This mud yields three million barrels of oil daily. It lies deep under West Texas. Wells reach it, then turn sideways and run for miles inside it. The mud itself once settled on a sea floor.
This is the Permian Basin, in West Texas and New Mexico. Oil has come out of it for about a hundred years. Pump jacks nod across the scrub. Since twenty twenty-two, about six thousand new sideways wells have been finished here every year. That is about sixteen a day.
Under the scrub, the rock lies in stacked layers, like a cake. Several of them are shale, which is mud pressed into rock. The deepest and thickest is a dark band that drillers call the Wolfcamp. This piece of it came up from more than a mile and a half down. That is deeper than six Empire State Buildings, one on top of another.
But this rock was once soft mud, at the bottom of a sea. At our calendar's date, West Texas sat near the equator. It lay on the western edge of a supercontinent called Pangaea. An arm of the sea reached in over it. Under that water lay two deep basins, the Delaware and the Midland. A shallow, raised platform split them.
Shallow shelves of lime and reef ringed both basins. Down on the deep floor, the water held little oxygen. Fine mud drifted down, with the remains of tiny sea life. Nothing burrowed into it. So it built up in thin, flat layers, rich in that dead life.
Every so often, the edge of a shelf gave way. An underwater avalanche of lime mud and silt slid down the slope and spread across the floor. Geologists call what it leaves a turbidite. Then the slow fall of mud began again on top.
Far away, volcanoes erupted. Their ash drifted over the sea and sank, leaving thin pale layers in the mud. Those layers can be dated. In the Wolfcamp's two richest parts, they give the date on our calendar.
More rock piled on top, thousands of feet of it. Buried deep, the mud grew hot. Slowly, the remains of that sea life turned into oil. Much of the oil never left. It stayed in the same rock that made it. Geologists call that a source rock, and here it also holds the oil.
But that rock is tight. Oil barely moves through it on its own. For decades, wells went straight down and took only what flowed from looser beds.
So drillers changed the method. They turned their wells sideways inside the band. Then they cracked the rock open with fluid at high pressure, stretch by stretch. That is fracking. In two thousand and five, a new Wolfcamp well's early flow averaged about thirty-seven barrels a day. By twenty eighteen it was over five hundred. That is fourteen barrels where there had been one.
And the sideways part of each well, the lateral, kept growing. Back then, a Wolfcamp lateral ran about half a mile. By twenty eighteen, it was more than a mile and a half. In twenty twenty-five, the average new well here ran about two miles sideways. That is about thirty football fields, end to end. Some now pass three miles. And the drill must stay inside a layer a few hundred feet thick.
The oil came fast. In January two thousand and ten, the whole Permian Basin made under nine hundred thousand barrels a day. By twenty twenty-five it made six point six million. That is more than seven times as much. It is now nearly half of all the crude oil America pumps.
In twenty sixteen, government geologists sized up just the Midland part of the Wolfcamp. They judged it held about twenty billion barrels not yet found, that today's methods could recover. At the time, that was the most oil of its kind they had ever assessed in America.
Of the basin's oil layers, the Wolfcamp yields the most. In twenty twenty-four it gave three point four million barrels a day. That matched every other shale field in America outside the Permian, put together. So mud from a Permian sea floor is now the biggest single source of America's shale oil.
America as a whole now pumps more crude oil than any country ever has. In twenty twenty-five it averaged thirteen point six million barrels a day. It has led the world every year since twenty eighteen.
This mud yields three million barrels of oil daily. Most of it began as tiny sea life, sinking through dark water.
