Mineral-component classification of the Bazhenov high-carbon formation deposits

Introduction. The Bazhenov high-carbon formation deposits are characterized by high lateral and vertical variability.

The aim of the work is developing a mineral-component classification and a three-component diagram of the Bazhenov high-carbon deposits to identify the diversity of lithological types and systematize research.

Materials and methods. The classification is based on a combination of data from lithological, mineralogical and geochemical studies. The main rock-forming minerals are three main components (siliceous, clay and carbonate matter). The concentration limits for each component are 5, 10, 25 and 50%.

Results. The following 15 main classes have been identified: 1) single-component, with the content of the main component of more than 50 %; 2) two-component, with the content of each of the two main components of more than 25 %; 3) three-component (mixed rocks), with the content of the three main components from 25 to 50 %.42 subclasses were identified in one-component and two-component rocks additionally. The name in additional classes is determined depending on the content of the mineral component in the amount of 5–10 % and/or 10–25 % and is indicated as an adjective to the main class. The name of the rock should reflect the content of minor minerals and organic matter for greater in detail. The mineral-component classification was actually applied to the Bazhenov deposits confined to the zone of the Frolovskaya megadepression and the Krasnoleninsky arch. 33 breed classes/subclasses have been identified. The most common are two-component (clay-siliceous and siliceous-clay) and one-component (siliceous) rocks. The class of one-component clay rocks is absent in the studied well sections.

Conclusions. The proposed mineral-component classification makes it possible to give a full and correct name to each rock, highlight the diversity of lithological types, trace their changes in the section of the Bazhenov highcarbon formation and perform spatial referencing.

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