crude oil

Last Week on ResearchBlogging.org

milhayser — Sun, 23 Feb 2014 11:02:24 +0000

Last Week on ResearchBlogging.org

Researchers observed tiny voids forming in silicon used for solar panels; these voids provide physical evidence of the Staebler-Wronski effect, "which reduces the solar cell efficiency by up to 15 percent within the first 1000 hours."

Using an online avatar with a skin color other than your own makes you less racist in real life; playing a hero makes you less cruel, and playing a villain less benevolent.

Old mouse muscles exhibit "elevated levels of activity in a biological cascade called the p38 MAP kinase pathway" which prevents stem cells from dividing and repairing muscle damage. By blocking this pathway with a drug, researchers grew a new generation of potent stem cells in a petri dish and transplanted them back into old mice. "Two months after transplantation, these muscles exhibited forces equivalent to young, uninjured muscles."

Continuing its exhaustive penetration into the ecosphere, plastic has been observed built into the hives of urban bees. The researcher notes, "although cells made with plastic may not hold together as well—and might have other, unseen effects on developing bees—they could have advantages too" such as keeping parasites away from eggs.

A protein normally necessary to shut down inflammation is undetectable in triple-negative breast cancer cells. Without the protein, these cells can proliferate rapidly, but a new drug treatment can prevent the protein degradation.

Boys playing football is not the only recipe for head trauma: girls playing soccer are also at risk. A total of 351 players were observed for one full season, and cumulatively suffered 59 concussions, mostly from player-to-player contact, heading the ball, and goal-tending.

A study surveying "leaky valves and pipes in the rapidly growing natural gas industry" observed 50% more methane leakage than expected, but the extra atmospheric contribution still causes less global warming than coal.

An isopod that infects California fish is the only known parasite to functionally replace a host's organ. The bug latches on to a fish's tongue and sucks out the blood, causing it to atrophy. After latching on to the diminished tongue it settles in for a life of "holding food up against the small teeth on the roof of the fish’s mouth" while also getting first dibs on all that fish food.

In the courtroom, weak evidence is strengthened by arbitrary precision. Precision (along with body language) communicates confidence, which makes people "more likely to believe what you are saying."

Engineered viruses can deliver instructions for making crucial growth factors to stem cells; when seeded onto a polymer scaffold incorporating the viruses, stem cells can achieve self-sufficient growth and replace the scaffold with (for example) a tailored piece of cartilage.

Alternatively, we could soon be able to print a piece of cartilage: researchers have "successfully printed two types of rat neural cells from the retina" through a piezoelectric inkjet printer without killing or sterilizing the cells.

Why oil spills are bad for fish: crude oil interrupts a cellular pathway "that allows fish heart cells to beat effectively," causing "slowed heart rate, reduced cardiac contractility and irregular heartbeats that can lead to cardiac arrest and sudden cardiac death."

Following a stroke, exercise confers a 91% reduction in mortality risk, versus anticoagulants and antiplatelet therapy, which showed no statistically significant benefit.

Silicon nanoparticles packed into a carbon shell like seeds in a pomegranate (so as to prevent silicon degradation) may power a new generation of hyper-efficient lithium-ion batteries.

New fuel cell design can convert any biomass into electricity with a little help from sunlight or waste heat.

When responding to "virtual customer service agents," people showed equal social engagement with human images and animated helpers. The VCSAs were regarded as most helpful when they seemed most social.

Like mercury, ionic silver can build up in ocean-dwelling organisms. In algae cells, silver stows away on a transport protein usually used by copper, and once inside the cell membrane, continues to pose as copper, damaging many proteins including those critical to energy generation and photosynthesis. The cells do their best to get rid of the silver, but with silver added to everything from "air sanitisers to cleansing face creams to odourless socks," sea life may be fighting an upstream battle.

For more visit researchblogging.org.

milhayser Sun, 02/23/2014 - 06:02

Not Oil, "Oil"

sastyk — Thu, 02 Aug 2012 12:53:06 +0000

Not Oil, "Oil"

I somehow forgot to draw your attention to Kurt Cobb's wonderful essay on the difference between oil and "liquids" - he does a better job than anyone I know in making clear what most Americans simply don't know about our energy - all liquid fuels are not equivalent. We have been told by implication that they are, and most people are not technically literate enough about oil and energy issues to understand the difference, so it looks like there's plenty of oil - but of course, this isn't oil at all. We could just as easily call it "oil."

But first, an important question. Why do government and industry officials, oil analysts, and energy reporters equate total liquids and total oil supply? They claim that these other liquids are essentially interchangeable with oil. (I will discuss some of the not-so-savory motives behind this claim later.) In a recent report the U.S. Energy Information Administration put it this way: "The term 'liquid fuels' encompasses petroleum and petroleum products and close substitutes, including crude oil, lease condensate, natural gas plant liquids, biofuels, coal-to-liquids, gas-to-liquids, and refinery processing gains." Let's see why the "close substitutes" assumption is demonstrably false when it comes to most natural gas plant liquids and decidedly disingenuous when it comes to biofuels.

First, crude oil is what you think it is. It's a black, hydrocarbon-rich liquid that comes out of underground reservoirs. It can also be made synthetically from other hydrocarbons such as the bitumen found in the Canadian tar sands. Oil also includes something called lease condensate which refers to the light hydrocarbons that often occur in oil reservoirs. They are gaseous in the high-temperature environment of the reservoir, but condense to liquids when they escape the wellbore and are captured by special equipment located on the oil lease. These condensates become part of the crude oil stream. They are highly prized because of the ease in refining them, though they make only a small contribution to world oil supplies.

But what are natural gas plant liquids and are they good substitutes for oil? Unfortunately, confusion reigns because a very similar but more inclusive term, natural gas liquids or NGL, includes lease condensate, already discussed above and which we know is included in the crude oil stream. Usually, when people refer to NGL, what they really mean is natural gas plant liquids (NGPL).

NGPL are hydrocarbons other than methane that are separated from raw natural gas at a processing plant. They include ethane, propane, butane and pentane. The amounts vary. For example, raw natural gas extracted off the coast of Malaysiacontains 11 percent ethane, 5 percent propane, 2 percent butane and about 2 percent of something called natural gasoline or drip gas, a low-octane fuel that is used today primarily as a solvent. Raw natural gas from the North Slope of Alaskacontains a higher percentage of methane and correspondingly smaller percentages of ethane (7 percent), propane (4 percent), butane (1 percent) and other components including carbon dioxide and pentanes (2 percent). In these two cases you can see that ethane makes up about half of the NGPL, propane makes up about a quarter, butane makes up 10 percent of Malaysian NGPL and 7 percent of Alaskan slope NGPL.

