Chemical methods to reduce water production include gel polymer systems, which have a penetration property greater both mechanical methods and cement squeezes, to provide a deeper barrier against the excess water. Polymers and metallic cross-linkers are placed downhole, adsorbed onto the rock surface, and gelling takes place insitu, so that water is trapped within the polymer. Often the reservoir is held under pressure for a predetermined amount of time. The effect is that the crosslinked polymer will collapse under pressure, and open up the pore throat to oil, while reducing the water production. The industry leaders in this market have produced solutions that reduce the water production for years, as opposed to months, proving a preferable method over the more expensive mechanical methods.