by Sonia Shah
Just over a fifth of the world’s carbon has been entombed this way, resting in the earth’s crust.25 Before people started to unearth oil, geologists from the U.S. Geological Survey figured around 2 trillion barrels26 of carbon-rich oil were secreted underground. By unleashing oil from its silent tomb and burning it, we send the carbon locked in oil’s hydrocarbons back into the atmosphere. During the last ice age, the carbon blanket in the atmosphere was only half as thick as it is today. Now, as more carbon wafts up to weave itself into that blanket, it thickens, keeping the planet warmer and warmer.27
If the world’s oil all resided underground in deeply buried layers of shale, that carbon-rich, plankton-blessed rock, people would have never known about it. Part of the story of oil is how it moves and gets trapped in places where humans can get at it.
Oily shale and mudstone source rocks are full of oil, it is true, but it is practically impossible to get the oil out of that sludgy rock, as it is too dense. Of course, people have tried. There’s a massive amount of oily shale in Colorado, deposited by a gigantic lake that covered parts of Utah, Colorado, and Wyoming more than 60 million years ago. Today, the lively lake is gone, but its oily sediments remain unburied, what one petroleum geologist dubbed an “unborn oilfield.”
Chunks of Colorado’s rich shale burn almost like coal, as railroad workers discovered when they used the rocks to encircle their campfire. There are tons of oil in that shale; if people could get it out, the amount would be roughly equal to all the world’s conventional oil.28
In the 1980s, Exxon, desperate for a new source of oil, spent over $1 billion trying to get oil out of Colorado shale, ultimately abandoning the project when the price tag zoomed to $8 billion for a measly fifty thousand barrels of oil a day.29 To deliver the unborn oil, the company would have to mine the rock, crush it, and then heat it, producing more waste than would fit into the hole they dug to mine the rock to begin with.30 The procedure is also highly polluting, releasing three to six times more greenhouse gases into the atmosphere than conventional oil production, according to Greenpeace, which has campaigned against shale oil development.31
Instead, people look for the places where geological forces have moved the oil out of the shale into a rock more suitable for drilling. That happens when the shale layers get squeezed, as the constantly moving plates start pushing and pulling on the rock. Millions of years of such pressure on the rocks squeezes the oil out, buoyed by its own relative lightness. A migrating stream of oil can travel long distances, sometimes more than a hundred miles.32 Where does it go? Crushed under tremendous pressure, under thousands of feet of shifting layers of rock, the oil searches for the easiest route out, through the tiny fractures and pore spaces in the rocks that suffocate it. It is a tortuous path, twisting and turning amid the miniscule gaps, aiming for the sun.33
The rock layers are heavy, but not all of them are very dense. Say the migrating oil encountered a rock made from a buried beach of white fine sand that had fused together into a porous sandstone. Even under great pressure, up to a quarter of the volume of that fine-sand-beach-turned-rock will be empty space. The even-sized sand grains stack upon each other like a pile of ping-pong balls, leaving plenty of room between them. Or say the traveling oil met up with limestone that had been lifted back up to the sea and exposed to fresh water again. The acidic water would have dissolved passageways for itself as it trickled through the rock, leaving behind a network of tiny connected veins. Or it could run into a buried reef, with its countless tubes and passageways created by living creatures, likewise riddled with connecting holes.34 Such a porous rock will start to soak up the oil like a sponge. The oil-saturated sandstone or limestone becomes what is known as a “reservoir rock.”35
The oil-soaked sandstone, this oily sponge, must also have a lid on it. Otherwise, the oil will keep on trickling out, dispersing itself over vast areas and becoming so spread out it will be impossible to collect. Something impermeable must sit on top of the sandstone, forming a kind of seal for the migrating oil. The very structure of the rocks may change in a way that could trap the seeping oils. An impermeable rock layer, perhaps more shale through which water and oil won’t flow, might be shifted into place above a stream of migrating oil, curling over it like an overturned soup bowl. Over millions of years, those curved layers (called “anticlines” by geologists) can capture the oil in the porous rock layer below. Natural gas from deeper layers may drift upwards and also become trapped above the oil, along with water migrating amidst the rock.36
Sometimes, if there are multiple layers of shale, sandstone, and salt, over and over again, the salt will tend to float upwards, because it is lighter than the other layers above it. The bulging salt layers will push up the sedimentary layers above them, forming a kind of dome. When the shale’s oil is squeezed into the sandstone, the dome will bar its further movement. Anticlines formed by salt domes are excellent traps for oil.37
However, years of erosion can occasionally wear down the rocks that entomb such oil-filled traps, bringing an entire oilfield to the surface. It happened in Alberta, Canada. All of the light oil and gas quickly dispersed into the air, leaving behind only a tarry, oily sludge—the infamous Alberta tar sands, a dead oilfield to shale’s unborn one.38
A worthwhile oil reserve, then, must have thick layers of oil-rich source rock, porous reservoir rock, and an impermeable “cap” rock, all in the right position to form a trap, and pressurized and heated to just the right conditions. It is an elaborate sequence of events that takes place over millions of years, enlisting the carcasses of billions of creatures, the rising and falling of seas, and the shifting of tons of rock. All told, earth has given birth to 2 trillion barrels of oil, a labor that appears as improbable as it is quite awesome in scale.
