Stratum three-dimensional stress measurement method and system based on fracture strain recovery

Abstract

The invention discloses a stratum three-dimensional stress measurement method and system based on fracture strain recovery, and relates to the technical field of rock mass stress measurement, and the method comprises the steps: measuring the temperature of a to-be-measured stratum, processing a rock core sample of the to-be-measured stratum into a rock test piece, and pasting a plurality of groups of strain rosettes on the surface of the rock test piece; performing a triaxial isobaric cyclic loading test on the rock test piece to obtain a loading and unloading curve of the rock test piece; decomposing the loading curve and performing temperature correction based on the formation temperature to be measured, and calculating fracture strain on multiple groups of strain rosettes; calculating a plurality of strain components of the rock test piece based on the fracture strain; based on the multiple strain components, the magnitude and direction of the main fracture strain of the rock test piece are calculated, and the confining pressure during fracture closing stress of the rock test piece serves as the maximum main stress; and calculating the three-dimensional stress of the stratum to be measured based on the ratio relationship between the maximum principal stress and the principal stress in each direction. The technical problems that in the prior art, the operation difficulty is large, and the measurement result error is large are solved.

Description

Technical Field

[0001] The invention relates to the technical field of rock mass stress measurement, and in particular to a formation three-dimensional stress measurement method and system based on fracture strain recovery. Background Art

[0002] Geostress is the stress naturally occurring in the strata. Geostress measurement is the main method to understand the state of stratum stress and obtain geostress parameters. Deep stress measurement is of great significance to the design and safety of underground rock engineering.

[0003] At present, the main methods for measuring rock mass in-situ stress are casing stress relief method, hydraulic fracturing method, acoustic emission method, differential strain curve analysis method, etc. However, casing stress relief method has high requirements for hole formation and a relatively long measurement cycle; hydraulic fracturing method can only measure biaxial stress and has high requirements for rock mass homogeneity and integrity; acoustic emission method not only has high requirements for rock mass quality, but also has high difficulty in operation and limited application; although differential strain curve analysis method is easy to operate, the measurement result has large errors. Summary of the invention

[0004] In order to solve the above technical problems existing in the prior art, the embodiment of the present invention provides a formation three-dimensional stress measurement method and system based on fracture strain recovery. The technical solution is as follows:

[0005] On the one hand, a method for measuring formation triaxial stress based on fracture strain recovery is provided, the method comprising: measuring the temperature of a formation to be measured, processing a core sample of the formation to be measured into a rock specimen, and pasting a plurality of strain rosettes on the surface of the rock specimen; performing a triaxial isobaric cyclic loading test on the rock specimen to obtain a loading and unloading curve of the rock specimen; decomposing the loading curve and performing temperature correction based on the temperature of the formation to be measured, and calculating the fracture strain on the plurality of strain rosettes; calculating a plurality of strain components of the rock specimen based on the fracture strain; calculating the magnitude and direction of the main fracture strain of the rock specimen based on the plurality of strain components, and taking the confining pressure at the fracture closure stress of the rock specimen as the maximum principal stress; and calculating the triaxial stress of the formation to be measured based on the ratio relationship between the maximum principal stress and the principal stresses in each direction.

[0006] Furthermore, before processing the core sample of the stratum to be tested into a rock specimen, the method also includes: drilling a deep hole in the stratum to be tested in a direction perpendicular to the direction of the tunnel to obtain the core sample; the sampling position of the core sample is greater than three times the tunnel diameter; and recording the position and depth of the core sample.

[0007] Furthermore, the rock specimen includes a cubic specimen or a cylindrical specimen; each group of strain rosettes includes four strain gauges; and a plurality of groups of strain rosettes are pasted on the surface of the rock specimen, including: pasting the strain rosettes on three common angle surfaces of the cubic specimen, respectively, or pasting a group of strain rosettes on a bottom surface of the cylindrical specimen and two groups of strain rosettes on the side surfaces.

