Table 3
Well test schedule and fluids composition.
| Water injection | Tracer injection | Water injection | Shut-in | Production | |
|---|---|---|---|---|---|
| Duration (days) | 10 | 0.5 | 1.5 | 3 | 5 |
| Cumulative duration (days) | 10 | 10.5 | 12 | 15 | 20 |
| Flow rate |
|
|
|
– |
|
| Aqueous composition | – |
 ppm |
– | – | – |
| Comment | Waterflood leading to a residual (immobile) oil saturation state S orw in the near wellbore region | Inert tracer and ester injection; ester partition between water and oil; small amount of alcohol generated | Ester pushed 5 m away from the well; small amount of generated alcohol is pushed downstream the ester | Significant amount of alcohol generated from ester degradation | Recovery of ester and tracer; production of alcohol; delay between alcohol and ester |