Рассмотрены результаты определения фильтрационно-емкостных свойств на примере образцов карбонатных пород из керна скважины 1-Юньяхинская (Приполярный Урал) традиционным и томографическим методами.Проведеным рентгенотомографическим методом исследования подтверждена связь фильтрационно-ёмкостных свойств с морфологией порового пространства и литологогенетическим типом породы.

Mechanisms of the emergence of mechanical stresses in rocks with different regimes of their heating are studied. Theoretical models of acoustic emission induced by these stresses are justified and analyzed.Introduction. The reason for the emergence of acoustic emission (AE) in rocks is the formation of new cracks or the growth of already existing cracks under the action of mechanical stresses. If such stresses are induced by temperature effects, they are usually called the thermal stresses and the corresponding emission is called the thermoacoustic emission.One possible mechanism of the emergence of thermal stresses induced by a temperature gradient on the edges of cracks separating structural elements of the geomaterial was considered in [1]. That paper also justified the corresponding theoretical model of thermoacoustic emission (TAE) and the thermoemission memory effect arising in the course of cyclic heating of rocks with the maximum temperature being increased from one cycle to another [2]. That model, however, was not perfect because it could not give a clear explanation for the experimentally observed fact of higher values of TAE parameters in polymineral media than in monomineral media; moreover, the model did not explain the influence of the rate of the temperature increase in the sample on TAE parameters [2, 3].The present paper offers justification of TAE theoretical models whose specific feature is the allowance for thermal stresses induced by the difference in the thermal coefficients of volume expansion (TCVE) of individual mineral grains forming the rock and by the nonuniformity of the temperature field in the sample. Thermoacoustic Emission in a Uniform Temperature Field in the Examined Sample.If there are no temperature gradients in a geomaterial consisting of elements with different TCVEs, the only parameter determining TAE is the current temperature. The greater the difference between the current temperature and the initial temperature (at which the absence of mechanical stresses inside the mineral grains and on their boundaries is assumed), the greater the values of local stresses and the higher the probability of the growth of existing cracks and the formation of new cracks; as a consequence, the higher the degree of the acoustic emission. As the value of thermal stresses is proportional to the temperature difference, the derivatives of the total acoustic emission N Σ with respect to temperature can be assumed to have close values for different rates of temperature variation.If the rocks are considered as ideally elastic and brittle media and the redistribution of stresses due to the formation of microscopic defects is neglected, then the growth of the existing cracks and the formation of new cracks (accompanied by acoustic emission) during cyclic heating of the rocks occur only on exceeding the maximum temperature reached during the entire process, which determines the mechanism of the thermoemission memory effect.Model No. 1. To obtain a qualitative estimate of TAE, we consider a simple mod...

A model for the thermal emission memory effect in rocks under cyclic heating with the temperature amplitude increasing from cycle to cycle is validated. The model is used to consider one of the possible mechanisms of the effect related to the temperature gradient on the faces of cracks dividing structural elements of a geomaterial.The thermal emission memory effect, which is manifested in cyclic heating of rocks with the temperature amplitude increasing from cycle to cycle, involves irreproducibility of acoustic emission before the attainment of the maximum temperature of the previous cycle and a sudden increase in the acoustic emission activity and the total acoustic emission upon the attainment of the indicated temperature [1].The thermal emission effect was discovered in the 1970es in studies of Westerly granite [2]; later, this effect has been found in rocks of various origin and composition, such a marble, potassium salt, basalt, anhydrite, quartz, etc. Results of experiments have shown that, for each type of rock, there is a characteristic range of temperatures and the maximum rate of temperature rise at which this effect is the most pronounced. However, for all rocks, the clarity of the effect in the (i+1)th cycle increases as the time of exposure of the samples to the maximum temperature of the ith cycle T i max is increased and as the time interval between successive heating cycles is decreased [3,4]. It should be noted that there have been a few experimental studies of the thermal emission memory effect because of difficulties in measurements of acoustic emission parameters in heated rock samples. Attempts to develop a model of the effect considered have not been undertaken. However, the development of such models is necessary for both a correct interpretation of results of thermal emission measurements and for solving research problems of the physics of strength, plasticity, and thermal failure of geomaterials.The thermal emission memory effect manifests itself as the Kaiser effect provided that mechanical effect on the subject of research is replaced by thermal effect [3]. However, the first of these effects is described by tensor quantities, and the second by scalar quantities, which prevents the use of the Kaiser effect model [5] to explain the nature and mechanism of the thermal emission memory of rocks. The purpose of the present paper is to develop a model for the thermal emission memory effect based on one of the possible mechanisms of formation and manifestation of the acoustic emission memory of rocks about the maximum thermal effects they experienced previously.To solve the problem considered, we make the following assumptions. 1. The rock volume is represented by a set of structural elements with different thermal properties (in particular, different thermal conductivities).2. The structural elements may be mineral grains, their aggregates or constituents of these aggregates that are not necessarily grains.3. On the boundaries between the structural elements there are microcracks of the char...

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Geological engineering often uses geomechanical modeling aimed to enhance efficiency of mining or performance of structures. One of the input parameters for such models are the static elastic moduli of rocks. This article presents the studies into the physical and mechanical properties of rocks-limestone of non-metamorphic diagenesis. The precision measurements of Pand S-waves are carried out to an accuracy of 0.2% by laser ultrasonics. The static moduli of elasticity and the deformation characteristics of rocks are determined in the uniaxial compression tests by the standards of GOST 21153.2-84 and GOST 28985-91, respectively. The correlation dependence is found between the static and dynamic elasticity moduli in limestone samples. The found correlation allows drawing the conclusion that the static modulus of elasticity can be estimated in non-destructive tests, which largely simplifies preliminary diagnostics of samples in case of limited number of test core.