The Gulf of Mexico's Eugene Island Block 330 Field (just off the coast of Louisiana) is often cited by proponents of the abiotic oil theory because of something very strange: its depleted oil wells found themselves, as if by magic, suddenly replenished with new oil - and no one could say exactly why.
From the Wall Street Journal, April 16, 1999:
Something mysterious is going on at Eugene Island 330. Production at the oil field, deep in the Gulf of Mexico off the coast of Louisiana, was supposed to have declined years ago. And for a while, it behaved like any normal field: Following its 1973 discovery, Eugene Island 330's output peaked at about 15,000 barrels per day (2,400 m3/d). By 1989, production had slowed to about 4,000 barrels per day (640 m3/d). Then suddenly -- some say almost inexplicably -- Eugene Island's fortunes reversed. The field, operated by PennzEnergy Co., is now producing 13,000 barrels per day (2,100 m3/d), and probable reserves have rocketed to more than 400 million barrels from 60 million.
According to a 2002 article by Robert Cooke in Newsday, the source of Eugene 330's new oil from nowhere was analyzed and suspected to be migrating through faults from much deeper and older subterranean faults. These "deep earth" faults have been surmised to be from the Jurassic and Cretaceous age. This new mystery oil contains biomarkers closely related to other extremely ancient oil deposits, trapped in very deep formations.
Eugene 330's effectiveness as a "smoking gun" for abiotic oil is limited, however. Skeptics point out that Eugene 330 is special precisely because what happened there has never happened before, and this begs the logical question, why isn't this phenomena more common if the deep strata of the Earth's crust is filled with endlessly self-replenishing reserves of abiotic oil?
What is a demonstrable fact, however, is that this "deep earth oil" carries further potential for natural radioactivity the deeper you go. NORM (Naturally Occuring Radioactive Materials) has been studied in locations such as New York and Texas. Uranium and Thorium are known by geologists to be plentiful deep in the Earth, so much so that modern oil companies use electronic detectors to sniff out helium and methane. Why? Because helium and methane are natural decay signifiers of Uranium and Thorium.
Therefore, the more methane you find from a "deep earth oil" reserve such as what BP and the Deepwater Horizon were drilling into, the greater possibility that you are releasing considerable amounts of radioactive material into the environment. That this radioactivity is "natural" is irrelevant, and doesn't make it any less deadly (in before Rush Limbaugh and Haley Barbour proclaim it to be all-natural and perfectly safe).
Considering that the flow from the BP leak is believed by experts to be 40% methane, this raises the question: how much natural radioactive material is correspondingly being spewed out with it?
No amount is a good amount.