WO2017204689A1

WO2017204689A1 - Method for determining the mechanical properties of reservoir rock

Info

Publication number: WO2017204689A1
Application number: PCT/RU2017/000337
Authority: WO
Inventors: Владимир Викторович АБАШКИН; Тагир Рустамович ЯЛАЕВ; Сергей Сергеевич САФОНОВ; Олег Юрьевич ДИНАРИЕВ; Андрей Владимирович КАЗАК; Евгений Михайлович ЧЕХОНИН; Юрий Анатольевич ПОПОВ
Original assignee: Шлюмберже Текнолоджи Корпорейшн; Владимир Викторович АБАШКИН; Сервисес Петролиерс Шлюмберже; Шлюмберже Канада Лимитед; Шлюмберже Текнолоджи Б.В.
Priority date: 2016-05-27
Filing date: 2017-05-23
Publication date: 2017-11-30
Also published as: RU2016120852A; RU2636821C1

Abstract

At least one sample of reservoir rock is selected and the density, porosity, and composition of the rock in the selected sample is determined. On the basis of the values obtained, a petrophysical model of the reservoir rock is created. The thermal conductivity of the sample is measured. The thermal conductivity of the rock sample is calculated using the petrophysical reservoir model that was created. The measured and the calculated thermal conductivities of the rock sample are compared, and if the measured and the calculated thermal conductivity values coincide, the mechanical properties of the rock are determined using the petrophysical reservoir model that was created. If the measured and the calculated thermal conductivity values diverge, the petrophysical reservoir model that was created is adapted at least once by changing the model parameters. The adapted petrophysical model is used to calculate the thermal conductivity of the rock sample, and the measured and the calculated thermal conductivities are compared until the measured and the calculated thermal conductivity values coincide. When the measured and the calculated thermal conductivity values coincide, the mechanical properties of the rock are determined using the adapted petrophysical reservoir model.

Description

METHOD FOR DETERMINING MECHANICAL PROPERTIES OF BREED OF COLLECTOR

The invention relates to the field of research of the mechanical, thermal and petrophysical properties of rocks and is intended to assess the properties of the reservoir and intensification of production.

When designing hydrocarbon production using hydraulic fracturing and / or thermal oil recovery enhancement methods, knowledge of various rock properties under atmospheric thermobaric conditions and elevated temperatures (e.g. mechanical - compressive strength, Young's modulus, Poisson's ratio; petrophysical - density , porosity, permeability, mineral composition, etc .; thermal - thermal conductivity, volumetric heat capacity, etc.). Knowledge of these properties may be key in the design and assessment of risks of such processes as drilling (including horizontal wells), cementation, hydraulic fracturing, stimulation of oil production by thermal methods, etc.

Creating models of the physical (e.g., mechanical or transport) properties of the formation is often done using commercially available software packages (e.g., Techlog, Petrel-Visage, CMG-STARS) in one-dimensional and three-dimensional approximations. For the correct operation of software packages simulating the enclosing, mechanical, or transport properties of the formation, it is necessary to use information on the corresponding rock properties and saturating formation fluids that are obtained from laboratory, logging or other experimental studies as input data.

Known method of estimating formation quality and quality of completions in wells drilled in unconventional (shale) oil and gas reservoirs, as described in U.S. Patent 8967249. In this method, the elastic properties of the rock are determined by two independent ways: direct measurements of V and V _s velocity and using models. However, direct measurements are carried out on single, prepared samples / rock particles, which reduces the representativeness of the sample and leads to low resolution of data on mechanical / elastic properties along the section / interval / well. In addition, the method does not provide for an assessment of the degree anisotropy, which is important for assessing reservoir quality and / or well completion quality. The reliability of the results of using the model without information on structural and microtexture factors, the structure of the void space of the rock (including, without limitation, the degree of cementation of the mineral grains of the skeleton, porosity, and features of the contacts between the grains of the mineral skeleton) is extremely low. The need to clean the sludge particles before measurements leads to an increase in time costs, moreover, the extraction of hydrocarbons from samples of oil source rocks can be performed only partially. The disadvantages of the method also include the lack of amendments for reservoir thermobaric conditions. It is known that during core extraction from the well to the surface, changes in the physical properties of rock samples occur (the discrepancy between the measured properties in atmospheric conditions and the real properties of rock samples can be significant).

