|Statoil employees tested shale samples for mineral content at Chesapeake Energy in Oklahoma. - Matt Nager for The New York Times.|
OKLAHOMA CITY - A new technique that tapped previously inaccessible supplies of natural gas in the United States is spreading to the rest of the world, raising hopes of a huge expansion in global reserves of the cleanest fossil fuel.
Italian and Norwegian oil engineers and geologists have arrived in Texas, Oklahoma and Pennsylvania to learn how to extract gas from layers of a black rock called shale. Companies are leasing huge tracts of land across Europe for exploration. And oil executives are gathering rocks and scrutinizing Asian and North African geological maps in search of other fields.
The global drilling rush is still in its early stages. But energy analysts are already predicting that shale could reduce Europe's dependence on Russian natural gas. They said they believed that gas reserves in many countries could increase over the next two decades, comparable with the 40 percent increase in the United States in recent years.
"It's a breakout play that is going to identify gigantic resources around the world," said Amy Myers Jaffe, an energy expert at Rice University. "That will change the geopolitics of natural gas."
More extensive use of natural gas could aid in reducing global warming, because gas produces fewer emissions of greenhouse gases than either oil or coal. China and India, which have growing economies that rely heavily on coal for electricity, appear to have large potential for production of shale gas. Larger gas reserves would encourage developing countries to convert more of their transportation fleets to use natural gas rather than gasoline.
Shale is a sedimentary rock rich in organic material that is found in many parts of the world. It was of little use as a source of gas until about a decade ago, when American companies developed new techniques to fracture the rock and drill horizontally.
Because so little drilling has been done in shale fields outside of the United States and Canada, gas analysts have made a wide array of estimates for how much shale gas could be tapped globally. Even the most conservative estimates are enormous, projecting at least a 20 percent increase in the world's known reserves of natural gas.
One recent study by IHS Cambridge Energy Research Associates, a consulting group, calculated that the recoverable shale gas outside of North America could turn out to be equivalent to 211 years' worth of natural gas consumption in the United States at the present level of demand, and maybe as much as 690 years. The low figure would represent a 50 percent increase in the world's known gas reserves, and the high figure, a 160 percent increase.
The projections suggest that the new method of producing gas "is the biggest energy innovation of the decade," said Daniel Yergin, chairman of the Cambridge consulting group. "And the amazing thing is there was no grand opening ceremony for it. It just snuck up."
|Engineers and geologists are learning how to extract natural gas from layers of shale, a sediment. - Matt Nager for The New York Times.|
Over the last five years, production of gas from shale has spread across wide swaths of Texas, Louisiana and Pennsylvania. All the new production has produced a glut of gas in the United States, helping to drive down gas prices and utility costs.
Now American companies are looking abroad for lucrative shale fields in countries hungry for more energy. They are focusing particularly on Europe, where gas prices are sometimes twice what they are in the United States, and large shale beds are located close to some cities.
Exxon Mobil has drilled a few exploratory wells in Germany in recent months. Devon Energy is teaming up with Total, the French oil company, seeking approval to drill in France. ConocoPhillips announced recently that it had signed an agreement with a subsidiary of a small British firm to explore a million acres in the Baltic Basin of Poland.
Early estimates of recoverable European shale gas resources range up to 400 trillion cubic feet, less than half the industry's estimates of what is recoverable in the United States. But European energy executives say they are excited about the prospects because the Continent's conventional gas reserves are too small to meet demand.
"It is obvious to everybody that it has huge potential," said Oivind Reinertsen, president of StatoilHydro USA and Mexico, a Norwegian company with growing shale interests. "You see a lot of land-grabbing by different companies in Europe, potentially spreading to the Far East, China and India."
Donald I. Hertzmark, a consultant who advises multinational oil companies on gas projects, said that in a decade or so, the new shale gas resources would improve Europe's ability to withstand any future reduction in Russian pipeline shipments. In 2006 and again last winter, Russia cut off natural gas deliveries shipped through Ukraine because of disputes between the two countries, causing shortages around Europe.
European companies are buying large interests in shale fields in the United States, partly to supply the American market, but also to learn the specialized mapping and drilling techniques required for shale gas.
Several of the European companies have entered into partnerships with smaller American companies. ENI of Italy paid $280 million in May for a stake in a 13,000-acre gas field north of Fort Worth operated by Quicksilver Resources. ENI has a crew of four engineers, a geologist and a geophysicist in Texas to learn from Quicksilver personnel.
One of the biggest marriages is between Chesapeake Energy of Oklahoma City and its strategic partner StatoilHydro.
Seeking cash, Chesapeake agreed to sell Statoil a large stake in its Marcellus shale holdings, centered in Pennsylvania, for $3.9 billion last November. The two companies are looking at shale fields in China, India, Australia and other countries. Seven Statoil employees are working in Oklahoma and Pennsylvania learning to map and fracture shale, and calculate shale gas pressures, and more are coming.
"We know the shale is out there," said Lars Erik Oino, a Statoil geologist working at Chesapeake headquarters here, as he rubbed hydrochloric acid on a shale sample to test its mineral makeup. "This could have a huge impact on the European energy situation."