Oil Beneath San Mateo County? You Betcha

Oil. Since Americans first understood its capacity to make all kinds of machines run, they began to dig under the soil. Now, when you think of oil drilling in California, you probably think of Southern California and the Inland Empire. But did you know there are oil fields in the Bay Area?

Alden Hughes knows. The 15-year-old Prospect High School student from Saratoga is a hiker. So is his mom, and when she encountered an oil seep, he started digging around on the internet and was surprised to discover there’s both oil and oil drilling on the Peninsula. Which prompted him to ask Bay Curious: What’s the history behind oil drilling in San Mateo County?

Ancient Times, Rich in Organic Matter

The history begins a long time ago in the Miocene Epoch, a period that ran from about 23 million to about 5 million years ago.

During the Miocene, the Bay Area was underwater, part of the Pacific Ocean. (As Bay Curious has recently explained, the only creatures around at that time were either swimming or flying.)

Still, these waters were rich in planktonic algae, according to Rick Stanley, a geologist with the U.S. Geological Survey who used to work in the oil business.

Stanley says these itty-bitty critters lived, died and drifted down to the sea bottom, where they mixed with mud. Over time, one layer of mud settled over another, piling up, “in some cases, thousands of feet thick.” Meanwhile, deep beneath the seafloor, “the heat from the interior of the earth caused the organic matter to undergo chemical reactions and actually convert into oil and gas,” Stanley explains.

While we don’t have video of the scene underwater, you can get a sense of the critters he’s talking about in this video by biological oceanographer Colleen Durkin of Moss Landing Marine Laboratories.

As every child learns in a California elementary school, the California coast is rife with seismic faultlines. Thanks to tectonic plates shifting about, layers of sediment and rock are bent and folded. Sometimes, when the layers buckle, you can get what geologists call an anticline. And oil is inclined (sorry, I couldn’t help myself) to rise to the top, despite the layers of impermeable materials above it.

So every now and then, hikers in the hills and beachgoers puttering about on the California coast will come upon a pool of black sticky stuff coming up out of the ground. They’re called oil seeps, and they hint at potentially deeper reserves of oil below.

Alden Hughes is interested in San Mateo County because that’s where he and his mom often hike. Sure enough, old place names hint at what lies beneath. There’s Oil Creek near Portola Redwoods State Park. There’s Tarwater Creek in Pescadero Creek Park. But most of the wells in the Bay Area have been capped and abandoned over the years. There are only two operating oil wells in San Mateo County, and they’re both located in the rolling green hills by Half Moon Bay.

The Gentleman Oil Driller of Half Moon Bay

We agree to meet on his pretty little farm for retired horses. The owner, John Tedesco, says he didn’t buy the land for the oil. He and his wife came here to retire, and it just so happened this property still had a couple of working pump units on it. “A very eccentric seller instructed me on the whole history of this, so I was very intrigued by it,” Tedesco says.

Before you ask: Yes, he does have the permits to pump for oil. “We’re totally regulated by everything, including Bay Area Air Quality Control,” Tedesco tells us almost as soon as we arrive.

We walk into the pasture, past the horses, to a fenced-in patch that’s home to a little pump unit painted green. When I say little, I say that because I’m from Southern California, home of the biggest urban oil field in the country, and those pumping units are several times the size of this one. This one is about 16 feet high when fully extended.

“This is a Lufkin, circa 1940s,” Tedesco says. One of the common nicknames is “grasshopper,” and like the name suggests, the unit does look like a grasshopper, with a head that moves up and down when it’s pumping.

If you were to put a rig in like this, what would it cost you? “$100,000, easily,” Tedesco says. Between both wells, he pumps about four to six barrels a month.

So is Tedesco getting rich off of this? Not exactly. He says it all depends on the price of crude on the open market — $150 a barrel, nice. $50, not so nice.

I ask Stanley why there aren’t more pump units like his grasshopper peppering the county, or the Bay Area, for that matter.

“Well, for one thing, the fields that have been discovered in the Bay Area are very small compared to the fields in Southern California,” Stanley says. “The total production here from Half Moon Bay Field is something like 60,000 barrels since the 1880s. Compare that with some of the big fields in Southern California. For example, Midway-Sunset, located west of Bakersfield. That one’s about 3 billion barrels that’s been produced, during that same period of time.”

But if Mother Nature didn’t deposit a lot of oil and gas under San Mateo County’s land mass, the story may be different offshore. According to the California Department of Conservation, more than 11 million barrels of oil were produced from offshore wells in California state waters in 2016. That’s not counting the oil production in federal waters more than three miles offshore.

That could be the subject of a political battle as the Trump administration pushes for more offshore drilling.

“There is a report that you can get online,” Stanley says. “It was prepared roughly 20 years by what was then called the Minerals Management Service, now Ocean Energy Management. They predicted a billion barrels of oil might be found offshore of San Mateo County. But there’s only two wells drilled out there. They found geology favorable to the occurrence of oil, but they didn’t find any commercial deposits. So the billion barrels is an estimate. It’s really just a guess,” Stanley says.

Will oil companies find that guess is worth a fight with many of California’s coastal communities?

That is an open question.