[0008] Furthermore, a triaxial isobaric cyclic loading test is performed on the rock specimen, including: placing the rock specimen in a pressure vessel, wrapping it with a heat shrinkable rubber sleeve, and performing a triaxial isobaric cyclic loading test.

[0009] Further, the loading curve is decomposed and the temperature correction is performed based on the formation temperature to be measured, and the fracture strain on the multiple groups of strain rosettes is calculated, including: decomposing the loading curve into rock micro-particle deformation, micropore strain and primary and secondary fracture strain caused by rock coring; based on the temperature correction coefficient of the core sample and the formation temperature to be measured, the elastic modulus of the core sample is corrected to obtain the corrected elastic modulus; based on the corrected elastic modulus and the loading and unloading curve, the fracture strain is calculated; wherein the corrected elastic modulus includes:

[0010]

[0011] Where v is Poisson’s ratio, K T is the elastic modulus after correction, α1, α2, α3 are temperature correction coefficients obtained through indoor experiments; it is related to the rock type; K is the unloading tangent modulus corresponding to the curve when the elastic body strain is maximum; T is the formation temperature to be measured; the fracture strain includes:

[0012]

[0013] ε vi is the total strain at the upper limit stress of the i-th group of strain gauges, is the micropore strain after the i-th group of strain gauges is completely unloaded, and P is the applied confining pressure.

[0014] Further, based on the fracture strain, multiple strain components of the rock specimen are calculated, including:

[0015]

[0016] Among them, ε i ′ is the crack strain measured by the i-th strain gauge, i = 1, 2...12; ε x , ε y , ε z is the normal strain value in three directions; xy , γ yz , γxz are the shear strains on the three planes.

[0017] Furthermore, the component calculation formula of the main crack strain includes:

[0018]

[0019] The direction cosines of the main crack strain include:

[0020]

[0021] in,

[0022]

[0023] ε i is the main crack strain, i = 1, 2, 3; l i 、m i ,ω i is the direction cosine of the i-th principal crack strain and the x-, y-, and z-axes, i=1, 2, 3.

[0024] Furthermore, the ratio relationship of principal stress in each direction includes:

[0025] σ1:σ2:σ3=[v(ε2+ε3)+(1-v)ε1]:[v(ε3+ε1)+(1-v)ε2]:[v(ε2+ε1)+(1-v)ε3]

[0026] Among them, v is Poisson's ratio, σ1, σ2, and σ3 are the principal stresses in three directions respectively.

[0027] On the other hand, a formation triaxial stress measurement system based on fracture strain recovery is also provided, comprising: a processing module, a test module, a first calculation module, a second calculation module, a third calculation module and a fourth calculation module; wherein the processing module is used to measure the formation temperature to be measured, process the core sample of the formation to be measured into a rock specimen, and paste multiple sets of strain rosettes on the surface of the rock specimen; the test module is used to perform a triaxial isobaric cyclic loading test on the rock specimen to obtain a loading and unloading curve of the rock specimen; the first calculation module is used to decompose the loading curve and perform temperature correction based on the formation temperature to be measured, and calculate the fracture strain on the multiple sets of strain rosettes; the second calculation module is used to calculate multiple strain components of the rock specimen based on the fracture strain; the third calculation module is used to calculate the magnitude and direction of the main fracture strain of the rock specimen based on the multiple strain components, and take the confining pressure at the fracture closure stress of the rock specimen as the maximum principal stress; the fourth calculation module is used to calculate the triaxial stress of the formation to be measured based on the ratio relationship between the maximum principal stress and the principal stresses in each direction.

[0028] On the other hand, an electronic device is provided, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method described in the first aspect when executing the computer program.

