Longitudinal transformation layer section optimization method and system for hot dry rock drilling

Abstract

The invention discloses an optimal selection method and system for a longitudinal transformation layer section of hot dry rock drilling. According to conventional logging data, well periphery sound wave scanning imaging logging data, micro-resistivity scanning imaging logging data, dipole array sound wave logging data and natural gamma-ray spectrum logging data, quantitative characterization of lithology, physical properties, thermal characteristics, rock mechanical characteristics and ground stress characteristics of a dry hot rock drilling longitudinal rock body is obtained. And comprehensively evaluating and determining the optimal hot dry rock drilling longitudinal transformation interval. According to the method, well logging five-property evaluation and optimization are carried out on the rock mass encountering dry hot rock drilling, analysis and optimization of the longitudinal dominant rock stratum of the dry hot rock are achieved, and high-temperature geothermal dry hot rock mass reservoir transformation is effectively guided.

Description

Technical Field

[0001] The invention belongs to the technical field of high-temperature geothermal new energy logging evaluation, and relates to a method and system for optimizing a vertical transformation layer section of a hot dry rock borehole. Background Art

[0002] As an important clean energy source in the future, hot dry rock has huge development potential and prospects. Currently, the patent documents disclosed involve the optimization of favorable horizontal zones of hot dry rock, such as CN107133878A "A hot dry rock selection analysis method for geothermal projects". Through comprehensive analysis of hot dry rock resource conditions, engineering conditions and post-development application conditions, the comprehensive analysis results of the hot dry rock selection area to be analyzed are obtained, and the horizontal sweet spot comparison analysis of multiple different hot dry rock selection areas can be carried out under a unified standard. However, how to use logging data to conduct vertical sweet spot comparison analysis of hot dry rocks and achieve favorable rock mass optimization still lacks systematic technical methods and processes, and no publicly published patent documents have been found. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention provides a method and system for optimizing the longitudinal transformation layer section of hot dry rock drilling, thereby solving the technical problem that the prior art cannot realize the optimization of longitudinal dominant rock layer analysis of hot dry rock.

[0004] The present invention is achieved through the following technical solutions:

[0005] A method for optimizing the longitudinal transformation of a hot dry rock borehole comprises the following steps:

[0006] Obtain conventional logging data, wellbore perimeter acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma ray spectrum logging data and dipole array acoustic logging data of hot dry rocks;

[0007] Obtaining the formation lithology, physical properties, thermal properties, rock mechanical properties and geostress properties of the vertical rock mass of the hot dry rock borehole according to the conventional logging data, wellbore perimeter acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma ray spectrum logging data and dipole array acoustic logging data;

[0008] The optimal hot dry rock borehole longitudinal transformation layer section is determined based on the obtained stratum lithology, physical properties, thermal properties, rock mechanical properties and ground stress properties of the longitudinal rock mass of the hot dry rock borehole.

[0009] Preferably, the stratigraphic lithology of the vertical rock mass of the hot dry rock borehole is obtained through conventional logging data and natural gamma spectral logging data; specifically, the stratigraphic lithology of the vertical rock mass of the hot dry rock borehole is obtained by applying a cluster analysis method based on the natural gamma spectral logging lithology identification chart.

[0010] Preferably, the physical properties of the vertical rock mass of 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 physical properties include matrix porosity, and the secondary physical properties include fracture porosity;

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

[0013] First, a high resistivity background dense layer segment is selected by using a histogram statistical method, and a density skeleton, an acoustic skeleton or a neutron skeleton of the corresponding formation is determined, and then the matrix porosity is determined by using at least one of the density skeleton, the acoustic skeleton or the neutron skeleton;

[0014] The fracture porosity is obtained specifically as follows:

[0015]

[0016] Where FVAH is the fracture porosity, FVTL is the fracture length, FCAH is the fracture width, and CAL is the wellbore diameter.

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

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

[0019] λ B =λ 1 V 1 +λ 2 V 2 ……+λ n V n

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

[0021] λ 1 ,λ 2 ·····λ n is the thermal conductivity of each rock component;

[0022] V 1 , V 2 ,·····V n is 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, C U is the abundance of uranium, C Th is the abundance of thorium, C K is the abundance of potassium;

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

[0027]

[0028] Among them, G step is the geothermal gradient, step is the given step length, T bottom is the bottom temperature within a given step range, T top is the top boundary temperature within a given step range.

