The invention concerns a conveyor system for oil or gas with an engine, which generates an exhaust gas flow 4; with a conveying device (2) driven by the engine in the form of a pump or compressor, which conveys and/or compresses said oil or said gas; with an exhaust gas energy recovery device, which converts the heat of the exhaust gas flow (4) into mechanical energy. The invention is characterised in that the exhaust gas energy recovery device comprises a working medium circuit (8) with the working medium water, water mixture, ethanol, ethanol mixture, ammoniac or ammoniac mixture, in which a heat exchanger (5) for transmitting the heat of the exhaust gas flow (4) to the working medium, to evaporate said medium partially or completely, include an expansion machine, in which the working medium expands by performing mechanical work, and a condenser (12) for condensation of the working medium is provided, and the expansion machine is coupled mechanically to the engine and/or the conveying device (2) and/or an additional work machine, to drive it them.