Tens Of Billions Of Additional Barrels Of Oil Remain To Be Tapped Miles Below Gulf Of Mexico

Science Daily ^ | 3-31-2003 | Cornell University

[blam]

Source: Cornell University News Service
Date: 2003-03-31

Tens Of Billions Of Additional Barrels Of Oil Remain To Be Tapped Miles Below Gulf Of Mexico, Cornell Geologist Says

NEW ORLEANS -- U.S. reliance on foreign oil production could be reduced by chemically mapping the subsurface streams of hydrocarbons, amounting to tens of billions of barrels, hidden well below the Gulf of Mexico, says a Cornell University geologist.

These untapped oil and gas reserves can be found by matching hydrocarbon chemical signatures with geologic models for stratigraphic layers under the sea floor, says Lawrence M. Cathles, a professor of chemical geology at Cornell in Ithaca, N.Y.

"The undiscovered gas and oil potential of the Gulf of Mexico is very large," says Cathles. "We have produced only a small fraction, and the deep-water potential for finding more there is big. In terms of potential, it is bigger than the North Sea. It's about a big a deal as there is."

Cathles will present his findings in a talk, "Massive Hydrocarbon Venting with Minor, Constantly Replenished (Flow-Through) Retention in a 100 x 200 km Area Offshore Louisiana Gulf of Mexico," at the 225th national meeting of the American Chemical Society in New Orleans at 1:30 p.m. CST on March 27.

The northern Gulf of Mexico basin is one of the world's most active areas of hydrocarbon exploration. A study of an area of about 9,500 square miles, found that hydrocarbons currently are being naturally generated from strata deposited during the Tertiary and Jurassic periods, miles below the sea floor. Hydrocarbons are leaking through natural vents at hundreds of locations, and these vent sites have been visited and studied by Cathles and other researchers using small submarines. What makes this area offshore of Louisiana important is the presence of two types of hydrocarbon deep below the gulf floor: the deeper, early-maturing Jurassic and the later-maturing Tertiary. Each has a distinctive chemistry. As these sources mature, the hydrocarbons migrate upward toward the surface through what can be thought of as a myriad of small streams and ponds, much like a natural water system. Just how much liquid hydrocarbon is retained within this subsurface network is a matter of crucial interest, Cathles says.

More than 70 percent of the hydrocarbons that have been naturally generated have made their way upward through the vast network of streams and ponds and vented into the ocean. The hydrocarbons are digested by bacteria, which then become food for the gulf's marine life. The earlier-generated, sulfur-rich, carbonate-sourced Jurassic hydrocarbons are replaced by the shallower, later-generated, shale-sourced Tertiary hydrocarbons which fill the producing reservoirs in the northern part of the study area. This displacement of Jurassic by Tertiary oil provides geologists with a measure of the remaining untapped oil and gas below the gulf's floor.

The hydrocarbons hidden within the subsurface ponds and streams are about 8 to 10 percent of the Gulf of Mexico's total hydrocarbons. In the study area this represents about 60 billion barrels of oil and 370 trillion cubic feet of gas and is the hydrocarbon that could be extracted, Cathles says. (The remaining hydrocarbons, about 20 percent, stay stored in the source strata.)

Cathles says that the telltale chemistry of the hydrocarbons reflects the streams and ponds through which they migrated, and thus could point to the ponds that remain to be discovered and produced. Ultimately he hopes that looking at the hydrocarbon chemistry in this new way could provide geologists with accurate information on the presence and size of the deeper reservoirs. He says: "By combining chemical data from currently producing reservoirs with seismic images of the subsurface using computer migration models, drilling for new deep reservoirs can be facilitated."

Funding for the research was provided by the Gas Research Institute in a joint project with the Woods Hole Oceanographic Institution.

[Trajan88]

We'll use all the Middle East's oil then throw the land of sand away... they can then fight over fig trees, camels, and fleas.

Trajan88

[Dog Gone]

Now, that's a scary thought. I don't want to fight for a hamburger.