[0029] The embodiment of the present invention provides a formation triaxial stress measurement method and system based on fracture strain recovery, and obtains the fracture strain value of the sample through a triaxial isobaric cyclic loading and unloading curve, thereby eliminating the error caused by obtaining micro-particle deformation by relying on a fracture-free quartz glass strain compensation specimen in the prior art. In addition, the present invention takes into account the temperature difference inside and outside the borehole, so that the measurement result is closer to the in-situ state of the rock specimen. The measurement method is relatively simple and easy to operate, and the result is more accurate, which alleviates the technical problems of the prior art of high difficulty in operation and large error in measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 It is a flow chart of a formation three-dimensional stress measurement method based on fracture strain recovery provided by an embodiment of the present invention;

[0032] Figure 2 It is a schematic diagram of pasting a strain rosette on the surface of a rock specimen provided by an embodiment of the present invention;

[0033] Figure 3 is a schematic diagram of a loading and unloading curve of a rock specimen provided by an embodiment of the present invention;

[0034] Figure 4 It is a schematic diagram of a formation three-dimensional stress measurement system based on fracture strain recovery provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0036] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0037] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0038] Embodiment 1

[0039] Figure 1 FIG. 1 is a flow chart of a method for measuring three-dimensional stress of a formation based on fracture strain recovery according to an embodiment of the present invention. Figure 1 As shown, the method specifically comprises the following steps:

[0040] Step S102, measuring the temperature of the formation to be measured, processing the core sample of the formation to be measured into a rock specimen, and pasting a plurality of sets of strain rosettes on the surface of the rock specimen.

[0041] Step S104, performing a triaxial isobaric cyclic loading test on the rock specimen to obtain a loading and unloading curve of the rock specimen.

[0042] Step S106, decomposing the loading curve and performing temperature correction based on the formation temperature to be measured, and calculating the fracture strains on the multiple groups of strain rosettes.

[0043] Step S108, calculating multiple strain components of the rock specimen based on the fracture strain.

[0044] Step S110, based on multiple strain components, the magnitude and direction of the principal crack strain of the rock specimen are calculated, and the confining pressure at the crack closure stress of the rock specimen is taken as the maximum principal stress.

[0045] Step S112, calculating the three-dimensional stress of the formation to be measured based on the ratio relationship between the maximum principal stress and the principal stress in each direction.

[0046] Specifically, the method provided in the embodiment of the present invention further includes, before step S102:

[0047] Drill deep holes in the stratum to be tested in a direction perpendicular to the direction of the tunnel to obtain core samples; wherein the sampling position of the core samples is greater than three times the diameter of the tunnel;

[0048] The position and depth of the core sample are recorded. Preferably, in the embodiment of the present invention, a complete core sample with no obvious cracks and a length greater than 100 mm is selected.

[0049] Preferably, in the embodiment of the present invention, the rock specimen comprises a cubic specimen or a cylindrical specimen; for example, the size of the cubic specimen is 40*40*40 mm, or the size of the cylindrical specimen is φ50*100 mm.

[0050] Preferably, each set of strain gauges includes four strain gauges.

[0051] Figure 2 FIG. 1 is a schematic diagram of pasting a strain rosette on the surface of a rock specimen according to an embodiment of the present invention. Figure 2 As shown, the pasting method of the strain rosette includes: pasting strain rosettes on three common corner faces of the cubic specimen respectively, or pasting a group of strain rosettes on a bottom face of the cylindrical specimen and pasting two groups of strain rosettes on the side face.

[0052] Preferably, the included angle between the centers of the two sets of strain rosettes pasted on the side of the cylindrical specimen is 120°.

[0053] Preferably, in the embodiment of the present invention, epoxy resin is used to stick the strain rosette and fix the lead wire.

[0054] Specifically, step S104 includes: placing the rock sample in a pressure vessel, wrapping it with a heat shrink rubber sleeve, and performing a triaxial isobaric cyclic loading test.

[0055] In an optional implementation provided in an embodiment of the present invention, the test loading rate is 0.008 MPa / s, the unloading rate is 0.008 MPa / s, and the loading upper limit is increased by 2 MPa in each cycle; the load is loaded to 1.5 times the inflection point of the stress-strain curve.

