Выпуск: 1 , Год издания: 2023

Издатель: Springer International Publishing

We consider the effect of frozen soil cryogenic texture on the signals measured at the day-surface and on the logging results. These measurement procedures are numerically simulated by means of finite element method in the paper. We thus estimate the impact of ground thawing on the results of electromagnetic investigations. At the macroscopic (surface or borehole) level, the cryogenic texture of the frozen soil presents a certain difficulty when introducing it into a geometric macromodel. We propose a two-step numerical modeling procedure. At the first step, a set of synthetic samples of frozen and thawed soils cores, is introduced. Their electrical properties, such as electrical conductivity and relative permittivity, are homogenized. The effective characteristics are considered as second-rank tensors. At the second step, we focus on simplified models of surface and borehole electromagnetic measurements. This is a half-space with a surface loop-source and loop-receivers for imitation of surface measurements. For logging simulation, the geometry is set as a half-space with a borehole and a three-coil probe. The electrophysical properties of the half-space are described by the homogenized tensors, obtained at the first step for frozen soils of different cryogenic textures. Vector finite element method on tetrahedra is used to solve these problems. These studies allow us to conclude about the influence of cryogenic texture and thawing process on surface and logging measurements efficiency at shallow depths.