A World of Plenty

Shale gas resources are potentially huge, but so far only the US that has taken advantage of this low permeability reservoir rock.
This article appeared in Vol. 10, No. 2 - 2013


IEA has evaluated shale gas resources in 48 basins in 32 countries worldwide, concluding that this unconventional resource has gigantic potential, with a low CO2 footprint compared to other fossil fuels. Shale gas has rejuvenated the natural gas industry in the US, starting in the 1980s and 1990s when engineers experimented with making deep shale gas production commercial in the Barnett Shale in Texas. By about 2005 output had reached 0.5 Tcf per year, and several other plays were being pursued in the lower 48 (e.g. Fayettville, Haynesville, Marcellus and Eagle Ford Shales).

Shale gas is nothing magical: it is natural gas trapped within its own source rock. Due to low permeability it cannot escape and migrate to nearby reservoir rocks. This is also why a combination of horizontal drilling and hydraulic fracturing is necessary to extract large volumes of shale gas. It is the development of these techniques that has made shale gas production a valuable venture, and which has increased US shale gas production by a factor of ten from 2000 to 2010. As a result, 23% of US gas production came from shales in 2010. The future also looks good: in 20 years’ time shale gas production may constitute almost 50% of US natural gas production.

The US is no doubt in the lead. Driven by huge resources, innovative companies, dedicated people and a wish to be self-sufficient with respect to gas, it has transformed the world gas market. Shale gas is now also being explored and exploited in other parts of the world. But exactly how much can be produced is unclear – the only certainty is that the number of countries with potentially large resources grows steadily.

Shale gas has been discovered on all continents except Antarctica. In Europe, Poland in particular may have significant resources, with the International Energy Association (IEA) suggesting the technical resources for shale gas to be 187 Tcf (35 Bboe). However, while 109 shale gas concessions for prospecting and exploration have been granted so far, no single shale gas field has yet been fully documented in Poland.

The biggest reserves in a world-wide perspective may be in China, which according to IEA may hold total recoverable resources in excess of 1,275 Tcf (242 Bboe). However, while China already produces lots of coal bed methane, the shale gas adventure has not taken off yet. According to The Economist, China is pushing shale gas exploration by encouraging domestic producers to form partnerships with foreign oil and gas companies, and several of the supermajors, like BP and Chevron, are already involved in joint ventures with Chinese partners.

With respect to world reserves, the US is second with technical resources of 862 Tcf (163 Bboe), Argentina third with 774 Tcf (147 Bboe) and other countries with potentially significant resources are Mexico, South Africa, Australia, Canada, Libya, Brazil and France. The world’s total shale gas resources are estimated at 6,622 Tcf (1,258 Bboe).

Interestingly, IEA has listed both Norway and Sweden on their technical resources list, although you cannot find a single Norwegian geologist who believes in shale gas production from Cambrian Alum shales in the Oslo Graben. In Sweden, Shell withdrew a couple of years ago after drilling three non-commercial wells in Lower Paleozoic rocks. The numbers from IEA therefore need to be regarded with scepticism. The shale gas venture is by no means mature yet.


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