So what is ethane used for? It's major use is as feedstock for the production of ethylene, one of the most widely used chemicals. Polyethylene is the world's most widely used plastic and found in such things as packaging film and trash bags. Other processes turn ethylene into automotive antifreeze. Yet others turn it into polystyrene which is used in insulation and packaging. Some ethane remains in the natural gas piped to our homes and factories, but not much. So far, it's hard to see how ethane, the most plentiful of the NGPLs, is a good substitute for petroleum-based liquid fuel products.

We are being played, folks - our collective scientific illiteracy is being used to ensure that none of us notice our oil supply issues. Read the whole article.

sastyk Thu, 08/02/2012 - 08:53

Tags

New EIA Data

sastyk — Fri, 20 Apr 2012 07:34:40 +0000

New EIA Data

The EIA, unlike the IEA, has been strident in its dismissal of peak oil. But the data that the EIA publishes tells a very different story than the one it wants us to hear. Gail the Actuary has a really good analysis up at the Oil Drum.. The essential message - that crude oil production remains basically flat, as it has since 2005, and that growth in non-crude "liquids" (all those things that have made up for the lack of crude growth in world demand) aren't growing as fast as desired or predicted.

Among the critical takeways - that unconventional oil production probably will cease to keep pace with demand at some point, and that China will need more imports as it has crossed its peak.

Jeffrey Brown observes that ANE (Available Net Imports, basically the amount of oil available after China's growing economy has purchased what it needs) is going to fall rapidly and that the AVAILABLE Crude oil depletion rate is already astonishingly high He writes:

Let's imagine that the total volume of post-2005 oil that would be (A) Net exported from Saudi Arabia; (B) Net exported around the world and (C) Net exported to importers other than China & India are in three big tanks: In tanks A, B & C. The 2005 to 2008 projections, which have been on the optimistic side already, show that these tanks are presently depleted (through 2010) by the following percentages:

Tank A (Saudi Arabia): 34% depleted
Tank B (GNE): 20% depleted
Tank C (ANE): 35% depleted.

In five years.

What's important about this is that despite the attempt to blame high oil prices on everything on earth from market speculation to lack of drilling to Ann Romney's hairdo, there are actual fundamentals at play here, and the laws of physics are generally less accomodating than any of us would like.

While the EIA isn't stepping back from its claims that we're always going to have all the oil we want, just because we want it to exist so bad, it can't hide the actual data. Meanwhile, the IEA which has been predicting severe supply constraints for quite a while now has just released a series of graphs showing the impact of high oil prices on the world economy - check them out here. This validates what many peak oil thinkers have been saying for years, and what most of us have already noticed - that high energy prices have a real effect on personal economies.

This doesn't change the fact that countries like Saudi Arabia still claim vast reserves - but in both 2007 and now, with extraordinarily high oil prices, we have to ask this question - if they COULD extract more crude, why aren't they, when the economic incentives to do so are so enormous? I'm fairly sure it isn't because OPEC doesn't like money.

Meanwhile, both the IEA and the EIA implicitly or explicitly move closer the real conclusion - that oil is peaking and high prices, volatile prices and the instability that accompanies it are here to stay.

Sharon

sastyk Fri, 04/20/2012 - 03:34

Tags

Sharon,

The thing that's been puzzling me for the last year or so is the question of whether (and when) we'll see an inflection point. Because liquids production has been increasing and there's been a slow substitution away from oil / pricing people out of oil, the economy has managed better than I would have expected. (Granted, there are a lot of possible reasons things are still afloat, like QE.)

Has the recent data made you rethink things? Not saying it should have, but it's made me wonder whether the downslope, at least this decade, will be as severe as I had expected. I completely agree that net exports will get us in the end.

This leads me to two possible outcomes (among many other possibilites): a) the liquids plateau leads to a false sense of security, so no real transition happens and then we get a sharp downtick in production ~2020 that wreaks havoc or b) oil starts declining ~2015 as projected by Skrebowski but NGL and other products keep things from falling apart as we transition.

My two cents Barath, I think a lot of what we see right now IS smoke and mirrors, that is QE and QE2, trying to hold the system together as best it can while unconventional liquids fill the gap for now in energy markets.

If nothing else, there's this: "The Federal Reserve is desperately trying to control interest rates. The Fed purchased approximately 61 percent of all government debt issued by the U.S. Treasury Department in 2011. This is the only thing that is keeping interest rates in the United States from soaring dramatically."

There's a bunch of other data points at "http://theeconomiccollapseblog.com/archives/19-signs-of-very-serious-ec…" that say we are not doing well at all.

Stephen -

Agreed. Though a possible outcome is that such extraordinary (unreasonable?) efforts being made by central banks will be a Japan-style lost decade instead of a sharp inflection point that marks the long descent, as long as liquid fuels production stays up. If production starts declining at anything greater than 2% I imagine we're in for a rough ride. But it's that latter question that I've begun to wonder about; maybe NGL production will remain high for the rest of the decade, filling the gap. I wouldn't have expected it a couple of years ago, but I don't want to be rigid in my thinking.

Economic permabears will always be right eventually (I know, I used to be one!), but timing matters. Ecologically and geologically we are in certain trouble, but that certainty is on a longer timescale (many decades rather than just one).

Oh come on, how many times do you expect to get away with the same faklse scare story without people noticing?

There have been hundreds, perhaps thousands of predictions over a century and a half, of peak oil real soon now, and none of them have been true.

A small sample http://rayharvey.org/index.php/2010/01/peak-oil/

Under what circumstances should anybody trust a word said by a movement which has been proven to be lying on this subject (& on hundreds of other global catastrophe scares - every one of which has obviously been false, yet have cost 10s of millions of lives & trillions of $s)?

Perhaps you would care to apologise, on behalf of the "environmental" movement, for even one of these false scare stories before going on to promote them, again.

Great news Sharon! You're a movement!

Dan I acknowledge that as the very closest anybody in the "environmental" movement is capable of getting to fact based discussion.

Clearly nobody can think of even one, out of these hundreds of eco-scare stories which was truthful.

While it's true that there have been outlandishhly scary Peak Oil scenarios circulating that have been proven to not be true it's also ridiculous to say there's nothing to it.

Oil is very expensive at the moment for a reason. One of the reasons why demand isn't higher is that those high prices have led to a lot of demand destruction. Oil supplies will match demand after some demand has been destroyed due to high prices. That's how a market economy works.

