A method and system for selecting the optimal vertically modified stratigraphic interval in hot dry rock boreholes.

Abstract

This invention discloses a method and system for selecting the optimal vertical stimulation interval for hot dry rock boreholes. The method quantitatively characterizes the lithology, physical properties, thermal properties, rock mechanical properties, and geostress characteristics of the rock mass along the borehole's vertical direction based on conventional logging data, wellbore acoustic scanning imaging logging data, microresistivity scanning imaging logging data, dipole array acoustic logging data, and natural gamma ray spectroscopy logging data. This comprehensive evaluation determines the optimal vertical stimulation interval for the hot dry rock borehole. This method performs logging evaluation and selection of the five properties of the rock mass encountered by the hot dry rock borehole, enabling the analysis and selection of the dominant vertical rock strata in hot dry rock, and effectively guiding the stimulation of high-temperature geothermal hot dry rock reservoirs.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature geothermal new energy logging evaluation technology, and relates to a method and system for selecting the vertical modification interval of a dry hot rock borehole. Background Technology

[0002] Hot dry rock, as an important clean new energy source for the future, has enormous development potential and prospects. Currently published patent literature involves the selection of favorable lateral zones for hot dry rock, such as CN107133878A, "A Method for Selecting Hot Dry Rock Zones for Geothermal Projects." This method comprehensively analyzes hot dry rock resource conditions, engineering conditions, and post-development application conditions to obtain comprehensive analysis results for the selected hot dry rock zones. It allows for comparative analysis of lateral sweet spots among multiple different hot dry rock zones under a unified standard. However, how to utilize well logging data for vertical sweet spot comparison analysis of hot dry rock to achieve the selection of favorable rock masses lacks a systematic technical method and process, and no publicly published patent literature has been found. Summary of the Invention

[0003] To address the problems existing in the prior art, the present invention provides a method and system for selecting the optimal longitudinal modified strata in hot dry rock boreholes, thereby solving the technical problem that the prior art cannot achieve the optimal selection of the optimal longitudinal strata in hot dry rock.

[0004] This invention is achieved through the following technical solution:

[0005] A method for selecting the optimal vertically modified strata in a hot dry rock borehole includes the following steps:

[0006] Acquire conventional logging data, peri-well acoustic scanning imaging logging data, micro-resistivity scanning imaging logging data, natural gamma spectroscopy logging data, and dipole array acoustic logging data for hot dry rocks.

[0007] Based on the conventional logging data, wellbore acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma spectroscopy logging data, and dipole array acoustic logging data, the formation lithology, physical properties, thermal properties, rock mechanical properties, and geostress properties of the longitudinal rock mass of the hot dry rock borehole are obtained.

[0008] The optimal vertical modification section for the dry hot rock borehole is determined based on the stratigraphic lithology, physical properties, thermal properties, rock mechanical properties, and geostress properties of the longitudinal rock mass obtained from the dry hot rock borehole.

[0009] Preferably, the stratigraphic lithology of the longitudinal rock mass of the hot dry rock borehole is obtained through conventional logging data and natural gamma ray spectroscopy logging data; specifically, cluster analysis is applied to obtain the stratigraphic lithology of the longitudinal rock mass of the hot dry rock borehole based on the natural gamma ray spectroscopy logging lithology identification chart.

[0010] Preferably, the physical properties of the longitudinal rock mass in the hot dry rock borehole are obtained based on conventional logging data and microresistivity scanning imaging logging data; the physical properties include matrix physical properties and secondary biological properties.

[0011] The matrix properties include matrix porosity, and the secondary bioactivity includes crack porosity;

[0012] The process of obtaining the matrix porosity is as follows:

[0013] First, a high resistivity background compact layer segment is selected using histogram statistics to determine the density framework, acoustic framework, or neutron framework of the corresponding stratum. Then, the matrix porosity is determined using at least one of the density framework, acoustic framework, or neutron framework.

