Abstract

It is a well known fact since the 1800's that water flood is an effective way to recover additional oil from the reservoir. There have been thousands of successful water flood in all part of the world. The major benefits from water flood are due to volumetric sweep efficiency, displacement efficiency and maintaining high well productivity index due to maintaining high reservoir pressure.

This paper will compare two reservoir simulation study, one a water flood in an earlier stage of development of the reservoir and another in which the water flood start up late in the development of the reservoir. Reservoir simulation study shows that early water flood at start up of the BNB and FWSA projects will yield incremental recovery to primary of 10% and 16% OOIP, respectively. A late water flood, 15 years after started up of the FK field only yields incremental recovery of 7% OOIP to the primary recovery. This water flood yields a lower incremental recovery than BNB and FWSA water flood because of sub-optimal well placement, less favorable displacement efficiency, and lower than initial PI because pressure was not built up to the original pressure.

Many ONWJ fields which were started up in the 1970's and 1980's were developed with minimum surface facilities for primary recovery to minimize cost. Water flooding the mature fields, i.e. FK field, will require costly surface facilities expansion. Developing the BNB and FWSA with water flood as part of the development design will be more cost effective than a late water flood because facility is built to accommodate water flood facility from the beginning.