A sandstone, opened up

Pore Lab

This cube is a few grains of reservoir rock, magnified. Three questions run through it:

1. How much space? Porosity is the room between the grains.
2. How much of it is hydrocarbon? Water clings to the grains; oil or gas sits in the pore centres.
3. How easily does it flow? Watch the streaks. Narrow pore throats slow them far more than lost porosity does.

Try Grain size: fine and coarse rock can hold the same amount of oil, but it flows at very different rates. Then open Slice and drag the glowing plane through the rock.