[0014] The specific method for obtaining the crack porosity is as follows:

[0015]

[0016] In the formula, FVAH is the fracture porosity, FVTL is the fracture length, FCAH is the fracture width, and CAL is the well diameter.

[0017] Preferably, based on natural gamma ray spectroscopy logging data, the thermal characteristics of the longitudinal rock mass of the dry hot rock borehole are obtained, and the thermal characteristics include thermal conductivity, heat generation rate and geothermal gradient;

[0018] The thermal conductivity is obtained specifically as follows:

[0019] λ B =λ1V1+λ2V2……+λ n V n

[0020] In the formula, λ B Total thermal conductivity;

[0021] λ1, λ2·····λ n The thermal conductivity of each rock component;

[0022] V1, V2, ... V n The volume content of each rock;

[0023] The heat generation rate is obtained specifically as follows:

[0024] H = 0.01ρ(9.53C) U +2.56C Th +3.48C K )

[0025] In the formula, H is the heat generation rate, ρ is the density, and C is the density. U C represents the abundance of uranium. Th For the abundance of thorium, C K The abundance of potassium;

[0026] The geothermal gradient is obtained specifically as follows:

[0027]

[0028] Among them, G step Let T be the geothermal gradient, step be the given step size, and T be the temperature gradient. bottom Given the bottom boundary temperature within a given step size range, T top The top limit temperature is defined within a given step size range.

[0029] Preferably, the rock mechanical properties of the longitudinal rock mass in the hot dry rock borehole are obtained based on dipole array acoustic logging data; the rock mechanical properties include one-dimensional static rock mechanical parameters and the magnitude of formation anisotropy;

[0030] The specific process for obtaining the one-dimensional dynamic rock mechanics parameters is as follows:

[0031] The longitudinal and transverse wave time differences extracted by array acoustic waves are combined with density and clay content curves from conventional well logging.

[0032] By combining the longitudinal and transverse wave time differences extracted by the array acoustic waves with the density and clay content curves from conventional well logging, dynamic Poisson's ratio, Young's modulus, bulk modulus, shear modulus, and Lamé constant are obtained, thus completing the acquisition of one-dimensional dynamic rock mechanics parameters.

[0033] The process of obtaining the magnitude of the formation anisotropy is as follows: the difference between fast and slow shear waves obtained by separating the shear wave field is used to obtain the magnitude of the formation anisotropy.

[0034] Preferably, the geostress characteristics of the longitudinal rock mass in the dry hot rock borehole are obtained based on well perimeter acoustic scanning imaging, microresistivity scanning imaging, and dipole array acoustic logging data; the determination of the geostress characteristics includes the determination of the geostress direction and the determination of the geostress magnitude.

[0035] Preferably, for wellbore acoustic scanning imaging and microresistivity scanning imaging logging data, the geostress direction is determined by the wellbore collapse method and the induced fracture method; for dipole array acoustic logging data, the geostress direction is determined by the fast shear wave azimuth method.

[0036] A system for selecting the optimal vertically modified strata in hot dry rock boreholes includes:

[0037] Data acquisition module: The data acquisition module is used to acquire conventional logging data, wellbore acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma ray spectroscopy logging data, and dipole array acoustic logging data of hot dry rocks.

[0038] First data processing module: The first data processing module is used to obtain the formation lithology, physical properties, thermal properties, rock mechanical properties and geostress properties of the longitudinal rock mass of the dry hot rock borehole based on the conventional logging data, well perimeter acoustic scanning imaging logging data, micro resistivity scanning imaging logging data, natural gamma ray spectroscopy logging data and dipole array acoustic logging data.

[0039] Second data processing module: The second data processing module is used to determine the optimal vertical modification section of the dry hot rock borehole based on the stratigraphic lithology, physical properties, thermal properties, rock mechanical properties and geostress properties of the obtained dry hot rock borehole longitudinal rock mass.

[0040] A terminal device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the steps of the above-described method when executing the computer program.

[0041] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described method.

