Synthesis gas, which includes a mixture of hydrogen and carbon monoxide, is an important intermediate component in the synthesis of the commodity petrochemicals such as dimethyl ether, methanol, motor oils and fuels. One of the most promising technologies for production of the synthesis gas is partial oxidation of a hydrocarbon fuel with a lack of oxidant, which is realized in a controlled high temperature reactor (HTR). The authors propose a method for production of the synthesis gas of a given composition, which ensures the desired ratio of the volume fractions of hydrogen and carbon monoxide, and the required power of HTR. These parameters are especially important for the use of the hydrocarbon fuels with a varying concentration of components in their chemical composition, which is typical for the associated gas in the oilfields (PNG). For example, in PNG the volumetric content of methane as a component with the largest hydrogen number may vary within a wide range from 0.4 up to 0.95. Control of the technological process is implemented by an associated regulation of the components, which are used in HTR, - mass flows of the hydrocarbon fuel and oxidizer. In the control algorithm the operational information about the current chemical composition of the fuel and the preliminary data of the thermodynamic calculations of a given pair of the fuel-oxidizer are used. A computational algorithm was developed intended for implementation of the process in real time. It ensures convergence of the calculation process of the control signals. The method is illustrated by an example of the calculation process of a partial oxidation by APG oxygen.