These shortcomings reduce the reliability of the results of determining the elastic properties, which makes it difficult / inefficient to assess the quality of the reservoir and the quality of well completion.

US patent jN ° 5285692 describes methods for measuring physical parameters, including the elastic properties of low permeability rocks under formation conditions. The method involves measuring the velocity of propagation of ultrasonic vibrations on rock samples (or in the well) along with the use of correlations. However, logging data may be absent, the use of correlations implies the presence of an extremely informative / voluminous database (due to the variety of rocks and fluids saturating them), and direct measurements of the propagation velocity of ultrasonic vibrations are carried out on single, prepared rock samples / particles, which reduces the representativeness of the sample and results in low resolution of mechanical / elastic properties data for section / interval / well. An assessment of the degree of anisotropy, which is important for assessing the quality of the reservoir and / or the quality of well completion, is not provided.

The technical result achieved by the implementation of the invention is to increase the efficiency and quality of assessing the properties of the reservoir by providing the ability to calculate the values of unknown (or not fully known) mechanical and / or enclosing properties of the reservoir. The obtained values of the mechanical and / or enclosing properties of the reservoir can be used to select the productive intervals of the reservoir, assess the suitability of the intervals of the borehole for opening and apply methods to increase oil recovery (hydraulic fracturing, acid treatment, etc.).

In accordance with the proposed method, at least one rock sample of the reservoir is sampled, the density, porosity and component composition of the rock are determined on the selected rock sample and a petrophysical model of the reservoir rock is created based on the values obtained. The thermal conductivity of the sample is measured. Using the created petrophysical model of the reservoir, the thermal conductivity of the rock sample is calculated. The measured and calculated thermal conductivities of the rock sample are compared, and if the measured and calculated thermal conductivities match, the mechanical properties of the rock are determined using the created petrophysical model of the reservoir. If there is a discrepancy between the values of the measured and calculated thermal conductivity, the created petrophysical model of the reservoir layer is adapted at least once by changing the model parameters. An adapted petrophysical model is used to calculate the thermal conductivity of the rock sample and the measured and calculated thermal conductivities are compared to ensure that the measured and calculated thermal conductivities match. If the measured and calculated thermal conductivities coincide, the rock mechanical properties are determined using an adapted petrophysical model of the reservoir.

In accordance with one embodiment of the invention, the mechanical properties of the reservoir rock are the propagation velocity of a longitudinal acoustic wave and a transverse acoustic wave through a sample.

In accordance with one of the embodiments of the invention, the selected samples before measurements are cleaned.

In accordance with another embodiment of the invention, the selected sample is saturated at least once with a fluid with known properties that differ from the properties of air by at least ten times, the thermal conductivity of the saturated sample is measured, and the measured thermal conductivity of the saturated sample and the calculated thermal conductivity are further compared. Adaptation of the created petrophysical model of the reservoir can be carried out by changing the parameters characterizing the structure of the void space of the reservoir rock or by changing the parameters characterizing the structural and texture factors, or by changing the parameters characterizing the mineral component composition of the reservoir rock.

Samples of the reservoir may be samples of a full-sized core or its fragments, samples of a standard core, particles of drill and / or landslide, as well as briquettes consisting of particles bonded together by a binder with known thermal and mechanical properties.

In accordance with one embodiment of the invention, a petrophysical model of the rock of the reservoir can be created based on the theory of effective media, while the heterogeneity of the rock is represented as ellipsoids of revolution with different aspect ratios of the main axes.

In accordance with another embodiment of the invention, the velocities of the longitudinal acoustic wave and / or transverse acoustic wave through the sample are measured, based on the created petrophysical model of the reservoir, the velocities of the corresponding acoustic wave are calculated, the measured and calculated acoustic wave velocities are compared, and additionally, the measured and calculated acoustic wave velocities.

