MessageA week ago Bill Hamilton sent an article entitled "Sustainable Oil?" by Chris Bennett that was taken from WorldNetDaily.com. In support of an inorganic source for major quantities of oil, the article made the following comments about a Eugene Island oil platform in the Gulf of Mexico:
About 80 miles off of the coast of Louisiana lies a mostly submerged mountain, the top of which is known as Eugene Island. The portion underwater is an eerie-looking, sloping tower jutting up from the depths of the Gulf of Mexico, with deep fissures and perpendicular faults which spontaneously spew natural gas. A significant reservoir of crude oil was discovered nearby in the late '60s, and by 1970, a platform named Eugene 330 was busily producing about 15,000 barrels a day of high-quality crude oil.
By the late '80s, the platform's production had slipped to less than 4,000 barrels per day, and was considered pumped out. Done. Suddenly, in 1990, production soared back to 15,000 barrels a day, and the reserves which had been estimated at 60 million barrels in the '70s, were recalculated at 400 million barrels. Interestingly, the measured geological age of the new oil was quantifiably different than the oil pumped in the '70s.
Analysis of seismic recordings revealed the presence of a "deep fault" at the base of the Eugene Island reservoir which was gushing up a river of oil from some deeper and previously unknown source.
The company I used to work for (Chevron) had an interest in the Eugene Island field, but I had never heard this story before; if it were true, it should have been big news. So I asked former colleague Bill Abriel, a current ChevronTexaco geophysicist formerly involved with Eugene Island, what he thought of the description quoted above. His reply by email:
I am familiar with the area and the general claim....
The reserves revisions seem to be rather big, and I think these would have to be checked. I am skeptical.
But after a 3D seismic program, we did do more drilling and increased production. Plus it was the focus of a government study on hydrocarbon migration along faults, and the claims for active current migration up the main field fault look pretty reasonable. Of course there is no "river" of oil involved, just the usual slow migration, but apparently recharging the reservoirs even as we speak. The situation is considered to be fairly unique.
By phone he explained that the observation of current oil migration should come as no surprise. After all, he said, the numerous oil seeps around the world are all examples of oil currently migrating from deeper levels to the surface. The Eugene Island migration is just an example of similar migration going on at deeper levels. No one involved in the project, he said, would have attached a whiff of credibility to the notion that the migration was evidence for inorganic generation of oil.
After more thought I realized that the most compelling argument against the existence of "vast pools" of inorganically generated oil is perhaps also the most obvious one: Where could these oil pools be? There are no vast underground caverns filled with oil. Rather, the oil we know and produce exists in rocks that, to the naked eye, are often indistinguishable from rocks we see every day in the local hills. Subsurface rocks can hold producible oil if the rocks are porous and if some permeability barrier has prevented leakage. Sandstones and dolomitized limestones often make good reservoirs because they often have significant porosity and permeability, but crystalline rocks such as granite have essentially zero porosity and permeability except for fractures. Hence the only large "pools" of oil are likely to be in porous sedimentary rock enclosed on top and sides by a good permeability barrier. But that kind of sedimentary structure is exactly what oil industry exploration has been seeking and finding all along. To the best of our geophysical knowledge, there just aren't any other likely candidates for "vast pools of oil." Even if oil had been generated inorganically, it is still likely to have accumulated in the conventional sedimentary traps.
So the question of oil origins reduces to whether or not organic matter in source rocks is adequate to account for observed oil. Industry scientists say it is.
Don
Received on Thu Jun 3 06:15:29 2004
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