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Hydrocarbons: a fossil but not (yet) extinct Image courtesy of the Shell Library

Continuing our energy series, Menno van Dijk introduces us to the past, present and future of hydrocarbons – still the most common of all fuels.

hile researchers today are isms. They all extracted the energy for Wworking on the development their organic molecules either directly of clean, renewable fuels, our society or indirectly from sunlight. is still almost entirely dependent on fossil fuels. How are they formed, Storage in reservoirs how much is there of them, and how Since then, the continents have long will they last? drifted apart, with some landmasses Hundreds of millions of years ago, disappearing into the depths and oth- the world was a wilderness, but not ers being heaved up. Wind, ice and void. A diversity of animals and rain caused erosion on land, which plants populated the landmass. The created great masses of sediment, seas bubbled with life and, like today, especially in river estuaries. Some the largest part of the biomass con- sediments were porous (such as sand sisted of microscopically small organ- or the skeletons of calcareous ani- mals), others impermeable (such as ly of carbon (C) and hydrogen (H), clay). Organic material was buried, they are collectively called ‘hydrocar- too, and the vertical movements of bons’. This fluid, mostly together with landmasses could take it several kilo- water that was also trapped, worked metres below the ground. There, it its way up through porous rock until was warmed up by heat from the it was – in some cases – stopped by interior of Earth. an impermeable layer of sediments. The high temperature and high Where the geometry, determined by pressure at that depth caused the breaks and deformations, had formed organic material to break down and three-dimensional enclosures, or be converted to a fluid with a diverse reservoirs, the fluid accumulated and collection of chemical structures: remained there to simmer quietly. volatile hydrocarbons such as Due to the absence of oxygen, the Detailed image of a carpet moss leaf methane and ethane, short and long solar energy stored as chemical ener- (Mnium hornum); the parts of the plant paraffinic molecules, aromatics, and gy in the molecules was not burned cells which store light energy as molecu- highly complex and large polycyclic up (oxygenated), but preserved for

Image courtesy of Kristian Peters and Hans Ferdinand Maßmann; image source: Wikimedia Commons Wikimedia Maßmann; image source: and Hans Ferdinand Image courtesy of Kristian Peters lar fuel (chloroplasts) are clearly visible. structures. Since they all consist main- millions of years. Sometimes a sepa-

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The Brent Alpha platform in the North Sea

Image courtesy of Mayumi Terao / iStockphoto ‘gas bubble’ formed. Note that such a its own character in terms of reservoir gas bubble, just as an oil reservoir, is shape and hydrocarbon composition. enclosed in porous rock, the pores of which are filled with oil and/or gas Energy hunger in the and/or water. modern world On land, organic material such as Over time, we humans have devel- trees and plants got buried, too. oped a great hunger for energy. Under favourable conditions, when Originally, this was fulfilled by fire- they were quickly covered by sedi- wood. When the growing of wood ment and thus sheltered from oxygen, couldn’t keep up with the growing preventing rot, these were converted demand for energy, we started dig- An offshore to thick layers of coal. In some places, ging up million-year-old firewood the hydrocarbons came into contact from coal mines. But the solid form of rate gas phase was formed above the with bacteria with an appetite for cer- coal was cumbersome, dangerous to oil, and on other occasions, when tain molecules, which changed their dig up and not very economical. only very small hydrocarbon mole- composition. So each reservoir storing Eventually, oil reservoirs were discov- cules found their way to a reservoir, a accumulated solar energy will have ered. While man’s use of oil dates to