In accordance with another embodiment of the invention, the dependence of the thermal conductivity of the sample on time, temperature and / or pressure is additionally measured. On the basis of the created petrophysical model of the reservoir, the corresponding dependence of the thermal conductivity of the sample on time, temperature and / or pressure is calculated, the measured and calculated dependencies are compared, and additionally, the measured and calculated dependences of the thermal conductivity of the sample on time, temperature and / or pressure coincide.

The invention is illustrated by drawings, where in FIG. 1 is a block diagram of one embodiment of the invention; in FIG. 2 compares the calculation of the velocity of a longitudinal acoustic wave of a briquette calculated by the theory of effective media with the measured velocity of a longitudinal acoustic wave; in FIG. Figure 3 shows a comparison of the velocity of a transverse acoustic wave of a briquette calculated by the method theories of effective media with measured shear acoustic wave velocity; in FIG. 4 shows a comparison of calculated and experimental data on thermal conductivity, longitudinal and transverse acoustic wave velocities for dry and water-saturated samples of Bentheimer sandstone; in FIG. 5 shows the experimental data of the dependence of thermal conductivity on the applied load during uniaxial compression; in FIG. Figure 6 shows how the internal pore space of the sample changes under the applied pressure using two histograms of the shape distribution density function (aspect ratio) of the pore space elements; in FIG. 7. presents the results of comparing the measured and calculated dependences of V and V _s on the stress of the applied axial load.

In FIG. 1 shows an example implementation of the method, including several steps. In the figure, _Corg is the content of organic carbon, H (T, P) is the thermal conductivity measured in the temperature range T and pressure P ranging from laboratory to reservoir conditions.

At step 1, at least one reservoir rock sample is taken. The rock samples may be a full-sized core or fragments thereof, standard core samples, particles of drill and / or landslide, briquettes consisting of particles bonded together by a binder with known thermal and mechanical properties. Profile studies of a full-sized core can compile statistics and compare the values of simulated mechanical properties with the results of acoustic logging (I. Bayuk, Yu. Popov, A. Parshin A New Powerful Tool For Interpreting And Predicting In Reservoir Geophysics: Theoretical Modeling As Applied To Laboratory Measurements Of Thermal Properties, International Symposium of the Society of Core Analysts held in Austin, Texas, USA, Septemberl8th - 21 st, 201 1; Popov YA, Mikhaltseva IV, Chekhonin EM, Popov EY, Romushkevich RA, Kalmykov GA and Latypov ID, Application of Effective Medium Theory to Reconstruction of Elasticity Tensor of Bentheimer Sandstone, 17th science and applied research conference on oil and gas geological exploration and development, 7 - 10 September 2015 Gelendzhik, R ussia Geomodel 2015).

Studies of standard core samples are preferred - for the Russian Federation, these are cylinders with a diameter of 30 mm and a height of 25 ... 60 mm - since there are a significant number of standard methods tested for determining the thermal and mechanical properties, density and porosity of such samples, and a significant amount of standard equipment has been produced for such measurements (GOST 21 153.2-84 Rock Formations. Methods for determining the tensile strength under uniaxial compression).

The particles of landslide sludge can be studied similarly to the samples of a standard core and a full-sized core if their linear dimensions are sufficient to determine the thermal conductivity by the method chosen by the experimenter.

The particles of drill cuttings after cleaning from the drilling fluid and drying are examined in the form of a suspension with an aqueous solution of salt; a briquette formed by compression with a binder (for example, fine-grained paraffin); tablets formed by gluing the sludge by any polymer (for example, a two-component epoxy resin).

In stage 2, a preliminary cleaning of the sample from hydrocarbons can be performed using standard methods (see, for example, API. Recommended Practices for Core Analysis. Recommended Practice 40, Second edition, February 1998. SECTION 3. Core Screening and Core Preparation. 3-6. PP. 3-5. Http://w3.energistics.org/RP40/rp40.pdf).

In step 3, the density, porosity, and component composition of the rock are determined using standard methods (US Pat. No. 8,967,249) from a selected rock sample. Also conduct measurements of thermal conductivity of the sample. Thermal conductivity measurements can be carried out, for example, by optical scanning (see, for example, Popov Yu.A. Theoretical models for determining the thermal properties of rocks based on mobile sources of thermal energy, 1983, University Bulletin, Geology and Exploration,, ° 9, pp. 97-103), or by the linear source method (ASTM D5334 - 08 Standard Test Method for Determination of Thermal Conductivity of Soil and Soft Rock by Thermal Needle Probe Procedure), etc.