Kenneth Deffeyes is a retired professor of geology from Princeton University, a cheery rotund man who grew up in the oil patch. His fondness for the oil he’s spent his life scrutinizing, for Shell, Princeton, and the various oil companies for whom he’s consulted, compels him to roll down his car window when he drives by a refinery, in order to take a deep breath. The story of oil’s unlikely ancestry appears to fill him with glee. “If any one of these conditions is missing, tough luck. If one of them is only partially developed, you get a small oilfield,” he says. “The chances of rolling a seven with the dice six times in a row is rather small!”
“So it does look like accidents on the highway, where you get a lot of little fender benders and a few of these giant pileups with forty cars in it,” he goes on. “Well, the Middle East is a giant freeway with a forty-car pileup. It is a place where everything was just right.”39
Around 180 million years ago, a warm shallow sea washed just above the equator, splitting the single continent that had previously covered the earth into two major subcontinents, Laurasia and Gondwanaland. Ancient reef-building organisms slowly built their wondrous reefs in this sea. It’s been named the Tethys, as in the mythical daughter of the Greek god of heaven and the goddess of earth who bore three thousand ocean nymphs and all the river gods.40 The Tethys sent its warm, equatorial ocean currents and its diversity of shelly and fishy Jurassic and Cretaceous life flowing all the way around the globe.41 Dolphin-like reptiles and sea-going crocodiles cruised its waters, with forty-foot plesiosaurs as kings of its underworld.
Up on the land, dinosaurs stomped amidst the spiky, pineapple-like cycads. Our ancestors among them, the early mammals, were just tiny vermin, “the cockroaches of their day,” as paleontologist Michael Benton put it, although we would claim the Tethys’ products of that time as our own, much later.42
For more than 100 million years, the Tethys sea floor collected rich layers of sediments, as abandoned shells, plankton, and other organic sediments descended gently on the seabed. Then the seas lapping up on the shore receded, leaving behind a salty crust on top of the organic layers. Sands rushed in and buried the salts. This happened over and over again, leaving thick sequences of source rocks, reservo
ir rocks, and evaporites. Slowly, the layers began to sink, which compressed them into that essence of ancient life, oil.43 Those sunken sea-bottoms of the Tethys now contain about two-thirds of the world’s oil.44
Much of it got trapped in the Middle East. Around 15 million years ago, the sea-floor under the Tethys was consumed into the earth, its sediments scraping up onto the surface. The continents of Arabia and Asia that once lined its shores collided. The impact smashed the land, throwing up the soaring, snow-capped Zagros mountains, which lie in today’s southwestern Iran. The southwest side of the mountains was left with a huge depression, the Mesopotamian basin, one of the largest sedimentary basins in the world, where the organic-rich sediments of the now-vanished Tethys came to rest. Meanwhile, the stress of the massive continental smash rippled, folded, and faulted the rock, squeezing the oil out of its deeply buried layers. The oil started to migrate. The long-gone beaches and reefs of the Tethys, buried and turned to sandstone and limestone, sucked up the migrating oils. In some places the salty layers sealed them in salt domes; in others, the stresses folded the sediments, forming huge anticlines that trapped the oil.45
With trillions of barrels of crude oil migrating through the twisted crevices in the rocks underfoot, it isn’t surprising that some of it managed to find its way to the surface. Some of it would simply vanish, evaporated into thin air. Some would linger, collecting in muddy pools, trickling down cliff faces, or burbling up under rivers, creeks, and seas.46 Bacteria would feed on the rich hydrocarbons, swirling in black puddles. In tropical seas, bacteria would crowd hungrily around the warm seeps of oil clouding the water, forming mounds later colonized by reef-building creatures.47
