Peak Oil News and Message Boards

ian807 wrote:For that matter, if either process was creating oil in significant amounts, we would have lakes of oil on the surface of the land, and giant slicks at sea. Microbes that ate oil would have evolved into sufficient abundance that we wouldn't be able to keep oil or gasoline without bacterial decay.

Doesn't add up, no matter how it's spun.

And wouldn't these microbes have to consume oxygen and output CO2 to get energy from eating oil (just like how we get energy from eating McGrease)? So we would have a CO2 atmosphere by now.

ian807 wrote:For that matter, if either process was creating oil in significant amounts, we would have lakes of oil on the surface of the land, and giant slicks at sea. Microbes that ate oil would have evolved into sufficient abundance that we wouldn't be able to keep oil or gasoline without bacterial decay.

There are microbes that eat oil. Oil does leak to the surface, a large part of all oil formed leaks to the surface. When it is trapped near the surface by geology is the exception rather than the rule.

Keith_McClary wrote:

ian807 wrote:For that matter, if either process was creating oil in significant amounts, we would have lakes of oil on the surface of the land, and giant slicks at sea. Microbes that ate oil would have evolved into sufficient abundance that we wouldn't be able to keep oil or gasoline without bacterial decay.

Doesn't add up, no matter how it's spun.

And wouldn't these microbes have to consume oxygen and output CO2 to get energy from eating oil (just like how we get energy from eating McGrease)? So we would have a CO2 atmosphere by now.

That simply does not follow. The release was slow and over millions of years, which is more than enough time for chemical weathering to remove CO2 when it comes down as carbonic acid via rain.

As for these species eating all our oil that is clearly not the case since there are none of these microbes in the oil we pull up from wells. The microbes cannot migrate through the rock matrix, but oil and natural gas can. These microbes dwell not too deep from the surface or the seabed.

http://www.pbs.org/newshour/rundown/201 ... spill.html

dissident wrote:That simply does not follow. The release was slow and over millions of years, which is more than enough time for chemical weathering to remove CO2 when it comes down as carbonic acid via rain.

My point was that if the release was fast enough to contribute significantly to current consumption then there would not be "more than enough time for chemical weathering to remove CO2".

Hydrocarbons are being continuously formed all over the Earth is many ways. That's a truth that is evident.

Those of us here that bitch about the constant burning of peak oil straw men by deniers should try to refrain from burning straw men of their own.

It's the -rate- of hydrocarbon formation that's important, not the -fact- of hydrocarbon formation.

If the planet were creating Hydrocarbons at the rate of consumption we would be swimming in the stuff, literally.

Edit:
Before the inevitable dipstick comes along ranting about the "planet" and "abiotic oil": By "planet" I mean the entire sphere and all of its living ecosystems. Have a nice day!

I saw something somewhere that showed oil formation starting at the mouth of a river. Organic deposits settle on the ocean floor and build up. But it didn't show what takes place between that and oil ending up in Pennsylvania. What happened geologically to get these "mouth of the river" deposits spread all over land or miles underneath the deep ocean floor?

google is your friend

plenty of articles on how oil is formed

Forbin

As Forbin says: more of such info on the web then you'll ever want to read. But here's a hint: not all oil has come from marine sediments...some came from fresh water deposits in river beds. And places such as PA haven't always been nice dry land. Consider that many of the rocks in the limestone fields in the Rockies were formed from marine deposits. Yes: a time long ago Denver was a nice shallow sea rather similar to the Bahamas today.

dashter,

To add a bit to what forbin and ROCKMAN say:

Pennsylvania's oil formed from organics in river sediment (mostly sands) laid down in the shallow sea that covered much of what is now central North America on the order of 350 million years ago. The rivers flowed from mountains to the east, roughly where the Appalachians are now; the sandstones are red and can be seen in southern New York state and other parts of back East. (Rocks of the same age and type can be seen in much of western and northern Great Britain, where the stuff is called the Old Red Sandstone. The rivers carrying the sand were flowing down the east side of the same mountains; the Atlantic didn't begin to open until 150 million years later.)

.
The arctic oil was formed when the arctic sea was pretty much closed and saw yearly bloom of floating vegetation
before the ice started to appear .
Geology is reading God's book in His own language and His own time

forbin wrote:google is your friend

plenty of articles on how oil is formed

Forbin

As I stated in my original post I am not looking to read a few general statements about "oil formation". You can find plenty references to organic matter falling to the bottom of the ocean and then being covered up by other sediment. But they don't take it all the way to the end. We don't drill for oil only on the ocean floor. In fact, we didn't drill for it on the ocean floor until modern times. A poster here and one site does mention rivers and swamps, but normally they only mention the ocean. But even with rivers and swamps, you have the issue of it being buried as deep as it is. I was looking for what happens to the earth to get this organic matter buried so deep.

