A method of removing a partial amount of water in a well, comprises deploying a differential filter downhole; and performing a downhole operation, wherein the differential filter comprises a swellable polymer that swells after contacting water such that permeability of the differential filter is reduced by removing said partial amount of water, the swellable polymer being non-soluble in the water and/or hydrocarbon and wherein the swellable polymer comprises at least one selected from the group consisting of polyacrylic acid, polyacrylate, polymethacrylic acid, poly maleic anhydride, polyacrylamide, polyvinyl alcohol, latex, polyamide, polyester, and a co-polymer thereof.