Modification of the Dakhnov–Archie electrical model with successive changes in the mineralization of pore waters under thermobaric conditions
https://doi.org/10.51890/2587-7399-2025-10-3-60-67
Abstract
Introduction. The article raises the issue of correct assessment of water saturation based on electrical logging data in intervals of clayey sandy-siltstone reservoirs. The combination of clay component and low mineralization of pore waters causes the effect of additional conductivity in terrigenous reservoirs. This leads to the need to adjust the classical Dakhnov–Archie equation, which in practice is done using semi-empirical models with a number of uncertainties.
The aim of the experimental part of the work is to test the hypothesis of the influence of formation water mineralization on the parameters “m” and “n” of the Dakhnov–Archie electrical model under various conditions: atmospheric and formation thermobaric. The theoretical part is devoted to the development of a method for empirical modification of the Dakhnov–Archie equation.
Materials and methods. The paper presents unique results of a laboratory study of the electrical properties of clayey sandstones of the Achimov formation. The studies were conducted under thermobaric conditions using an individual PCRI-807 capillary meter manufactured by Weatherford Laboratories using a cyclic program with a change in the mineralization of the formation water model. The ranges of mineralization changes were from 3 to 200 g/l under atmospheric conditions and from 3 to 10 g/l under thermobaric conditions.
The results of the work are presented in the form of diagrams and the identified patterns of variations in the parameters of the Dakhnov–Archie electrical model. The correlation dependencies of the parameters “m” and “n” on the resistivity of the formation water models are demonstrated.
Conclusion. Based on the identified patterns, a method for modifying the Dakhnov–Archie electrical model has been developed and resented, which may be in demand in cases of complex geological conditions with proven variability of formation water mineralization.
About the Authors
Danil B. Rodivilov
Tyumen Petroleum Research Center LLC
Russian Federation
Russian Federation
Danil B. Rodivilov — Сand. Sci. (Geol.-Min.), Senior expert
BTS «Ovental», 79/1, Osipenko str., 625002, Tyumen
Evgenii N. Salomatin
Tyumen Petroleum Research Center LLC
Russian Federation
Russian Federation
Evgenii N. Salomatin — Chief specialist of the laboratory of special petrophysical research
Tyumen
Roman S. Shul’ga
Tyumen Petroleum Research Center LLC
Russian Federation
Russian Federation
Roman S. Shul’ga — Head of the Laboratory Research Department of the Core Research Center
Tyumen
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Review
For citations:
Rodivilov D.B., Salomatin E.N., Shul’ga R.S. Modification of the Dakhnov–Archie electrical model with successive changes in the mineralization of pore waters under thermobaric conditions. PROneft. Professionally about Oil. 2025;10(3):60-67. (In Russ.) https://doi.org/10.51890/2587-7399-2025-10-3-60-67
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