Short-term Pressure Transient Analysis performed in open-hole well with wireline pressure gauge.
Can be complemented by downhole fluid sampling with the same toolstring.
The key objective is to measure formation pressure and permeability at specified downhole locations.
It usually does not reach the fully developed radial flow to assess the reservoir thickness.
Below is the table summary of typical WFT Readings, the typical diagnostics and typical recommendations.
| WFT Readings | Diagnostics | Typical Recommendations |
|---|---|---|
| Pressure Gradient Change | Either OGC or FWL | Pick OGC/FWL |
| The pressure of some Hydrocarbon Beddings stay at initial pressure while most others deplete | The beddings are not depleted | The overlooked Hydrocarbon Beddings should be connected to production |
| The pressure of some Hydrocarbon Beddings is much lower than most others | The layers deplete faster | Revise geological model in terms of connectivity of Hydrocarbon Beddings Arrange pressure support to depleted Hydrocarbon Beddings |
| The pressure of some Hydrocarbon Beddings is much higher than most others | The Hydrocarbon Beddings are getting a better pressure support from aquifer or gas cap or water injection | Revise geological model in terms of connectivity of Hydrocarbon Beddings Restrict injection in these Hydrocarbon Beddings |
| The pressure in overlying/underlying water reservoir is regular | The area around the new well was most probably not facing the thief production/injection | The expectations from the current reservoir model check out ! |
| The pressure in overlying/underlying water reservoir is lower than that of oil/gas pay | The area around the new well was most probably subject to thief production | Check which offset well is having a thief production and shut it off |
| The pressure in overlying/underlying water reservoir is higher than that of oil/gas pay | The area around the new well was most probably subject to thief injection | Check which offset well is having a thief injection and shut it off |
See Also
Petroleum Industry / Upstream / Subsurface E&P Disciplines / Well Testing / Subsurface Well Testing / Open-Hole Well Test
[ Well & Reservoir Surveillance ]