When you factor in the falling $ oil isn't expensive by historic terms. The basic fact is that nobody is able to claim that any of the "environmentalist" scare stories have been truthful. When you have estabnlished a record like that trusting Bernis Madoff looks like a much smarter deal than trusting any "environmentalist".

Why We (should) Care about Methane in the Gulf of Mexico

dblum — Mon, 07 Jun 2010 12:47:04 +0000

Why We (should) Care about Methane in the Gulf of Mexico

(Just a note: The giveaway period for the audiobook of The Poisoner's Handbook has ended. If your comment is not published, it's too late to be considered for a free copy. But still glad to hear your ideas! Winners to be notified on Wednesday).

One of the most interesting - and I think important - comment threads on this blog has concerned risks posed by the gas methane, blamed (along with BP) for the devastating oil spill in April and still seeping into the water from the broken drill pipe.

"We don't know the composition of the crude oil as it is leaving the well head. This crude is reported to have a very high methane content," wrote one smart reader, noting that one of the greatest risks related to methane (composed, by the way, of one carbon atom to every four hydrogen atoms, CH4) is that as bacteria break it down, the metabolism process can involve sulfates in the water and lead to formation of the much more poisonous gas, hydrogen sulfide (two hydrogens for every one sulfur, H2S).

I was reminded of unanswered questions about methane while reading a recent piece in Newsweek entitled "What the Spill Will Kill" which reports that "Giant plumes of crude oil mixed with methane are sweeping the ocean depths with devastating consequences."

What devastating consequences exactly I wondered and did the presence of methane make a difference, in how the plumes formed, in how poisonous they were. But the article didn't answer those questions, partly because this is all one big chemical experiment and partly because methane in water lacks the obvious drama of poisonous chemical dispersants and toxic and visibly murderous crude oil.

But let's pay methane a little respect here. By all accounts, BP and its cohorts were remarkably careless in managing methane risks in their deep-sea drilling. It's common knowledge that where we find fossil fuel deposits be they coal mines (see earlier post, The Methane Calculation) or oil deposits, they're accompanied by methane which is primary component of "natural gas" (the user-friendly named coined by big energy companies.)

At the bottom of the Gulf of Mexico, at what we'll call BP oil spill depth, almost a mile down, a combination of high water pressure and low temperatures - reportedly hovering just above freezing, around 34 degrees fahrenheit - methane tends to form into ice-like crystalline structures, called methane hydrates or clathrates. You may remember that this icy version of methane stymied one of BP's first efforts to put a containment dome over the leaking riser pipe. By the way, the oil industry is now working to mine methyl hydrates, which change into gaseous methane as they rise, warm, and depressurize, and harness them for energy.

One of the theories of the BP disaster is that a chemical reaction, perhaps triggered by the compounds used for sealing cement around the drill hole, caused rapid heating, converting hydrates to a soaring building up gas, which rocketed up the pipe to the rig. Methane being highly flammable - as anyone owning a gas stove knows - was ignited by sparks coming off equipment off the rig, triggering the horrifying fiery explosion that followed.

But back to the bottom. At depth, the Gulf of Mexico is unusually rich in methyl hydrates, so much so that it supports a flourishing community of methanotrophs or methanophiles- methane-digesting bacteria - and also a community of very strange creatures called ice worms that live on the bacteria.

Which is another way of letting us know that there's a lot of methane down there. In fact, by some accounts the hydrocarbons pouring out of the BP leak (yes, I do enjoy making that connection) are about 60 percent crude oil and 40 percent methane. In fact, so much methane has been pouring into the gulf - by one estimate a million times more than from the natural seepage - that scientists are now preparing to measure the extent of the spill's reach - those underwater plumes, in fact, by tracking methane.

Very handy, you might say. But the more interesting point is that the scientists tracking these plumes believe that their massive spread underwater is largely being driven by the methane component in this leak. To quote the Gulf Oil Blog of the University of Georgia Department of Marine Sciences: "Think of it as gas-saturated oil that has been shot out of a deep sea cannon under intense pressure - it's like putting olive oil in a spray can, pressurizing it and pushing the spray button. What comes out when you push that button? A mist of olive oil. This well is leaking a mist of oil that is settling out in the deep sea."

There are also those who believe that an excess of methane in water is poisonous to fish. Part of this argument is that fish are designed to take in dissolved gases through their gills, making methane fairly insidious. There's some evidence that shows that high concentrations of methane are harmful to the nervous system and circulatory system of many fish species. To be fair, not everyone considers this a serious problem; methane is not the most reactive of gases in terms of toxicity.

But it all adds up to a reminder that this isn't just an "oil" spill. It isn't just about what we see. It's also about what we don't see. And the time to acknowledge that - and here's an idea, actually try to do something about it - happens to be now. That would be: NOW.

dblum Mon, 06/07/2010 - 08:47

Tags

I find it unlikely that methane at any plausible concentration in the environment is toxic to fish, and certainly the very questionable link you cite doesn't show that. Toxicologically, methane is classified as a simple asphyxiant.

Methane is actually rather inert, chemically speaking.

I would imagine that fish get more people invested in the story, but the real story is how this massive amount of methane will impact the bacterial consortia in the oceans that do the grunt work of balancing out the mineral pathways that the whole complex ecosystem uses to survive. H2S is poisonous to us I suppose, but to some microbes it is their lifeblood.

Eventually, life will win out. It's a drastic event and things won't be the same - that's for sure. But I look to the recent NOVA program and Science News cover story on Mt. St. Helens and know that whatever seems beyond repair in nature will end up surprising us.

But when I hear dire consequences being projected by my fellow scientists, I have to wonder about the humility involved in those leading the cry. How many experiments have confounded them? And if they are so sure of certain things happening in the future, how much science do they really think they know?

Did your smart reader point out that H2S is often consumed right away by sulfur oxidzing microbes and that this whole reaction is dependent upon sulfate concentrations?

If anything can clean this up - its microbial communities. Who are we to doubt them - they have survived on this Earth for billions of years. The oldest known living things.

So I guess my question is - if you were in charge right now what would you do exactly?

And the methane that does get to the surface will add to climate warming.
One sign that the recent capping was working is the methane flaring from the recovery rig. Which leads me to wonder whether there is a good method of recovering methane rather than just burning it. And a *lot* of methane does get flared. These flares are the most obvious points of light according to pi8ctures from space.

Gerard-

Methane may be inert in most systems but is the KEY component in the carbon cycling of the underwater ecosystem. Anaerobic methane oxidation and its partner methanogenesis forms the absolute bottom of the food chain in marine environments. If Venter and his group ever publish their shotgun sequencing of the ocean we may get better vision of the more detailed metagenomic look at these consortia, but the genetic mechanisms found to date are incredibly complex.