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

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

[0031] The time difference between longitudinal and shear waves extracted by array acoustic wave is combined with the density and mud content curves in conventional logging;

[0032] The dynamic Poisson's ratio, Young's modulus, bulk modulus, shear modulus and Lame constant are obtained by combining the longitudinal and transverse wave time differences extracted by the array acoustic wave with the density and mud content curves in conventional logging, thereby completing the acquisition of one-dimensional dynamic rock mechanics parameters;

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

[0034] Preferably, the geostress characteristics of the longitudinal rock mass of the hot dry 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.

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

[0036] A vertical transformation layer section optimization system for hot dry rock drilling, comprising:

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

[0038] The first data processing module: The first data processing module is used to obtain the formation lithology, physical properties, thermal properties, rock mechanical properties and ground stress properties of the vertical rock mass of the hot dry rock borehole according to the conventional logging data, wellbore acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma ray spectrum logging data and dipole array acoustic logging data;

[0039] Second data processing module: The second data processing module is used to determine the optimal hot dry rock borehole longitudinal transformation layer section based on the obtained stratigraphic lithology, physical properties, thermal properties, rock mechanics properties and ground stress properties of the longitudinal rock mass of the hot dry rock borehole.

[0040] A terminal device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0041] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

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

[0043] The present invention discloses a method for optimizing the vertical transformation layer section of a hot dry rock borehole. First, the formation lithology, physical properties, thermal properties, rock mechanical properties and geostress properties of the vertical rock mass of the hot dry rock borehole are obtained through conventional logging data of the hot dry rock, wellbore acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma ray spectrum logging data and dipole array acoustic logging data; then the optimal vertical transformation layer section of the hot dry rock borehole is determined through the formation lithology, physical properties, thermal properties, rock mechanical properties and geostress properties of the vertical rock mass of the hot dry rock borehole. The method is based on conventional logging, acoustic, microresistivity scanning imaging logging and array acoustic logging data obtained from the hot dry rock borehole, and performs logging "five properties" evaluation and optimization for the rock mass encountered in the hot dry rock borehole, thereby realizing the analysis and optimization of the vertical dominant rock formations of the hot dry rock, and effectively guiding the transformation of the high-temperature geothermal hot dry rock reservoir. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0045] Figure 1 It is a schematic flow chart of a method for optimizing the longitudinal transformation of a hot dry rock borehole in the present invention;

[0046] Figure 2 A schematic diagram of the process of obtaining the formation lithology of the vertical rock mass of a hot dry rock borehole by applying a cluster analysis method based on the natural gamma ray spectrum logging lithology identification chart in the present invention;

[0047] Figure 3 It is a structural schematic diagram of a longitudinal transformation layer section optimization system for hot dry rock drilling in the present invention;

[0048] Figure 4 This is a technical flow chart of a method for optimizing the longitudinal transformation of a hot dry rock borehole in Example 3 of the present invention;

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

[0050] Figure 6 This is a result diagram of using wellbore collapse in wellbore acoustic wave scanning data to determine the direction of ground stress in Example 3 of the present invention;

[0051] Figure 7 This is a result diagram of using induced fractures in wellbore acoustic scanning data to determine the direction of ground stress in Example 3 of the present invention;

[0052] Figure 8 This is a result diagram of using fast shear waves in array acoustic logging data to determine the direction of ground stress in Example 3 of the present invention;

[0053] Fig. 9 This is a result diagram of calculating fracture parameters using electrical imaging logging data in Example 3 of the present invention;

[0054] Fig.10 This is a comprehensive rock mass evaluation index diagram determined based on the “five properties” in Example 3 of the present invention. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0056] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

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

[0059] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which 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 is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0062] Example 1

[0063] like Figure 1 As shown, the present invention discloses a method for optimizing the longitudinal transformation of a hot dry rock borehole, comprising the following steps:

[0064] S1: Acquire conventional logging data, perimeter acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma ray spectrum logging data and dipole array acoustic logging data of hot dry rocks;

[0065] S2: Obtaining the formation lithology, physical properties, thermal properties, rock mechanical properties and geostress properties of the vertical rock mass of the hot dry rock borehole according to the conventional logging data, wellbore perimeter acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma ray spectrum logging data and dipole array acoustic logging data;

[0066] Among them, the stratigraphic lithology of the vertical rock mass of the hot dry rock borehole is obtained through conventional logging data and natural gamma ray spectrum logging data; specifically: Figure 2 As shown in the figure, the cluster analysis method is used to obtain the stratigraphic lithology of the vertical rock mass in the hot dry rock borehole based on the natural gamma ray spectrum logging lithology identification chart.

