Using Reservoir Saturation Monitoring and Production Logging to Improve Waterflood Sweep Efficiency in the Badri/Morgan Complex

By

Neil C Hewitt¹, Trevor Runge¹, Gamal Ragab Gaafar²

(1) British Petroleum, Cairo, Egypt (2) GUPCO, Cairo, Egypt

 Badri and El Morgan are a side-by-side pair of giant reservoirs located offshore in the Gulf of Suez in Egypt. Production began in 1967 with startup of El Morgan and together the reservoirs have produced 1.53 billion barrels. The complex still accounts for 26% of the total daily production of the operator, Gupco.

Recovery factor varies significantly within the complex. The thick, well connected, well waterflooded sand layers in El Morgan appear to have reached as high as 70% recovery, exceeding the predicted ‘ultimate’ field recovery of 55 percent. However, the thinner, more faulted, less efficiently waterflooded areas have only reached an average of 35% recovery. As the average watercut is now 89 percent, cost of water handling is becoming a determining factor in the economic viability of the 200 plus wells in the complex.

The exploitation team continually monitors and optimizes the waterflood, redirecting injected water through the thinner, more faulted, less efficient areas. Making the task more difficult, the complex is broken up aerially into dozens of fault blocks, separated by isolating or semi-isolated (leaky) faults, and vertically into the Belayim series with its four layers (Z1 thru Z4) and the Kareem with its eight layers (K1 thru K8). Each layer within each fault block must be individually considered as a waterflood unit.

The Reservoir Saturation (RST) tool has proved beneficial to these efforts , helping identify which sand layers in a given area are not swept by the low salinity injection water . This leads the team to better waterflood management decisions.

This paper will present the findings of this work in several fault blocks, show results of the successful sweep efficiency improvement work, and how the results were achieved.