ON THE ISSUE OF HYDRODYNAMIC MODELLING OF UPWARD MIGRATION OF RHEOLOGICALLY COMPLEX INHOMOGENEOUS FLUIDS FROM DEEP UNDERGROUND RESERVOIRS

The relevance of the article is caused by the need to develop new mathematical models, methods, experimental approaches when investigating migration problems of deep hydrocarbon fluids from underground reservoirs of the oil and gas basin. The aim of the research is to develop a universal physical and mathematical model of a detailed forecast of migration over a limited space of a ground collector of arbitrary geometry; make recommendations to the practice of studying the problems of hydrodynamics and heat- and mass transfer in these conditions and to compare the relative values of forces that cause the migration of deep fluids in vertical and lateral directions. Methods of the research are based on general principles of mechanics of continuous homogeneous and heterogeneous media, hydrodynamics and heat and mass transfer. Results. The paper introduces the data of analysis of effects accompanying hydro- and gas dynamics, and heat- and mass transfer at flows of homogeneous and heterogeneous rheologically simple and complex viscous mixtures in fields of action of external forces from underground regions with arbitrary geometry of slot and pore space. The authors have carried out the analysis of the correctness of the physical modeling of the problem on underground hydrocarbons migration and establishment of determining mechanisms for their lifting from large depths. It was found that upward migration is formed under the defining influence in the resulting force: floating force (Fв), which takes into account the features of changes in the fields of thermodynamic parameters (composition (ci), temperature (T), pressure (P)); gravity (FG): phase phenomena and processes at the boundaries of the analysed volume of the hydrocarbon medium, as well as pressure gradient force (FPR), the behavior of which is complicated by the distribution of the entire spectrum of external and internal forces in the conjugated system. The paper introduces the conclusions on details of fluid flow modeling, formulations of defining numbers and criteria within the framework of the theory of similarity of the considered problems, useful for understanding and clarifying the essence of effects, processes, forces, mechanisms accompanying migration. The results can be used to predict migration especially at the conditions complicated by: abnormal phase and rheological small-scale diffusion changes in composition; conjugated heat and mass transfer between rock and mixture; instability of modes in local areas of fluid flow at arbitrary thermodynamic and geometric configurations of underground collector.