Continuous, long-term injection of an environmentally sound colloidal dispersion gel (CDG) provides a solution to in-depth, away from the well bore, channeling and crossflow problems inherent with waterflooding. This unique in-depth permeability modification process has been applied in 37 field projects over the last 11 years. In the 29 successful projects, the gels increased oil production at lower water/oil ratios. To date, the successful projects have recovered an estimated 12.3 million bbl of incremental cumulative oil at an average chemical cost of $1.09/incremental oil bbl. Six projects were unsuccessful for a variety of reasons.