Newly evolved humans walked out of their ancestral Africa, using the land bridge formed by the crash between Africa and Asia that had swallowed the Tethys, and settled in the fertile valley between the Tigris and Euphrates Rivers. It wasn’t long before they found the remains of that ancient rich sea. Its oils were slowly oozing out onto the fertile soils basking in the sun.48
The first thing they noticed was the otherworldly sound. Natural gas percolated through the fissures under the ground, sending up a ghostly echo. It sounded to the people above, craning their ears to the earth, like the voices of the gods of the underworld. They found oily pools and gathered some of the strange liquid, divining the future from the shapes that the liquid would make when thrown into water. Soon the stuff was put to more practical use, gummed onto boats and houses to create watertight seals. The seeps were so plentiful that the Mesopotamians were able to dig up over fifty thousand kilograms of solid petroleum sludge. They found some light liquid oil as well, but deemed it useless. Pliny declared it too combustible and therefore “quite unfit for use.”49
The Persians filled pots and other vessels with a stinky volatile mix of sulfur and crude oil, which they’d set afire and then hurl at their enemies. The ancient Greeks greased their arrows and lances with petroleum to make flaming torches. By the seventh century AD, the Byzantine Empire had perfected a liquid combustible made primarily of boiled petroleum called “Greek Fire,” which set hearts trembling throughout the region for centuries.50 They used the combustible mixture to fend off waves of attacks from Muslims, Western Europeans, and Russians. Soldiers cavorted with long tubes full of crude, which they would light and throw into their enemies’ faces. Muslim states used incendiary warfare—weapons made fiery with oil—to fend off Christian invaders.51
Tethys’ hydrocarbons inspired godliness as well as aggression. In Baku, the ancient Persian city that is now the capital of Azerbaijan, some of the oil escaped with gusts of natural gas and burned continuously. The Persians worshipped those miraculous everlasting fires. The prophet Zoroaster, born in Azerbaijan or Iran more than two thousand years ago, created a new religion based on fire worship, which flourished as the official religion of Persia for over four hundred years. His followers, the Zoroastrians, tended perpetual fires in their temples. When Muslim Arabs conquered Persia in the seventh century, extinguishing the eternal flames, the Zoroastrians fled to India. Today, 270,000 Zoroastrians in India and Iran pray to the sacred fire five times a day, a modern testament to an ancient wonder, pure combustion spurting out of the belly of the earth.52
Oil has become so enmeshed in our lives that, like the air we breathe and the ground underfoot, many of us barely notice much about it, aside from a slightly pungent odor at the pump during the weekly five-minute ritual of refueling the car. But oil, as part of our planet, its legacy of life, and its capacity for change, is not something we can so easily separate from our own organic earthbound selves, pouring it into our machines at arm’s length, noses held.
The way oil is created, its ancient pedigree, its tortuous journey to the places in the earth where we can find it, its elaborate chemistry—all of this makes it precious. Yet, it has rarely been treated as such. Once we encountered oil, we wallowed in it, consuming crude about one hundred thousand times faster than it could possibly accumulate again.53
CHAPTER ONE
The Eclipse of Coal
BY THE MID - 1500S, England’s forests were dwindling. People needed to feed their fires and they turned to a strange, fiery black rock that they clawed out of the ground. They didn’t know it at the time, but the rich rocks they found were the ancient condensed remains of ferns and other plants that had rotted in swamps eons before: coal. Burning it wasn’t a great option. The black coals reminded them of the black swellings of bubonic plague. The smoke made them sick. Extracting coal was time-consuming, dangerous, and inconvenient. The mines held poisonous and explosive gases, and were apt to unexpectedly fill with water. But it was better than the alternative: freezing to death among the denuded hills of England.
