Pump jacks seen in the Midway Sunset oilfield, California. The nearby vast Monterey shale formation is estimated by the US Energy Information Administration to hold 15 billion barrels of technically recoverable oil, or four times that of the Bakken formation centred on North Dakota.
Most of that oil is not economically retrievable except by hydraulic fracturing, or fracking, a production-boosting technique in which large amounts of water, sand and chemicals are injected into shale formations to force hydrocarbon fuels to the surface.
The Peninsula