If you are sure that the reference makes methane non-toxic for fish I doubt that the microbial enhanced depletion of oxygen in aerobic methane oxidation will make easy for the fish to breathe. I guess there is more than one way for methane to become an asphyxiant. Try a complex asphyxiant...

Good question and wouldn't it be great to have the solve-all answer? Here's what I wouldn't do - waste time trying to convince the public that underwater plumes couldn't possibly exist. Here's what I would do - if I had BP's deep pockets, anyway - put some serious money toward a comprehensive and detailed study of the undersea spread of oil and do it now. I'd want thoroughly researched answers to all these troubling questions. And I'd share every answer in the most transparent way so that other smart scientists could build on the research. Would this have immediate benefits - probably not. Would we learn a lot more than we're likely to do otherwise - probably yes. And would I - Ms. In Charge of It All - have no credibility than if I spent my time denying that any problem existed whatsoever. For that, a simple yes.

I posted something but it had two links and didn't make it. I will try dividing it in two and see if it does.

Methane is probably not that toxic. The greatest danger to wildlife is almost certainly the loss of O2 as methane is metabolized. It takes two molecules of O2 per molecule to oxidize one of methane. Methane and O2 have just about the same solubility in water, and it increases with depth. Unfortunately the O2 level of sea water is set at the surface at 1 atmosphere. The methane concentration is determined by the depth at which the methane dissolved, so the methane levels can be many times the O2 level.

Many fish have what is called a gas gland, where they can extract gas from the water and put it in their swim bladder for buoyancy. They concentrate all gases from the ambient level in sea water to pure gas at the pressure at depth. They can develop very high pressures of gas in their gas glands. In a methane environment, they would concentrate methane along with O2. They would also concentrate trace inert gases which would be an excellent tracer, confirming that the fish were exposed to the plume.

http://www.ncbi.nlm.nih.gov/pubmed/13514011

Marine mammals do not have a gas gland, so they are only able to remove gases from their blood when they exchange air at the surface. Partially soluble gases like methane will be much more difficult for marine mammals to get rid of because blood will only hold so much at 1 atmosphere when the mammal is on the surface breathing. I suspect that marine mammals beach themselves when they get bubbles of gas in their bodies/blood stream or gut. This gas may come from the gas bladders of the fish they eat, or from bacterial action in the marine mammal gut. In some of the pictures from marine mammals stranding, the livers are full of bubbles (the liver gets blood from the gut and so bubbles would be trapped there).

http://www.ncbi.nlm.nih.gov/pubmed/15872375

When there are marine mammal strandings, they should look at the composition of the gas in any bubbles in the liver. I suspect these will be methane. There may even be helium and other inert gases with the same isotopic ratios as what is coming out of BP's leak. Those isotope ratios might be preserved in gas concentrated by fish gas glands. That would be an excellent way to track the extent of the plumes and to implicate BP for the marine mammal strandings when they occur.

... rich in methyl hydrates, so much so that it supports a flourishing community of methanogens - methane-digesting bacteria...

Not that it really matters for the context of this post, but methanogens are the archaea that produced the methane in the first place ( from genesis meaning origin). Methyltrophs are the bacteria that eat methane. [/pedantry]

A really good catch, in my opinion. Thanks so much - it's fixed.

Just finished The Poisoner's Handbook and it was great! I was fascinated and educated, by both the science and history, and your storytelling and writing style made it a very compelling read. As scary as death by cyanide sounds, I found the Radium poisoning to be most disturbing. A creeping, insidious, disintegrative death by something associated with discovery, vitality, and even fun.

Thanks so much. And I agree with you about radium. It's one of the great cautionary tales in science, the embracing of a discovery as something miraculous, the gradual realization that what makes it so powerful also makes it deadly.

As someone who has taught inorganic and biochemistry for 30+ years:
In the 2nd paragraph, the writer claims that the breakdown of methane can produce H2S. I know of no such reaction, and it is certainly impossible without a plausible source of sulfur. As others have noted, methane is remarkably inert chemically, except for its tendency to burn in oxygen to produce CO2.

Thanks for a reminder that I needed to state that a lot more clearly. You'll see I've tweaked it in the piece, based on my understanding that as bacteria (methanophiles) breakdown methane, they may use sulfates in the water to help with digestion of the hydrocarbons.. It's a byproduct of that process that may create hydrogen sulfide.

Boy, I've been way too chatty about this post. But this very smart interview on the Rachel Maddow show:

http://maddowblog.msnbc.msn.com/_news/2010/06/08/4479112-two-hidden-dis…

reminded me of a point I didn't raise in my post, which follows on the hydrogen sulfide discussion. Methane-digesting bacteria use sulfates but also consume a lot of oxygen during the breakdown process. Which means they deplete oxygen levels in the water. Which, as dicussed in the interview, is also a significant threat to aquatic life.

Energy man, sea water has 910 ppm sulfur as sulfate. When bacteria oxidize methane, first they consume all the O2, then the nitrate, and then the sulfate. When they do that they produce H2S.

good points made in posts but no discussion on dilution in the water column, sea currents, and the shear volume of sea water in the gulf vs the well output. Any thoughts on this and the actual long-term effects. i.e. we as humans drink low concentrations of chorine and fluoride in water every day. Also regarding sulfur i believe crude itself contains high concentrations of sulfur.

Seawater has about 0.22 moles of O2 per cubic meter. That is 7753 ton /km3. There are reports that the spill is leaking about 1 million gallon per day. That is ~3500 tons per day, which takes ~ 14,000 tons of O2 to metabolize, or about the O2 in 2 km3 of sea water. The leak has been going for ~50 days, that is enough to remove 100% of the O2 from about 100 km3 of sea water.

Rendering 100 km3 of sea water devoid of O2 is pretty serious, no multi-cellular organism can live where there is no O2.

Oil and gas seeps are natural events and, occasionally, leave behind massive tar sands deposits such as those mined Athabaska. The billions of barrels of liquids and gases released into the environment hasn't sterilized the earth yet. However; sugar, fats and alcohols, sold to humans for comfort food kill millions annually. Why not fight to eliminate those disasters, and leave poor 'ol BP alone.

Crude Comments

dblum — Thu, 27 May 2010 09:32:33 +0000

Crude Comments

The latest news from the Gulf of Mexico offers both relief (the "top kill" approach to ending the oil spill may be working) and dismay (the amount of oil pouring into the water is now thought to be closer to 20,000 barrels a day rather than the 5,000 barrels that BP has insisted on for weeks.)

