The recovery rate in a oil reservoir can increased by pumping water into the reservoir.
Enhanced oil recovery can be achieved injecting water into the reservoir. The mechanism where the injected water creates enhanced oil recovery varies between reservoirs. The type of injected water will also vary between different reservoirs. Injection water can be sea water that is filtered, it can have sulfate removed, it can be desalinated or have the salinity modified to match a specific reservoir reason. The injection water can have the ionic balance modified or/and have chemicals added like sodium silicate or polymers.
Enwa has participated in the development of new technology for enhanced oil recovery. One example is Snorre B where Enwa designed and manufactured, installed and operated the water maker plant with a 4000m3/day product capacity.