Rock mechanics test system

Abstract

The present invention belongs to the field of rock mechanics tests. Provided is a rock mechanics test system. The system comprises: a sealed compartment body, a mechanics simulation apparatus, a temperature control apparatus and a deformation monitoring apparatus, wherein the deformation monitoring apparatus comprises: a resistive monitoring unit and a differential transformer-type displacement sensing unit; the mechanics simulation apparatus is used for providing confining pressure for a core sample; the temperature control apparatus is used for providing a first temperature environment, a second temperature environment or a third temperature environment for the sealed compartment body; the resistive monitoring unit is used for monitoring, in the first temperature environment, feature information of deformation generated in a core sample to be tested under the action of the confining pressure; the differential transformer-type displacement sensing unit is used for monitoring, in the second temperature environment, feature information of deformation generated in the core sample to be tested under the action of the confining pressure; and the resistive monitoring unit and the differential transformer-type displacement sensing unit simultaneously monitor, in the third temperature environment, feature information of deformation generated in the core sample under the action of the confining pressure.

Description

Rock mechanics testing system

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202510035292.0, filed on January 9, 2025, the contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of rock mechanics testing technology, and more specifically to a rock mechanics testing system. Background Technology

[0004] As oil and gas exploration and development deepens, it increasingly extends into deep and ultra-deep formations. In these deep and ultra-deep formations, the temperature and stress environments become extremely harsh, posing new challenges to drilling, completion, and reservoir stimulation operations. Rock mechanics is the fundamental cause of complex downhole accidents. Currently, the constitutive and fracture mechanisms of rocks under ultra-high temperature and ultra-high stress conditions are poorly understood, and existing experimental capabilities cannot meet the needs of in-situ rock mechanics research in ultra-deep formations.

[0005] Existing rock mechanics instruments cannot accurately monitor rock deformation under extreme conditions of ultra-high temperature and ultra-high pressure. They face many challenges such as easy failure of seals and low accuracy of strain gauge monitoring, making it difficult to carry out rock mechanics tests under extreme conditions effectively. Summary of the Invention

[0006] To address the aforementioned technical deficiencies, this invention provides a rock mechanics testing system. The deformation monitoring device within this system comprises a resistance monitoring unit and a differential transformer displacement sensing unit. The resistance monitoring unit monitors the deformation characteristics of the core sample under confining pressure when the sealed chamber is in a first temperature environment. The differential transformer displacement sensing unit monitors the deformation characteristics of the core sample under confining pressure when the sealed chamber is in a second temperature environment. Furthermore, the resistance monitoring unit and the differential transformer displacement sensing unit simultaneously monitor the deformation characteristics of the core sample under confining pressure when the sealed chamber is in a third temperature environment. By employing different monitoring methods to monitor the deformation characteristics of the core sample under different temperature environments, accurate monitoring data can be obtained, improving monitoring precision.

[0007] The present invention provides a rock mechanics testing system, comprising: a sealed chamber, and a mechanical simulation device, a temperature control device, and a deformation monitoring device disposed within the sealed chamber, wherein the deformation monitoring device comprises: a resistance monitoring unit and a differential transformer displacement sensing unit.

[0008] The sealed chamber is equipped with a test bench, the mechanical simulation device is set on the test bench, the core sample to be tested is placed inside the mechanical simulation device, and the mechanical simulation device is used to provide confining pressure for the core sample;

[0009] The temperature control device is used to provide a first temperature environment, a second temperature environment, or a third temperature environment for the sealed compartment, wherein the temperature value of the first temperature environment is lower than the temperature value of the second ambient temperature, and the temperature value of the second ambient temperature is lower than the temperature value of the third ambient temperature.

[0010] The resistive monitoring unit is used to monitor the characteristic information of the deformation of the core sample under confining pressure when the sealed chamber is in the first temperature environment.

[0011] The differential transformer displacement sensing unit is used to monitor the deformation characteristics of the core sample under confining pressure when the sealed chamber is in a second temperature environment.

[0012] When the sealed chamber is in a third temperature environment, the resistive monitoring unit and the differential transformer displacement sensing unit simultaneously monitor the characteristic information of the deformation of the core sample under the confining pressure.