As an example, if a boy was driving by an Oklahoma oil well with his father and asked - how did the oil get down there?, I think it is an insufficient answer to say "organic deposits from long ago that got covered by other matter and the pressure turned them into oil". But that is what you see "using google".

dashter,

There's more than one way that regions can subside and later rise. In the case of what's now the eastern US back in the times I described above, a previous ocean had closed (it's called Iapetus) and the collision between our continent and what are now Europe and Africa created that mountain range I mentioned, and also produced very large-scale flexure in the middle of the continent that took much of it below sea level. The weight of the sediment being deposited in the margins of the mid-continent sea added to the sinking there so that enough material accumulated to lead to burial temperatures that reached the oil window.

When the Central Atlantic began to open about 200 million years ago the eastern side of the North American plate sagged and the interior flexure relaxed, allowing rocks that had been buried deeply to rise again.

dashster wrote:We don't drill for oil only on the ocean floor.

You are not listening to the answers to your question.

The earth's crust is dynamic, FFs are organic matter trapped and cooked in the process. A few hundred millions years ago when oil was still swamp muck, you'd not have recognized the neighborhood.
What is mountain top now might have been ocean floor.
What is ocean floor today might have been mountain top.
In fact much of what is ocean floor today was once creamy mantle nougat.

Pictures

dashter - And here's a very specific answer to your valid question. The term is geosyncline: an area of the planet that's in a continuous state of subsiding. And one of the greatest hydrocarbon generating geosynclines in right here in the US: it's the northern section of the Gulf of Mexico. How much subsidence? On the La. coast there are wells producing hydrocarbons at depths greater then 3 miles. And the rocks containing those hydrocarbons were deposited in water depths of less than 100'. And in some cases in just a few feet. Today you can find roads in S La and Texas running directly into Gulf waters. Originally they didn't: the subsidence continues today.

Also let me point out why the vast majority of the world's oceans have zero hydrocarbon potential. While there might be abundant organic material on the deep ocean floors they also lack the type of rocks needed to create reservoirs. Look at a global map and you'll notice that the big offshore oil/NG trends are along the coastlines of the continents. The continents have eroded over hundreds of millions of years. Those sediments get carried to the oceans (just as the Mississippi River drains N American
and carries sediments to the GOM geosyncline) where they accumulate. The Deep Water GOM exist so far from the shore thanks to turbidites. The turbidite mechanism to transport sediments so far from the continent was only recognized about 50 years ago.

Geology is reading God's book in His own language and His own time

Quote of the day...

Carl Sagan might have added cosmology to that definition.

ROCKMAN,

Geosyncline! Nobody talks about geosynclines--they are so, so yesterday! Positively pre-plate tectonic.

You're letting your age show, ROCK...wait a minute: I'm older than you are...

Never mind.

Just a comment from the organic geochemist in the neighborhood.
It is often difficult to summarize hydrocarbon generation in any basin in a few sentences. There are almost invariably numerous phases of uplift and successive burial. Hydrocarbon generation is a product of not just temperature (i.e. burial depth and geothermal gradient) but also time. As a consequence many basins see numerous phases of maturation, generation and migration of the various source rocks present through it's history.
Beyond that the devil is in the details. Kerogen type is significant in terms of the activation energy necessary to convert to hydrocarbon. As a consequence a Type I kerogen would mature at a different rate under the same boundary conditions as would a Type II or Type III kerogen.
Since the 1980's we have been able to model historical hydrocarbon generation in any given basin based on knowledge of source rock characteristics, burial history (burial and tectonic uplift), geothermal gradients through time. More recently we have been able to integrate all of those models with migration models based on reconstructed structural topography and that now in 3D. It should be no surprise that many of the remaining significant conventional fields have been discovered throughout this period.
The shales, however, have a whole different nuance. They are both the source rock and the seal, migration not playing a role.

>Re: The formation of oil

There is good reason to believe its formed abiotically in the mantle

Kenney et al. (2002) analyzed theoretically, via thermodynamic computations, the possibilities for hydrocarbon generation at high pressures and temperatures and showed that it is possible. They went on and performed successful experiments, using a specially built high pressure apparatus (Nikolaev and Shalimov, 1999) at pressures of 50 kbar, temperatures to 1500 °C . Using only as reagents solid iron oxide and 99.9% pure marble, wet with triple distilled water, they were able to generate methane. They reported that at pressures lower than 10 kbar only methane was formed while at pressures greater than 30 kbar a multi-component hydrocarbon mixture was formed including methane, ethane, propane, n-alkanes as well as alkenes, in distributions characteristic of natural petroleum.

http://origeminorganicadopetroleo.blogspot.co.uk/

rockdoc is wrong.

Hi I'm new here . . . just joined

I heard a theory that oil may be made deep underground through superheating water and pressure geologically. The carbon from rocks and hydrogen from the breakdown of water form long chain hydrocarbons etc into what we know as oil. It makes sense to me this could happen, but it probably take millions of years to happen, so even if this theory is valid I'm sure we are burning more oil than can be sustained long term,

Just wonder what everyone thinks of this. I think I heard this on Coast to Coast radio like 12 years ago or more, The show deals with UFO topics and other weird topics, so this one may be out there.

Just wonder if this could be the way oil is actually formed. What do you think ?