[0042] Compared with the prior art, the present invention has the following beneficial technical effects:

[0043] This invention discloses a method for selecting the optimal vertical stimulation interval for hot dry rock boreholes. First, it obtains the lithology, physical properties, thermal properties, rock mechanical properties, and in-situ stress characteristics of the rock mass along the borehole's vertical direction using conventional logging data, wellbore acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma ray spectroscopy logging data, and dipole array acoustic logging data. Then, it determines the optimal vertical stimulation interval for the hot dry rock borehole based on these lithology, physical properties, thermal properties, rock mechanical properties, and in-situ stress characteristics. This method, based on conventional logging, acoustic, microresistivity scanning imaging logging, and array acoustic logging data obtained from hot dry rock boreholes, evaluates and optimizes the five properties of the rock mass encountered by the borehole, achieving the analysis and selection of the dominant vertical rock strata in hot dry rock, and effectively guiding the stimulation of high-temperature geothermal hot dry rock reservoirs. Attached Figure Description

[0044] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1This is a flowchart illustrating a method for selecting the optimal longitudinal modification layer in a hot dry rock borehole according to the present invention.

[0046] Figure 2 This is a schematic diagram of the process of obtaining the stratigraphic lithology of the vertical rock mass in a dry hot rock borehole using cluster analysis based on the natural gamma ray spectroscopy logging lithology identification chart in this invention.

[0047] Figure 3 This is a schematic diagram of the structure of a preferred system for longitudinal modification of strata in hot dry rock drilling according to the present invention;

[0048] Figure 4 This is a flowchart illustrating the technical process of a method for selecting the optimal longitudinal modification layer in a hot dry rock borehole according to Embodiment 3 of the present invention.

[0049] Figure 5 This is a lithology identification chart established based on the total natural gamma (GR) and thorium (TH) / uranium (U) content ratio in natural gamma spectroscopy logging in Example 3 of the present invention.

[0050] Figure 6 This is a result diagram of the application of wellbore collapse in wellbore scanning data to determine the direction of geostress in Embodiment 3 of the present invention;

[0051] Figure 7 This is a result diagram of the application of induced fractures in wellbore acoustic scanning data to determine the direction of geostress in Embodiment 3 of the present invention;

[0052] Figure 8 This is a diagram showing the results of using fast shear waves from array acoustic logging data to determine the direction of geostress in Embodiment 3 of the present invention.

[0053] Figure 9 This is a diagram showing the results of calculating fracture parameters using electrical imaging logging data in Embodiment 3 of the present invention.

[0054] Figure 10 This is a comprehensive evaluation index diagram of rock mass determined based on the "five properties" in Embodiment 3 of the present invention. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0056] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0057] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0058] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0059] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0060] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0061] The present invention will now be described in further detail with reference to the accompanying drawings:

[0062] Example 1

[0063] like Figure 1 As shown, this invention discloses a method for selecting the optimal longitudinally modified strata in hot dry rock boreholes, comprising the following steps:

[0064] S1: Acquire conventional logging data, wellbore acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma spectroscopy logging data, and dipole array acoustic logging data for hot dry rocks.

[0065] S2: Based on the conventional logging data, wellbore acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma ray spectroscopy logging data, and dipole array acoustic logging data, obtain the formation lithology, physical properties, thermal properties, rock mechanical properties, and geostress properties of the longitudinal rock mass of the hot dry rock borehole.

[0066] Specifically, the stratigraphic lithology of the vertical rock mass in the hot dry rock borehole was obtained using conventional logging data and natural gamma spectroscopy logging data; for example: Figure 2 As shown, cluster analysis was used to obtain the stratigraphic lithology of the longitudinal rock mass in the dry hot rock borehole based on the natural gamma spectral logging lithology identification chart.

[0067] In addition, the physical properties of the longitudinal rock mass in the dry hot rock borehole are obtained based on conventional well logging scanning imaging data, well perimeter acoustic scanning imaging data, and micro-resistivity scanning imaging data; the physical properties include matrix physical properties and secondary biological properties.