[0013] In this embodiment of the invention, the mechanical simulation device includes: a strain-controlled upper pressure head, a strain-controlled lower pressure head, a first heating module, and a simulation shell;

[0014] The strain control pressure head penetrates the top of the simulation shell and is movably disposed inside the simulation shell to apply downward confining pressure to the core sample to be tested;

[0015] The strain-controlled indenter is movably disposed within the simulation shell and is used to apply an upward confining pressure to the core sample to be tested.

[0016] The first heating module is disposed inside the simulation housing and is used to provide a high-temperature environment for the mechanical simulation device.

[0017] In this embodiment of the invention, the first heating module includes: a heating rod and a solid heat-conducting layer;

[0018] The solid thermally conductive layer is attached to the inner wall of the simulated shell;

[0019] The heating rod is located inside the simulated housing.

[0020] In this embodiment of the invention, the resistive monitoring unit includes a resistive monitoring strain gauge and a resistance extensometer, and the differential transformer displacement sensing unit includes a differential transformer displacement strain gauge and a differential transformer displacement sensor.

[0021] The resistance strain gauge is installed on the core sample to be tested. The resistance strain gauge is used to monitor the characteristic information of the deformation of the core sample under confining pressure when the sealed chamber is in the first temperature environment.

[0022] The differential transformer type displacement strain gauge is installed on the core sample to be tested. The differential transformer type displacement strain gauge is used to monitor the characteristic information of the deformation of the core sample under confining pressure when the sealed chamber is in a second temperature environment.

[0023] The probes of the resistance extensometer are placed on both sides of the core sample to be tested, and the probes of the differential transformer displacement sensor are placed at the end of the strain control pressure head located outside the simulation shell. The measuring bodies of the resistance extensometer and the differential transformer displacement sensor are placed outside the simulation shell. When the sealed chamber is in a third temperature environment, the resistance extensometer and the differential transformer displacement sensor monitor the characteristic information of the deformation of the core sample under confining pressure.

[0024] In this embodiment of the invention, the sealed compartment includes: a compartment body, a hydraulic lifting door, a sensor probe, a hydraulic tank, operating buttons, and a remote control console for the lifting door;

[0025] The sensing probe is installed on the hydraulic lifting door to monitor environmental information within a preset range outside the hydraulic lifting door, obtain environmental monitoring signals, and send the environmental monitoring signals to the controller of the hydraulic lifting door;

[0026] The controller of the hydraulic lifting door selects to connect to the remote control console or operation button of the lifting door according to the environmental monitoring signal, and is used to lift or lower according to the control command of the remote control console or the control command of the operation button.

[0027] The hydraulic tank is connected to the hydraulic lifting door and is used to provide the hydraulic lifting door with the power to lift and lower, so as to close the body of the compartment.

[0028] In this embodiment of the invention, the temperature control device includes: a temperature sensor and a second heating module;

[0029] The second heating module is used to heat the internal environment of the sealed compartment so that the sealed compartment is in a first temperature environment, a second temperature environment, or a third temperature environment.

[0030] The temperature sensor is used to monitor the temperature inside the sealed compartment.

[0031] In this embodiment of the invention, the second heating module includes an electromagnetic heating unit disposed on the outer wall of the sealed compartment.

[0032] In this embodiment of the invention, the system further includes: a pressure control device, which is used to provide an extreme pressure environment for the sealed compartment and to provide circumferential confining pressure for the mechanical simulation device.

[0033] In this embodiment of the invention, the pressure control device includes: a confining pressure sensor, a confining pressure oil tank, a first booster, and a second booster;

[0034] The confining pressure sensor is installed inside the sealed compartment to monitor the pressure value inside the sealed compartment.

[0035] The first or second intensifier is used to apply circumferential confining pressure to the sealed compartment and the mechanical simulation device individually;

[0036] The confining pressure oil tank is connected to the first intensifier and the second intensifier respectively, and is used to provide the confining pressure oil required to generate pressure for the first intensifier and the second intensifier.

[0037] In this embodiment of the invention, the system further includes a cooling device, which includes a coolant pumping module, a cooling pipe, a cooling medium cooler, a confining pressure oil cooler, a top cooling loop, and a bottom cooling loop.