[0056] Figure 3 FIG. 1 is a schematic diagram of a loading and unloading curve of a rock specimen provided according to an embodiment of the present invention. Figure 3 As shown in Figure 2, when the slope of the stress-strain curve no longer changes and remains stable, it is considered to have reached the inflection point.

[0057] Specifically, the rock sample is placed in a pressure vessel, wrapped with a heat shrink rubber sleeve, and subjected to a cyclic loading and unloading test. A hydrostatic pressure is applied at a rate of 0.008 MPa / s to a preset value. During unloading, the sample is unloaded at a rate of 0.008 MPa / s to a value greater than 0 MPa, and the stress rises by a fixed value of 2 MPa during each cycle. The above steps are continued until the slope of the stress-strain curve no longer changes and exceeds 1.5 times the inflection point.

[0058] Specifically, step S106 also includes the following steps:

[0059] Step S1061: The total strain ε of the loading curve is vi Decomposed into rock micro-particle deformation and micro-pore strain Primary and secondary fracture strains caused by rock coring

[0060] Step S1062, based on the temperature correction coefficient of the core sample and the formation temperature to be measured, correct the elastic modulus of the core sample to obtain the corrected elastic modulus;

[0061] Step S1063, calculating the crack strain based on the corrected elastic modulus and the loading and unloading curve;

[0062] Among them, the corrected elastic modulus includes:

[0063]

[0064] Where v is Poisson’s ratio, K T is the corrected elastic modulus, α1, α2, α3 are temperature correction coefficients obtained through indoor tests, which are related to the rock type, K is the unloading tangent modulus corresponding to the curve when the elastic body strain is maximum; T is the formation temperature to be measured;

[0065] Crack strain values ​​include:

[0066]

[0067] ε vi is the total strain at the upper limit stress of the i-th group of strain gauges, is the micropore strain after the i-th group of strain gauges is completely unloaded, and P is the applied confining pressure.

[0068] In an optional implementation provided by an embodiment of the present invention, step S106 further includes: dividing the deformation of the rock specimen into rock micro-particle deformation, rock micro-pore strain, and primary and secondary fracture strains caused by rock coring pressurization.

[0069] Specifically, the rock specimen includes six strain components and twelve strain gauges, including:

[0070]

[0071] Among them, ε i ′ is the crack strain measured by the i-th strain gauge, i = 1, 2...12; ε x , ε y , ε z is the normal strain value in three directions; xy , γ yz , γ xz are the shear strains on the three planes.

[0072] In step S110, the orientation of the principal stress of the formation is obtained according to the orientation of the core sample, and the confining pressure at the time of the fracture closure stress of the rock specimen is regarded as the maximum principal stress.

[0073] Specifically, the calculation formula for the components of the main crack strain includes:

[0074]

[0075] The direction cosines of the principal crack strain include:

[0076]

[0077] in,

[0078]

[0079] ε i is the main crack strain, i = 1, 2, 3; l i 、m i ,ω i is the direction cosine of the i-th principal crack strain and the x-, y-, and z-axes, i=1, 2, 3.

[0080] Specifically, the relationship between the ratios of the principal stresses in each direction in step S112 includes:

[0081] σ1:σ2:σ3=[v(ε2+ε3)+(1-v)ε1]:[v(ε3+ε1)+(1-v)ε2]:[v(ε2+ε1)+(1-v)ε3]

[0082] Among them, v is Poisson's ratio, σ1, σ2, and σ3 are the principal stresses in three directions respectively.

[0083] From the above description, it can be seen that the embodiment of the present invention provides a formation triaxial stress measurement method based on fracture strain recovery, obtains a core of a certain orientation by drilling, considers the temperature difference between the borehole and the press, corrects the elastic modulus, uses triaxial isobaric cyclic loading and unloading to obtain a characteristic curve for decomposition, and finally decomposes and calculates the orientation of the principal stress of the formation. The present invention obtains the fracture strain value of the sample through the triaxial isobaric cyclic loading and unloading curve, eliminates the error caused by the prior art of obtaining micro-particle deformation by relying on a crack-free quartz glass strain compensation specimen, and the present invention considers the temperature difference inside and outside the borehole, so that the measurement result is closer to the in-situ state of the rock specimen, the measurement method is relatively simple and easy to operate, and the result is more accurate, which alleviates the technical problems of the prior art of high difficulty in operation and large error in measurement results.