Then, based on the obtained values of density, porosity and component composition of the rock, a petrophysical model of the rock of the reservoir is created and, using the created petrophysical model of the reservoir, the thermal conductivity of the rock sample is calculated (step 4). The petrophysical model of the reservoir may include data on the mineralogical composition of the rock, texture and structural features of the pore space and skeleton, and open porosity, which are taken into account in models constructed using the theory of effective media. In the simplest case, the model can be reduced to models of layered media, where the properties of the studied rock are determined by averaging the average 0 _/ Λ ^{and the} geometric mean according to Reuss

the empirical dependence of the measured properties with the properties of its individual components is the average logarithmic averaging according to Lichtenekker I = I ^ ¹ · ... · I ^ "and more complex variants of the properties of the mineralogical components and the fluid filling the pores.

At stage 5, the values of the measured thermal conductivity are compared with those calculated by the petrophysical model and the model is adapted (in the simplest case, by correction of the mineralogical composition, or by choosing an alternative method of averaging the properties while maintaining the composition, in more complex cases, by correction of the texture and structural parameters of the model).

At stage 6, an adapted model is used to calculate the mechanical properties of the rock (stage 7), based on knowledge of the mechanical properties of the mineralogical components of the skeleton and the fluid filling the pores.

In addition to measuring thermal properties, the mechanical properties of a fraction of the samples can be measured, for example, the propagation velocity of a longitudinal and transverse acoustic wave, since additional input data can improve the accuracy of modeling mechanical properties.

In accordance with another embodiment of the invention, the sample is saturated at least once with a fluid with known thermal and mechanical properties that differ by at least ten times with respect to air and conduct additional measurements of thermal conductivity on a saturated rock sample. This allows you to increase the number of unknown model parameters and characterize complex types of reservoirs.

The following is an example implementation of a method for determining the mechanical properties of a reservoir rock by creating a petrophysical model of the reservoir material from the results of measurements of the thermal conductivity of pressed briquettes and the propagation velocities of the longitudinal and transverse ultrasonic waves, the adaptation of this model and the calculation of the longitudinal and transverse wave velocities of the source rock. Briquettes are made of fine-grained paraffin and particles of these materials, such as: Bentheimer sandstone, white marble, low-porous sandstone,

First, at least one reservoir rock sample is taken. In this example, briquettes are made from crushed rock fragments sifted and sieved on a sieve with a mesh size of 1 mm mixed with Hoenscht paraffin powder (particle density of paraffin 1 g / cm ³ ) in a Retsch MM400 vibratory ball mill. Mass fractions of the components were 4: 1 (solid material: paraffin). Briquettes were pressed in a Retsch PP25 hand press with a load of 25 tons. The diameter of the briquettes was 32 mm, the height was 6 ... 9 mm.

Then determine the physical properties of the samples and measure the thermal conductivity. The thermal conductivity of the briquettes is measured, for example, by optical scanning, the propagation velocity of a longitudinal and transverse ultrasonic wave (V and V _s , respectively) - through sounding at a frequency of 2.5 MHz under room conditions. The porosity of the briquette is determined by the known mineral density of the solid material from which the fragments of the solid phase are made (determined, for example, by hydrostatic weighing), the known density of the binder paraffin and the mass fractions of the weight of the briquette made of. The thermal conductivity of pure paraffin is determined by optical scanning on several briquettes pressed without the inclusion of a solid phase.

The physical properties of the obtained briquettes with a known component composition are presented in Table 1.

