NGlobal Magazin 01-2010

Niedersachsen Global www.nglobal.de Energy 23 Niedersachsen’s Hidden Treasures With its natural gas resources the federal state is a ‘small sheikdom’. by Inka Ziegenhagen Large farms, handsome half-timbered houses and lush greenery as far as the eye can see. At first sight the villages of Völkersen, Bötersen and Söhlingen on the edges of the Lüneburg Heath do not appear as being very spectacular at all. However, unseen, thou- sands of metres below the surface of the earth, the region conceals immense treasures: this is where Ger- many’s largest reserves of natural gas are located. “A small ‘sheikdom’,” is how the—otherwise quite so- ber — people of Niedersachsen proudly put it. As a matter of fact, 14.7 billion cubic metres of gas were extracted last year—that is 17 times more than in the rest of Germany. “Not only is Niedersachsen self-suf- ficient regarding the supply of natural gas, we also make an important contribution to ensure the energy supply of other federal states,” explains Dr. Gernot Kalkoffen, Chairman of the Association of German Oil and Gas Producers and European head of ExxonMo- bil. Niedersachsen indeed covers 15 percent of Ger- many’s natural gas requirements. Gas supplies in the federal state may well exceed re- gional demand. Yet, here, too, the times of easy and cheap natural gas are long over. The abundance is not going to last indefinitely. According to recent es- timates, gas supplies for commercial production are likely to be exhausted in 20 to 30 years. “We are aware of all the large deposits, and by now new find- ings have become as rare as a Blue Mauritius,” states Niedersachsen’s Prime Minister Christian Wulff. This is why in the future extraction is to be expanded to deeper and less accessible layers of the earth. Close to the Dutch border is an area where ExxonMobil sus- pects large quantities of the so-called unconventional gas. The Texan gas and oil giant with German head- quarters in Hannover is planning to invest a three-dig- it million sum to explore the zone by this summer. If the company’s scientists and engineers do discover gas, Kalkoffen hopes, availabil- ity of the fossil fuel could extend to 30 or 50 years. World Record in Söhlingen Uncoventional gas types include tight gas, a challenging type of resource since it is found in compact and virtually impenetrable rock. ExxonMobil started to extract tight gas in the Söhlingen gas field ten years ago—and in the process reinvented extraction technology. To bring the precious gas to the surface, a flexible drill string bores some 5,000 metres deep into the earth. Given that gas fields tend to occur more frequently as horizontal layers than as vertical ones, the drill string, in its second phase, changes direction and moves into the deposit horizontally. This cre- ates higher production rates with considerably fewer drillings. To induce gas flow in impenetrable sandstone, the stone is opened up by inserting liquid under high pressure. Then the cracks, which may be several hundred metres long, are filled with a propping agent which allows the gas to flow easily. To ensure precision drilling in those deep layers of rock, civil engineers of the U.S. American oil and gas service provider Baker Hughes Inteq have developed a highly intelligent, “autonomous” as it were, drill robot. AutoTrak Rotary Closed Loop Drilling System® can follow a given course with unprecedented accuracy for as many as twelve kilometres, both in a horizontal and in a vertical direction. This pre- cision allows an easier, faster and more economic extraction. The robot was devel- Photo: ExxonMobil “Not only is Niedersachsen self-sufficient regarding the supply of natural gas, we also make an important contribution to ensure the energy supply of other federal states.” Dr. Gernot Kalkoffen, Chairman of the Association of German Oil and Gas Producers and European head of ExxonMobil ›