Geology · Exploration
Fluid Contacts
Inside the trap the fluids separate by density: gas on top, oil in the middle and water at the bottom.
What it does
The gas oil and oil water contacts set the size of each zone and the volumes in place. They are usually close to horizontal with a gradual transition zone, and production disturbs them.
Basics
| Order | Gas, oil, water by density |
| Contacts | Gas oil (GOC) and oil water (OWC) |
| Found with | Fluid samples and tests, logs, cores, pressure profiles |
Common failures
- Contact placed too deep, which overstates the oil in place
Troubleshooting
- Symptom
- Early water in the first producers
- Likely cause
- Oil water contact shallower than assumed
- What to check
- Check contacts with pressure versus depth data and test results