Localization of the residual oil reserve areas of the rightbank group of fields of PJSC "Slavneft-Megionneftegaz"
The article considers the method of ranking the zones of localization of residual recoverable reservoir reserves by the degree of risk for further design of sidetracking and ensuring their involvement in the development. Modern reservoir simulation software permits history matching of almost any object. However, due to the geological heterogeneity of the formation, it is difficult to take into account the actual direction of the filtration flows. To improve the effectiveness of implemented measures, an integrated approach and a comprehensive analysis of the structure of residual reserves is required. An integrated approach enables to establish not only the physical causes of the entrapment or retention of oil in the porous medium, but also to evaluate the distribution of current oil saturation area and cut deposits to establish containment zones of residual reserves, to predict technological efficiency of drilling operations, to identify prospective areas for drilling. According to the results of geophysical and field-geophysical studies of wells, when analyzing the heterogeneity of the reservoir's geophysical properties by area and section, an uneven distribution of residual reserves across productive formations was established. An assumption is made about the advanced development of reserves in the upper part of the formation and a conclusion is made about the presence of zones of high concentration of residual oil reserves in the lower part of the formation. The authors have developed an express method that can be used to identify zones that are not involved in the development due to vertical anisotropy for planning the sidetracking without building of reservoir simulation model. The application of the method is considered on the example of formation X of the Western Siberia deposit, represented by cretaceous deposits. The proposed method is supposed to be scaled to objects with similar geological and physical characteristics for planning geological and technical activities.