Published: 01/28/2014
Published: 01/28/2014
Wintershall Holding GmbH drilled a well in Libya that produced with a water cut higher than 90%. Previous reservoir-saturation and production-logging testing results showed that the water rose to reach the top perforation; as much as 70% of the total water production was found to come from the lower perforation. Moveable oil was detected at the upper perforation interval, and production logging proved that the oil did not significantly contribute to the flow due to the high water cut.
The operator sought a solution that could be used to
Schlumberger proposed combining the RSTPro reservoir saturation tool and PLT data to select the optimal remedial action. Using reservoir saturation measurements along with the production logging data helped ensure data consistency and reliability. This helped Wintershall be certain that no moveable oil was left in the formation, enabling them to confidently plug back the water-entry zone. Integrating the information obtained during reservoir and borehole monitoring would be helpful to selecting the proper remedial strategy and improving well production.
Wintershall isolated the lower perforation to optimize oil production and reduce water cut. Doing so increased oil production by 843 bbl/d and reduced water cut by 25%. To ensure isolation of the wellbore and its vicinity, a mechanical plug-back tool (MPBT) was set across the tar mat, which proved effective in improving production from the remaining perforations. Additionally, the reduced water cut improved vertical-lift performance, optimizing gas-lift allocation at both well and field scales.
“We identified the current saturation and inflow profiles, which led to the decision to shut off the watered-out zone. This successfully reduced water cut and increased oil production rate. The freed-up gas lift volume was reallocated to other oil producers as part of our continuous production optimization.”
Emad Kaawan, Senior Reservoir Engineer Wintershall Holding GmbH
Challenge: Pinpoint the well interval that produced with a high water cut and identify opportunities for remedial intervention.
Solution: Perform petrophysical evaluation of integrated data measured by the RSTPro reservoir saturation tool and production-logging tools (PLTs).
Results: Isolated the proper perforation interval, increasing oil production by 843 bbl/d and reducing water cut by 25%.