[0068] The matrix properties include matrix porosity, and the secondary bioactivity includes crack porosity;

[0069] The process of obtaining the matrix porosity is as follows:

[0070] First, a high resistivity background compact layer is selected using histogram statistics to determine the density skeleton, acoustic skeleton, or neutron skeleton of the corresponding strata. Then, the matrix porosity is determined using at least one of the density skeleton, acoustic skeleton, or neutron skeleton. Since the target dry hot rock is of pure lithology, clay correction is not considered in the calculation process, and the matrix porosity is calculated using a well-known porosity model in the field.

[0071] The acquisition of fracture porosity is specifically as follows: First, using the micro-resistivity scanning imaging and wellbore acoustic scanning imaging processing modules in industry-specific processing software, fractures are picked up interactively from static or dynamic image channels obtained from micro-resistivity scanning imaging and wellbore acoustic scanning imaging. Then, statistical analysis is performed to obtain the fracture length and fracture width, and then the fracture porosity is calculated, specifically as follows:

[0072]

[0073] In the formula, FVAH is the fracture porosity, FVTL is the fracture length, FCAH is the fracture width, and CAL is the well diameter.

[0074] Meanwhile, based on natural gamma spectral logging data, the thermal characteristics of the longitudinal rock mass in the dry hot rock borehole are obtained. These thermal characteristics include thermal conductivity, heat generation rate, and geothermal gradient. The thermal conductivity can be quantitatively characterized based on logging lithology. The continuous thermal conductivity within the borehole is obtained through a dispersion model. Based on this, temperature and pressure correction can be performed to accurately obtain the in-situ thermal conductivity of the reservoir.

[0075] The thermal conductivity is obtained specifically as follows:

[0076] λ B =λ1V1+λ2V2……+λ n V n

[0077] In the formula, λ B Total thermal conductivity;

[0078] λ1, λ2·····λ n The thermal conductivity of each rock component;

[0079] V1, V2, ... V n The volume content of each rock;

[0080] The heat generation rate is obtained using the Rybach calculation model, specifically:

[0081] H = 0.01ρ(9.53C) U +2.56C Th +3.48C K )

[0082] In the formula, H is the heat generation rate, uW / m 3 ρ is density, g / cm³ 3 C U C represents the abundance of uranium. Th For the abundance of thorium, C K The abundance of potassium;

[0083] The geothermal gradient is obtained specifically as follows:

[0084]

[0085] Among them, G step The temperature gradient is represented by step, where step is the given step size in meters (m). The temperature gradient is T. bottom T represents the bottom boundary temperature within a given step size range, in °C. top The top limit temperature (°C) is given within a given step size range.

[0086] Furthermore, based on dipole array acoustic logging data, the rock mechanical properties of the longitudinal rock mass in the hot dry rock borehole are obtained; the rock mechanical properties include one-dimensional static rock mechanical parameters and the magnitude of formation anisotropy;

[0087] Specifically, by combining the P-wave and S-wave time differences extracted from array acoustic waves with density and clay content curves from conventional well logging, and using well-known models in the field, one-dimensional dynamic rock mechanics parameters such as dynamic Poisson's ratio, Young's modulus, bulk modulus, shear modulus, and Lamé constant can be calculated. If laboratory rock sample rock mechanics parameter analysis results are available, the dynamic-to-static conversion coefficients of Young's modulus and Poisson's ratio can be calibrated, thereby obtaining one-dimensional static rock mechanics parameters. The difference between fast and slow S-waves obtained from S-wave field separation can be used to quantitatively characterize the magnitude of formation anisotropy.

[0088] Furthermore, the geostress characteristics of the longitudinal rock mass in the dry hot rock borehole are obtained based on wellbore acoustic scanning imaging, microresistivity scanning imaging, and dipole array acoustic logging data; the determination of the geostress characteristics includes the determination of the geostress direction and the determination of the geostress magnitude.

