NUMERICAL SIMULATION METHOD IN LOW PERMEABLE ANISOTROPIC RESERVOIRS IN ORDER TO INCREASE OIL RECOVERY

Abstract


 
 The object of study is the filtration process in weakly permeable anisotropic formations (SAP). The work is devoted to the evaluation of the process of oil-bearing formation depletion, using as a criterion the distribution of reservoir pressure near the system of production and injection wells, taking into account the anisotropy of the permeability of the oil phase. In the course of the study, a combined numerical modeling method based on the finite element and finite difference methods is presented, which allows determining the value of reservoir pressure at any point in the computational domain. The finite-element-difference method proposed in this paper, which combines the advantages of the finite-element method and the finite-difference method to solve the nonstationary piezoelectric conductivity problem, taking into account the heterogeneous distribution of various filtration parameters within the deformed formation and at its boundaries, allows us to adequately calculate the distribution of reservoir pressure in real-world well operation conditions, which gives a number of advantages over existing methods. It was found that the effect of oil phase permeability in the shear direction dominates the effect of permeability in the axial directions. This is due to the fact that, according to the information obtained, for the effective use of anisotropic low-permeability formations, it is necessary to place production and injection wells in areas with relatively low anisotropy of formation permeability, especially to avoid areas with the presence of shear permeability of the formation. It is important to locate wells so that, on the one hand, there is no blockage of oil from the low permeability side, and, on the other hand, there is no rapid depletion of the formation from the high permeability side and the mutual exchange between the production and injection wells does not stop. When placing a system of production and injection wells in anisotropic formations of an oil field, it is necessary to conduct a systematic analysis of the surrounding anisotropy of the formations in order to place them in such a way that would ensure effective dynamics of filtration processes around these wells and increase oil recovery.