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

[0068] The matrix physical properties include matrix porosity, and the secondary physical properties include fracture porosity;

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

[0070] Firstly, the high resistivity background dense layer section is selected by the histogram statistics method to determine the density skeleton, acoustic skeleton or neutron skeleton of the corresponding formation, and then the matrix porosity is determined by at least one of the density skeleton, acoustic skeleton or neutron skeleton. Since the lithology of the target hot dry rock mass is pure, the mud correction is not considered in the calculation process, and the matrix porosity is calculated using the porosity model known in the field.

[0071] The fracture porosity is obtained as follows: First, the microresistivity scanning imaging and wellbore acoustic scanning imaging processing modules in the industry professional processing software are used to perform human-computer interaction to pick up fractures for the static or dynamic image channels of microresistivity 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:

[0072]

[0073] Where FVAH is the fracture porosity, FVTL is the fracture length, FCAH is the fracture width, and CAL is the wellbore diameter.

[0074] At the same time, based on the natural gamma ray spectrum logging data, the thermal characteristics of the vertical rock mass in the hot dry rock borehole are obtained, and the thermal characteristics include thermal conductivity, heat generation rate and geothermal gradient; among them, the thermal conductivity can be quantitatively characterized based on the logging lithology, and the continuous thermal conductivity in the borehole can be obtained through the dispersion model. On this basis, temperature and pressure correction can be performed to accurately obtain the in-situ thermal conductivity of the heat reservoir.

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

[0076] λ B =λ 1 V 1 +λ 2 V 2 ……+λ n V n

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

[0078] λ 1 ,λ 2 ·····λ n is the thermal conductivity of each rock component;

[0079] V 1 , V 2 ,·····V n is 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] Where H is the heat generation rate, uW / m 3 ; ρ is density, g / cm 3 ; C U is the abundance of uranium, C Th is the abundance of thorium, C K is the abundance of potassium;

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

[0084]

[0085] Among them, G step is the geothermal gradient; step is the given step length, m; T bottomis the bottom temperature within a given step range, °C; T top is the top temperature within a given step range, ℃.

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

[0087] Specifically, the time difference between longitudinal and shear waves extracted by array acoustic waves is combined with the density and mud content curves in conventional logging, and the well-known models in the field are used to calculate the one-dimensional dynamic rock mechanics parameters such as dynamic Poisson's ratio, Young's modulus, bulk modulus, shear modulus, and Lame constant. If there are rock mechanics parameter analysis results of indoor rock samples, the dynamic-static conversion coefficient of Young's modulus and Poisson's ratio can be calibrated to obtain the one-dimensional static rock mechanics parameters. The difference between fast and slow shear waves obtained by shear wave field separation can be used to quantitatively characterize the size of formation anisotropy.

[0088] Furthermore, the geostress characteristics of the vertical rock mass of the hot dry 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) Based on the wellbore acoustic scanning imaging and microresistivity scanning imaging logging data, the direction of geostress can be determined by the borehole collapse method and the induced fracture method (including pressure fractures, stress release fractures, and drill bit vibration fractures); (2) Based on the array acoustic logging data, the direction of geostress can be determined by the fast shear wave azimuth method; (3) The above three methods complement and verify each other.

[0090] Calculation of geostress: including the calculation of maximum horizontal principal stress, minimum horizontal principal stress and vertical stress in three directions. Combined with the results of the previous geostress fixed-point test in the target area, a reasonable stress calculation model is selected to achieve the characterization of the continuous geostress size of the target well section. Commonly used maximum horizontal principal stress and minimum horizontal principal stress calculation models include the poroelastic horizontal geostress model, the Mohr-Coulomb stress model, and the Huang model. The vertical stress is obtained through the known formula in the field.