[0089] Specifically, the determination of the direction of geostress is as follows: (1) For wellbore acoustic scanning imaging and microresistivity scanning imaging logging data, the direction of geostress can be determined by two methods: wellbore collapse method and induced fracture method (including pressure fracture, stress relief fracture, and drill string vibration fracture); (2) For array acoustic logging data, the direction of geostress can be determined by fast shear wave azimuth method; (3) The above three methods complement and verify each other.

[0090] Calculation of geostress magnitude: This includes calculating the maximum horizontal principal stress, minimum horizontal principal stress, and vertical stress—a total of three-dimensional stresses. Based on the results of previous geostress point testing in the target area, a reasonable stress calculation model is selected to characterize the continuous geostress magnitude in the target well section. Commonly used models for calculating the maximum and minimum horizontal principal stresses include the porous elastic horizontal geostress model, the Mohr-Coulomb stress model, and the Huang model. Vertical stress is obtained using well-known formulas in the field.

[0091] S3: Determine the optimal vertical modification section for the dry hot rock borehole based on the stratigraphic lithology, matrix physical properties, secondary biological properties, thermal properties, rock mechanical properties, and geostress properties of the longitudinal rock mass obtained from the dry hot rock borehole.

[0092] Specifically, the following principles are generally followed when selecting the best lithological intervals for hot and dry rock mass modification: intervals with the aforementioned regional advantages, intervals with high matrix porosity and fracture porosity, intervals with high heat generation rates, intervals with high Young's modulus and low Poisson's ratio, and intervals with low minimum horizontal in-situ stress and small stress differences. All of these conditions should be met simultaneously or as much as possible, and specific considerations should be made based on the actual drilling conditions.

[0093] Furthermore, based on the quantitative evaluation of the above five parameters, individual evaluation indices are constructed respectively. Combined with the needs of hydraulic fracturing stimulation of hot dry rocks, different weights are assigned according to priority levels to obtain the comprehensive evaluation index of advantageous rock masses, providing a well logging quantitative evaluation method for rock mass optimization.

[0094] In a preferred embodiment, the process for obtaining the comprehensive evaluation index of the dominant rock mass in the dry hot rock borehole is as follows:

[0095] The lithology index F1 was determined by reverse normalization of the TH / U ratio.

[0096] The physical property index F2 was determined by positive normalization of matrix porosity and negative normalization of fracture porosity.

[0097] The thermal index F3 was determined by positive normalization of thermal conductivity, positive normalization of heat generation rate, and positive normalization of geothermal gradient.

[0098] The rock mechanical index F4 was determined by positive normalization of Young's modulus and negative normalization of Poisson's ratio.

[0099] The geostress index F5 is determined by reverse normalization of the minimum horizontal principal stress and the horizontal stress difference.

[0100] By prioritizing the physical property index F2 > thermal index F3 > geostress index F5 > rock mechanics index F4 > lithology index F1, and assigning different weight coefficients to each index, the comprehensive evaluation index F of the dominant rock mass is obtained.

[0101] F=W1*F1+W2*F2+W3*F3+W4*F4+W5*F5

[0102] This invention, based on conventional logging and wellbore acoustic scanning imaging, micro-resistivity scanning imaging, and array acoustic imaging logging data, achieves continuous and detailed characterization of the five properties of the longitudinal rock mass in hot dry rock boreholes: lithology, physical properties, thermal properties, rock mechanical properties, and geostress properties. This provides crucial selection criteria for optimal longitudinal reinforcement of hot dry rock boreholes and also offers detailed and reliable foundational data for further detailed lateral three-dimensional geological modeling of target areas. The method of this invention is clear, focused, highly operable, and easy to apply in the field.

[0103] Example 2

[0104] like Figure 3 As shown, the present invention also provides a system for selecting the optimal longitudinal modified strata in hot dry rock boreholes, comprising:

[0105] Data acquisition module: The data acquisition module is used to acquire conventional logging data, wellbore acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma ray spectroscopy logging data, and dipole array acoustic logging data of hot dry rocks;

[0106] First data processing module: The first data processing module is used to obtain the formation lithology, physical properties, thermal properties, rock mechanical properties and geostress properties of the longitudinal rock mass of the dry hot rock borehole based on the conventional logging data, well perimeter acoustic scanning imaging logging data, micro resistivity scanning imaging logging data, natural gamma ray spectroscopy logging data and dipole array acoustic logging data.

