How Much Oil Underneath?

A friend asked me a few days ago why the Karnataka government were giving two different estimates for iron ore potential in the state. One file says that the iron ore reserves are about 3,447 million tonnes, while another department file says that the state has about 9,000 million tonnes of iron ore resources.

I replied that assuming the Karnataka government is using the words as they are commonly used in industry, reserves are the fraction of resources that can be economically exploited at any given time. Neither is a static quantity. Both will change given new finds, technological breakthroughs that enable recovery of previously out of bound deposits and the economic and political climate.

Coincidentally Scientific American has an article in their recent issue on the current reserves of oil and how that quantity is changing with new finds and new technology. They give one example:

When Kern River Oil Field was discovered in 1899, analysts thought that only 10 percent of its unusually viscous crude could be recovered. In 1942, after more than four decades of modest production, the field was estimated to still hold 54 million barrels of recoverable oil, a fraction of the 278 million barrels already recovered. “In the next 44 years, it produced not 54 [million barrels] but 736 million barrels, and it had another 970 million barrels remaining,” energy guru Morris Adelman noted in 1995. But even this estimate proved wrong. In November 2007 U.S. oil giant Chevron, by then the field’s operator, announced that cumulative production had reached two billion barrels. Today Kern River still puts out nearly 80,000 barrels per day, and the state of California estimates its remaining reserves to be about 627 million barrels.

This story will apply to a wide range of mineral/oil deposits all over the world.  Famously the United States has produced a cumulative 200 billion barrels of oil from reserves that never at any one time exceeded 40 billion barrels.

In the many responses to the Scientific American article I thought this one from JR Wakefield stood out as it explains what peak oil means from different perspectives:

Its not about how much oil is in the ground, it's how fast you can get it out and at what net energy.  This thus article is highly misleading.   Here are the Five Horsemen of Peak Oil:

1) Geological Peak. That is the point where we have consumed half the oil in the ground. So far we have consumed a trillion barrels. Estimates of remaining oil range, but the number appears to be 3 trillion barrels remaining in the ground. So we are not at geological peak. Hence skeptics of peak oil use this for their arguments, like this SA article does.

2) Flow Rate Peak. That's the point at which you cannot extract the oil fast enough to meet demand. This is especially so with old fields in decline (which is a fact) and new fields which have difficult geology (like this one).  The flow rate from them does not keep up with decline, nor keep up with growing demand. The article failed to mention that North Sea is all in terminal decline and the UK has to now import oil. Indonesia peaked years ago and has to import oil forcing them out of OPEC.  The Cantarell field in Mexico, the third largest in the world, and the US's 3rd import source, was producing 2.3mb/day at it's height.  Today it's 560kb/day with a 41% drop from last year.  WE ARE AT FLOW RATE PEAK NOW.

3) Geopolitical Peak. That's when exporting countries, due to their own growing demand, decide not to sell their oil abroad any longer but decide to keep what's in the ground for their own future domestic needs. So far only the US does this, but expect other countries to soon follow that.

4) ERoEI peak. This is the point at which it takes as many joules to extract the oil than you get from the oil extracted. That is, one barrel in to get 1 barrel out. Conventional wells in the 1960s were 100:1. That has dropped to about 25:1 today. Aging fields and new unconventional fields have very low ERoEI. The tar sands in Alberta for example is less than 6:1. Our entire society is based on the NET energy, not what's extractable. Calculations show that we will reach over all break even in oil extraction between 2020 and 2030. Once that is reached it basically means we have completely run out of oil.

5) economic peak.  This is the point where the economy cannot tollerate high oil prices and plunges the world into a recession, like this one which was caused by $140.barrel oil.

The challenge before us in terms of combating global warming is to ensure a transition from hydrocarbon energy to low emissions renewable energy much much before we start running out of the stuff not just in geological terms - which is not going to occur anytime soon - but by the other measures like Flow Rate and ERoEI as well. Likely even the Flow Rate Peak and the ERoEI peak are not constant but will keep shifting as more efficient ways of extracting oil and other hydrocarbon resources are discovered.

