Method and device for analyzing strength of wall surrounding rock of oil shale under oil-based mud condition

Abstract

The invention discloses an oil shale well wall surrounding rock strength analysis method and device under an oil-based mud condition, and relates to the technical field of well wall stability of petroleum and natural gas drilling engineering.The method comprises the steps that engineering coring is conducted on a target oil shale stratum, and multiple sets of core samples are prepared; performing soaking experiments on the multiple groups of core samples in the oil-based mud in different time periods respectively; performing comprehensive rock mechanical property testing on the multiple groups of soaked core samples to obtain rock mechanical parameters of the oil shale samples under different oil-based mud conditions; based on the rock mechanical parameters, establishing a mathematical characterization model of the dynamic relationship between the drilling mud invasion degree and the rock mechanical parameter evolution of the oil shale sample; and based on the mathematical representation model, predicting the collapse pressure and the potential collapse period of the oil shale stratum under different drilling parameters and stratum conditions. The technical problem that in the prior art, analysis precision and analysis reliability of stratum strength parameters of the stratified oil shale under the oil-based mud environment are low is solved.

Description

Technical Field

[0001] The invention relates to the technical field of wellbore stabilization in oil and gas drilling engineering, and in particular to a method and device for analyzing the surrounding rock strength of an oil shale wellbore under oil-based mud conditions. Background Art

[0002] Safe and efficient drilling in complex formations is crucial to improving the efficiency of oil and gas resource exploration and development. During the drilling process in complex formations, when drilling into oil shale formations, the drilling mud invades the formation matrix and bedding plane, which can easily induce strength degradation of the surrounding rock and wellbore collapse. The stress, strain and strength degradation of the surrounding rock are more heterogeneous, the collapse cycle is more difficult to predict, and the difficulty of wellbore stability analysis is greater than that of homogeneous sandstone formations. Accurately evaluating the interaction process between oil-based mud and stratified oil shale formations is conducive to improving the prediction accuracy of strength degradation and wellbore collapse in stratified oil shale formations, providing engineering parameter references for wellbore instability intervention measures, and improving the design effectiveness of the safe density window of oil shale mud.

[0003] The seepage process of oil-based mud invading stratified oil shale formations is complex and controlled by mechanical coupling. The distribution of surrounding rock pressure, stress, and strength parameters evolves non-uniformly. The pore pressure field, deformation field, and failure field in the surrounding rock of the wellbore evolve to varying degrees in the oil shale matrix and bedding plane. It is difficult to fully and accurately quantify this mechanical coupling process using conventional mechanical and chemical experiments and mathematical model analysis methods, which has limitations in analyzing the strength degradation of oil shale formations and wellbore stability in an oil-based mud environment, resulting in low analysis accuracy and reliability of strength parameters of stratified oil shale formations in an oil-based mud environment. Summary of the invention

[0004] The purpose of the present invention is to provide a method and device for analyzing the strength of oil shale well wall surrounding rock under oil-based mud conditions in order to solve at least one of the above technical problems.

[0005] In the first aspect, an embodiment of the present invention provides a method for analyzing the strength of oil shale well wall surrounding rock under oil-based mud conditions, comprising: performing engineering coring on a target oil shale formation and preparing multiple groups of core samples; subjecting the multiple groups of core samples to immersion experiments in oil-based mud for different time periods to obtain multiple groups of core samples after immersion; conducting comprehensive rock mechanical property tests on the multiple groups of core samples after immersion to obtain rock mechanical parameters of the oil shale samples under different oil-based mud conditions; based on the rock mechanical parameters, establishing a mathematical characterization model of the dynamic relationship between the degree of drilling mud intrusion and the evolution of the rock mechanical parameters of the oil shale samples; based on the mathematical characterization model, predicting the collapse pressure and potential collapse period of the oil shale formation under different drilling parameters and formation conditions.

[0006] Furthermore, engineering coring is performed on the target oil shale formation, and multiple groups of core samples are prepared, including: obtaining geological data information of the target oil shale formation; performing engineering coring on the target oil shale formation in combination with the geological data information to obtain outcrop rock samples; processing the outcrop rock samples into cylindrical cores with flat and parallel end faces; grouping the cylindrical cores according to lithology and bedding direction to obtain the multiple groups of core samples.

