Two "smart" polymer systems have been developed for the oil producing industry. One system designed for water control in a producing well finds the site of the water influx by itself and blocks it. The other system is designed for use in hydraulic fracturing and acts as a thickener in an aqueous medium, including that at elevated temperatures; at the same time, in contact with hydrocarbons, the system transforms into a low-viscosity liquid, providing for a high permeability of the medium to petroleum.