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Image courtesy of Jupiterimages Corporation prehistory, the first modern much as the first source in Miri pro- was drilled in the United States on 27 duced in 60 years: that’s 650 000 bar- August 1859 by Edwin Drake in rels of oil, about 100 000 m3. Pennsylvania. Later, wells were drilled especially in the Middle East, Where to go from here? where vast resources of fairly easily One thing is clear: all the oil or gas extractable oil appeared to be situated that has been pumped out is gone for- under the sand. ever. Slochteren is running out, the The combustion engine caused an famous North Sea fields are running explosive growth in the demand for out, and even in the , oil. This grew so quickly that the end the most important oil source for the of the supply seemed near. The Club most energy-hungry country in the of Rome, a global think tank for polit- world – the USA – the fields being ical issues, warned that mankind was found are increasingly small. Will the quickly running out of energy hydrocarbon economy soon die a reserves. So people started to search slow, or perhaps a quick, death? in more inaccessible places and dis- Ultimately, supplies are certainly covered much more oil under water: finite, but there are still a few aces up the North Sea, the Gulf of Mexico, the the hydrocarbon sleeve. in Nigeria. Driven by high oil prices, technology was devel- A pumpjack oped to recover oil from increasingly Depending on the precise circum- deep water. Moreover, natural gas technique that the Chinese had used stances of an oil reservoir, approxi- came into view. Originally, striking for centuries to drill for salt. In the 60 mately one-third of the available oil is gas on a drill was considered bad years of its existence, 100 000 m3 of oil generally extracted. The rest stays luck. Locally, you may have been able were retrieved by a pumpjack. behind in the pores of the rock. Using to use it, but exporting it over long Today, oil is extracted from reserves technology, something can still be distances was far too expensive. Here in up to 2.5 km deep water, 6 km done to extract more oil: from rela- too, technological developments below the seabed. This requires the tively simple water injection to press changed the situation. precise drilling of a 6 km deep, 50 cm the oil from the reservoir, to sweeps diameter hole from a drilling platform with surfactants and polymers to Liquefied gas bobbing a few kilometres higher up loosen some of the oil from the rock. With liquefied natural gas technolo- on the sea. Then, at the bottom of the Thanks to high oil prices, these gy, natural gas is compressed to about sea, a construction called a subsea enhanced oil recovery techniques are th 1/600 the volume, and became trans- well head has to be placed on the becoming very interesting. portable over long distances. Recently, well, from which the oil must flow to it also became possible to chemically a production platform which some- Heavy oils and transform gas on a commercial scale times lies dozens of kilometres away. There are also reservoirs which con- to heavier (liquid) hydrocarbons such This is not to be confused with the tain very heavy, i.e. viscous, oil. as or diesel fuel (GtL, gas to drilling platform, which drills and Previously, these were not economi- liquid). Thus, huge gas reserves (in constructs the wells and then goes cally developed, but here too, technol- the , for example, there is away. Production platforms instead ogy can bring about change. But it is a reservoir 10 times as large as contain the processing equipment. not easy and will require large invest- Slochteren in the Netherlands, the Between the reservoir and the plat- ments, also in knowledge building. largest European natural gas field, form, a multitude of problems can Hyperheavy oil is still in abun- estimated at 1.5 × 1012 m3; Russia also occur which must be known and mas- dance. In oil sands and , holds vast gas reserves) could be used tered. Besides knowhow and technol- reserves of hydrocarbons are stored – to satisfy the hunger for energy. ogy, this requires a lot of money, and the size of many times the amount of All this was possible thanks to the this type of oil field can only be prof- ‘easy’ oil. In Canada, 200 000 m3 of oil development of highly advanced itable if it produces large quantities of are produced daily from excavated tar technology. The first oil well for Shell oil per day: off the coast of Malaysia, sands. This is a costly and difficult in Malaysia, in Miri, was only 140 m a new field has recently been found, process, if only because of the deep, and was drilled in 1910 with a which will produce in four days as extremely low temperatures that pre-