[0007] Furthermore, comprehensive rock mechanical property tests are performed on the multiple groups of core samples after immersion to obtain rock mechanical parameters of oil shale samples under different oil-based mud conditions, including: performing nuclear magnetic resonance tests on the multiple groups of core samples after immersion to obtain T2 relaxation time spectra of each group of core samples after immersion; and analyzing the T2 relaxation time spectra to determine the pore size and fluid distribution characteristics of each group of core samples after immersion.

[0008] Furthermore, a comprehensive rock mechanical property test is performed on the multiple groups of core samples after immersion to obtain rock mechanical parameters of oil shale samples under different oil-based mud conditions, which also includes: performing a triaxial compression test on the first core sample to obtain corresponding compressive strength and fracture characteristics; performing a direct shear test on the second core sample to obtain corresponding shear resistance; performing a tensile strength test on the third core sample to obtain corresponding tensile strength; wherein the first core sample, the second core sample and the third core sample are different parallel samples in the same group of core samples after immersion.

[0009] Furthermore, the mathematical representation model includes:

[0010] Flow equations within the oil shale matrix:

[0011]

[0012] Flow equation within the bedding weak plane:

[0013]

[0014] Poroelastic equation within the oil shale matrix:

[0015] σ′=σ―αpI

[0016] Mechanical behavior equation of bedding weak plane:

[0017] σ′ f =σ―α f pI

[0018] Deformation equation within the oil shale matrix:

[0019] σ=2Gε+λtr(ε)I

[0020] Interaction equation between bedding weak plane and oil shale matrix:

[0021]

[0022] Where q is the flow velocity, k is the permeability, μ is the viscosity, p is the pressure, the subscript f represents the weak plane, σ is the stress, G is the shear modulus, α is the poroelastic coefficient, I is the unit matrix, ε is the strain, and λ is the Lame constant.

[0023] In a second aspect, an embodiment of the present invention further provides an oil shale well wall surrounding rock strength analysis device under oil-based mud conditions, comprising: a preparation module, an immersion module, a test module, an establishment module and an analysis module; wherein the preparation module is used to perform engineering coring on the target oil shale formation and prepare multiple groups of core samples; the immersion module is used to perform immersion experiments on the multiple groups of core samples in oil-based mud for different time periods, respectively, to obtain multiple groups of core samples after immersion; the test module is used to perform comprehensive rock mechanical property tests on the multiple groups of core samples after immersion, to obtain rock mechanical parameters of oil shale samples under different oil-based mud conditions; the establishment module is used to establish a mathematical characterization model of the dynamic relationship between the degree of drilling mud intrusion and the evolution of rock mechanical parameters of oil shale samples based on the rock mechanical parameters; the analysis module is used to predict the collapse pressure and potential collapse cycle of oil shale formations under different drilling parameters and formation conditions based on the mathematical characterization model.

[0024] Furthermore, the preparation module is also used to: obtain geological data information of the target oil shale formation; perform engineering coring on the target oil shale formation in combination with the geological data information to obtain outcrop rock samples; process the outcrop rock samples into cylindrical cores with flat and parallel end faces; group the cylindrical cores according to lithology and bedding direction to obtain the multiple groups of core samples.

[0025] Furthermore, the testing module is also used to: perform nuclear magnetic resonance testing on the multiple groups of core samples after immersion to obtain the T2 relaxation time spectrum of each group of core samples after immersion; analyze the T2 relaxation time spectrum to determine the pore size and fluid distribution characteristics of each group of core samples after immersion; perform a triaxial compression test on the first core sample to obtain the corresponding compressive strength and fracture characteristics; perform a direct shear test on the second core sample to obtain the corresponding shear resistance; perform a tensile strength test on the third core sample to obtain the corresponding tensile strength; wherein the first core sample, the second core sample and the third core sample are different parallel samples in the same group of core samples after immersion.

[0026] In a third aspect, an embodiment of 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 described in the first aspect when executing the computer program.

[0027] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and when the computer instructions are executed by a processor, the method described in the first aspect above is implemented.

