Hamed Naderi Salem - Institute of Petroleum Engineering, School of Chemical Engineering, College of Engineering, University ofTehran, Tehran, Iran
Yasin Rigi - Institute of Petroleum Engineering, School of Chemical Engineering, College of Engineering, University ofTehran, Tehran, Iran
Elahe Tahmaseb - Institute of Petroleum Engineering, School of Chemical Engineering, College of Engineering, University ofTehran, Tehran, Iran
Behnam Sedaee - Institute of Petroleum Engineering, School of Chemical Engineering, College of Engineering, University ofTehran, Tehran, Iran

The challenge of excess water production from a low permeable layer of a stratified gas reservoir isinvestigated in this study. Bullhead and Relative Permeability Modifier (RPM) treatment often fails toachieve the desired result, as in most cases the situation warrants isolation and protection of the oil producingzones, from highly damaging polymeric gels. Protection of oil zones in a highly fractured reservoir istechnically and economically a huge challenge because of knowledge of the complexity of fracture networksand considering the fluid flow behavior in heterogeneous porous media, placing a blocking agent within thelower permeable layer and protecting the adjacent higher permeable layer from damage is practicallyimpossible. To overcome such challenges, a novel cation sensitive smart bio-polymer is utilized in a wisesequential polymer injection/gas production scenario that includes a protective gas flow and application ofthree chemical fluid compositions in sequence, as an alternate rigless water control option whose selfselectivityand effectiveness in controlling water production are verified in the laboratory in simulatedfractured reservoir condition. To evaluate the conceptual proposition, a series of flow and flood tests havebeen conducted in stratified micromodels and core plugs respectively. it is shown that the proposed treatmentefficiently restrains saline water in the lower permeable layer and protects the higher permeable layer fromundesired damage or vice versa. The technology could be suitably applied without rig deployment andcheaply. However, the fluid composition, pumping pressure and flow rate need to be customized based on thecandidate well and the actual reservoir parameters. The results indicate that being smart in water shutoffTreatment employs smart materials, and the engineered application is the key to success.

Water shutoff, Gel, Core Flooding, Micromodel