[0107] Second data processing module: The second data processing module is used to determine the optimal vertical modification section of the dry hot rock borehole based on the stratigraphic lithology, physical properties, thermal properties, rock mechanical properties and geostress properties of the obtained dry hot rock borehole longitudinal rock mass.

[0108] Example 3

[0109] To further explain the technical solution of the present invention, the following embodiments are provided:

[0110] like Figure 4 As shown, for conventional logging data, wellbore acoustic scanning imaging, microresistivity scanning imaging, and array acoustic logging data of dry hot rock boreholes in a certain area, the evaluation of the "five properties" logging parameters—lithology, physical properties, thermal properties, rock mechanical properties, and geostress properties—is carried out first.

[0111] Among them, such as Figure 5 As shown, a lithology identification chart is established based on the total natural gamma (GR) and thorium (TH) / uranium (U) element content ratio in natural gamma spectral logging. Further, the stratigraphic lithology of the vertical rock mass in the hot dry rock borehole is obtained based on this lithology identification chart.

[0112] In addition, such as Figure 6 As shown, wellbore collapse data from wellbore perimeter acoustic scanning is used to determine the direction of geostress. The first track is natural gamma (GR), with dual wellbore diameters (C13, C24) and bit size (BIT); the second track is the depth track; the third track is the acoustic scanning time-amplitude static imaging (CBIL_AMP); the fourth track is the acoustic scanning time-dynamic imaging (CBIL_AMP_DYN); the fifth track is the dip angle of the wellbore collapse; and the sixth track is the tendency of the wellbore collapse statistically analyzed according to a specified well section, its orientation indicating the direction of the minimum horizontal principal stress in the rock mass.

[0113] like Figure 7 As shown, the direction of in-situ stress is determined by induced fractures in the wellbore sonic scanning data. Specifically, the first channel is the natural gamma (GR), with dual wellbore diameters (C13, C24) and bit size (BIT); the second channel is the depth channel; the third channel is the fast and slow shear wave waveforms; the fourth channel is the wave velocity anisotropy and the time difference between fast and slow waves; the fifth channel is the maximum energy and minimum energy; and the sixth channel is the dip direction of the induced fractures statistically analyzed according to the specified well section, whose orientation indicates the direction of the maximum horizontal principal stress in the rock mass.

[0114] like Figure 8 The image shows the results of using fast shear waves from array acoustic logging data to determine the direction of geostress. The first channel represents natural gamma, borehole diameter, and drill bit size; the second channel represents depth; the third channel represents static imaging of acoustic scanning time amplitude (CBIL_AMP); the fourth channel represents dynamic imaging of acoustic scanning time (CBIL_AMP_DYN); the fifth channel represents the induced dip angle (dega); the sixth channel represents the anisotropy distribution; and the seventh channel represents the fast shear wave azimuth, which indicates the direction of the maximum horizontal principal stress in the rock mass.

[0115] like Figure 9 The image shown is a result of calculating fracture parameters using electrical imaging logging data. The first track represents natural gamma ray, wellbore diameter, and drill bit size; the second track represents depth; the third track represents fracture density; the fourth track represents fracture length; and the fifth track represents fracture porosity.

[0116] like Figure 10 The table shows the comprehensive rock mass evaluation index determined based on the "five properties". The first property is natural gamma ray, uranium-free gamma ray, borehole diameter 13, borehole diameter 24, and drill bit size; the second property is depth; the third property is deep lateral resistivity and shallow lateral resistivity; the fourth property is density, compensated neutron, acoustic transit time, and photoelectric cross-section index; the fifth property is lithological classification; the sixth property is matrix porosity; the seventh property is fracture porosity; the eighth property is heat generation rate; the ninth property is Young's modulus and Poisson's ratio; the tenth property is vertical stress, maximum horizontal principal stress, and minimum horizontal principal stress; and the eleventh property is the comprehensive rock mass evaluation index.