[0028] The present invention provides a method and device for analyzing the strength of oil shale well wall surrounding rock under oil-based mud conditions. By combining indoor experiments and mathematical model analysis, the method calculates and predicts the stress-strain distribution and strength parameter degradation of the well wall surrounding rock oil shale under the oil-based mud environment during drilling, clarifies the rock mechanics mechanism of well wall collapse and the damage characteristics of the layer, and alleviates the technical problems of low analysis accuracy and analysis reliability of stratified oil shale formation strength parameters under the oil-based mud environment in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 A flow chart of a method for analyzing the strength of oil shale well wall surrounding rock under oil-based mud conditions provided by an embodiment of the present invention;

[0031] Figure 2 A schematic diagram of an oil shale well wall surrounding rock strength analysis device under oil-based mud conditions provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0033] Embodiment 1

[0034] Figure 1 1 is a flow chart of a method for analyzing the strength of oil shale well wall surrounding rock under oil-based mud conditions provided by an embodiment of the present invention. Figure 1 As shown, the method specifically comprises the following steps:

[0035] Step S102: perform engineering coring on the target oil shale formation and prepare multiple groups of core samples.

[0036] Step S104, conducting immersion experiments of multiple groups of core samples in oil-based mud for different time periods to obtain multiple groups of core samples after immersion.

[0037] Step S106, conducting comprehensive rock mechanical property tests on multiple groups of soaked core samples to obtain rock mechanical parameters of oil shale samples under different oil-based mud conditions.

[0038] Step S108, based on rock mechanics parameters, a mathematical representation model of the dynamic relationship between the drilling mud invasion degree and the evolution of the rock mechanics parameters of the oil shale sample is established.

[0039] Step S110, predicting the collapse pressure and potential collapse period of the oil shale formation under different drilling parameters and formation conditions based on the mathematical characterization model.

[0040] Specifically, step S102 also includes the following steps:

[0041] Step S1021, obtaining geological information of the target oil shale formation.

[0042] Specifically, the basic geological conditions of the oil shale formation and the basic physical and chemical properties of the formation rocks are determined, and key parameters such as the wellbore trajectory and wellbore structure of typical wells in the area are analyzed.

[0043] Step S1022, coring the target oil shale formation is performed in combination with geological data information to obtain outcrop rock samples.

[0044] Step S1023, processing the outcrop rock sample into a cylindrical rock core with flat and parallel end surfaces;

[0045] Step S1024, grouping the cylindrical cores according to lithology and bedding trends to obtain multiple groups of core samples, wherein the core samples are parallel samples selected from the cylindrical cores.

[0046] Specifically, step S106 also includes:

[0047] Step S1061, performing nuclear magnetic resonance testing on multiple groups of soaked core samples to obtain a T2 relaxation time spectrum of each group of soaked core samples;

[0048] Step S1062, analyzing the T2 relaxation time spectrum to determine the pore size and fluid distribution characteristics of each group of core samples after immersion.

[0049] Specifically, core samples at different stages and in different immersion states were taken out, tested using a nuclear magnetic resonance instrument, and the signal was recorded. The T2 relaxation time spectrum was analyzed, and the pore size and fluid distribution characteristics were determined using their distribution characteristics to characterize the oil-based mud penetration process.

[0050] Specifically, step S106 also includes:

[0051] Step S1063, performing a triaxial compression test on the first core sample to obtain corresponding compressive strength and fracture characteristics;

[0052] Step 1064, performing a direct shear test on the second core sample to obtain corresponding shear resistance characteristics;

[0053] Step 1065, performing a tensile strength test on the third core sample to obtain a corresponding tensile strength;

[0054] The first core sample, the second core sample and the third core sample are different parallel samples in the same group of core samples after immersion.

[0055] For example, for sample A in the same group of parallel samples, a triaxial compression test is carried out to test the stress-strain law under confining pressure conditions, and to obtain the compressive strength and rupture characteristics;

[0056] For sample B of the same group of parallel samples, a direct shear test was carried out to determine the shear resistance of the sample;

[0057] A tensile strength test experiment was conducted on sample C of the same group of parallel samples, and the tensile strength was tested after the sample was prepared as a characterization sample.

[0058] Then, based on rock mechanics parameters, the dynamic relationship between the drilling mud invasion degree and the evolution of rock mechanics parameters of oil shale samples is jointly established to determine the influence of the rock physics and rock mechanics properties of oil shale on the wellbore collapse mode, clarify the action law of the main control parameters, and provide support for drilling parameter optimization. At the same time, a mathematical characterization model is established, which is combined with the experimental process and experimental test results to optimize the description accuracy of the oil-based mud invasion characteristics and its influence on the mechanical characteristics.

