Oil shale

• 1. Introduction

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  Oil shale has been burning beneath human feet for longer than most civilizations have existed. Around 3000 BC, the people of Mesopotamia were already putting it to work, using what they called "rock oil" to bind the stones of roads and hold together architectural structures. That is not a metaphor for something ancient and irrelevant. It is the starting point of a story that runs directly into the present, into decisions about energy, climate, and the economics of desperation.

  Beneath the surface of more than 30 countries lies a resource so vast that a 2016 estimate placed the total world deposits at the equivalent of 6.05 trillion barrels of oil. By comparison, the world's proven conventional oil reserves at that time stood at roughly 1.7 trillion barrels. So oil shale, at least on paper, dwarfs what the world currently relies on.

  Yet only Estonia and China have built true industries around it. Brazil, Germany, and Russia use it to some extent. The rest of the world has largely tried and walked away. The question the rest of this documentary will answer is: why, and what does that mean for the future of energy?

• 2. What Oil Shale Actually Is

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  Adrian C. Hutton, a petrologist at the University of Wollongong, drew a line in the sand that geologists still argue about. He wrote that oil shale is not a "geological nor geochemically distinctive rock" but rather an "economic" term. In other words, it is defined by what people want from it, not by what it actually is.

  The rock contains kerogen, a solid mixture of organic chemical compounds that has not yet completed the transformation into petroleum. Heat and pressure would eventually do that job over geological time, but the kerogen in oil shale has not reached that point. Its maturation, as geologists put it, does not exceed early mesocatagenetic.

  The organic matter inside can come from a remarkable range of sources: algae, spores, pollen, plant cuticles, fragments of woody plants, and cellular debris from both aquatic and land organisms. Some deposits carry significant fossil material. Germany's Messel Pit, which holds oil shale, carries UNESCO World Heritage Site status because of its extraordinary fossil record.

  Kerogen in oil shale may also contain iron, vanadium, nickel, molybdenum, and uranium. The ratio of organic matter to mineral matter in commercial grades sits roughly between 0.75 to 5 and 1.5 to 5. That means the rock is mostly rock, with a valuable but minority share of organic material locked inside. The most commonly used classification system for oil shales was developed between 1987 and 1991 by Hutton himself, adapted from coal terminology, and groups deposits as terrestrial, lacustrine, or marine depending on where the original biomass settled.

• 3. A History of False Starts

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  Modern industrial mining of oil shale started in 1837 in Autun, France. Scotland, Germany, and several other countries followed. The products that drove the 19th-century industry were kerosene, lamp oil, and paraffin, each filling a gap in the supply of lighting fuel that the Industrial Revolution had created.

  Scottish production grew into a formidable operation. Around 1913, Scotland ran 120 oil shale works processing 3,332,000 tonnes of oil shale and generating around 2% of global petroleum production. The British Admiralty's need for reliable fleet fuel as war approached in Europe helped sustain that expansion, alongside the mass production of automobiles and the rising consumption of gasoline.

  After World War II, the economics shifted badly. Cheaper conventional petroleum undercut oil shale in most markets, and most national industries collapsed. The 1973 oil crisis briefly reversed that trend. World production of oil shale reached a peak of 46 million tonnes in 1980, then fell to roughly 16 million tonnes by 2000 as conventional oil prices dropped again.

  The most dramatic single moment in oil shale's troubled history came on the 2nd of May 1982. Exxon canceled its 5 billion dollar Colony Shale Oil Project near Parachute, Colorado, because of low oil prices and rising costs. More than 2,000 workers lost their jobs that day, a day some called "Black Sunday," and a wave of home foreclosures and small business bankruptcies followed in the surrounding communities. Four years later, President Ronald Reagan signed the Consolidated Omnibus Budget Reconciliation Act of 1985, which abolished the United States' Synthetic Liquid Fuels Program.

• 4. How the Rock Becomes Oil

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  The most common mining approaches are open-pit and strip mining, both of which remove the overlying material to reach deposits near the surface. Underground mining, by contrast, uses the room-and-pillar method, which takes less of the surface away but accesses less of the deposit.

  Once mined, the shale typically goes through pyrolysis, a chemical process triggered by heat. Temperatures between 450 degrees Celsius and 500 degrees Celsius cause the kerogen to break down into gas, condensable liquid, and solid residue. The process begins at around 300 degrees but accelerates significantly at higher temperatures. Cooling the vapor that pyrolysis produces separates the liquid shale oil from the combustible oil-shale gas.

  A newer category of methods performs this process underground, without mining the rock to the surface first. These in-situ techniques can in principle reach deeper deposits and extract more oil from a given area of land than surface processing can. Some in-situ approaches use explosives to fracture the deposit, creating pathways for gas to move through the rock. However, most in-situ methods remain experimental.

  By 2006, only four retorting technologies had reached commercial use: Kiviter, Galoter, Fushun, and Petrosix. Hundreds of patents for retorting technologies exist, but only a few dozen have been tested in practice.

