A chemical gel system having a polymer and a graphene oxide Janus nanosheets crosslinker for treating thief zones in carbonate formations. The polymer and graphene oxide Janus nanosheets crosslinker may form a crosslinked polymer gel to reduce or prevent water production via thief zones during hydrocarbon production. The graphene oxide Janus nanosheets crosslinker includes a first side having negatively charged functional groups and a second side having amines. The negatively charged functional groups may include carboxyl groups, negatively charged oxygen groups, and hydroxyl groups. Methods of reducing water production in a thief zone using the graphene oxide Janus nanosheets crosslinker and methods of manufacturing the graphene oxide Janus nanosheets crosslinker are also provided.