[0059] Specifically, the mathematical representation model includes:

[0060] Flow equations within the oil shale matrix:

[0061]

[0062] Flow equation within the bedding weak plane:

[0063]

[0064] Poroelastic equation within the oil shale matrix:

[0065] σ′=σ―αpI

[0066] Mechanical behavior equation of bedding weak plane:

[0067] σ′ f =σ―α f pI

[0068] Deformation equation within the oil shale matrix:

[0069] σ=2Gε+λtr(ε)I

[0070] Interaction equation between bedding weak plane and oil shale matrix:

[0071]

[0072] Where q is the flow velocity, k is the permeability, μ is the viscosity, p is the pressure, the subscript f represents the weak plane, σ is the stress, G is the shear modulus, α is the poroelastic coefficient, I is the unit matrix, ε is the strain, and λ is the Lame constant.

[0073] Specifically, in step S110, the rock mechanical parameters of the oil shale sample in the oil-based mud environment are first obtained through experiments, including compressive strength and fracture characteristics, shear properties, tensile strength and other parameters; then the established mathematical characterization model is substituted to calculate the stress-strain distribution and strength parameter degradation of the oil shale surrounding rock in the oil-based mud environment, so as to predict the collapse pressure and potential collapse cycle of the oil shale formation under different drilling parameters and formation conditions.

[0074] From the above description, it can be seen that the present invention provides a method for analyzing the strength of oil shale wellbore surrounding rock under oil-based mud conditions. By combining indoor experiments and mathematical model analysis, the stress-strain distribution and strength parameter degradation of the wellbore surrounding rock oil shale in the oil-based mud environment during drilling are calculated and predicted, and the rock mechanics mechanism of wellbore collapse and the damage characteristics of the layer are clarified, thereby alleviating the technical problems of low analysis accuracy and analysis reliability of stratified oil shale formation strength parameters in the oil-based mud environment in the prior art.

[0075] Embodiment 2

[0076] In an optional implementation provided by an embodiment of the present invention, a shale oil drilling scenario in an offshore oil field is selected as an implementation object:

[0077] (1) The geological data of the area were analyzed in detail, including rock sequences, sedimentary characteristics, tectonic development history and its relationship with regional tectonic activities. By analyzing the seismic profiles and historical drilling data obtained on site, we deeply understood the stratigraphic structure and lithological changes of the well location to ensure the accuracy of subsequent model settings. In addition, we collected rock physical and mechanical property data of the formation, such as the porosity, permeability, clay content, organic carbon content and brittleness of the rock, so as to more accurately simulate the interaction between oil-based mud and rock.

[0078] (2) Collect and prepare rock samples. During the drilling process, coring technology is used to obtain representative cores from different depths, especially in sections with high-level rationality and developed fractures. All core samples are strictly cleaned and dried in the laboratory, and processed into standard test cylinders of specified sizes using high-precision rock cutting and grinding equipment. During the preparation process, the processing is accurate to the millimeter level to ensure that the end surface flatness and parallelism of each sample meet the international rock mechanics testing standards.

[0079] (3) Simulation of oil-based mud penetration experiment. We selected a variety of commercially formulated oil-based muds and conducted immersion experiments on standard core samples for different time periods to simulate the invasion process of oil-based mud in actual drilling. In the experiment, nuclear magnetic resonance imaging technology was used to regularly detect the internal fluid dynamics of the core samples. By analyzing the T2 relaxation time spectrum, the fluid distribution in the pore structure and its changes over time were quantitatively analyzed, and the microscopic mechanism of the interaction between mud penetration and rock was determined.

[0080] (4) Comprehensive rock mechanics property testing. A series of rock mechanics tests were conducted in the laboratory under mud immersion conditions. Triaxial compression tests were conducted to perform stress-strain analysis on the cores soaked in oil-based mud under simulated formation confining pressure conditions to obtain their compressive strength and fracture mode. Direct shear tests were conducted to measure the shear strength of the cores to evaluate the stability of the bedding plane under shear force. Tensile strength tests were conducted to evaluate the tensile strength of the rock through the Brazilian disc test to determine the fracture behavior of the rock under tension.

