The Permian Basin is a sprawling sedimentary basin covering roughly 75,000 square miles across West Texas and southeastern New Mexico. It is the most prolific oil-producing region in the United States, accounting for around 44% of all US drilling rigs in recent years. Unlike a single reservoir, the Permian is a stack of productive layers laid down over hundreds of millions of years, which lets operators target many "benches" from a single drilling pad.
| Key fact | Detail |
|---|---|
| Location | West Texas & SE New Mexico |
| Produces | Oil & natural gas (mostly tight/unconventional) |
| Reservoir type | Unconventional, ~85% horizontal wells |
| Sub-basins | Delaware (west), Midland (east) |
| Key formations | Wolfcamp, Spraberry, Bone Spring |
Delaware and Midland sub-basins
The Permian is split into two main producing sub-basins by the Central Basin Platform, a structural high running down the middle. To the west lies the Delaware Basin, and to the east the Midland Basin. Both are deep, thick troughs filled with organic-rich shale and tight sandstone, but they differ in depth, pressure and the specific intervals operators chase.
Because the productive rock is "stacked," a single section of land may hold a dozen or more economic targets layered on top of one another. This vertical stacking — combined with horizontal drilling and multi-stage hydraulic fracturing — is what makes the Permian so capital-efficient compared with conventional plays.
Key formations: Wolfcamp, Spraberry, Bone Spring
The headline reservoirs are the Wolfcamp (subdivided into benches A through D), the Spraberry, and the Bone Spring. Together these "tight oil" intervals dominate Permian output. The combined Spraberry, Wolfcamp and Bone Spring play produced roughly 5.7 million barrels of oil per day and about 20.8 billion cubic feet of gas per day as of late 2025.
About 85% of Permian wells are now drilled horizontally, allowing a single wellbore to contact thousands of feet of oil-bearing rock within a thin "bench."
The Permian's scale, infrastructure and stacked pay continue to make it the backbone of US crude supply — and a benchmark for how unconventional resource plays are developed worldwide.
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Frequently asked
The Permian Basin covers roughly 75,000 square miles across West Texas and southeastern New Mexico. Major operating hubs include Midland and Odessa, Texas.
The Delaware Basin lies to the west and the Midland Basin to the east, separated by the Central Basin Platform — a structural high running down the middle of the play.
The Permian holds many oil-bearing layers, or benches, piled vertically. Operators can target multiple formations such as the Wolfcamp, Spraberry and Bone Spring from a single drilling pad.