Аннотация:The article evaluates the efficiency of injection of hydrocarbon gas, takinginto account the risks of precipitation of asphaltene compounds. Experiments were carried out to determine the pressure of the onset of asphalteneprecipitation when mixed with hydrocarbon gas and carbon dioxide. The oilgas displacement ratio and the minimum miscibility pressure were preliminarily estimated on slim-tube tests and a core column displacement. In additionto the standard research program, tests of oil swelling, phase behavior of thefluid during the dissolution of the gases considered for injection in given volumes by filtration and microscopic methods were carried out for a number ofprepared gas-oil mixtures. The obtained experimental data on the phase stability of asphaltenes were used to construct a calibration dependence of thedissolved asphaltenes in oil on the molar fraction of the added gas and wereused for hydrodynamic modeling of the gas methods for EOR. The PVTmodel was adjusted to the results of laboratory studies using the SRKPeneloux equation of state. During the model tuning, a pseudo-componentof asphaltenes was isolated, which has the main properties of asphaltenehydrocarbons obtained from experimental data. The results of slim-tube experiments and core displacement experiments were replicated using hydrodynamic simulation to verify the tuned PVT fluid model. The PVT model isused for predictive calculations on the prepared sectoral hydrodynamicmodel with the modeling of asphaltene deposition during oil-gas mixing. Conclusions are drawn about the possibility and necessity of using the asphaltene precipitation model in the simulation of hydrocarbon gas injection. Theresults of the calculation showed significant changes in the technological indicators of the project implementation on the sectoral model.