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Tankers and pipelines

The technology of oil transportation has evolved ures, and explosions are much larger, with 84% of alongside the oil industry. Break-bulk boats and barges these involving losses of more than 700 tonnes. were originally used to transport oil in wooden barrels. Modern pipelines have existed since 1860, , and today But such barrels were heavy, leaky, and expensive, span the world in a growing network millions of kilo- accounting for up to half the cost of produc- metres long, with Russia and the rest of Europe each tion. In 1876, Ludvig and Robert Nobel, brothers of contributing about 250 000 km of gas and oil pipelines Alfred Nobel, founded Branobel in Baku, , (70% of these transport gas). They generally constitute one of the largest oil companies in the world during the most economical way to transport large quantities the late nineteenth century. They pioneered successful of oil or natural gas over land. Oil pipelines are made oil tanker engineering, but also experienced some of from steel or plastic tubes with inner diameters ranging the first tanker disasters. Today’s supertankers are up to from 10-120 cm, and are typically buried 1-2 m deep. 400 m long, with a capacity of up to 500 000 DWT The oil flow of about 1-6 m/s is ensured by pump sta- (deadweight tonnage, a measure of how much weight tions along the pipeline. Multi-product pipelines are of cargo a ship can safely carry). They can transport used to transport two or more different products in two million barrels of oil, which corresponds to the oil sequence in the same pipeline. There is usually no consumption of France per day in 2007. physical separation between the different products, so A new tanker of 250 000-280 000 DWT cost US$116 some mixing occurs, producing polluted interface million in 2005 – but oil tankers are often sold second- which is removed from the pipeline at the receiving hand. As of 2007, the CIA statistics counted 4295 oil facilities. For natural gas, pipelines are constructed of tankers of 1000 DWT or greater worldwide: this carbon steel and vary from 5-150 cm in diameter, depending on the type of pipeline. The gas is pres- amounts to about 37% of the world’s fleet in terms of surised by compressor stations and is odourless unless DWT. In 2005, 2.42 billion tonnes of oil were shipped mixed with a mercaptan odorant, where required by a by tanker: 76.7% of this was crude oil, the rest consist- regulating authority. ed of refined petroleum products. With the exception of the pipeline, the tanker is the most cost-effective Gas and oil pipelines are not merely an element of way to move oil today. trade: they connect to issues of geopolitics and inter- national security, and their construction, placement, By the sheer amount of oil carried, modern oil tankers and control often figure prominently in state interests have to be considered a threat to the environment, and actions. Pipelines cross areas prone to earthquakes with oil spills having devastating effects. Crude oil and wars, nature reserves and the bottom of seas. As contains polycyclic aromatic hydrocarbons which are they contain flammable or explosive material, they very difficult to clean up, and last for years in the sed- pose special safety concerns, with ruptures and dead- iment and marine environment. Marine species con- ly explosions being the most common accidents. stantly exposed to them can exhibit developmental problems, susceptibility to disease, and abnormal reproductive cycles. The International Tanker Owners Pollution Federation has tracked 9351 accidental spills that have occurred between 1974 and 2008. Most spills result from routine operations such as loading and discharging cargo, and taking on fuel oil. While over 90% of the operational oil spills are small, result- ing in less than seven tonnes per spill, spills resulting from accidents like collisions, groundings, hull fail- BACKGROUND

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Image courtesy of Rob Belknap / iStockphoto Image courtesy of Ivars Zolnerovichs / iStockphoto

A handful of the black, oil-rich sand recovered in Fort McMurray, Alberta, Canada A coal train