Table 1. Physical properties of briquettes

Dense

Heat conduction - K-t Heat conduction

Name t

briquette density, V km / s V, km / s Poisson solid phase, pp sample briquette,

W / (m K) briquette W / (m-K) g / cm3

1 MR-1 1.846 0.87 1.10 1.75 0.24 2.76

2 MR-3 1.920 0.94 1.18 1.54 0.14 2.76 3 BTN-1 1.854 0.92 0.65 1.98 0.33 2.80

4 BTN-2 1.740 0.81 0.60 2.23 0.37 2.80

5 BTN-3 1.829 0.81 0.64 1.89 0.31 2.80

6 SSX- 8442-1 1.801 0.97 1.02 1.85 0.29 3.42

7 SSX- 8442-2 1.836 0.97 0.88 1.97 0.33 3.42

8 SSX- 6417-1 1,862 1,06 1,07 1,58 0,16 3,47

9 SSX- 6417-2 1, 984 1.29 1.03 1.59 0.17 3.47

10 SSX- 6238-1 1.807 1.04 1.08 1, 65 0.21 3.74

11 SSX- 6238-2 1.843 1.10 1.03 1.52 0.12 3.74

12 SSX- 5005-1 1.919 1.15 1.08 1.55 0.14 3.32

13 SSX- 5005-2 1.961 1.19 0.97 1.75 0.26 3.32

14 Paraffin 0.929 0.25 0.92 2.22 0.37 -

To determine the propagation velocities of longitudinal and transverse waves in the solid phase of the briquette from the results of measurements of the thermal conductivity of the briquette and the velocities, a model of the briquette is constructed using the theory of effective media, as described below.

To solve this problem, based on the obtained density, porosity and component composition, a petrophysical model of the reservoir rock is created using the theory of effective media. The theory of effective media allows us to associate the effective properties of a briquette with parameters that describe the features of its structure. In addition to the volume content and physical properties of the components of the produced briquette, such parameters can also be the shape of individual grains or elements of the pore space of the briquettes.

The description of the parameters that most closely approximate the mathematical model of the medium with the real medium allows one to relate the various effective properties of the briquette by means of a formula relating the transport and elastic properties of the briquette.

The effective elasticity tensor is reconstructed using the method of the theory of effective media in the generalized singular approximation (see Bayuk I.O. Basic principles of mathematical modeling of macroscopic physical properties of hydrocarbon reservoirs. Seismic technology, Ne 4, 2013, pp. 5-18), according to to which transport properties are associated with the elastic properties of the rock through parameters describing its structure:

X ^* = <X (r) (/ - q * (X (z) - X ^e )) ^"1 ) - <(/ - q - (X (z) - X ^e )) ^" V ¹ (2) where X ^* is the thermal conductivity or elasticity tensor for a thermal or elastic rock model, respectively, 'g is the second derivative of the tensor Green function of the equilibrium equation, depending on the shape of cracks and pores and the properties of the reference body; X ^e is the corresponding tensor of the so-called comparison body, which is selected depending on the structure of the medium; / is the unit tensor. Here, triangular brackets indicate averaging over the volume of the sample.

The mathematical model of briquettes can be determined as a result of a comprehensive visual and experimental analysis of available samples. For briquettes, for example, it is possible to establish the presence of air gaps associated with the manufacturing conditions of these briquettes. After determining the structural features of the briquettes, the model should be built in two stages:

At the first stage, the properties of the known components of the mineral composition and paraffin are averaged using formula (2) using the self-consistency method, i.e. instead of X ^e substitute X ^* . The shape of the grains of minerals is established as a result of analysis of thin sections, or microphotograms of sludge particles, for some sandstones it is spherical. Then, the effective properties of this medium are calculated. This medium is called intermediate.

In the next step, air layers are introduced into the intermediate medium. Using the formula (2) using the same method of self-consistency, the effective properties (thermal and elastic) of the briquette are calculated.

Then, the obtained data are compared with the experimental ones. Solving the problem of optimizing the discrepancy between the calculated and experimental values, unknown parameters are determined. So, for briquettes, two values are unknown - this is the volume of air layers and their shape.

Subsequently, the unknown values found are used for this type of test breed. It is postulated that one type of rock corresponds to a single value of unknown parameters. The constructed model is used to calculate the longitudinal and transverse acoustic velocities of the studied rocks, as well as the calculation of dynamic elastic moduli (Young's modulus, bulk compression modulus, etc.) using standard conversion formulas.

