Facies models of hydrocarbon-bearing formations of Podneytinskiy reservoir at Bovanenkovskoye and Kharasaveyskoye fields

Abstract

Background. Significant part of hydrocarbons at Bovanenkovskoye and Kharasaveyskoye fields are contained in Podneytinskiy reservoir, and study of geological features of its productive strata is important for development planning for the fields in a whole. 
 
 Aim. The paper reflects the results of integrating well and seismic data to characterize the formations of Podneytinskiy reservoir at Bovanenkovskoye and Kharasaveyskoye fields. 
 
 Materials and methods. As part of the study, sedimentological description of core was analyzed, the core, well logging and seismic survey information were assessed, and the facies schemes were prepared. 
 
 Results. As a result of the work, the reservoir architecture features and the distribution of reservoir properties of the target interval were revealed. It has been established that the considered formations of Podneytinskiy reservoir can be divided into two parts, the lower one is represented by deposits of predominantly deltaic origin, and the upper one is of continental and subcontinental genesis. The sedimentary conditions of rocks influenced the complexity of their architecture, so, in the formations referred to the lower part of the studied interval, the reservoirs, as a rule, are laterally continuous, in contrast to the deposits of the upper part of the section, which are typically characterized by extremely high lateral heterogeneity. Depositional conditions also influenced the reservoir properties of productive sediments. As a result of the work, it was revealed that the reservoirs of better quality are formed in fluvial and tidal channels, distributary channels and proximal parts of deltas, they have higher reservoir properties, are characterized by thicker sandstone interlayers and lower portion of carbonated interlayers in comparison with reservoirs formed in other conditions. 
 
 Conclusions. The article provides quantitative characteristics of reservoir properties depending on sedimentary conditions. The results obtained form the basis for creation of geological models of Bovanenkovskoye and Kharasaveyskoye fields.