vail in that region. Moreover, the Gas hydrates estimated to be greater than those of process of producing useful fluids all other known fossil fuels combined from oil sands requires quite a bit of Methane, of bacterial or fossil ori- – ever. However, people don’t have energy and is not so efficient. For the gin, which is released at the bottom of even the slightest idea yet of how to deeper stocks (80% of the total), no the sea, can form what are known as exploit these reserves (safely). recovery method is yet available. gas hydrates. This is a kind of ice For a science fiction outlook on which, due to methane trapped inside what might happen if these hydrate Coal (under pressure), has a higher melting fields were to be destabilised, see Coal reserves are still in abundance, point. Great quantities of methane are Schätzing (2004). too. In recent years, coal has been the likely to be stored in such huge fastest growing energy source. This is hydrate fields at the bottom of the Reserves and production because of the growing economy – ocean, including the east coast of the Large parts of Earth have been and consequent demand for energy – United States. The total energy examined for the presence of oil and in China, which itself has only limited resources in gas hydrates on Earth are gas fields. Most hydrocarbon regions oil and gas reserves, but a lot of coal. China consumes about 40% of the global coal production. But this is not Reserves Annual production R/P without its price: the deaths of dozens of miners per day (!) and huge envi- m3 Joules m3 Joules

ronmental damage (by acid rain, Crude oil 1.9 x 1011 6.8 x1021 4.7 x109 1.7 x1020 41 among other causes) are associated 14 21 12 19 with the burning of coal. With Natural gas 1.8 x 10 6.4 x10 2.7 x10 9.6 x10 67 modern processes (such as transfor- Coal 8.0 x 1017 1.7 x1021 2.9 x1015 6.1 x1019 277

mation of coal to gas) it is possible to 21 20 TOTAL 3.0 x10 3.3 x10 93 produce energy from coal in a less environmentally damaging way. And with more money and less haste, Global proven reserves and annual production of hydrocarbons in terms of volume (m3 gas under standard condition of 1 bar, 15 °C) and in terms of energy content. R/P the safety situation can also be is the ratio of reserve to annual production, giving the amount of years the known improved. reserves will still last if exploited at the current production rate. Source: BP statistical review (www..com)

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and take a long time from concept to production. A simple oil well costs around €1 million, but a Hydrocarbon facts deep-water well may be more than €100 million. A small production platform costs €1 billion. In the Estimated R/P: up to 93 years project in Cost per kWh: The cost depends enormously on the source. Canada, $45 billion has already Production costs range from a handful of dollars per barrel for easy been invested, and there are still oil in Saudi Arabia to tens of dollars per barrel for heavy oil in $50 billion to come by 2012. remote locations. Between the discovery of a reser- Risks: Pollution during transport and production; CO2 production voir and the first production, eight when used years can easily pass. So sharehold- Estimated research time: Research will be done for as long as these ers and politicians have to supply fuels exist, to make them cheaper, cleaner and more energy effi- time and money, but they generally cient, to extract a greater fraction of oil from a reservoir (e.g. by have little patience. If there is no enhanced oil recovery), and to be able to economically exploit short-term reason to invest, we will

BACKGROUND small reservoirs, too. therefore create a long-term energy shortage. · For many sites, poorly predictable political complications play a role. Therefore, it may not be possible to access the resources. have been found: those are the known · Processes to retrieve heavier oils There are many factors which play oil and gas regions, including our also require more energy, so less a role in finding and producing fossil own North Sea. Within these areas, energy will effectively be at our fuels, but the main ones are that the reservoirs are still being found, but disposal from these than from amount of hydrocarbons is finite and the really big ones are known, and it ‘easy’ oils. that the proven reserves should not is becoming increasingly difficult and · When the energy consumption, and be seen as a reserve barrel that we can costly to develop the new ones. The consequently its production, open at any moment: a lot of time and table on page 70 gives an overview of grows, the number of years we can money has to be invested before they the current proven reserves. There is still use the reserves decreases can be used. It is conceivable that considerable uncertainty in these (R/P). there will be production problems numbers, though, both of a technical · New projects that could add before the lack of reserves becomes (estimating the size of a reservoir is reserves require huge investments problematic. very difficult) and of a political nature (countries and companies can have all sorts of reasons to Public domain image; image source: Wikimedia Commons make the reserves look larger or smaller). According to this table, at the cur- rent consumption level we would still have 93 years ahead of us if we were to use all fossil energy. That sounds more reassuring than it is, for several reasons: · There is a large uncertainty in the number 93. It doesn’t mean that after exactly 93 years of wasting energy, time will suddenly be up – we are already starting to feel the effects of the fossil fuels running out. Figure from the original proposal by Hubbert in 1956