[0084] Embodiment 2

[0085] Figure 4 FIG. 1 is a schematic diagram of a formation three-dimensional stress measurement system based on fracture strain recovery according to an embodiment of the present invention. Figure 4 As shown, the system includes: a processing module 10 , a test module 20 , a first calculation module 30 , a second calculation module 40 , a third calculation module 50 and a fourth calculation module 60 .

[0086] The processing module 10 is used to measure the temperature of the formation to be measured, process the core sample of the formation to be measured into a rock specimen, and paste multiple sets of strain rosettes on the surface of the rock specimen;

[0087] The test module 20 is used to perform a triaxial isobaric cyclic loading test on the rock specimen to obtain a loading and unloading curve of the rock specimen;

[0088] A first calculation module 30 is used to decompose the loading curve and perform temperature correction based on the measured formation temperature, and calculate the fracture strains on the multiple sets of strain rosettes;

[0089] A second calculation module 40 is used to calculate multiple strain components of the rock specimen based on the fracture strain;

[0090] The third calculation module 50 is used to calculate the magnitude and direction of the main crack strain of the rock specimen based on multiple strain components, and take the confining pressure of the crack closure stress of the rock specimen as the maximum principal stress;

[0091] The fourth calculation module is used to calculate the three-dimensional stress of the formation to be measured based on the ratio relationship between the maximum principal stress and the principal stress in each direction.

[0092] Specifically, the processing module 10 is also used to: drill deep holes in the stratum to be tested in a direction perpendicular to the direction of the tunnel to obtain core samples; and record the position and depth of the core samples.

[0093] Specifically, the first calculation module 30 is also used to: correct the elastic modulus of the core sample based on the temperature difference between the indoor temperature of the core sample and the temperature of the formation to be measured to obtain the corrected elastic modulus; calculate the fracture strain based on the corrected elastic modulus and the loading and unloading curve.

[0094] The present invention further provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method in the above-mentioned embodiment 1 when executing the computer program.

[0095] The present invention further provides a computer-readable storage medium, in which program codes are stored. The program codes can be called by a processor to execute the method in the above-mentioned embodiment 1.

[0096] It should be understood that in various embodiments of the present invention, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0097] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0098] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described equipment, devices and units can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0099] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for measuring formation triaxial stress based on fracture strain recovery, characterized in that: The method comprises: Measuring the temperature of the formation to be measured, processing the core sample of the formation to be measured into a rock specimen, and pasting a plurality of sets of strain rosettes on the surface of the rock specimen; Performing a triaxial isobaric cyclic loading test on the rock specimen to obtain a loading and unloading curve of the rock specimen; Decomposing the loading curve and performing temperature correction based on the formation temperature to be measured, and calculating the fracture strains on the multiple groups of strain rosettes; Based on the fracture strain, calculating a plurality of strain components of the rock specimen; Based on the multiple strain components, the magnitude and direction of the principal crack strain of the rock specimen are calculated, and the confining pressure at the crack closure stress of the rock specimen is taken as the maximum principal stress; Based on the ratio relationship between the maximum principal stress and the principal stresses in various directions, the three-dimensional stress of the formation to be measured is calculated.

2. The method according to claim 1, characterized in that Before processing the core sample of the formation to be tested into a rock test piece, the method further comprises: Drilling a deep hole in the stratum to be measured in a direction perpendicular to the direction of the tunnel to obtain the core sample; the sampling position of the core sample is greater than three times the tunnel diameter; The location and depth of the core sample are recorded.

