TY - JOUR AU - Guliyev, H. H. AU - Aghayev, K. B. AU - Sultanova, G. A. PY - 2019/12/26 Y2 - 2024/03/29 TI - Determination of stress in the geological medium on the basis of well data using acoustoelastic correlations JF - Geofizicheskiy Zhurnal JA - GJ VL - 41 IS - 6 SE - Articles DO - 10.24028/gzh.0203-3100.v41i6.2019.190074 UR - https://journals.uran.ua/geofizicheskiy/article/view/190074 SP - 173-182 AB - <p>A method has been developed to determine normal components of the stress tensor in deformed geological media on the basis of geophysical well logging. The theoretical basis of the method is the acoustic correlations of the non-classical linearized approach of nonlinear elastodynamics. Analytical formulae are obtained to calculate the stress in the geological medium in cases of small and large deformations. Geophysical well logging data located in the South Caspian basin have been used. Thin-layered one-dimensional models of the medium have been compiled on velocities of pressure and shear waves, density and lithology of rocks. The thickness of each layer of the model is several centimeters, which is equal to the observations in the well. The data of each model related to the same rock lithology is divided into clusters using artificial neural networks to consider the influence of changes of thermobaric conditions of the geological medium on acoustic properties of rocks. Values of elasticity moduli of the second and third orders and components of normal stress tensor have been calculated according to models for each lithology of rocks and a cluster of data. It has been revealed that elasticity moduli of the third order are much more sensitive to the variability of elastic properties of the medium than moduli of the second order. The obtained numerical results on all clusters of each lithology of rocks are averaged. At the same time, the number of medium layers on each data cluster has been used as weights. The number of medium layers in each rock has been used as weights while averaging the results for all the rocks. The correlations between numerical values of normal components of stress tensor caused by geostatic pressure and similar values caused by geodynamic changes of stress tensor have been studied. It has been revealed that values of stress bulk caused by geostatic pressure are significantly lower than stress caused by geodynamic changes. The obtained acoustic formulae allow determining values of stress in the geological medium of any region considering the influence of modern geodynamic processes.</p> ER -