Geology · Exploration
Reservoir Rock
A body of rock with enough porosity to store fluids and enough permeability to let them flow to a well.
What it does
It holds the oil and gas. Porosity sets how much it can store; permeability sets how fast it can deliver. Sedimentary rocks such as sandstones and carbonates are the most common reservoirs.
Basics
| Key properties | Porosity and permeability |
| Most common | Sedimentary rocks |
| Measured by | Cores and well logs |
Common failures
- Rock with porosity but very low permeability, so it holds oil that will not flow without stimulation
Troubleshooting
- Symptom
- Oil in the logs but the test flows little
- Likely cause
- Low permeability or damage near the wellbore
- What to check
- Check core permeability and consider stimulation