The Probability Of Evolutionary Pathways

Joe Thornton of the University of Oregon and the Howard Hughes Medical Institute writes these thoughts about how to understand and appreciate the probability of evolution following one specific pathway among many possible:

Consider the future: there are countless possible that could emerge from our present state, making the probability of the one that actually does evolve extraordinarily  low.  Does this mean that the future state that will ultimately emerge is  impossible?  Obviously not.  To say that our present biology did not evolve  deterministically means simply that other states could have evolved instead; it does not imply that it did not evolve.

Consider your own life history as an analogy.  We can all look back at the road  we have traveled and identify chance events that had profound effects on how our lives turned out.  “If the movie I wanted to see that night when I was 25 hadn’t been sold out,  I never would have gone to that party at my friend’s house, where I met my future spouse….”  Everyone can tell a story like this.  The probability of the life we actually lead is extraordinarily small.  That obviously doesn’t mean that its historical unfolding was impossible.

That we inhabit an improbably reality requires a divine explanation only if we, like Behe, take the teleological view that this is the only reality that could exist.  But if we recognize that the present is one of  many possibilities, then there is no difficulty reconciling the nature of  evolutionary processes with the complexity of biological forms. As history unfolds, potential pathways to different futures are constantly opening and  closing. Darwinian processes are entirely adequate to move living forms  along these pathways to a remarkable realization – but just one realization out of many others that could have, but didn’t, take place.

Beautifully written.

The entire article is worth reading as it explains how complex traits with interlocking components can evolve through a combination of natural selection and random genetic drift acting on adaptive mutations and neutral intermediates. And this is not just theory. Joe Thornton leads a team that does experiments to show how this can happen. The article encapsulates modern evolutionary thinking about the evolution of complexity quite well.

That it is a devastating put down of the arguments made by the Intelligent Design community makes it especially pleasurable to read. 

A 20 Million Year History Of Atmospheric CO2

From Brave Blue Words I found out a day late that yesterday was Blog Action Day for Climate Change. Bloggers all over the world are writing about various aspects of climate change.

Being a geologist I want to point to a study that reconstructs atmospheric CO2 levels as far back as the Miocene  - a 20 million year history. Atmospheric CO2 levels have been reconstructed with some confidence for the last 800,000 years or so using gas bubbles trapped in the Antarctic ice sheets. Before that the data was thin.

Aradhna Tripati and colleagues have used the boron to calcium ratio in foraminifera shells to calculate ancient CO2 levels. As atmospheric CO2 increases some of it diffuses into the ocean increasing the dissolved CO2 content of sea-water. That in turn reduces the amount of boron that is incorporated in a growing calcium carbonate shell of the foraminifer individual. The variation in the boron to calcium ratio over time as recorded in foraminfera fossils of different ages should tell us something about transitions in CO2 levels.

The scientists first validated their calculations using the 800 K record of CO2 trapped in ice. They compared their results with those obtained by the direct measurement of CO2 trapped in gas bubbles. It was a good match. The scientists calculate that the uncertainty in their results is about 14 parts per million.

Their results show that there is a close coupling between CO2 levels, sea-level and temperature over the last 20 million years.  In the middle Miocene (~ 20 ma) CO2 levels were about 400 ppm - comparable to modern levels - and that sea-levels at that time were 30 -40 meters higher than today (geologists estimate this using distribution of ancient shorelines), with temperatures about 3-6 deg C higher (using geochemical proxies like the oxygen isotope composition of shells which depend partly on temperature of the water from which they precipitate). Decreases in CO2 levels in the later part of Miocene and Pliocene were synchronous with major episodes of cooling and glacial expansion.

Its important to establish that historical connection to answer doubts expressed on what exact impact would increasing levels of CO2 have on climate and sea-level. Many climate change doubters are not happy with computer simulations and models of CO2 increase and climate change. This study shows that CO2 has been a strong driver and amplifier of climate change in the deep geological past. History is also a guide and often a reliable one.

Go here for the press release.A minor quibble. The press release calls the shells used by the scientists as belonging to single celled marine algae. Foraminifera are not algae. They are protists.