In other words - at worst case - the U.S. Geological Survey estimates that the spill amount may be closer to 39 million gallons of oil so far, rather than the 11 million previously suspected. Now, I've spent the last week or so focusing on the chemical dispersants used to break down the oil, partly because they're a lot more poisonous than crude oil and partly because as they spread through the oil, they make it more poisonous too.

But given the ratio - about a million gallons of dispersant to that 39 million or so figure - it makes sense to me to spend a moment also obsessing about the chemistry of crude oil. Oil spills wreak most havoc, as we know, by simply enveloping living things - from grass to birds to insects to fish - rolling out a dense, greasy blanket that suffocates, immobilizes, and kills.

But - and this is not news - oil is also just plain poisonous without any help from dispersants at all. This is why you don't find people generally lapping up gasoline down at the corner station or setting up petroleum bars where people can grab a quick shot of Sweet Louisiana Crude. So what's the chemical recipe that makes them so hazardous?

As the American Petroleum Institute points out, all crude oils are slightly chemically different, according to where they are extracted. Emphasis on the word slightly. The average crude oil, according to API, is about 84 percent carbon and 14 percent hydrogen - in other words, no surprise again - a hydrocarbon fuel. If the remaining two percent contains sulfur - which mixes with hydrogen to form the toxic, famously smelly hydrogen sulfide gas - the crude is considered "sour". A sulfur-free crude, like that from Louisiana, then is tagged as sweet. Other trace elements typically include nitrogen, oxygen, and a sprinkling of minerals, ranging from arsenic to vanadium.

And, yes, arsenic is poisonous but here the amount is usually not large enough to be alarming. The toxicity issues really arise from the way that those atoms of carbon and hydrogen bond together, combining into an assortment of materials long linked to health problems. Petroleum experts actually have an acronym for four famously troublesome compounds in crude oil: BTEX. This stands for benzene, toluene, ethylbenzene and xylenes.

Benzene is probably the best known of these compounds, because it's been flagged as a human carcinogen for a couple decades. I've always rather admired the elegant structure of a benzene molecule, which is a beautifully arranged ring of six carbon atoms and six hydrogen atoms:

But while the benzene ring has an elegant structure, the compound itself is considered so dangerous that the U.S. Environmental Protection Agency has set the maximum permissible level in drinking water at .005 mg/l. The problem with benzene is that it directly damages bone marrow, making it suspect in environmentally induced leukemias. We didn't learn this from studying oil spills, of course, but from occupational exposures to benzene in factories that process petroleum products, from tobacco smoke, which also contains benzene, and from studies at gas stations.

The second compound flagged by BTEX is toluene, which is sometimes refered to as methylbenzene, because it consists of a benzene ring with some additional carbon and hydrogen atoms attached to it (known as a methyl group).

It looks like this:

Is toluene also poisonous? Well, if I tell you that it is used as an industrial solvent in the making of everything from paint thinners to dynamite does that hint at an answer? Like all the BTEX compounds, toluene is a "volatile aromatic hydrocarbon" which basically means that it evaporates easily when heated and mixes poorly with water, tending to float on top. Because these are not readily water soluble, the body has a difficult time washing them away once they enter cells and toluene appears particularly toxic to nervous system cells.

As for the other two, ethylbenzene and xylene are also built around benzene rings and like toluene have additional clusters of carbon and hydrogen attached to the basic ring. And, yes, they are also poisonous. Oh, and remember, that these compounds are volatile, meaning that they evaporate easily? This is great for breaking down the oil slick. But it also means that as the sun heats an oil slick, the rising vapors are rich with BTEX compounds, which can be both inhaled and, as they settle on skin, absorbed there.

These are not the only toxic compounds in crude oil but they make enough of a point for me. Far out in the Gulf, we can be somewhat reassured that dilution works wonderfully in the favor of aquatic creatures living there. By some estimates, even at worse case, the mixing bowl of the Gulf contains 5 billion drops of water for every one drop of spilled oil.

But once the oil washes ashore, we have an environment awash in benzene, toluene, ethylbenzene and xylene. And that's why biologists worry when oil-soaked birds groom their feathers and swallow the oil. And that's why health officials worry about clean-up workers and Gulf coast residents breathing tainted air and touching oil-soaked materials.

And that's why there's still no one lining up at the BTEX bar for just a quick drink of even the sweetest crude on earth.

dblum Thu, 05/27/2010 - 05:32

Tags

Chemistry

oil spill

poison

U.S. Environmental Protection Agency

A Lethal Concentration

dblum — Sat, 22 May 2010 10:42:21 +0000

A Lethal Concentration

The standard toxicity test for chemical compounds is called the LD50. LD stands for Lethal Dose and 50 indicates 50 percent. In other words, LD50 means the lowest dose at which a material kills half of the test subjects.

The results are usually given in milligrams of compound per kilograms of body weight. Many of these tests are conducted on laboratory rats. To give you a few rat results: the LD50 of table sugar (sucrose) is 29,700 mg/kg. For table salt (sodium chloride, NaCl) it's 3,000 mg/kg. Really poisonous substances, though, measure in the single digits: Sodium cyanide (NaCN), for instance, possesses an LD50 score of 6.4 mg/kg.

Basically, the lower the number, the deadlier the compound. Poisons in water and air are usually measured in lethal concentration rather than dose - in other words an LC50. Which got me wondering about the oil pouring into the Gulf of Mexico from BP's shattered oil rig. Not to mention the chemical dispersants being used in attempt to break down the spreading oil. What kind of lethal concentration might be building up in those waters?

The U.S. Environmental Protection Agency data on dispersants provide the LC50 in parts per million. Of course, these tests aren't done on rats but sea creatures, in this case Menidia, a small silvery fish that likes to hover near the water's edge and Mysidopsis, a tiny brine shrimp.

As has been earlier reported, Corexit, the compound chosen by BP, has some of the lowest LC50 numbers on the list, meaning that it's among the most poisonous. Also, it's among the least effective on Louisiana crude (the type flowing from the Deepwater break). Why the EPA went along with this choice remains a mystery to me - or maybe I just think the answer would depress me - but under public pressure the agency has now ordered BP to find an immediate alternative.

Nearly 700,000 gallons of Corexit have already been poured into gulf waters. But that pales, obviously, beside the amount of Louisana crude, now estimated at a minimum of 6 million gallons. So, I wondered, what is the LC50 of Louisiana crude on small salt water dwellers?

