APPLICATION OF CROSS-BEDDING OF DELTAIC SEDIMENTATION ENVIRONMENT TERRIGENOUS DEPOSITS TO IDENTIFY RESIDUAL RECOVERABLE OIL RESERVES AT A STAGE IV FIELD

The article studies the structure of terrigenous reservoirs from the standpoint of facies heterogeneity using the BS-9 formation of the Sugmutskoye field, which is at stage IV of development, as an example. The facies nature of the reservoir determines the differences in its textural features and the manifestation of layered heterogeneity. Spatial orientation of oblique layers in relation to the coastline, which depends on the facies affiliation, can become an important tool not only for establishing facies and spatial forecasting of sand bodies, but also for improving the elements of the hydrodynamic model, which will allow designing non-standard schemes for the development of oil deposits located at stage IV of development. Taking into account the fact that alternating layers are barriers to the movement of oil and injected water in the reservoir during the exploitation of hydrocarbon deposits, it is possible to use layered texture to increase the recovery factor. The article describes an approach to identifying residual recoverable oil reserves in terrigenous reservoirs with ordered oblique bedding using the Sugmutskoye field as an example. The study of cross-bedding features in various sedimentation environments, as well as the analysis of the current state of development and operation of injection and production wells, made it possible to determine the influence of these factors on the adaptation of the hydrodynamic model. The refined model contributed to the localization of zones of concentration of undeveloped oil reserves «sandwiched» between rows of injection wells.