A Government Scientist Speaks Out On Flood Management

You don't hear many Indian Government scientists opining about science, policy, the environment, civic criticism...well you get the picture.

There are restraints....to put it politely.

But Chetan Pandit of the Central Water Commission has broken the shackles and in the October issue of Current Science comes out sparring strongly against - in his opinion - the woolly headed arguments of the environmental community  and the media on the subject of big dams and flood control.

He puts forth several fallacies and myths regarding dams and flood control and argues very well that big dams have served as effective flood managers.

And I had to chuckle at this:

We Indians seem to be particularly susceptible to this ‘romancing with the past’. Everything, be it water management, or agriculture, Ayurveda, mathematics, literature, astrology, etc., we like to believe that in India all learning had reached its peak in some distant past, and the best thing for us to do is, to continue to do what our ancestor’s did. And this is given a lofty name ‘wisdom of the centuries’.

You may be inclined to view big dams as destroyers of forests and biodiversity and so on but Chetan Pandit has made some good points about the intellectual environment in which debates on these issues take place and are presented to the public in India. One of the most important points he makes is that many people who get involved in criticizing government projects are numerically challenged. Arguments are high on the emotional quotient but there is little quantitative analysis of data to go with it.

I am sure not all environmentalists are so mathematically naive, nor should every developmental project be reduced to just numbers. But this is a government scientists view. When presented with a  rare opportunity to speak out he doesn't restraint himself.

Read the article here.

Update: Chetan Pandit via an email to me wants to clarify:

I never said that those criticizing government projects are “numerically challenged”, or mathematically naïve, etc. Even a high school student would be able to import the data on flood affected area into a spread sheet and plot a graph to see whether or not there is any increasing trend. What happens is, if they do that their argument will collapse, the numbers do not favour them, they know it, and therefore they have to willfully ignore the numbers. Which is why I wouldn’t describe the environment in which debate takes place as “intellectual”. It is pseudo-intellectual.

Chetan Pandit

Sure, he didn't use the words numerically challenged and mathematically naive. Those are my words but he does imply this. For example he writes about noted anti-dam activist Shripad Dharmadhikary -

In his exhaustive critique of the Bhakra dam, noted anti-dam activist Shripad Dharmadhikary writes, ‘Even after the Sutluj flows were augmented by the transfer of Beas water into the Bhakra reservoir, the reservoir has not filled up in most of the years’4. This was probably intended as a critical comment on filling of the Bhakra reservoir. But its implication, which probably escaped Dharmadhikary, is – Bhakra is very successful in flood control. In the years, the dam did not even fill; it is obvious that all the floods were absorbed 100%. And this, despite transfer of a substantial quantity of water from Beas to Sutlej through the Beas–Sutlej link.

But its implication, which probably escaped Dharmadhikary,...

So I read this as meaning Dharmadhikary did not understand the topic well enough. It certainly doesn't read as meaning that Dharmadhikary churned out the numbers, didn't like what he saw and then ignored the finding.

Dinosaur Eggs And Some Stratigraphic Thoughts

The discovery of dinosaur eggs from Cretaceous fluvial sediments near the village of Ariyalur in the state of Tamil Nadu , South India is getting lots of press cover ...here and here. Hundreds have been found in clusters of about 8 over an area of about 2 sq km. Looks likely to be a nesting site. On a sadder note I read in the Times of India a few days ago that there has been no protection given to the site by the government despite requests from the scientists. Locals are already taking away the fossils eggs and disturbing and damaging the site in the process. What a shame!

There also has been some silly press coverage calling this a Jurassic treasure trove, a  holdover of the popular link between anything dinosaur and the word Jurassic....as in Jurassic Park the movie. This particular south Indian sedimentary basin does not have Jurassic sediments. It contains an Early Cretaceous to Early Cenozoic sequence.

What caught my eye was that the sedimentary layer containing the eggs were capped by a volcanic layer. The scientists from Periyar University, Salem, seem to think that this volcanism represents the Deccan volcanic activity dated to around 65 million years ago and that the field relationship between the volcanic layer and the underlying sediment could suggest that this particular volcanic event may have killed or damaged those eggs.

