Off the coast of Southern California there were oil rigs that are now mostly shut down.(A few are left but they won’t allow new ones to be built) People say the oil just seeps up from the ocean bottoms and forms tar balls on some of the beaches. California won’t allow any more off shore drilling but there’s tons of oil there if they wanted to get it!
There was a really bad oil spill off Santa Barbara in 1969, a Union Oil platform.
It made a hell of a mess, lots of dead fish, birds and mammals, miles of pristine beach fouled. It was a massive blowout, over a 1,000 psi at the rig. Modern drilling methods would have prevented it from happening.
That’s what put the kibosh on coastal drilling, especially in California.
There is an ocean of oil beneath the California coast. Not too deep either.