Beneath the farms, orchards and vineyards of Central and Southern California lies a prehistoric soup worth a fortune. The mineral-rich Monterey and Santos shale formations stretching 1,750 square miles across the San Joaquin Valley and the Los Angeles Basin hold a watery mixture of oil and gas – but it’s the oil that may trigger another gold rush. That is, if companies can figure out a profitable way to tap it.
The U.S. Energy Information Administration reported that the contiguous 48 states hold an estimated 23.9 billion barrels of recoverable oil, of which an astounding 15 billion barrels are in the Monterey/Santos formations. California has been plumbed for oil extraction and production for 150 years, but getting to the Monterey’s mother lode is no easy task.
“Producing Monterey Shale oil could make panning for gold look easy,” wrote David Brown in the American Association of Petroleum Geologists’ publication The Explorer. The formation is fractured and faulted. But that’s not all. The shale is, on average, almost 1,900 feet thick and 11,200 feet deep. This makes accessing the oil tricky, and conventional methods won’t suffice.
Increasingly, companies are turning to new technologies. In California they’ve tried using water and steam flooding, gravel packing, and acidization (injecting hydrochloric or hydrofluoric acid) to coax the oil to the surface. And then there is hydraulic fracturing, or fracking, where a mixture of chemicals, water and sand are forced at high pressure underground vertically, and sometimes horizontally as well.