* Shallow drilling: In some cases, oil can be found relatively close to the surface, within a few hundred feet. This is common in onshore fields with sedimentary rock formations.
* Average drilling depth: The average depth for oil wells is around 1 to 3 miles (1.6 to 4.8 kilometers).
* Deepwater drilling: In offshore locations, where oil reserves are often found deeper beneath the ocean floor, drilling depths can reach 5 miles (8 kilometers) or more.
* Ultra-deep drilling: The deepest oil wells drilled to date have reached depths of over 8 miles (13 kilometers).
It's important to note that drilling depth is not a reliable indicator of the amount of oil available. The quantity and quality of oil are influenced by various factors like the size and porosity of the rock formations, the geological structure, and the pressure within the reservoir.
While oil rigs drill deep into the Earth's crust, they remain far from reaching the Earth's mantle. The Mohorovičić discontinuity (Moho), which marks the boundary between the crust and the mantle, typically lies around 19 miles (30 kilometers) beneath the surface.
