A reforming experiment was performed using a nickel catalyst, with the goal of suggesting a mechanism for the autothermal reforming of methane (ATR), under thermally neutral conditions. To bring the process to future scale-up at a fixed-bed reactor, kinetic-operational evaluations were made while taking into account the parameters of the gas phase flow and the temperature. From these evaluations, based on conversions, yields, and selectivities, it was possible to develop a novel approach to a descriptive mathematical model of the process behavior. A thermodynamic evaluation of the ATR was performed to measure the effects of operational conditions (temperature, pressure, and composition of the feed), in relation to the established limit values of the chemical equilibrium.