Abstract
Business management of oil and gas in Pertamina, state oil enterprises, was handed over to one of its subsidiaries, Pertamina EP (PEP). With a vast working area of 140,000 km2, consists of 214 field where 80 percent is an old field (mature field or brown field), The conditions that have to be faced are as follows: production from existing field is declining, data is collected and interpreted over a long time period, huge amount of production data, and reservoir model and simulation are not frequently updated
The issue of maintaining production with small investment has changed due to the management and government board that urged to increase oil & gas production as result from national production increasing program. To get better recovery of those brown fields, it is necessary to have a long term project such as EOR. Some screening criteria had been completed to select an appropriate method which could be applied in certain field. It is obvious that the potential increase in oil reverse through EOR is quite significant. Pertamina EP is currently preparing a program Enhanced Oil Recovery (EOR) to be applied in some oil field with subsurface and surface potential consideration.
The implementation of waterflood project in Rantau field was initiated by EOR Department, Pertamina EP. The pilot project which was proposed in two patterns and it was successfully executed in January 2009. The increase in oil recovery by waterflooding results from displacement efficiency and volumetric sweep efficiency when injected water maintains reservoir energy and displaces remaining oil to production well ahead of advancing water.