[0091] S3: Determine the optimal hot dry rock borehole longitudinal transformation layer section according to the formation lithology, matrix physical properties and secondary biological properties, thermal properties, rock mechanical properties and ground stress properties of the hot dry rock borehole longitudinal rock mass obtained.

[0092] Specifically, the following principles are usually followed for the optimization of hot dry rock transformation layers: select the above-mentioned regional dominant lithology layers, layers with large matrix porosity and fracture porosity, layers with high heat generation rate, layers with large Young's modulus and small Poisson's ratio, layers with small minimum horizontal ground stress and small stress difference. The above conditions should be met at the same time or as much as possible, and the specific considerations are based on the actual drilling situation.

[0093] Furthermore, based on the quantitative evaluation of the above five parameters, individual evaluation indexes were constructed respectively. Combined with the demand for hydraulic fracturing transformation of hot dry rocks, different weights were assigned according to the priority levels to obtain the comprehensive evaluation index of the dominant rock mass, providing a quantitative logging evaluation method for rock mass optimization.

[0094] In a preferred embodiment, the process of comprehensive evaluation index of the hot dry rock drilling dominant rock mass is:

[0095] Determination of lithology index F by reverse normalization of TH / U ratio 1 ;

[0096] The physical property index F is determined by forward normalization of matrix porosity and reverse normalization of fracture porosity. 2 ;

[0097] The thermal index F is determined by the positive normalization of thermal conductivity, heat generation rate and geothermal gradient. 3 ;

[0098] The rock mechanical index F is determined by normalizing the Young's modulus forward and the Poisson's ratio backward. 4 ;

[0099] Determine the geostress index F by reverse normalization of the minimum horizontal principal stress and the horizontal stress difference 5 ;

[0100] Through the physical index F 2 >Heat Index F 3 >Ground stress index F 5 > Rock Mechanics Index F 4 > Lithology Index F 1 According to the priority sorting, different weight coefficients are assigned to the above indexes respectively to obtain the comprehensive evaluation index F of the dominant rock mass.

[0101] F=W 1 *F 1 +W 2 *F 2 +W 3 *F 3 +W 4 *F 4 +W 5 *F 5

[0102] Based on conventional logging and wellbore acoustic scanning imaging, microresistivity scanning imaging, and array acoustic imaging logging data, the present invention realizes the continuous and fine characterization of the "five properties" of lithology, physical properties, thermal properties, rock mechanical properties, and geostress properties of the vertical rock mass of the hot dry rock borehole, providing an important section selection basis for the vertical optimization and transformation of the hot dry rock borehole, and also providing detailed and reliable basic data for further carrying out the horizontal three-dimensional fine geological modeling of the target area. The method of the present invention has a clear process, prominent focus, strong operability, and is convenient for field application.

[0103] Example 2

[0104] like Figure 3 As shown, the present invention also provides a vertical transformation layer section optimization system for hot dry rock drilling, comprising:

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

[0106] The first data processing module: The first data processing module is used to obtain the formation lithology, physical properties, thermal properties, rock mechanical properties and ground stress properties of the vertical rock mass of the hot dry rock borehole according to the conventional logging data, wellbore acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma ray spectrum logging data and dipole array acoustic logging data;

[0107] Second data processing module: The second data processing module is used to determine the optimal hot dry rock borehole longitudinal transformation layer section based on the obtained stratigraphic lithology, physical properties, thermal properties, rock mechanics properties and ground stress properties of the longitudinal rock mass of the hot dry rock borehole.

[0108] Example 3

[0109] In order to further explain the technical solution of the present invention, the following examples are used for illustration:

[0110] like Figure 4 As shown in the figure, based on the conventional logging data, wellbore acoustic scanning imaging, microresistivity scanning imaging and array acoustic logging data of hot dry rock boreholes in a certain area, we first carried out a "five-property" logging parameter evaluation of lithology, physical properties, thermal properties, rock mechanical properties and geostress properties.

