Implementation of new approaches to petrophysical interpretation at the geological exploration stage in the Samara region

UDK: 550.832:553.98

DOI: 10.24887/0028-2448-2025-10-24-31

Key words: well logging, core, three-dimensional mineralogical model, petrophysical interpretation, seismic inversion, reservoir, carbonate deposits, Paleozoic

Authors: M.V. Gubarev (NK Rosneft-NTC LLC, RF, Krasnodar); I.A. Gontarenko (NK Rosneft-NTC LLC, RF, Krasnodar); L.S. Oks (NK Rosneft-NTC LLC, RF, Krasnodar); S.P. Papukhin (Samaraneftegas JSC, RF, Samara); M.A. Solomeina (Samaraneftegas JSC, RF, Samara)

There are two main approaches to address well logs petrophysical interpretation challenges for seismic projects: standard which is performed using reserve estimation algorithms and inversion which is performed for the purpose of seismic inversion using three dimensional mineralogical models. Each method has its advantages and disadvantages. However, both approaches produce different results, which affect the quality of predictive models. The first method is commonly used for all carbon deposits and is applied in the most of Samara projects. Unfortunately, this method does not use the full range of well studies, especially sonic well. This leads to the fact that with the standard approach, it is impossible to obtain a stable separation of reservoirs and non-reservoirs based on impedance characteristics and perform a dynamic forecast. The second approach produces three-dimensional mineralogical model of reservoir rocks with a wide range of petrophysics. This method is assumed to use for seismic interpretation and based on seismic inversion technique. The obtained comparative assessments and results of petrophysical modeling at various fields indicate the feasibility of implementing this method. The authors' researches and tests were based on practical experience of geological exploration in the Samara region, Volga-Ural Petroleum and Gas Province. The target for geological exploration is the Paleozoic terrigenous-carbonate deposits located within the Buzuluk Basin.

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