Of course, I realize, that comparing lethal concentrations is not straightforward. The results differ by species and by time as well as by amount of poison, The EPA numbers for Corexit 9500 (the formula used most heavily by BP) show that at 2.62 ppm, the dispersant kills half the silver fish in 96 hours/ four days. At a slightly higher concentration - 3.4 ppm - the compound kills half the little shrimp in two days.

As for crude oils, a very decent analysis by the American Petroleum Institute shows that all are toxic, but their effects vary with thickness and with the different chemistry seen in say, oil from the Gulf of Mexico and oil from Kuwait. The best estimate I've seen for South Louisiana Crude - after hours of exasperated research - comes from thesis work done at Louisiana State University several years ago. For instance, the study found that Louisiana crude had an LC50 of 4250 ppm for the warm-water loving killifish.

This suggests that crude oil is less acutely poisonous than chemical dispersants. But here's the really interesting finding in that terrific little study. Adding a dispersant - specifically Corexit 9500 - made the oil more poisonous. A lot more poisonous.

The "dispersed" oil had an LC50 of 317.7 ppm, making it more than 11 times more lethal in its effects. The study found a similar worsening for white shrimp, although not quite as dramatic. "Dispersed oils were more toxic than crude oils," noted the report.

Oh, definitely. Still, you might argue that this is only a master's thesis conclusion. But as it turns out there are plenty of other studies raising very similar warnings and they go back quite a ways. A report in the journal Environmental Toxicology a decade ago concluded that "LC50 values indicate that dispersed oil combinations were significantly more toxic to these organisms than .. crude oil." Another study, this time of snails and amphipods reached exactly the same conclusion.

To be fair, a study of the Australian octopus found no increased toxicity. But don't you wonder what we're doing out there in the fragile environment of the Gulf, whether we're reducing the spill damage or just turning the whole area into one ever-more poisonous bowl of toxic soup?

And don't you wish our officials gave any indication that they knew more about it than we do? I love doing this kind of research but in this case I'd much rather have our country's so-called regulators waving the LC50 red flag ahead of me.

dblum Sat, 05/22/2010 - 06:42

Tags

poison

U.S. Environmental Protection Agency

chemical dispersants

crude oil

EPA

EPA U.S. Environmental Protection Agency

IME, three links is too many. This post with two, will try another with 3 in a moment.

one
two

I've heard some rumors that BP's lawyers are getting all Cuccinelli on scientists reporting on the gulf gusher.

To BP's lawyers, discrediting masters theses and the scientists who wrote them is just their duty to their shareholders.

That we're trying to fix an enormous chemical pollution problem by pumping 700,00 gallons of additional pollutants into the Gulf is staggering. For tiny spills they may have some utility, although I'd like to see the data first. But for this? It's like sending paper towels to New Orlean's 9th Ward after Katrina.

One point: "As has been earlier reported, Corexit, the compound chosen by BP, has some of the highest LC50 numbers on the list, meaning that it's among the most poisonous."

Shouldn't the most poisonous compounds have the lowest LC50 numbers, as with the LD50 numbers?

As far as I could see the thesis you linked to didn't try to control for oil-water surface area differences. Without some sort of mechanical dispersion of the oil to match the particle size created by the chemical dispersants how can the concentrations be directly compared? The portion of crude oil that will spread into the water column without dispersal of some sort is a small fraction of the total oil.

From the abstract of Another study

These LC50 and EC50 values indicated that dispersed oil combinations were significantly more toxic to these organisms than WAF of crude oil.

If you have access to the paper, can you find out if the concentrations were of water saturated with the WAF or the WAF itself? A LC50 of 19% (190,000 ppm again from the abstract) seems a bit high if it is referring to the hydrocarbons rather then saturated solution of hydrocarbons in water.

A very interesting and useful post, but it would be good to fix the beginning of paragraph 5. After giving a nice explanation of LC50 and how lower numbers mean higher toxicity, you say that "Corexit has some of the highest LC50 numbers on the list". You meant to say that it has some of the LOWEST numbers, and hence highest toxicity, on the list.

Fixed it - and thanks for the heads up.

Good point and I'll take another look at the paper. What's interesting to me is the consistency of the findings that dispersants do not do good things to oil. Here's a link - again an abstract but I'll try to do better - to a paper in which the authors actually recommend against using dispersants at all if the spill is near a coral reef because of the increased toxicity issue: http://bit.ly/anV66Q

If I understand correctly the dispersants are designed to break the oil into tiny droplets that will disperse throughout the water column, vastly increasing surface area, and allowing much faster degradation of the oil by microbes. This same effect would vastly increase the amount of interaction that an animal a few hundred feet under water would have with the oil, because without dispersant only the WAF would be in the water column with the rest of the oil at, or very near the surface. You can't increase the dispersal of the oil without increasing the amount of oil that interacts with everything in the water. There may very well be some nasty synergistic toxicity between the oil and Corexit, but I'd love to see some tests showing toxicity comparison between chemical dispersants and mechanical dispersion, say with a ultrasonic emulsifier.

Two links that may be interesting, first, how they prep a WAF sample the lab: http://video.google.com/videoplay?docid=-5344865627579685963#

Ultrasonic Emulsification /dispersion: http://www.youtube.com/watch?v=v8qHKwiBvhI

Thanks for sending the links - they and you make a great point. Agreed that the toxicity data is only one part of the story. I've been fairly focused on Louisiana crude, since that's the oil in question here, but you may remember that the thesis I cited also looked at Alaskan crude. That obviously harks back to the Exxon Valdez spill and I'm now wondering if the kind of experiment that you're talking about might have been done there or if there might be some other interesting data that sheds some light here. Appreciate the shove in a good direction!

I posted something yesterday but it had 3 links in it. It that the magic number that makes comments never appear?

That's so odd. But I rechecked and it never showed up in the message queue. Do you want to test the theory - send it with two links? Or just try again. The Scienceblog folks never mentioned that as an issue to me.

I posted it again, with 3 links. I tried posting immediately afterward and it wouldn't let me, too many posts too soon.

well, this turns out to be more of an experiment than i could of wished. but try with two - we all know that one link works fine.