[0111] Among them, Figure 5 As shown, based on the lithology identification chart established by the total natural gamma (GR) and the thorium (TH) element / uranium (U) element content ratio in the natural gamma ray spectrum logging, the stratigraphic lithology of the vertical rock mass of the hot dry rock borehole is further obtained based on the lithology identification chart;

[0112] In addition, if Figure 6 As shown in the figure, the borehole collapse in the wellbore acoustic scanning data is used to determine the direction of ground stress. Among them, the first track is natural gamma (GR), dual wellbore diameters (C13, C24), and drill 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 inclination of the borehole collapse; the sixth track is the inclination of the borehole collapse according to the statistics of the specified well section, and its orientation indicates the direction of the minimum horizontal principal stress of the rock mass.

[0113] like Figure 7 As shown in the figure, the induced fractures in the wellbore acoustic scanning data are used to determine the direction of ground stress, specifically: the first track is natural gamma (GR), dual well diameters (C13, C24), and drill bit size (BIT); the second track is the depth track; the third track is the fast and slow shear wave waveforms; the fourth track is the wave velocity anisotropy, the difference in time between fast and slow waves; the fifth track is the maximum energy and the minimum energy; the sixth track is the inclination of the induced fractures counted according to the specified well section, and its orientation indicates the direction of the maximum horizontal principal stress of the rock mass.

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

[0115] like Fig. 9 The figure shows the results of calculating fracture parameters using electrical imaging logging data. The first track is natural gamma, well diameter, and drill bit size; the second track is depth; the third track is fracture density; the fourth track is fracture length; and the fourth track is fracture porosity.

[0116] like Fig.10 As shown in the figure, it is a comprehensive evaluation index of rock mass determined based on the "five properties". Among them, the first track is natural gamma, uranium-free gamma, well diameter 13, well diameter 24, and drill bit size; the second track is depth track; the third track is deep lateral resistivity and shallow lateral resistivity; the fourth track is density, compensated neutron, acoustic wave time difference, and photoelectric cross-section index; the fifth track is lithology classification; the sixth track is matrix porosity; the seventh track is fracture porosity; the eighth track is heat generation rate; the ninth track is Young's modulus and Poisson's ratio; the tenth track is vertical stress, maximum horizontal principal stress, and minimum horizontal principal stress; and the eleventh track is a comprehensive evaluation index of rock mass.

[0117] Based on the above process, the evaluation results correspond to Figure 7 The fifth, sixth-seventh, eighth, ninth and tenth channels. Finally, after comprehensive analysis, the borehole 3681.0-3728.2m was selected as a favorable rock mass for artificial fracturing transformation.

[0118] Example 4

[0119] A schematic diagram of a terminal device provided in 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, the steps in the above-mentioned method embodiments are implemented. Alternatively, when the processor executes the computer program, the functions of the modules / units in the above-mentioned device embodiments are implemented.

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

[0121] The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

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

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

[0124] If the module / unit integrated in the terminal device is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased 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 electric carrier signals and telecommunication signals.

[0125] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for selecting the optimal layer for vertical transformation of hot dry rock boreholes. It is characterized in that The following steps are involved: Obtain conventional logging data, wellbore perimeter acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma ray spectrum logging data and dipole array acoustic logging data of hot dry rocks; Obtaining the formation lithology, physical properties, thermal properties, rock mechanical properties and geostress properties of the vertical rock mass of the hot dry rock borehole according to the conventional logging data, wellbore perimeter acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma ray spectrum logging data and dipole array acoustic logging data; The optimal hot dry rock borehole longitudinal transformation layer section is determined based on the obtained stratum lithology, physical properties, thermal properties, rock mechanical properties and ground stress properties of the longitudinal rock mass of the hot dry rock borehole.

2. A method for optimizing the longitudinal transformation of a hot dry rock borehole according to claim 1, It is characterized in that The stratigraphic lithology of the vertical rock mass in the hot dry rock borehole is obtained through conventional logging data and natural gamma spectral logging data; specifically, the stratigraphic lithology of the vertical rock mass in the hot dry rock borehole is obtained by applying the cluster analysis method based on the natural gamma spectral logging lithology identification chart.

