In-situ salinity adjustment to improve waterflooding performance in oil-wet carbonate reservoirs

A method for increasing hydrocarbon production from a hydrocarbon-bearing reservoir, the method comprising the steps of:

• preparing a saltwater solution suitable for injection into the hydrocarbon-bearing reservoir for water flooding, the saltwater solution having a salinity;
• adding to the saltwater solution a plurality of nanocapsules to form an enhanced recovery suspension, where the nanocapsules are operable to be suspended amongst the saltwater solution, where the nanocapsules have an overall positively charged outer surface at respective outer shells of the nanocapsules, where the nanocapsules encapsulate water molecules without salt or minerals within the nanocapsules, and where the nanocapsules are operable to release the water molecules in the hydrocarbon-bearing reservoir proximate overall negatively charged zones to reduce salinity and alter wettability via release of water molecules in situ proximate an area of release;
• and
• injecting the enhanced recovery suspension into the hydrocarbon-bearing reservoir to increase hydrocarbon production.