No abstract

In case when the upper part of the medium has complex geological structure and geodynamic processes occur in it, the necessity of these data increases in projecting of the object under construction. Purpose. Studying of acoustic, elastic and anisotropic properties of the upper part of section of complicatedly constructed geological media. Methodology. Seismic observations are conducted in shallow wells in the areas of construction objects located in various seismogeological conditions by NSCW (Near-Surface Cross Well testing) method. Field seismic records are processed. Kinematic and dynamic parameters of pressure and differently polarized shear waves are determined. Thin-layered one-dimensional models of physical properties of the medium are created and interpreted on the basis of nonlinear theory of elastodynamics. Results. It is determined that the medium with high porous, water saturated rocks and anomalous high reservoir pressure has anomalous low value of velocities and gradient of their increase with depth. When this medium was re-examined after deep piles were built there, the overestimated seismic velocities are obtained, which is explained by a decrease in the section of anomalously high reservoir pressure and, accordingly, the porosity of the rocks after piles were built. When the hollowness is increased in unsaturated pebble rocks, the negative value of Poisson's ratio is obtained on the standard method. Seismic anisotropy related with the direction of the grains packing of the rocks is revealed on velocities of shear waves. The change of property of rocks on depth is manifested clearer on frequencies of waves than on their amplitudes. Scientific novelty. The elasticity moduli of the 3rd order are determined which are more sensible to variability of nonlinear elastic properties of rocks of the medium than the moduli of the 2nd order. The values of Poisson's ratio are recalculated for one and the same rocks located in different conditions of rock pressure on the basis of nonclassical theory of deformation. Practical importance. The obtained results can be applied to study the media characterized by complex seismogeological hydrodynamic conditions with clay-sandy rocks of high porosity and water saturation.

Object. Development of a method for predicting a two-three dimensional velocity model of a medium by using a shear wave. Complexly structured geological medium is studied on the basis of geophysical and geological data using an artificial neural network. Method. It provides the construction and use of medium models according to geophysical well logging data and other terrestrial geophysical methods. In contrast to existing methods, the proposed method also uses additional data on the medium. They include the thermodynamic state of the medium, stratigraphic confinement of deposits, rock lithology, distribution of data clusters, physical properties of the medium etc. According to the method, one-dimensional models are first constructed on various properties of the medium based on data of complex of well logging. Then, the neural network is studied to predict the shear wave velocity on a set of models. Subsequently, two-three-dimensional models of the medium are constructed according to the results of terresterial geophysical studies. Two-threedimensional velocity model of a shear wave is predicted by using a complex of these models studied by a neural network. Results. Velocity model of shear wave is predicted for complexly structured geological medium of the South Caspian Basin using the method. Scientific novelty. It is possible to increase the accuracy and resolution of prediction the medium model by increasing the number of types of data used. Practical value. Improving the efficiency of seismic exploration in determining oil and gas saturation, elastic geodynamic state and other physical properties of the geological medium.

has found wide use in researches of various problems of modern geodynamics and seismic exploration. The basis of this approach is the study of the prop