R. R. Rajan and P. Delaney
ABSTRACT
We have shown here a reconciliation of water saturation from logs and capillary pressure data in the Fateh Thamama reservoir, offshore Dubai. These saturations helped explain apparently anomalous production performance from some of the wells in the reservoir. Also outlined is a method to infer formation wettability from log saturations and RFT/DST pressure measurements.
Reconciled water saturations from revised log analysis and laboratory capillary pressure measurements are presented with supporting field production data. These saturations are in agreement with high oil production rates seen in some of the wells that were previously considered to be “wet’ from initial log analysis. The technique to infer formation wettability from logs and RFT data indicates that the formation is neutrally wet, which was also confirmed by laboratory wettability measurements.
As a result of this study, the original oil in place was revised upwards by 40 percent. Potential areas were identified for future infill drilling. In addition, the new saturation profiles became the basis for modelling studies. The in situ method to infer wettability from logs and RFT data can help in quickly assessing the formation wettability, and even help validate laboratory data.