[0117] Based on the above process, the evaluation results correspond to respectively Figure 7 The fifth, sixth-seventh, eighth, ninth, and tenth boreholes were drilled. Finally, based on comprehensive analysis, the 3681.0-3728.2m section of the borehole was selected as the most favorable rock mass, and artificial fracturing was implemented.

[0118] Example 4

[0119] A schematic diagram of a terminal device according to an embodiment of the present invention. The terminal device of this embodiment includes: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps in the various method embodiments described above. Alternatively, when the processor executes the computer program, it implements the functions of each module / unit in the various device embodiments described above.

[0120] The computer program can be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention.

[0121] The terminal device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0122] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0123] The memory can be used to store the computer program and / or module. The processor implements various functions of the terminal device by running or executing the computer program and / or module stored in the memory and calling the data stored in the memory.

[0124] If the modules / units integrated into the terminal device are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0125] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A preferred method for longitudinal reformation of a section of a hot dry rock borehole, characterized in that, The method comprises the following steps: obtaining conventional logging data, borehole acoustic scanning imaging logging data, micro-resistivity scanning imaging logging data, natural gamma-ray spectral logging data and dipole array acoustic logging data of the hot dry rock; obtaining formation lithology, physical property, thermal property, rock mechanics property and ground stress property of the longitudinal rock mass of the hot dry rock drilling hole according to the conventional logging data, borehole acoustic scanning imaging logging data, micro-resistivity scanning imaging logging data, natural gamma-ray spectral logging data and dipole array acoustic logging data; determining the optimal longitudinal reconstruction interval of the hot dry rock drilling hole according to the formation lithology, physical property, thermal property, rock mechanics property and ground stress property of the longitudinal rock mass of the hot dry rock drilling hole; constructing single evaluation indexes respectively based on the five-property parameter quantitative evaluation, combining with the hydraulic fracturing reconstruction requirement of the hot dry rock, and giving different weights according to the priority level to obtain an advantage rock mass comprehensive evaluation index; the process of obtaining the advantage rock mass comprehensive evaluation index of the hot dry rock drilling hole comprises the following steps: Determination of lithology index by thorium / uranium element back normalization ; Determination of physical property index by forward normalization of matrix porosity and forward normalization of fracture porosity ; Determination of thermal index by thermal conductivity positive normalization, heat generation rate positive normalization, geothermal gradient positive normalization ; Determination of rock mechanics index by positive normalization of Young's modulus and negative normalization of Poisson's ratio ; Determination of stress index by minimum horizontal principal stress reverse normalization and horizontal stress difference reverse normalization ; Through physical property index Heat Index Geostress Index Rock Mechanical Index Lithology Index By prioritizing and assigning different weight coefficients to the above indices, a comprehensive evaluation index of the dominant rock mass is obtained. ; 。 2. A method of longitudinal reformation of a dry hot rock borehole according to claim 1, characterized in that, obtaining formation lithology of the longitudinal rock mass of the hot dry rock drilling hole through the conventional logging data and the natural gamma-ray spectral logging data; specifically, obtaining the formation lithology of the longitudinal rock mass of the hot dry rock drilling hole based on a natural gamma-ray spectral logging lithology identification chart and using a clustering analysis method.

3. A method of longitudinal reformation of a dry hot rock borehole according to claim 1, characterized in that, obtaining physical property of the longitudinal rock mass of the hot dry rock drilling hole based on the conventional logging data and the micro-resistivity scanning imaging logging data; the physical property comprises matrix physical property and secondary physical property; the matrix physical property comprises matrix porosity, and the secondary physical property comprises fracture porosity; the process of obtaining the matrix porosity comprises the following steps: firstly, selecting a high-resistivity background dense layer through a histogram statistical method to determine a density skeleton, an acoustic skeleton or a neutron skeleton corresponding to the formation, and then determining the matrix porosity by using at least one of the density skeleton, the acoustic skeleton or the neutron skeleton; the process of obtaining the fracture porosity comprises the following steps: wherein, is fracture porosity, is fracture length, is fracture width, is hole diameter.