I found another paper on crude oil toxicity

http://www.iosc.org/papers/02201.pdf

This one also has a comparison with a known surfactant, sodium dodecyl sulfate (aka sodium lauryl sulfate). That is an extremely common surfactant used in just about every detergent, even in toothpaste. It has a LC50 comparable to the dispersant Corexit 9527.

here is the first post with one link

Thanks for this one. It definitely reinforces the studies I'd cited earlier. I don't know if you've seen this one, which compares the toxic effects of sodium dodecyl sulfate and another Nalco dispersant. http://scialert.net/fulltext/?doi=rjet.2010.13.22&org=10

The acute toxicity is probably a generic property of strong surfactants. I found this nice paper which looks at a lot of different surfactants.

http://www.sklog.labs.gov.cn/atticle/B06/B06001.pdf

The increased toxicity associated with surfactant addition to crude oil comes from the dispersant activity. With the crude oil dispersed better in the water, there is greater access of the soluble hydrocarbons (which are toxic, especially the aromatics) to the water and so the hydrocarbon level dissolved in the water goes up, and so does the toxicity per dose of crude oil. The dispersed oil is more toxic, but is diluted faster and degrades faster. There is greater local toxicity, but there might be reduced toxicity over time. This is a very complicated thing to try and figure out.

My understanding is that the reason dispersants are used is so that the oil doesn't move as quickly to the surface and so doesn't move as quickly to shore. Because oil floats, there is a large tendency for it to collect at the water-air interface.

Yes, that's my understanding too, that it breaks the oil into smaller particles, which tend to settle, and which are more readily degraded by microbes. But I like your description of what happens. it makes a lot of sense in explaining what's going on. And all of this - including the paper you just sent over - reminds me that I should at some time do a blog on the topic of surfactants. Meanwhile, we seem to be caught in this zero-sum game that I don't think any of us are sure how to play out. But, I figure, the more we know the better.

Here is a reasonable discussion of a number of past oil spills.

Http://www.interspill.com/PDFs/UK/2006/marine_ecological_doc.pdf

My guess is that using oil dispersants off shore is probably a good thing, because it keeps the lighter and more toxic hydrocarbons off shore, even if they are in the water column. The heavier stuff will still float to the surface but without the lighter stuff it is more benign. I think once the oil is onshore or near shore, then dispersants are a bad thing and should not be used. Gathering the oil up in things like straw is probably the best thing to do once it hits shore.

I finally got around to checking this blog out, and this post is wonderful.

I think you're using LC50 numbers for dispersed oil with Corexit 9500 instead of the dispersant alone. Corexit 9500 alone has LC50s of 25.2 and 32.23 ppm for the silver fish and shrimp, respectively. The lower LC50s stem from experiments where they monitor the critters' response to water with oil and dispersant mixed in. And those numbers are about 10x lower.

That's average for modern dispersants. A 2005 National Research Council report (http://books.nap.edu/openbook.php?record_id=11283&page=207), they list dispersant LC50 ranges as 190-500 mg/L and dispersed oil LC50 ranges as 20-50 mg/L (why they don't use ppm, I don't know).

You're right. I went back and looked at that EPA data set, which is in ppm, and it's for a mix for Corexit and No. 2 Fuel OIl. Comparing the LC50s seems to reinforce the other studies I found which show that dispersant makes fuel oil up to ten times more poisonous. In other words, a very consistent finding for shrimp and silver fish species but not necessarily good news. I think I'll add that into the next blog post, which will be about crude oil.

Every membrane of every cell of every living thing is composed of lipids, so the toxicity of surfactants is no surprise. Plus, crude kills mostly by smothering, not toxicity.

The "data" on toxicity gives the impression of false precision. The adverse health effects are complex over time, space, species, tissue compartments, concentration and with multiple interactions between variable components and cannot be reduced to a single number even for a single species at a single life stage. All of these effects are non-linear and coupled which makes modeling them essentially impossible.

Roland is absolutely correct, every cell has a lipid membrane. Every lipid membrane has proteins that are partly in that membrane and partly in the cytoplasm and external to the cell. Hydrocarbons partition into that lipid membrane and change its properties. The proteins in the lipid membranes are there because there are hydrophobic regions in the proteins that are âattractedâ to the lipid membrane more strongly than they are attracted to the aqueous phase. When hydrocarbons get into the lipid membrane, they change the properties of the membrane and change the interactions of the membrane with the proteins in it. If that change exceeds a certain amount, then the proteins won't work properly. If enough proteins don't work properly, then the organism exhibits metabolic stress, physiological damage, and eventually death.

I don't think that differences in the âtoxicity numberâ by even an order of magnitude are necessarily important or significant. A lot of these âtoxicity numbersâ are going to be quite sensitive to the ratio of dispersant to oil, and to the detailed composition of that crude oil and to the idiosyncratic conditions of the test (O2, temperature, species, nutritional state, test duration, etc.) The toxicity effects of dispersant on diesel fuel and on this crude oil is expected to not be identical; the details which are unknown will have larger effects than the stuff that is known.

Getting rid of the insoluble but visible oil water emulsion on the surface may slow the degradation of the more soluble but invisible aromatic compounds which are more toxic by removing bacteria that can degrade them.

If you want to discuss âeffectivenessâ of clean-up, you really need to define what you mean and over what time frame; and appreciate that what ever you define âeffectiveâ to be will mean that the relative effectiveness of treatments will change as your definitions and time frames change. In many cases the order of ranking of methods will change.

One also has to consider the effects over time.
If the dispersal agent causes the oil to break down (through natural processes) much more quickly into non-toxic compounds (or less toxic), the toxic effects will be contained in a smaller area than would otherwise be the case, as would the smothering effect that causes marine animals (as well as marine birds and animals in lithoral zones) to be killed by suffocation or starvation by being unable to fly/swim/hunt/eat.

Thus while in a small area there might be an increased dieoff due to toxic materials (probably partially compensated by a smaller dieoff due to smothering, but that's nitpicking) the effects would be more contained.
Whether that's ever been studied I don't know. I do know similar studies have been done on nuclear waste dumping that showed conclusively that leakage would have a far smaller effect than had been assumed prior (effectively, dispersal of the nuclear waste material by sea currents would be so effective that even at relatively short distances from the spillage site there would be no adverse effects on the biosphere, the same may well be true if spilled oil were well dispersed).
I don't know if this study was ever published internationally (let alone online), I do know we had big trouble getting it published at all because of political pressure (this was in the mid 1990s, when the anti-nuclear movement was even stronger than it is now and (like the CO2/global warming fanatics now) didn't want anything published that would not support their ideas.

"Why the EPA went along with this choice remains a mystery to me - or maybe I just think the answer would depress me"

My understanding is that the EPA did not go along with it, and BP simply ignored them. De-list 'em and nationalize their assets.

I am wondering how Corexit interacts as moisture evaopration takes place after it has been used as a dispersant? oceanic circulation is not the only concern--though a big one, certainly! Air circulation and weather patterns, impacted such as they are by oceanic temperatures and currents, is another matter, altogether and I am curious if there are any studies as to the effects?

