Evaluation of the nature of saturation of the reservoirs of the achimov formation by well-logging in conditions of low permeability and facies heterogeneity

Abstract

Despite the fact that the history of studying the geology of the achimov formation spans several decades, the volume of depletion of the reserves of these deposits is small, and the number of fields where the achimov formations have been put into commercial development is few. This is due to the complex geological structure of the reservoirs, vertical and lateral heterogeneity, reduced porosity and permeability properties, and low values of the oil saturation factor. In the presented work, a generalization and analysis of all petrophysical information was made, typification of sections according to well logging with the possibility of using individual petrophysical function to assess the nature of reservoir saturation and the hydrocarbon saturation index. To create a petrophysical substantiation of well logging interpretation, both historical and current core studies in the framework of this study by the authors of the article were involved. The typification of the sections of the achimov formation was carried out on the basis of a detailed lithological study of the core using special studies such as scanning electron microscopy and computed microtomography. Identification of different types of section will allow in the future to correct the further hydrodynamic model for predicting the nature of the inflow and will significantly increase the reliability of assessing the nature of saturation and the hydrocarbon saturation index of heterogeneous deposits of the achimov formation.