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.
Drone strikes on Saudi Arabian oil facilities have disrupted about half of the kingdom's oil capacity,...
