compensated by greater numbers of new ones.

But the current shale fever is resulting in one enormous benefit, the emergence of new drilling technologies, thanks to which bores can be made under the earth’s surface much faster than ever before.

The current wave of euphoria has a series of causes; it reflects a political game with energy independence as the prize and efforts to transfer economic risks to minor shareholders, but it is also a genuine technological breakthrough and certainly a change in the rules of the energy game. But the future of the sector is not yet clear.

*Václav Cílek is a geologist and climatologist.