INFLUENCE OF SECONDARY CHANGES ON THE COLLECTOR RELIABILITY COEFFICIENT IN GEOLOGICAL MODELS OF OIL AND GAS DEPOSITS

Abstract

Secondary changes in reservoir rocks, depending on their type, have a significant effect on filtration-capacitive properties (FCP). The result of this effect is a significant complication of the pore space of the reservoir and, as a consequence, the connectivity of the reservoir. The connectivity parameter is an important criterion when choosing multivariate modeling methods and sandstone cube construction parameters when creating geological models. The paper discusses the methods used today to calculate reservoir connectivity in geological models of oil and gas deposits, evaluate their effectiveness and propose a new approach to determining the connectivity parameter depending on the type of secondary changes in reservoir rocks and the geometry of the natural reservoir. In addition, an example shows the dependence of the coupling coefficient on the main parameters of the geological model: sandiness, ranks of variograms and the nugget effect. The proposed method allows to estimate the anisotropy of the main types of secondary changes in various directions and to assess FCP changes in geological models.