LITHOLOGICAL MODEL OF THE BAZHENOV FORMATION BASED ON INTEGRATED INTERPRETATION OF GEOLOGICAL AND GEOPHYSICAL MATERIALS

Abstract

The relevance of the study is associated with the need to develop and improve technological methods for increasing oil production from the Bazhenov Formation in relation to the depletion of reserves in traditional granular reservoirs in the West Siberian oil and gas province. The features of the industrial development of these low-permeability rocks largely depend on their mineral-component composition. To identify different types of reservoirs of the Bazhenov Formation in wells that are not characterized by core material, it is necessary to develop a method for predicting its lithological composition. The main aim: to identify and study the relationships between the mineral component composition, and electrical rocks and radioactive properties of Bazhenov Formation in the central part of the West Siberian sedimentary basin for developing methods of calculating the content of basic rock-forming components in this formation section. The object of the research is the carbonate-argillaceous-siliceous rocks of the Bazhenov Formation, characterized by a large heterogeneity of the mineral-component composition along the section. Methods: identification of relationships between the mineral-component composition of the rocks of the Bazhenov Formation and its electrical and radioactive properties; statistical analysis of the obtained relations; calculation on their basis of the lithological composition of the Bazhenov rocks in the base, as well as in adjacent wells. Results. The article presents the results of an integrated lithological and geophysical interpretation of data from a wide range of electrical and radioactive logging and the results of analytical core studies, on the basis of which a methodological approach to calculating the concentrations of the main rock-forming components of the Bazhenov Formation has been developed. It is based on the identified relationships between the mineral-component composition of rocks and their physical properties. Satisfactory convergence of the calculated values ​​and core data is shown, volumetric lithological models are built for the wells of the Druzhnaya and Povkhovskaya areas. It is shown that the obtained dependences can be used to reliably calculate the lithological composition of the Bazhenov Formation in closely spaced wells that are not characterized by core material. The impossibility of using the proposed methodological approach in thin-layered sections is substantiated due to the fact that the thickness of the interlayers is much less than the resolving power of geophysical borehole probes.

Keywords

• bazhenov formation
• west siberia
• core
• well-logging data
• lithological composition
• methodical approach