Abstract :
The huge run-up in oil prices over the last several years, reaching a peak of close to US $150 per barrel this past summer, has given energy companies a big incentive to find new ways of harvesting unconventional oil, especially in North America. Technology firms targeted oil from tar sands in Canada and from shale, a sedimentary rock abundant in the western United States. But in the fourth quarter of 2008, oil prices plummeted, and that could put the brakes on the development of new extraction technologies, say experts.
