A pilot Gravity Assisted Water (Dumpflood) Injection scheme was executed in 1997 in X1 reservoir of a Niger Delta field 'Alpha'. Post performance analysis showed that the injection has been successful in maintaining good pressure support and in supporting future recovery from the reservoir. However due to X1 reservoir uncertainities and variabilities in Water Dumpfllod injection rates, expected range of future recoveries could not be quantified.

Water Dumpflood for reservoir pressure support is a non-conventional but simpler and cheaper alternative to Surface Water Injection. With dumpflood technology, a single well serves as the water producer and injector hence; the complexities of water treatment on surface can be avoided. A pilot Water Dumpflood scheme was executed 1997 in the Egbema West field and post performance analyses showed it has been successful in maintaining good pressure support since its inception 12 years ago. Opportunity exists to increase oil recovery significantly from this same reservoir by drilling additional water dumpflood wells for increased oil withdrawal given corresponding pressure support. With this, oil wells that were shut in many years ago, to minimise further pressure depletion, can be brought back to production and maintained with good well and reservoir management. There also exists an opportunity to supply the associated gas from these wells to a nearby power plant currently undergoing construction with a capacity to utilize as much as 100 MMscf per day. This paper explores the benefits of increased water dumpflooding in the depleted reservoir and describes the selection of number and position of dumpflood wells for optimal recovery using dynamic modelling. It also reviews the historical performance of the pilot scheme and applies learning to improve the well completion design, injection rates and effective sand control for the additional wells. The application of Smart Technology for improved well and reservoir management have also been explored. Water dumpflood can be very effective with good selection of well position, number, source aquifer, and target reservoir, completion design and sand control mechanism. Increasing the scope in this reservoir will not only increase oil recovery but also support energy demand through gas supply to the power plant.