Is the American Oil Boom Turning Into a Bust?

The stubborn rock that the energy industry breached to unleash a nationwide oil and gas rush remains a worthy foe, as producers must turn their drills ever faster to keep the boom’s lifeblood flowing.

Engineers have long known that shale, the source rock that fed North American sandstone reservoirs for millennia, could never muster the natural pressure producers need to extract oil and gas. Its molecules are too tightly packed: Shale is about 1,000 times denser than brick, and so far, only hydraulic fracturing can induce enough artificial permeability to clear a path for the fossil treasure.