[0081] (5) Data analysis and establishment of collapse pressure prediction model. By integrating the core test results with the basic physical and chemical properties of the rock, mathematical models and computer simulations are established to analyze in detail the impact of oil-based mud invasion on the mechanical properties of oil shale. The model considers the changes in rock microstructure, the interaction between chemical reactions and mechanical responses, and how these factors jointly affect the stability of the wellbore. Through models and modeling analysis, the collapse pressure and potential collapse cycle of oil shale formations under different drilling parameters and formation conditions are predicted, providing scientific parameter optimization suggestions for drilling operations.

[0082] (6) Result verification and uncertainty analysis. Based on the model prediction results, a set of optimized drilling parameters is provided for the safe density window and the risk of wellbore collapse is reduced. By continuously monitoring the wellbore stability during the actual drilling process, the laboratory research results are converted into practical operation suggestions on the spot for effective engineering application.

[0083] Embodiment 3

[0084] Figure 2 Schematic diagram of an oil shale well wall surrounding rock strength analysis device under oil-based mud conditions provided by an embodiment of the present invention. Figure 2 As shown, the system includes: a preparation module 10, a soaking module 20, a testing module 30, a building module 40 and an analysis module 50.

[0085] Specifically, the preparation module 10 is used to perform engineering coring on the target oil shale formation and prepare multiple groups of core samples;

[0086] The soaking module 20 is used to soak multiple groups of core samples in oil-based mud for different time periods to obtain multiple groups of core samples after soaking;

[0087] The testing module 30 is used to perform comprehensive rock mechanical property tests on multiple groups of core samples after immersion, and obtain rock mechanical parameters of oil shale samples under different oil-based mud conditions;

[0088] Establishing module 40, for establishing a mathematical characterization model of the dynamic relationship between the drilling mud invasion degree and the rock mechanical parameter evolution of the oil shale sample based on the rock mechanical parameters;

[0089] The analysis module 50 is used to predict the collapse pressure and potential collapse period of the oil shale formation under different drilling parameters and formation conditions based on the mathematical characterization model.

[0090] Specifically, the preparation module 10 is also used for:

[0091] Obtain geological information on target oil shale formations;

[0092] Combined with geological information, engineering coring is carried out on the target oil shale formation to obtain outcrop rock samples;

[0093] Process the outcrop rock samples into cylindrical cores with flat and parallel end faces;

[0094] The core columns are grouped according to lithology and bedding trend to obtain multiple groups of core samples.

[0095] Specifically, the testing module 30 is further used for:

[0096] Performing nuclear magnetic resonance tests on multiple groups of core samples after immersion to obtain T2 relaxation time spectra of each group of core samples after immersion;

[0097] The T2 relaxation time spectra were analyzed to determine the pore size and fluid distribution characteristics of each group of core samples after immersion;

[0098] A triaxial compression test was performed on the first core sample to obtain the corresponding compressive strength and fracture characteristics;

[0099] A direct shear test was conducted on the second core sample to obtain the corresponding shear resistance characteristics;

[0100] Conducting a tensile strength test on the third core sample to obtain the corresponding tensile strength;

[0101] The first core sample, the second core sample and the third core sample are different parallel samples in the same group of core samples after immersion.

[0102] 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.

[0103] The present invention also provides a computer-readable storage medium, which stores computer instructions. When the computer instructions are executed by a processor, the method in the above-mentioned embodiment 1 is implemented.

[0104] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0105] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for analyzing the strength of oil shale well wall surrounding rock under oil-based mud conditions, characterized in that: include: Conduct engineering coring of the target oil shale formation and prepare multiple sets of core samples; The plurality of core samples are immersed in oil-based mud for different time periods to obtain a plurality of core samples after immersion; Performing comprehensive rock mechanical property tests on the multiple groups of soaked core samples to obtain rock mechanical parameters of the oil shale samples under different oil-based mud conditions; Based on the rock mechanical parameters, a mathematical characterization model for the dynamic relationship between the drilling mud invasion degree and the rock mechanical parameter evolution of the oil shale sample is established; Based on the mathematical characterization model, the collapse pressure and potential collapse period of the oil shale formation under different drilling parameters and formation conditions are predicted.

