Smart Technique in Water Shutoff Treatment for a Layered Reservoir through an Engineered Injection/Production Scheme

The challenge of excess water production from low permeability layer of a stratified gas reservoir is investigated in this study. Considering the fluid flow behavior in heterogeneous porous media, placing a blocking agent within the lower permeability layer and protecting the adjacent higher permeable layer from damage is practically impossible. To overcome such challenge, a novel cation sensitive smart biopolymer is utilized in a wise sequential polymer injection/gas production scenario that includes a protective gas flow. To evaluate the conceptual proposition, a series of flow tests have been conducted in a stratified micromodel. It is shown that the proposed treatment efficiently restrains saline water in the lower permeability layer and protects the higher permeable layer from undesired damage. The results indicate that being smart in water shutoff treatment is not only employing smart materials but engineering their application is the key for success.