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– technology of the future – also for explosion protectionby Thorsten Arnhold

Pioneer USA The public debate on pros and cons of fu-ture exploitation of large resources of so-called shale oil, and in particular shale gas, has increased significantly in many coun-tries in frequency and intensity. The debate has mainly been inspired by the impressive news and information from the USA where exploitation of unconventional deposits of fossil fuels started several years ago. The USA has the largest known shale oil and gas reserves in the world and these resources are mainly in sparsely populated areas. In such areas, large-scale exploitation can be achieved with relative ease. To be able to assess the extent of the available resources and their importance for the US economy, the following facts should be taken into ac-count:> As of 2015, the USA will presumably be-

come the world’s largest producer of nat-ural gas through the exploitation of shale gas deposits, and as of 2017 they will be-come the largest producer of natural oil through the exploitation of shale oil.

> As in the past years, energy prices have plummeted the USA has become an at-tractive location for energy-intensive in-dustries. As of 2008, gas prices have de-creased by more than 80% and the electricity rates have plummeted similar-ly.

> According to the estimations of the com-pany IHS (IHS Inc. a leading global source of information and analytics), in 2012 alone, the addition of 1.7 million new jobs and 238 billion US dollars to the gross domestic product could be attribut-ed to the effect of the shale gas and oil boom.

Legislation, Standards and Technology

Page 10 | Ex-Magazine 2013

Fracking

No wonder in Texas people talk about ›game-changer‹ when talking about the new technology for the exploitation of unconven-tional deposits. Hydraulic fracturing (Frack-ing) technology is on the other hand not new at all. For example, in Germany it has been used for several decades for the exploitation of deposits that are difficult to access, with-out public notice and without incident de-spite opponents more or less well grounded claims of possible environmental risks that fracking may cause.

The procedure During fracking, oil and gas deposits that are several hundred to more than a thou-sand metres deep, are tapped first by a ver-tical drilling, followed by horizontal drilling (see figure 1). To protect the drinking water resources that occur mostly in near-surface depth, the vertical drillings are lined with steel tubes that are subsequently sealed with concrete. Then, small openings are blasted into the shale layers in the horizon-tal range of the drilling with the help of a so-called perforation gun. Afterwards, several million litres of fracturing fluid are pumped into the drilling under high pressure. More than 98% of this fluid consists of water and solid filler material like coarse-grained sand. Two per cent of the fluids are different chemicals, including antibacterial ones, ones that are anticorrosive or that decrease the surface tension of the raw materials that are exploited and thus make exploitation easier. With the hydrostatic pressure, the shale layers are opened and direct access to the oil or gas fracking is provided. Then, ca. 40% of the fluids are pumped out again. The rest that remains consists in large part of solid particles that now have the task of

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keeping the small burst channels in the shale open during the production process. The fluid that has been pumped out is recy-cled at the surface in special wastewater treatment plants and can be used again lat-er for the exploitation of new deposits.

Why is there strong opposition from differ-ent environmental protection organisations to fracking? First there is the suspicion that highly toxic chemicals are introduced into the soil poisoning the drinking water and cause oth-er long-term damages. However, examina-tions have shown that with correct sealing of the vertical drilling and by keeping a dis-tance of several hundred metres between the drinking water resources and the depos-its of the fossil raw material, poisoning of the drinking water can be avoided. Spectac-ular videos that can be viewed on the Inter-net, showing that in Texas the drinking wa-ter that flows from the tap can be ignited with a match have proven to be fraudulent . Problematic is that the production com-panies do not completely publish the com-position of the chemicals used as they want to protect their intellectual property. The op-ponents of the technology consider this to be a confession that the environment is en-dangered. Another point of criticism is that fracking has caused isolated earth tremors. However, this hazard can be met by careful seismic surveys before the beginning of the exploitation. A more serious argument is the huge wa-ter consumption fracking involves. On a world level, and especially in certain re-gions, drinking water is a very scarce re-source. Particularly in China, who wants to start fracking on a large scale in the coming

years, suffers from chronic water shortage. An efficient recycling process with largely closed cycles spares the freshwater re-serves and ensures that only a few of the hydrocarbons in the fracturing fluid that has been pumped back are released.

Where is explosion protection required dur-ing fracking? In principle, fracking is just a special type of extraction of flammable hydrocarbons. Explosion protection is required for produc-tion, transport and processing of the raw materials, i.e. in principle of the same type and to the same extent as it has been re-quired up to now for the exploitation of con-ventional deposits. Due to the low yield of the shale deposits, however, several drill-

ings per deposit are required, which leads to a multiplication of the drilling equipment. Storage and recycling of the used fracturing fluid holds explosion hazards as well, as there are hydrocarbons in the fluid. If the majority of the studies on unconventional deposits and the statements in these studies on the expected range of the raw material deposits can be believed, it looks like explo-sion protection in the oil and gas industry will have a long future.

Figure 1: Basic principal of Fracking

vertical drilling

horizontal drilling

protective seal

fractured deposite

What can be expected of fracking in future? Aside from the USA, there are numerous nations that have substantial shale gas and shale oil deposits. Examples are Argentina, Mexico, Chile, China, Libya, Algeria and Rus-sia. In Europe, particularly Poland, Great Brit-ain, France and Germany have noteworthy reserves. While there is a comprehensive prohibition of fracking in France, countries like Great Britain and Poland prepare for an intensive exploitation of their national de-posits. Given that the large Polish reserves may ensure the national gas supply for about 300 years and will make Poland inde-pendent of the expensive, politically charged imports, this is more than under-standable. In Germany, the government is now dealing with this technology under the absolutely essential prerequisite of protect-ing the environment with strict safety stand-ards while at the same time exploiting the substantial resources. Independent of the

Figure 2: Shale gas potential – worldwide known reserves and resources 2010 (Source: Study of the Federal Institute for Geosciences and Natural Resources (BGR), Germany).

development of the German exploitation of uncon-ventional fossil raw material depos-its, intensive use of the fracking technology may in future be expected throughout the world. The demand for energy and raw ma-terials of the industrial and developing coun-tries, and the temptation to become inde-pendent of external suppliers for decades to come is too great. Taking the optimistic forecasts into account, the summit of the oil and gas production, which seemed to be im-minent a few years ago, now has been pushed some decades or even centuries away on the time axis.

Fracking – technology of the future – also for explosion protection

USA

Arg

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a

Mex

ico

Chin

a

Sout

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fric

a

Aus

tral

ia

Russ

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Lybi

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Alg

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Bra

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Pola

nd

Fran

ce

Cana

da

Nor

way

Chile

Indi

a

Para

guay

Paki

stan

Bol

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Ger

man

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Ukr

aine

Oth

erCc

ount

ries

Bill. m3

5

10

15

20

25

24

22

19

17

14

1110

87

65 5

4

21,21,31,41,41,81,81,8

9

North America

Latin America

Europe

GUS

Africa

Australia

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