During the development of the deposit, as the gas is extracted, the reservoir pressure drops and water rise begins, that is, the reservoir is impregnated in reverse with bottom water .If the process of water displacing from the reservoir is well understood, then the process of water or hydrocarbon fluid absorbing by the reservoir is relatively poorly studied. The methodological basis for such studiesis also e laborated poorly. This is largely caused by the long duration of the necessary experiments, which in our case amounted to 6 months. In this work, a methodology of sample reverse impregnation with a hydrocarbon fluid was developed at a displacement pressured drop in order to simulate the processes occurring in the developed deposit. As a result of the work, on the basis of the semi-permeable membrane method used in the "drainage-impregnation" mode, the actual existence of the reverse impregnation of a sample by hydrocarbons at a displacement pressured drop is proved on rock collectors samples of the Belsky field productive horizon G-7-10, methodological issues related to the specifics of impregnation with specifically hydrocarbon fluid have been solved, main features of the process have been recognized and its main regularities have been determinate qualitatively. In order to reduce the duration of the study, it is recommended to substitute the semi-permeable membrane method with the centrifugation method at the stage of drainage. The parent theoretical ideas are given, the method of research and the used core material are described briefly, graphs illustrating the conduct of drainage and impregnation processes over time are given, the correlation of the current sample water saturation with the displacement pressure and pore characteristic of the sample, the inferences are enunciated briefly. The results of the carried out work will be used in the study of the processes of gas displacement by oil from oil rims, oil or gas displacement by water, oil and gas mixture displacement during the cycling process, etc.