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Data source: www.inflationdata.com/inflation/Inflation_Rate/Historical_Oil_Prices_Table.asp 100 Oil price development since the 1940s 80

60

40 $/barrel

20

0 1940 1950 1960 1970 1980 1990 2000 2010

Year

Hubbert peak cessfully predicted the peak produc- passed the production per Based on an analysis of the cycle of tion rate of oil on the American conti- capita. discovery, development, investment nent for 1970. He made this predic- Finally, it should be noted that in infrastructure, more discoveries, tion in 1956. His theory can be hydrocarbons are not only used for and then slowly running out of applied to an individual oil field or a energy. Approximately one-tenth is reserves, Marion King Hubbert, a whole a country, and also worldwide. used in the (petro)chemical industry geoscientist who worked at the Shell Applying this method to our planet, to produce a huge range of products: research lab in Houston, Texas, devel- we should have reached this peak from plastics to solvents, drugs and oped a method of analysis which suc- point by now. If so, we have already detergents. Just like energy, these

Image courtesy of Vienna Leigh

Top world oil producers and consumers (thousands of barrels per day)

565 097 10 248 9 874 8 457 4 034 3 912 3 500 3 4222 9482 6702 6162 2 3532 2542 1742 Saudi Arabia

Russia Venezuela Japan

US Kuwait India

Iran Norway Germany

0 China Nigeria UK 210 08 2 2 820 20 68 1 7 7 565 2 1192 3642 400 5 007 2 8002 4561 7402 2141 9501 702 Mexico Brazil S. Korea

Canada Algeria France UAE Iraq Italy

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The technology may be dinosaurial, but fossil-fuel burning contin- ues to be an integral and increasingly costly part of our modern way of living, not least because of the rapid industrialisation of the most populous nations on Earth. Along with pharmaceuticals, oil is big business with massive sci- ence input. Van Dijk’s article can give science teachers a route into discussing some of the following issues with their classes. Students could consider the economics of how even relatively inaccessible fossil fuel reserves are worth extracting today. How much will a bar- rel of oil have to cost before exploiting the ‘hyperheavy’ reserves described is worth the hassle? Students could look at how the dis- tribution of hydrocarbon reserves across our planet has affected international relations, from both strategic and economic perspec- tives. And while the non-renewable nature of this resource is well known to most students, the fact that around one-tenth isn’t used as fuel at all is less appreciated. What arguments could the students develop to reduce consumption of fossil fuels to secure reserves of fossil feedstock for uses including ‘plastics, solvents, drugs and deter- gents’? The energy question will require a host of answers, and today’s science students may develop some of the solutions, as well as being made to live with a smaller hydrocarbon footprint in the future.

REVIEW Ian Francis, UK

fossiel maar (nog) niet uitgestorven. have become an essential part of our Nederlands Tijdschrift voor lives. In short, fortunately, there are Naturkunde 73 (7): 206-209 still fossil fuels, but concerning the R/P, we should not think of it as and has been republished online at Reasonably Problem-free but as www.kennislink.nl. It has been ResPite! translated and adapted for Science in School with the help of Roland References van Kerschaver, Jos de Graaf and Salvatore Accardi. Schätzing F (2006) The Swarm. Hodder & Stoughton (London, UK): ISBN- 13 978-0340895238 Menno van Dijk works for the flow Resources assurance department at the Shell For a full list of Science in School arti- technical centre in Amsterdam, the cles about energy, see: Netherlands. The article was written www.scienceinschool.org/energy on his own account, not in connection to his work. Acknowledgments The article was originally published in Dutch: van Dijk M (2007) Koolwater stoffen:

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