[aruanan]

Oil doesn't migrate through "streams" or collect in "ponds." Maybe they dumbed this down for the general public, but it's grossly misleading and casts doubts on the seriousness of this study.

Actually petroleum does flow in streams and collect under regions of relatively more impermeable overburden. This would make a pond or pool of oil, albeit upsidedown. Water flows because of gravity. Petroleum flows because of pressure gradients. Water collects in places out of which it cannot flow and in which the porosity is overcome by the inflow. Petroleum collects under formations the porosity of which is insufficient to handle the flow. In places where such overburden doesn't exist, the oil and accompanying methane flows right out of the ground. In some places the porosity is such that the petroleum is blocked from reaching the surface but not the methane, resulting in people lawns or fields catching on fire.

[aruanan]

Ancient earthquake faults provide leaks from one rock strata to another, but it's still nothing that can be accurately described as a stream.

Even in the absence of ancient earthquake faults, the migration of oil can accurately be described as a stream. Anything that streams from one place to another is a stream just as anything that flows is a fluid. The rate at which the phenomenon occurs in one versus another instance doesn't alter the fundamental nature the phenomenon, just the perception of it.

[killermosquito]

Please forgive this question but it is one I've pondered often:

"If we pump out all the oil isn't there a huge empty space underground where the oil was and why doesn't the ground that was over where the oil was cave in? "

[Dog Gone]

Yes, anything that flows can technically be called a stream. Even if it flows a few inches every million years.

Nobody that I know of would describe an oil-charged rock as a pond.

[avenir]

"Nah, the oil is ours by the nature of one simple fact, Mexico does not have the capabilities to retrieve it."

A book I'm reading on the U.N. describes some shenanigans concerning "The Law of the Sea" treaty, in which non- seafaring nations attempted to claim a portion of the profits made from mining the sea (while abstaining from sharing the costs).

Their con? They labelled the sea "the common heritage of mankind."

Reagan said no cigar and killed the thing. Don't know if it has been resurrected though.

[AM2000]

ping me when you get an answer to that. I'd like to hear.

[TaMoDee]

My dear Fellow Freepers here's the very large and very long range strategy: The USA will use oil from other parts of the world before we even think about using the oil readily available to us. This makes sense in the very long time frame! Think about it! We will have the "nuts" stored away when the winter comes.

[Hanging Chad]

P-s-s-t
the answer you seek lies in post #39.

[txoilman]

These reserves are in deeper water that are expensive to drill and produce. Therefore, the key ingredient to make this happen is higher oil and gas prices.

[Moonman62]

Perhaps this has something to do with the favors Bush has been doing for Vicente Fox.....?

I doubt it. The illegal mexican vote is much more important than the oil.

[TaMoDee]

Oil is contained in the rock like water is contained in a sponge. The interconnected pores allow the oil to flow through the rock to the well bore which was drilled into oil reservoir. There is no lake of oil as if there is an
open cavity.

Yes, the ground in some case depresses because oil in the pores is removed. The oil helped to hold up the 1000's of feet on overburden over the reservoir. The Long Beach,CA
beach receded many feet downward until water was pumped back into the reservoir to replace the removed oil.

Next question.

HIGH pressures down there.

[bribriagain]

"Ancient earthquake faults provide leaks from one rock strata to another, but it's still nothing that can be accurately described as a stream."

Thank you.

[sharktrager]

Time to launch Operation Crude Freedom.

[m18436572]

no kidding

[Lx]

Sounds like we need to hire Montgomery Burns' Slant drilling oil company.

Exxxxxxxxxcellent!

[killermosquito]

Another question I don't know the answer too: How do I ping a person?

[blam]

"If we pump out all the oil isn't there a huge empty space underground where the oil was and why doesn't the ground that was over where the oil was cave in? "

In some cases, the ground does subside. I've seen before and after pictures that are amazing.

[deport]

Once the oil comes forth to see the sun what is the projected recovery rate with todays technogoly? If I remember correctlly it used to be said that we only recovered something like 15 % or so of the oil from the well. The remainder stayed down hole.

What's the price/bbl needed to make steam injection a viable recovery method today?