P.S. Does anyone know how much methane is being released or was released along with the crude that continues to spew? And, how might this add to the complexity of chemical reactions and maginified toxicity of crude and Corexit in the seawater?

Methane is probably the most benign of the oil constituents after CO2. Methane isn't toxic except at very high levels where it is probably narcotic, but those are very high levels. It is metabolized by bacteria into CO2 and biomass and that consumes O2, or (worse) generates H2S from sulfate. H2S is toxic to just about every multicellular life form. It is only an acute toxin, if the organism survives, it probably will do ok.

What would be considered a high level? Thanks for the info--I am also concerned about the amount of methane being released into the Gulf as that additional amount applies to global warming from greenhouse gases.

Also, I was recently reading an article by Peter Ward in Earth Science, regarding a hydrogen sulfide mass extincion theory postulated for the some of the mass extinctions not explained by asteroid theory. He cites the work of a couple of researchers, that formed the background for my initial question on methane. I quuote here--

"Calculations by geoscientists Lee R. Kump and Michael A. Arthur of Pennsylvania State University have shown that if oxygen levels drop in the oceans, conditions begin to favor the deep-sea anaerobic bacteria, which proliferate and produce greater amounts of hydrogen sulfide. In their models, if the deepwater H2S concentrations were to increase beyond a critical threshold during such an interval of oceanic anoxia, then the chemocline separating the H2S-rich deepwater from oxygenated surface water could have floated up to the top abruptly. The horrific result would be great bubbles of toxic H2S gas erupting into the atmosphere."

Now... first of all, since oxygen is present in oceans today in essentially equal concentrations from top to bottom because it dissolves from the atmosphere into the water and is carried downward by ocean circulation, only under unusual circumstances would anoxic conditions below the surface permit a wide variety of oxygen-hating organisms to thrive in the water column.
Now, would you say this is one of those unusual circumstances, or not?

Touched, I would not think that these circumstances are unusual. This oil spill is not going to change the ocean circulation.

What could change the ocean circulation would be global warming. Particularly when Greenland melts, the fresh water on top of the salt water will prevent the cold salt water from sinking at the North pole. That will stop the ocean circulation. Without cold water from the Arctic sinking, the ocean depths will heat up which could destabilize the methane hydrates there.

You compare the LCs of oil and dispersed oil, showing that the LC of dispersed oil is about 11 times lower. This means that dispersed oil is toxic at one eleventh of the concentration of oil.

However, I assume that dispersed oil is more dispersed than oil. The question is whether it is more than 11 times more dispersed.

I would find it hard to believe that in a large supply of water (eg the Gulf) dispersed oil would be many more than 11 times more dispersed than oil.

So your conclusion should be that adding even a highly toxic dispersal agent lowers the overall toxicity as the dispersal overcomes the increased toxicity.

What it did do is to make the oil more difficult (impossible) to see with the naked eye which presents a huge problem for desalinization plants (people's health) and nuclear power plants that can't take in oil. All by design in my humble opinion. My question is what happens when corexit mixes with frozen methane (in the case of a collapse of the seabed). Is that explosive mix of chemicals?

How does one detect the dispersants in their water? Considering its inevitable that it has or will reach us from the clouds and rained on most of North America by now how do we test for this dispersant in our water? I would like to check my tap and see if I need to setup water distillation to purify my water, will distillation process be able to exclude corexit from the water?

The components of Corexit 9500 are not as scary as the term "chemical dispersant" might suggest. Along with some light gasoline, it contains SPAN and TWEEN emulsifiers commonly found in foodstuffs, a common laxative, propanediol (a less toxic relative of antifreeze), and a hand cleaner that has a not-so-bad LC50 of 841. I'm surprised that its LC50 is as low as 25. Perhaps dispersing these materials in water for testing makes them more toxic than eating them does. Or perhaps any detergent-like compounds are tough on aquatic organisms.

The thorium revival

razib — Thu, 28 Jan 2010 02:37:14 +0000

The thorium revival

Mike the Mad Biologist points me to an interesting article in Wired, Uranium Is So Last Century -- Enter Thorium, the New Green Nuke. Of course Wired is a booster of many things which never take off, but in general I think it's probably safe to bet on nuclear power becoming more prominent in the near-to-medium-future. I recently have been reading a bit about oil, stuff that's not written by Daniel Yergen, and was fascinated by this chart of long term crude prices:

The inflation adjusted values are of interest. But look at the lack of volatility before 1974! My whole life has been characterized by volatility of crude oil prices, so I simply assumed that that was the nature of the beast....

razib Wed, 01/27/2010 - 21:37

Tags

US oil production peaked in 1970. Volatility began shortly thereafter. Perhaps these two things are connected.
Perhaps more importantly, world-wide per-capita oil production peaked sometime in the 1970s.

If you go back before WWII you'd see more volatility in the "real" inflation-adjusted price. The global situation immediately after WWII gave western oil companies a lot of power to control prices in the Middle East. OPEC was formed to allow producer nations to have a unified bargaining position, and the big spike in 1973 was in part a political response to the US support of Israel in the Yom Kippur War. OPEC was also concerned about the weakening of the dollar as the Bretton-Woods regime collapsed. This, of course, is the very oversimplified short version of the story.

Typically when I want to see the price of something over time with the effects of inflation removed, I compare it to the price of gold. (It's not perfect, but seems pretty good towards that goal.)

I did a quick Google search but didn't find any graphs of Oil prices in terms of ounces of Gold (for the relevant dates). Maybe I should have tried harder :-) But I did find this, that I think can still be used...

http://www.gold-eagle.com/gold_digest_00/hamilton070300.html

If you look at the graphs they have, oil doesn't deviate too much from the gold price around 1974.

Perhaps what you are seeing in your graph around 1974 is due to Nixon getting rid of the direct convertibility of the U.S. dollar to gold. From what my father has told me, around that time no one wanted the U.S. dollar, and you were seeing a flight from it (to other currencies).

One other thing, there is also this PDF that does actually show Oil in terms of Gold, but it is only from 2001 to 2008...
http://www.agiweb.org/workforce/Currents-007-OilByCurrency.pdf

It shows the oil price in terms of gold as basically a "flat line". But given the short time span (of 2001 to 2008) I don't want to make any claims based on it, about long term trends.

Actually... thinking about it a bit more (in addition to my previous comment). There was an oil "crisis" around that time.

http://en.wikipedia.org/wiki/1973_oil_crisis

I think the stability of oil prices before 1974 was due to the Railroad Commission of Texas.