I don't know enough details about the deposit to answer that with certainty but I did have some random thoughts on event deposits i.e layers deposited almost instantaneously and how geologists use such deposits to ascertain the age of the associated sediments. In this case they suggest that sedimentation and the volcanism took place in quick succession and by quick I mean volcanism took place immediately after the dinosaurs laid those eggs....before those eggs hatched.

If a sediment unit is capped by a volcanic layer that is dated to say 65 ma (million years old) then that would mean that the sediment cannot be younger than 65 ma. But does the relationship mean that the sediment too is 65 ma? And what does it mean when you say the sediment is 65 ma. How much 65 ma plus minus ...years, or uncertainty is there in a calculation like this? 

Lets say we get lucky and that the sediment layer is sandwiched between two volcanic layers that can be dated with radiometric methods. Let's say both layers give a date of 65 ma. What does that tell you? Radiometric dates that old come with a sizable uncertainty on the order of hundred thousand years or so. That means the date of the overlying layer might come out as say 65 ma with an uncertainty of 300 thousand years. The date of the layer underlying the sediment may come out say 65.2 ma with an uncertainty of 300 thousand years. The two dates are statistically unresolvable. So, even if the sediment is sandwiched between two volcanic layers that indicate the same statistical date there could still be a time lag of tens to a hundred thousand years or so between the sediment being deposited and the volcanic activity.

Fossils are not much use either for this purpose.  Fossils can eliminate the possibility that the events took place in quick succession if the sediment contains fossils which are obviously much older that 65 ma. But again fossil species have temporal ranges of a hundred thousand years or more. Even if the sediment underlying the volcanic layer contains fossils that are indicative in this case of the latest Maastrichtian age (close to 65 ma) there will be an uncertainly of tens of thousands of years and so their presence won't resolve events taking place on smaller time scales.

Geologists have then to rely on the detailed physical relationship within and between the sediment and the volcanic material.

Preserved sedimentary layers are mostly time averaged deposits. That means that material at the bottom of a particular bed is not necessarily older than the material in the upper part of the same layer. During deposition waves and currents keep reworking the same bundle of sediment. Animals may burrow into it and churn up sediment. Material at the bottom part may get transported to the upper part of the layer. The layers thus becomes time-averaged. Organisms who have lived at different times through that depositional episode are all distributed randomly - with respect to their age - throughout the deposit.

A good recent example of a time averaged deposit is the sediment unit that contains the remains of Ardipithecus ramidus the early hominin found in Ethiopia. Scientists lucked out there and realized that the sediment is sandwiched between two volcanic layers dated to about 4.4 ma. Each layer differed in their radiometric age by about 30 thousand years with an uncertainty of about 75 thousand years. Based on this information and the internal characters of the layers the scientists concluded that the geological unit was a time averaged deposit representing a few thousand years of deposition.

This layer containing the dinosaur eggs does not have the characters of a time averaged deposit at least not one representing hundreds or thousands of years. The eggs were found in clusters of 7-8 eggs per nest and these nests are found in successive layers of the sequence. These two indicators suggest that the sediment was not disturbed much. Rather the setting, fluvial floodplains, would have meant that the eggs were buried rapidly and entombed during seasonal floods, a sort of an event deposit just like volcanic eruptions. That may have been the main cause of the eggs not hatching. The layers immediately underlying the volcanic cap may thus represent sedimentation taking place over a few tens of years, each nest bearing layer essentially preserving or freezing ecosystem conditions as they existed at that time. There is the possibility that the uppermost layer containing eggs represents maybe the last egg laying season before the eruption.

Volcanism when it occurred would have sealed the deposit from further damage from the elements. How close in time was that event to the last egg laying season? Again the scientists will have to look closely at the relationships. Are the eggs in the uppermost layers caked with volcanic ash? Do they show signs of being baked or cracked due to heat, a kind of a Cretaceous hard boiled feast?

Detailed sedimentology and stratigraphy will provide more clarity than absolute radiometric dating and fossil ranges when posed with questions of this nature.