4. A method of longitudinal reformation of a dry hot rock borehole according to claim 1, characterized in that, obtaining thermal property of the longitudinal rock mass of the hot dry rock drilling hole based on the natural gamma-ray spectral logging data; the thermal property comprises thermal conductivity, heat generation rate and geothermal gradient; the process of obtaining the thermal conductivity comprises the following steps: In the formula, Ktotai is the total thermal conductivity; , thermal conductivity of each rock component; , , for each rock volume content; the process of obtaining the heat generation rate comprises the following steps: wherein is the heat generation rate, is the density, is the abundance of uranium, is the abundance of thorium, is the abundance of potassium; the process of obtaining the geothermal gradient comprises the following steps: wherein, is the geothermal gradient, is the given step size, is the bottom temperature of the given step size range, is the top temperature of the given step size range.

5. A method of longitudinal reformation of a dry hot rock borehole according to claim 1, characterized in that, obtaining rock mechanics property of the longitudinal rock mass of the hot dry rock drilling hole based on the dipole array acoustic logging data; the rock mechanics property comprises one-dimensional static rock mechanics parameters and formation anisotropy size; the process of obtaining the one-dimensional dynamic rock mechanics parameters comprises the following steps: obtaining the one-dimensional dynamic rock mechanics parameters by combining the array acoustic wave extracted P-wave and S-wave time difference with the density and shale content curves in the conventional logging data; if there are indoor rock sample rock mechanics parameter analysis results, the Young's modulus and Poisson's ratio dynamic-static conversion coefficient can be calibrated to obtain the one-dimensional static rock mechanics parameters; the process of obtaining the formation anisotropy size comprises the following steps: obtaining the formation anisotropy size by using the difference between the fast and slow S-waves obtained by the S-wave field separation. ​ 6. A method of longitudinal reformation of a dry hot rock borehole according to claim 1, characterized in that, The geostress characteristics of the longitudinal rock mass of the hot dry rock drilling hole are obtained based on the borehole acoustic scanning imaging, the micro-resistivity scanning imaging and the dipole array acoustic logging data; the determination of the geostress characteristics comprises the determination of the geostress direction and the determination of the geostress size.

7. A method of longitudinal reformation of a dry hot rock borehole according to claim 6, characterized in that, The geostress direction is determined by the borehole collapse method and the induced fracture method for the borehole acoustic scanning imaging and the micro-resistivity scanning imaging logging data; the geostress direction is determined by the fast shear wave azimuth method for the dipole array acoustic logging data.

8. A dry hot rock borehole longitudinal reformation section, preferably system, characterized in that, The preferred method for realizing the longitudinal reconstruction interval of the hot dry rock drilling hole according to any one of claims 1-7 comprises: The data acquisition module is used to acquire the conventional logging data, the borehole acoustic scanning imaging logging data, the micro-resistivity scanning imaging logging data, the natural gamma ray spectroscopy logging data and the dipole array acoustic logging data of the hot dry rock; The first data processing module is used to acquire the formation lithology, the physical property, the thermal characteristics, the rock mechanics characteristics and the geostress characteristics of the longitudinal rock mass of the hot dry rock drilling hole according to the conventional logging data, the borehole acoustic scanning imaging logging data, the micro-resistivity scanning imaging logging data, the natural gamma ray spectroscopy logging data and the dipole array acoustic logging data; The second data processing module is used to determine the optimal longitudinal reconstruction interval of the hot dry rock drilling hole according to the formation lithology, the physical property, the thermal characteristics, the rock mechanics characteristics and the geostress characteristics of the longitudinal rock mass of the hot dry rock drilling hole.

9. A terminal device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor executes the computer program to realize the steps of the method according to any one of claims 1-7.

10. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1-9. The computer program is executed by the processor to realize the steps of the method according to any one of claims 1-7.

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