2. The method according to claim 1, characterized in that: Carry out engineering coring of the target oil shale formation and prepare multiple sets of core samples, including: Obtaining geological information of the target oil shale formation; Carrying out engineering coring of the target oil shale formation in combination with the geological information to obtain outcrop rock samples; Processing the outcrop rock sample into a cylindrical rock core with flat and parallel end surfaces; The columnar cores are grouped according to lithology and bedding trends to obtain the multiple groups of core samples.

3. The method according to claim 1, characterized in that: The multiple groups of soaked core samples are subjected to comprehensive rock mechanical property tests to obtain rock mechanical parameters of oil shale samples under different oil-based mud conditions, including: Performing nuclear magnetic resonance testing on the multiple groups of soaked core samples to obtain a T2 relaxation time spectrum of each group of soaked core samples; The T2 relaxation time spectrum is analyzed to determine the pore size and fluid distribution characteristics of each group of core samples after immersion.

4. The method according to claim 1, characterized in that: Conducting comprehensive rock mechanical property tests on the multiple groups of soaked core samples to obtain rock mechanical parameters of oil shale samples under different oil-based mud conditions, also includes: A triaxial compression test was performed on the first core sample to obtain the corresponding compressive strength and fracture characteristics; A direct shear test was conducted on the second core sample to obtain the corresponding shear resistance characteristics; Conducting a tensile strength test on the third core sample to obtain the corresponding tensile strength; The first core sample, the second core sample and the third core sample are respectively different parallel samples in the same group of core samples after immersion.

5. The method according to claim 1, characterized in that: The mathematical representation model comprises: Flow equations within the oil shale matrix: Flow equation within the bedding weak plane: Poroelastic equation within the oil shale matrix: σ′=σ―αpI Mechanical behavior equation of bedding weak plane: in f =s―a f pI Deformation equation within the oil shale matrix: σ=2Gε+λtr(ε)I Interaction equation between bedding weak plane and oil shale matrix: Where q is the flow velocity, k is the permeability, μ is the viscosity, p is the pressure, the subscript f represents the weak plane, σ is the stress, G is the shear modulus, α is the poroelastic coefficient, I is the unit matrix, ε is the strain, and λ is the Lame constant.

6. An oil shale well wall surrounding rock strength analysis device under oil-based mud conditions, characterized in that: include: Preparation module, soaking module, testing module, establishment module and analysis module; wherein, The preparation module is used to perform engineering coring on the target oil shale formation and prepare multiple groups of core samples; The immersion module is used to perform immersion experiments on the multiple groups of core samples in oil-based mud for different time periods to obtain multiple groups of core samples after immersion; The testing module is used to perform comprehensive rock mechanical property testing on the multiple groups of core samples after immersion to obtain rock mechanical parameters of the oil shale samples under different oil-based mud conditions; The establishment module is used to establish a mathematical representation model of the dynamic relationship between the drilling mud invasion degree and the rock mechanical parameter evolution of the oil shale sample based on the rock mechanical parameters; The analysis module is used to predict the collapse pressure and potential collapse period of the oil shale formation under different drilling parameters and formation conditions based on the mathematical characterization model.

7. The device according to claim 6, characterized in that: The preparation module is also used for: Obtaining geological information of the target oil shale formation; Carrying out engineering coring of the target oil shale formation in combination with the geological information to obtain outcrop rock samples; Processing the outcrop rock sample into a cylindrical rock core with flat and parallel end surfaces; The columnar cores are grouped according to lithology and bedding trends to obtain the multiple groups of core samples.

8. The device according to claim 6, characterized in that: The test module is also used for: Performing nuclear magnetic resonance testing on the multiple groups of soaked core samples to obtain a T2 relaxation time spectrum of each group of soaked core samples; Analyzing the T2 relaxation time spectrum to determine the pore size and fluid distribution characteristics of each group of core samples after immersion; A triaxial compression test was performed on the first core sample to obtain the corresponding compressive strength and fracture characteristics; A direct shear test was conducted on the second core sample to obtain the corresponding shear resistance characteristics; Conducting a tensile strength test on the third core sample to obtain the corresponding tensile strength; The first core sample, the second core sample and the third core sample are respectively different parallel samples in the same group of core samples after immersion.

9. 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 5 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and when the computer instructions are executed by a processor, the method according to any one of claims 1 to 5 is implemented.

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