• 5. The Estonian Exception

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  Roughly 80% of all oil shale extracted globally, as of the most recent figures available, comes from Estonia, a country of fewer than two million people on the Baltic coast. The reason is infrastructure: Estonia runs several oil-shale-fired power plants with a combined installed capacity of 2,967 megawatts. In 2016, oil shale produced 90.3% of Estonia's electrical generation.

  For comparison, China's oil shale power capacity stood at 12 megawatts, and Germany's at 9.9 megawatts. A 470 megawatt oil shale plant in Jordan was under construction as of 2020. Israel, Romania, and Russia each ran oil-shale-fired plants in the past but shut them down or converted them to natural gas.

  The global picture in 2008, as recorded by the World Energy Council, showed total production of shale oil from oil shale at 930,000 tonnes, equal to about 17,700 barrels per day. China produced 375,000 tonnes of that, Estonia 355,000 tonnes, and Brazil 200,000 tonnes. Meanwhile, conventional oil and natural gas liquids production in the same year amounted to 3.95 billion tonnes, or 82.1 million barrels per day. Oil shale, globally, was producing a fraction of a fraction of the world's liquid fuel supply.

  Estonia's sustained commitment traces back to the Soviet era and the country's lack of conventional fossil fuel resources. China's smaller but growing industry reflects both domestic energy security concerns and the existence of significant deposits accessible enough to exploit.

• 6. The Economics of Barely Breaking Even

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  A 2005 analysis by the RAND Corporation calculated that producing a barrel of oil at a surface retorting complex in the United States would cost between 70 and 95 US dollars, expressed in 2005 values. That figure assumed a mine, a retorting plant, an upgrading facility, support utilities, and spent shale reclamation all running together.

  RAND also modeled how those costs might fall over time. After a hypothetical facility produced its first 500 million barrels, the analysis projected a cost reduction of 35 to 70 percent, potentially bringing the price down to 35 to 48 dollars per barrel within 12 years of starting commercial production. After reaching 1 billion barrels produced, the costs might fall further to 30 to 40 dollars per barrel.

  A 1972 article in the journal Pétrole Informations compared oil shale unfavorably with coal liquefaction. Coal liquefaction, it argued, cost less, produced more oil, and caused fewer environmental harms. The numbers cited were stark: coal could yield 650 liters of oil per tonne of feedstock, while oil shale yielded only about 150 liters per tonne.

  A concept called energy return on investment, or EROI, provides another measure of viability. A 1984 study estimated the EROI of known oil shale deposits at between 0.7 and 13.3. The World Energy Outlook 2010 estimated that surface retorting typically achieves an EROI of 4 to 5, while in-situ processing may reach as low as 2. An EROI below 1 means the process consumes more energy than it produces.

• 7. Environmental Costs and Complications

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  Above-ground retorting requires between one and five barrels of water for every barrel of shale oil produced. A 2008 programmatic environmental impact statement issued by the U.S. Bureau of Land Management found that surface mining and retort operations generate 2 to 10 gallons of waste water per short ton of processed oil shale. In-situ processing uses roughly one-tenth as much water, but carries its own risks.

  Water contamination from oil shale processing includes oxygen and nitrogen heterocyclic hydrocarbons. Among the most commonly detected are quinoline derivatives, pyridine, and various alkyl homologues of pyridine including picoline and lutidine. These concerns become particularly sharp in arid regions: plans to expand oil shale extraction in the western United States and in Israel's Negev Desert have both drawn attention to the tension between resource extraction and water scarcity.

  Greenhouse gas emissions from oil shale processing and combustion exceed those from conventional fossil fuels, according to environmental organizations. Greenpeace and other activists have mounted sustained campaigns against the industry. One outcome: Queensland Energy Resources placed the proposed Stuart Oil Shale Project in Australia on hold in 2004.

  Acid drainage, erosion, mercury introduction into surface and groundwater, sulfur-gas emissions, and particulates from processing and transport round out the list of environmental concerns. Carbon capture and storage technologies may reduce some of those impacts in the future, but their deployment on oil shale operations remains a future prospect rather than a current reality.

• 8. Beyond Earth

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  Halley's Comet yielded a surprise in 1986, when a probe flew through its tail and detected hydrocarbons corresponding to those found in high-grade oil shale. Comets, it turns out, can carry massive amounts of organic material almost identical in composition to oil shale, with some containing the equivalent of cubic kilometers of such material mixed with other substances.

  That finding reframes oil shale from a purely terrestrial curiosity into something connected to the chemistry of the solar system itself. The organic compounds that make oil shale potentially valuable were not generated only by life on Earth. They arise through processes operating across space, accumulating in bodies that eventually collide with planets.

  Back on Earth, the question of whether oil shale will ever realize its scale remains genuinely open. The deposits in the Green River Formation alone, covering portions of Colorado, Utah, and Wyoming, represent more than 80% of the United States' share of global oil shale resources, and more than 70% of that sits on land owned or managed by the federal government. What happens to those deposits will depend less on geology and more on the price of oil, the cost of carbon, and decisions that governments and markets have not yet made.