In FIG. 2 shows a comparison of calculating the velocity of a longitudinal acoustic wave of a briquette using the theory of effective media with a measured velocity, and FIG. 3 is a comparison of the calculation of the velocity of a transverse acoustic wave of a briquette by the theory of effective media with a measured speed. In figure 2 and fig.Z the following notation is used. MR - samples made from white marble, BTN - samples Bentheimer, SSX - low porous sandstone. The abbreviations “exp.” Mean experimental data, and “calculation” mean calculated data obtained using the constructed model.

Let us consider another example of the creation, calibration, and application of a petrophysical model for measuring the thermal conductivity of standard core samples for modeling the mechanical properties of Upper Cretaceous (2) Bentheimer sandstone. This sandstone is well studied and used as a model rock in various laboratory studies, due to the stable mineralogical composition (> 90% of quartz), capacitive (23-25%) and filtration (2-4 D) properties. In the presented example, the study was carried out on 20 samples with a length of 50 mm and a diameter of 30 mm in dry and water-saturated (NaCl solution with a concentration of 15 g / l) conditions. The thermal properties of water differ from the thermal properties of air by more than ten times (thermal conductivity of air is 0.024 W / (m-K), and thermal conductivity of water is 0.60 W / (m-K)).

The thermal conductivity of the samples was measured by optical scanning.

The propagation velocity of the longitudinal and transverse ultrasonic waves (V _p and V _s , respectively) - through sounding method at a frequency of 250 kHz under room conditions. Variations in the measured thermal conductivity and V did not exceed 5% for each sample, and, subsequently, they were considered isotropic.

To calculate the effective properties of the rock, formula (2) is used. The form of pore space elements for a given Bentheimer sandstone is described aspect ratio (the ratio of the semiaxes of an ellipsoid), obeying a two-parameter beta distribution for elements of the pore space:

^PW Γ (α) Γ (0) ^S)

where p (s) is the probability density of the beta distribution of the aspect ratio s, Γ is the gamma function, and β are the parameters of the beta distribution. The selection of a comparison body for a given Bentheimer sandstone is carried out using the method with the parameter of connectivity of pore space elements, in which a linear combination is chosen as the comparison body

where X ^mat , X ¹ⁱ is the corresponding thermal conductivity or elasticity tensor for the mineral matrix and fluid, f is the coupling parameter in the range from 0 to 1 (the boundary values correspond to the values of effective properties according to the upper and lower Hashin-Shtrikman boundaries).

Based on the results of the structural analysis, a rock model is constructed, which is a medium composed of rounded quartz grains (mainly) and intergranular space in the form of finite elements of various shapes. Due to the isotropy of properties in the medium model, there are no distinguished directions of both mineral grains and pore space elements, while equation (2) is simplified, and only two independent parameters are used to describe the elastic tensor, and one is used for thermal conductivity.

Application of the method with the parameter of connectivity of the elements of the pore space to the entire set of experimental data allows us to solve the problem with acceptable accuracy. Deviation between calculated and measured data for all samples

(Fig. 4) was not more than 2.5%, 12% and 15% for thermal conductivity, V _p and V _s, respectively, in a dry and water-saturated state.

Consider another example in which the dependence of the thermal conductivity of the sample on time, temperature and / or pressure is additionally measured. Based on the created petrophysical model of the reservoir, the corresponding dependence of the thermal conductivity of the sample on time, temperature and / or pressure is calculated, the measured and calculated dependencies are compared, and additionally, coincidence of the measured and calculated dependences of the thermal conductivity of the sample on time, temperature and / or pressure.

Thermal conductivity is measured for two cylindrical 050 mm Bentheimer sandstone samples using a linear source method, depending on the magnitude of the applied axial load (Fig. 5). The load is increased to a value of 20 MPa, providing elastic deformation of the sample (ARMA-16-128. Yalaev, TR Bayuk I. O., Tarelko NF, Abashkin VV Connection of Elastic and Thermal Properties of Bentheimer Sandstone Using Effective Medium Theory (Rock Physics). Proceedings of American Rock Mechanics Association Conference, Houston, 26-29 of July, 2016).

