Improving Sweep Efficiency

Low salinity water is produced from seawater using various membrane based techniques including Reverse Osmosis (RO) & Nanofiltration (NF). These processes are geared towards removing components which cause scaling in the well such as sulphates and hardness while maintaining a fixed salinity. Waterflooding with low salinity water improves sweep efficiency by assisting the release of hydrocarbons from clays in the reservoir. This is advantageous as it allows greater hydrocarbon recovery without the injection of additional chemicals into the well. However low salinity water may also be used to improve the performance of Chemical Enhanced Oil Recovery (CEOR) processes.