3. A method for optimizing the longitudinal transformation of a hot dry rock borehole according to claim 1, It is characterized in that Based on conventional logging data and micro-resistivity scanning imaging logging data, the physical properties of the vertical rock mass in the hot dry rock borehole are obtained; the physical properties include matrix physical properties and secondary biological properties; The matrix physical properties include matrix porosity, and the secondary physical properties include fracture porosity; The process of obtaining the matrix porosity is specifically as follows: First, a high resistivity background dense layer segment is selected by using a histogram statistical method, and a density skeleton, an acoustic skeleton or a neutron skeleton of the corresponding formation is determined, and then the matrix porosity is determined by using at least one of the density skeleton, the acoustic skeleton or the neutron skeleton; The fracture porosity is obtained specifically as follows: Where FVAH is the fracture porosity, FVTL is the fracture length, FCAH is the fracture width, and CAL is the wellbore diameter.

4. A method for optimizing the longitudinal transformation of a hot dry rock borehole according to claim 1, It is characterized in that Based on natural gamma ray spectrum logging data, thermal characteristics of the vertical rock mass of the hot dry rock borehole are obtained, wherein the thermal characteristics include thermal conductivity, heat generation rate and geothermal gradient; The thermal conductivity is obtained specifically as follows: l B =λ 1 V 1 +λ 2 V 2 ......+λ n V n In the formula, λ B is the total thermal conductivity; λ 1 ,λ 2 ·····λ n is the thermal conductivity of each rock component; V 1 , V 2 ,·····V n is the volume content of each rock; The heat generation rate is obtained specifically as follows: H=0.01ρ(9.53C U +2.56C Th +3.48C K ) In the formula, H is the heat generation rate, ρ is the density, C U is the abundance of uranium, C Th is the abundance of thorium, C K is the abundance of potassium; The geothermal gradient is obtained specifically as follows: Among them, G step is the geothermal gradient, step is the given step length, T bottom is the bottom temperature within a given step range, T top is the top boundary temperature within a given step range.

5. A method for optimizing the longitudinal transformation of a hot dry rock borehole according to claim 1, It is characterized in that Based on the dipole array sonic logging data, the rock mechanical properties of the vertical rock mass of the hot dry rock borehole are obtained; the rock mechanical properties include one-dimensional static rock mechanical parameters and the size of formation anisotropy; The process of obtaining the one-dimensional dynamic rock mechanics parameters is specifically as follows: The time difference between longitudinal and shear waves extracted by array acoustic wave is combined with the density and mud content curves in conventional logging; The dynamic Poisson's ratio, Young's modulus, bulk modulus, shear modulus and Lame constant are obtained by combining the longitudinal and transverse wave time differences extracted by the array acoustic wave with the density and mud content curves in conventional logging, thereby completing the acquisition of one-dimensional dynamic rock mechanics parameters; The process of obtaining the magnitude of the formation anisotropy is specifically as follows: obtaining the magnitude of the formation anisotropy by utilizing the difference between the fast and slow shear waves obtained by separating the shear wave field.

6. A method for optimizing the longitudinal transformation of a hot dry rock borehole according to claim 1, It is characterized in that The geostress characteristics of the vertical rock mass of the hot dry 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.

7. A method for optimizing the longitudinal transformation of a hot dry rock borehole according to claim 6, It is characterized in that Based on the wellbore acoustic scanning imaging and microresistivity scanning imaging logging data, the direction of ground stress is determined by the wellbore collapse method and the induced fracture method; based on the dipole array acoustic logging data, the direction of ground stress is determined by the fast shear wave azimuth method.

8. A vertical reconstruction layer section optimization system for hot dry rock drilling, It is characterized in that include: Data acquisition module: The data acquisition module is used to acquire conventional logging data, wellbore perimeter acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma ray spectrum logging data and dipole array acoustic logging data of hot dry rocks; The first data processing module: The first data processing module is used to obtain the formation lithology, physical properties, thermal properties, rock mechanical properties and ground stress properties of the vertical rock mass of the hot dry rock borehole according to the conventional logging data, wellbore acoustic scanning imaging logging data, microresistivity scanning imaging logging data, natural gamma ray spectrum logging data and dipole array acoustic logging data; Second data processing module: The second data processing module is used to determine the optimal hot dry rock borehole longitudinal transformation layer section based on the obtained stratigraphic lithology, physical properties, thermal properties, rock mechanics properties and ground stress properties of the longitudinal rock mass of the hot dry rock borehole.

9. A terminal device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, It is characterized in that When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program. It is characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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