As a reference model, use the model developed for 20 samples of Bentheimer sandstone at room conditions, described in the example above. The following assumptions are made: when the axial load stress is up to 20 MPa, the change in porosity is insignificant (less than 0.5%), and the properties of the mineral components that make up the sample do not change. For various pressures, unknown structure parameters were calculated from the obtained experimental data from the solution of the optimization problem. By constructing a histogram of the distribution density function for different axial stresses, a change in the structure of the pore space of the sample is evaluated. For example, it can be seen from (Fig. 6) that with the application of an axial load, voids with a high aspect ratio (cracks) partially close.

The found structure parameters are used to calculate the dependence of V _p and V _s on the applied load. On (Fig. 7) presents the results of comparing the measured and theoretical dependences of V and V _s on the stress of the applied axial load.

Claims

Claim

1. The method of determining the mechanical properties of the rock of the reservoir, in accordance with which:

"at least one reservoir rock sample is taken,

"on the selected rock sample determine the density, porosity, and component composition of the rock,

"measure the thermal conductivity of the rock sample,

“based on the obtained values of density, porosity and component composition of the rock, a petrophysical model of the reservoir rock is created,

"using the created petrophysical model of the reservoir, calculate the thermal conductivity of the rock sample,

"compare the measured and calculated thermal conductivity of the rock sample,

"if the measured and calculated thermal conductivities match, the mechanical properties of the rock are determined using the created petrophysical model of the reservoir,

"if there is a discrepancy between the values of the measured and calculated thermal conductivity, the created petrophysical model of the reservoir is adapted at least once by changing the model parameters, the adapted petrophysical model is used to calculate the thermal conductivity of the rock sample and the measured and calculated thermal conductivity are compared until the values of the measured and calculated heat capacities,

• if the values of the measured and calculated thermal conductivities coincide, the mechanical properties of the rock are determined using an adapted petrophysical model of the reservoir.

2. The method according to claim 1, wherein the mechanical properties of the reservoir rock are the longitudinal and transverse waves passing through the sample material.

3. The method according to n.l, according to which the selected samples are cleaned before measurements.

5. The method according to claim 1, whereby the adaptation of the created petrophysical model of the reservoir is carried out by changing the parameters characterizing the structure of the void space of the rock of the reservoir.

6. The method according to claim 1, in accordance with which the adaptation of the created petrophysical model of the reservoir is carried out by changing the parameters characterizing the structural and texture factors.

7. The method according to claim 1, whereby the adaptation of the created petrophysical model of the reservoir is carried out by changing the parameters characterizing the mineral component composition of the rock of the reservoir.

8. The method according to claim 1, in accordance with which the samples of the reservoir are samples of a full-sized core or its fragments.

9. The method according to claim 1, in accordance with which the samples of the reservoir are samples of standard core.

10. The method according to claim 1, in accordance with which the samples of the reservoir are particles of drill and / or landslide.

1 1. The method according to claim 1, in accordance with which the samples of the reservoir are particles bonded together by a binder material with known thermal and mechanical properties.

12. The method according to claim 1, in accordance with which the petrophysical model of the rock of the reservoir is created on the basis of the theory of effective media and heterogeneity of the rock is represented in the form of ellipsoids of revolution with different aspect ratios of the main axes.

13. The method according to claim 1, in accordance with which at least one additional mechanical characteristic of the sample is measured, based on the created petrophysical model of the reservoir, the corresponding mechanical characteristic of the sample is calculated, the measured and calculated mechanical characteristics of the sample are compared, and additionally, the measured and calculated coincide mechanical characteristics of the sample.

14. The method according to item 13, in accordance with which the additional mechanical characteristic of the sample is the speed of transmission of a longitudinal and / or transverse acoustic wave.

15. The method according to claim 1, in accordance with which the selected sample is saturated at least once with a fluid with known properties that differ from the properties of air by at least ten times, the thermal conductivity of the saturated sample is measured, and the measured thermal conductivity of the saturated sample and calculated thermal conductivity.

15. The method according to claim 1, according to which the dependence of the thermal conductivity of the sample on time, temperature and / or pressure is additionally measured, based on the created petrophysical model of the reservoir, the corresponding dependence of the thermal conductivity of the sample on time, temperature and / or pressure is calculated, and the measured and the calculated dependencies and additionally ensure that the measured and calculated dependences of the thermal conductivity of the sample on time, temperature, and / or pressure are consistent.