And so, coal was dug out of the ground to feed Britain’s fires, coating the cities with a thick layer of grime and filling the skies with low-hanging dark clouds. By the 1700s, the coal that ran in shallow veins close to the earth’s surface was gone. They’d have to dig deeper to get more, risking even worse flooding and explosions.1
Continuing to rely on such a difficult, costly fuel source would be risky, possibly even foolhardy. The amount of energy needed to pump the water out of those deep holes that burrowed beneath the water table might be equal to, or even greater than, the amount of energy that the lumps of coal that came out of the ground could pay back.2 Yet coal was already a business worth fighting for. Mine-owners calculated that they could still profit from bigger and deeper mines, even if they had to foot the bill for more workers and more machines, as long as they could recoup their investments by selling even more coal.
In other words, the more depleted the coal became, the more trouble it would be to get more out and, at the same time, the more coal they’d have to sell to make it all worthwhile. Yet the topsyturvy formula worked. By consolidating, hiring more workers, and attracting greater investment, coal mining soon became one of the biggest, most capital-intensive industries in Britain.
In 1712 the steam engine was invented and quickly employed to drain the water out of ever-deeper coal mines. The steam engine, “the most wonderful invention which human ingenuity had yet produced,” wrote historians, bestowed “the art of converting fuel into useful power for the benefit and convenience of humanity.”3 The additional coal made accessible by the steam engine was used, in part, to fuel the steam engines and the fires that smelted the iron to make the engines. It was a self-sustaining cycle that allowed both coal production and iron production to intensify, driving the price of both down. Soon, the industrial revolution—that frenzied partnership among iron, steel, and coal—was banging along. Britain, with its huge coal reserves, and its formidable Navy kept honed by accompanying the coal convoys down the English coast, sat at the very top of it.
Coal bestowed power in the eighteenth and nineteenth centuries, but it came at a price. Coal’s black smoke was so thick that it could be seen hovering over English cities from miles away, in some cases blocking the sun’s rays entir
ely. Londoners, squinting by their sooty windows, switched on their lamps to read the morning papers. Children toiled in the coal-fired factories, and even worse, in the dank, toxic coal mines themselves. “For watching the doors the smallest children are usually employed,” noted economist Friedrich Engels, “who thus pass twelve hours daily, in the dark, alone, sitting usually in damp passages without even having work enough to save them from the stupefying, brutalizing tedium of doing nothing.” Children dragged themselves homewards after their long shifts in the mines so tired that many were found, hours later, asleep on the road.4 Deprived of sunlight, subject to poisoned air and explosions, they died in droves. Most of the poor in mid-nineteenth-century Manchester didn’t survive to see their eighteenth birthdays. Those who did aged prematurely. Some of the tragedies that befell coal workers were hidden, for a time, by coal-mine owners who conspired with local newspapers to censor coverage of mine explosions.
Nevertheless, London was affectionately dubbed “The Big Smoke,” a smog-shrouded city that Lord Byron romantically described as “a wilderness of steeples peeping on tiptoe through their sea-coal canopy.”5 Painters such as James Abbott McNeill Whistler, Joseph Mallord William Turner, and Claude Monet captured the city’s foggy phantasmagoria, and Charles Dickens wrote of coal’s “soft, black drizzle.” Jack the Ripper stalked his prey under cover of coal’s thick brown haze.6
Across the Atlantic, a different story was unfolding. People found tons of black coal, but they also found something else, a liquid fuel that would slowly gain in popularity until it overtook coal altogether.
By the 1850s, people in northwestern Pennsylvania had noticed the black grease floating on top of their creeks and springs. Skimming it off the top, or soaking their rags in the oily waters, they used the liquid for the first thing that would come to mind in those rough days: to try to ward off the bewildering array of illnesses that plagued them. At the time, cholera, yellow fever, influenza, and smallpox epidemics ravaged the North American populace. Some entrepreneurial types started selling the oil under the name “Seneca Oil,” as a cure for worms, deafness, toothaches, and dropsy.