3. The method according to claim 1, characterized in that The rock specimen includes a cubic specimen or a cylindrical specimen; each set of strain gauges includes four strain gauges; and a plurality of sets of strain gauges are pasted on the surface of the rock specimen, including: The strain rosettes are respectively pasted on three faces of the cubic specimen that share a corner, or one group of strain rosettes are pasted on a bottom surface of the cylindrical specimen and two groups of strain rosettes are pasted on the side surface.

4. The method according to claim 1, characterized in that: The triaxial isobaric cyclic loading test is performed on the rock specimen, comprising: placing the rock specimen in a pressure vessel, wrapping it with a heat shrinkable rubber sleeve, and performing the triaxial isobaric cyclic loading test.

5. The method according to claim 1, characterized in that Decomposing the loading curve and performing temperature correction based on the formation temperature to be measured, and calculating the fracture strains on the multiple groups of strain rosettes, including: Decomposing the loading curve into rock micro-particle deformation, micro-pore strain and primary and secondary fracture strain caused by rock coring; Based on the temperature correction coefficient of the core sample and the formation temperature to be measured, the elastic modulus of the core sample is corrected to obtain the corrected elastic modulus; Calculating the crack strain based on the corrected elastic modulus and the loading and unloading curve; Wherein, the corrected elastic modulus includes: Where v is Poisson’s ratio, K T is the elastic modulus after correction, α1, α2, α3 are the temperature correction coefficients obtained through indoor experiments; K is the unloading tangent modulus corresponding to the curve when the elastic body strain is maximum; T is the formation temperature to be measured; The crack strain includes: ε vi is the total strain at the upper limit stress of the i-th group of strain gauges, is the micropore strain after the i-th group of strain gauges is completely unloaded, and P is the applied confining pressure.

6. The method according to claim 1, characterized in that Based on the fracture strain, multiple strain components of the rock specimen are calculated, including: Among them, ε i ′ is the crack strain measured by the i-th strain gauge, i = 1, 2...12; ε x , ε y , ε z is the normal strain value in three directions; xy , γ yz , γ xz are the shear strains on the three planes.

7. The method according to claim 6, characterized in that The component calculation formula of the main crack strain includes: The direction cosines of the main crack strain include: in, ε i is the main crack strain, i = 1, 2, 3; l i 、m i ,ω i is the direction cosine of the i-th principal crack strain and the x-, y-, and z-axes, i=1, 2, 3.

8. The method according to claim 7, characterized in that The relationship between the ratios of principal stresses in various directions includes: σ1:σ2:σ3=[v(ε2+ε3)+(1-v)ε1]:[v(ε3+ε1)+(1-v)ε2]:[v(ε2+ε1)+(1-v)ε3] Among them, v is Poisson's ratio, σ1, σ2, and σ3 are the principal stresses in three directions respectively.

9. A formation three-dimensional stress measurement system based on fracture strain recovery, characterized in that: include: processing module, test module, first calculation module, second calculation module, third calculation module and fourth calculation module; wherein, The processing module is used to measure the temperature of the formation to be measured, process the core sample of the formation to be measured into a rock specimen, and paste multiple sets of strain rosettes on the surface of the rock specimen; The test module is used to perform a triaxial isobaric cyclic loading test on the rock specimen to obtain a loading and unloading curve of the rock specimen; The first calculation module is used to decompose the loading curve and perform temperature correction based on the formation temperature to be measured, so as to calculate the fracture strains on the multiple groups of strain rosettes; The second calculation module is used to calculate multiple strain components of the rock specimen based on the fracture strain; The third calculation module is used to calculate the magnitude and direction of the main crack strain of the rock specimen based on the multiple strain components, and take the confining pressure of the crack closure stress of the rock specimen as the maximum principal stress; The fourth calculation module is used to calculate the three-dimensional stress of the measured formation based on the ratio relationship between the maximum principal stress and the principal stress in each direction.

10. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method according to any one of claims 1 to 8 when executing the computer program.

Images