Well · Exploration
Wireline Logging Unit
A truck with a winch and armored cable that lowers measuring tools into the open hole and records the data as they come up.
What it does
The winch runs the tool string to total depth and logs upward, with an encoder tracking depth. Repeat passes check data quality. The logs confirm hydrocarbons, reservoir quality and seal, and tie the well to the seismic.
Basics
| Equipment | Winch, armored cable, depth encoder |
| Direction | Logs from total depth upward |
| Quality | Repeat passes for depth matching |
Common failures
- Depth mismatch between runs, so logs and cores do not line up
Troubleshooting
- Symptom
- Logs offset from the core depths
- Likely cause
- Cable stretch or encoder error
- What to check
- Correlate to a marker and apply a depth shift