Reservoirs identification in the Bazhenov formation by combining nuclear magnetic logging and thermal analysis methods

UDK: 550.822.3

DOI: 10.24887/0028-2448-2025-11-72-76

Key words: core, porosity, physically bound water, chemically bound water, fluid content, water content, thermoanalysis, nuclear magnetic resonance, well logging

Authors: A.V. Glotov (RN-Upstream design LLC, RF, Tomsk; Oil and Gas Research Institute of the RAS, RF, Moscow); P.B. Molokov (National Research Nuclear University МEPhI, RF, Moscow); A.A. Rogov (OFS Technologies, RF, Moscow); A.R. Rakitin (RN-Upstream design LLC, RF, Tomsk); N.N. Michailov (Oil and Gas Research Institute of the RAS, RF, Moscow; Gubkin University, RF, Moscow)

Currently, the use of classical approaches to identify reservoirs in the Bazhenov formation is an urgent and time-consuming task based on well log data. The main problem is the absence, on an ongoing basis, of direct qualitative signs on well logs indicating the presence of mud filtrate penetration into the well wall. Therefore, various quantitative boundary criteria, such as porosity, shale content, organic matter content, and rock mechanical properties (brittleness), are used to identify effective thicknesses from well logs in interval of the Bazhenov formation. Porosity in the Bazhenov interval, for example, is predicted from various logging methods. Taking into account the high lithological heterogeneity of the rocks under consideration, as well as the type and properties of the organic matter contained in the rock, it is very difficult to take a detailed account of the influence of these factors on the assessment of porosity according to standard log data (density, neutron and acoustic methods). In order to minimize the impact of the previously mentioned factors on the porosity forecast, it seems logical to use nuclear magnetic logging data as the most independent method. At the same time, the porosity values obtained from nuclear magnetic logging data should be monitored by comparing them with the porosity values obtained from laboratory core studies, which is a non-trivial task taking into account the changes that the core of the Bazhenov formation undergoes during sampling and lifting from the well to the surface.

References

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DOI: https://doi.org/10.24887/0028-2448-2021-3-28-33

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