[0038] The output end of the coolant pumping module is connected to the coolant input end of the cooling medium cooler through the cooling pipe. The coolant output end of the cooling medium cooler is connected to the coolant input end of the confining pressure oil cooler. The coolant output end of the confining pressure oil cooler is connected to the input end of the top cooling loop. The output end of the top cooling loop is used to connect to the input end of the bottom cooling loop. The output end of the bottom cooling loop is connected to the input end of the coolant pumping module.

[0039] In this embodiment of the invention, the system further includes: a crack monitoring device, the crack monitoring device including: an optical fiber monitor;

[0040] The fiber optic monitor is installed on the core sample to be tested and is used to monitor the characteristic information of the cracks generated in the core sample under confining pressure.

[0041] In this embodiment of the invention, the system further includes: an ultrasonic monitoring device, which is installed on the core sample to be tested and is used to emit ultrasonic signals in different directions to the core sample to be tested;

[0042] The ultrasonic signal propagates from one end of the core sample to the other end and is received by the ultrasonic monitoring device at the other end of the core sample. The ultrasonic monitoring device determines the anisotropic characteristic information of the core sample based on the received ultrasonic signal.

[0043] In this embodiment of the invention, the ultrasonic monitoring device includes: an ultrasonic transmitter, an ultrasonic receiver, an ultrasonic probe, and a universal coupling;

[0044] The ultrasonic transmitter is used to generate an ultrasonic emission signal and transmit the ultrasonic emission signal to the ultrasonic probe.

[0045] The ultrasonic probe is mounted on the universal coupling and is used to send the ultrasonic signal to one end of the core sample to be tested according to a preset direction.

[0046] The ultrasonic probe is also used to receive ultrasonic signals from the other end of the core sample to be tested and to transmit the received ultrasonic signals to the ultrasonic receiver.

[0047] In this embodiment of the invention, the system further includes: a coupling agent replenishment device, which includes: a coupling agent storage mechanism, a coupling agent pump, and a coupling agent nozzle; the ultrasonic monitoring device further includes: an ultrasonic pressure head automatic opening and closing mechanism.

[0048] The coupling agent pump is used to inject the coupling agent stored in the coupling agent storage mechanism onto the core sample to be tested through the coupling agent nozzle;

[0049] The ultrasonic indenter automatic opening and closing mechanism is located between the couplant replenishment device and the core sample to be tested. The ultrasonic indenter automatically opens when the ultrasonic monitoring device is working, so that the couplant replenishment device automatically injects couplant onto the core sample to be tested.

[0050] In this embodiment of the invention, the system further includes: an internal damage monitoring device, which includes: an acoustic emission monitoring device, which is used to receive the acoustic wave signal generated by the core sample under test under confining pressure, and obtain characteristic information of the internal damage generated by the core sample under test under confining pressure based on the acoustic wave signal.

[0051] In this embodiment of the invention, the internal damage monitoring device further includes: an environmental monitoring module and a noise reduction processing module;

[0052] The environmental monitoring module is used to monitor the environmental noise signal inside the sealed compartment.

[0053] The noise reduction processing module is connected to the environmental monitoring module and is used to receive the environmental noise signal, identify the noise decibel value of the environmental noise signal, and perform noise reduction processing on the sound wave signal received by the acoustic emission monitoring device according to the identified noise decibel value of the environmental noise signal.

[0054] The deformation monitoring device in the rock mechanics testing system provided by this invention includes a resistance monitoring unit and a differential transformer displacement sensing unit. This invention monitors the deformation characteristics of the core sample under confining pressure in a sealed chamber under a first temperature environment using the resistance monitoring unit. It monitors the deformation characteristics of the core sample under confining pressure in a sealed chamber under a second temperature environment using the differential transformer displacement sensing unit. Furthermore, it simultaneously monitors the deformation characteristics of the core sample under confining pressure in a sealed chamber under a third temperature environment using both the resistance monitoring unit and the differential transformer displacement sensing unit. By employing different monitoring methods to monitor the deformation characteristics of the core sample under different temperature environments, accurate monitoring data can be obtained, improving monitoring precision.

[0055] Other features and advantages of the technical solution of the present invention will be described in detail in the following detailed embodiments section. Attached Figure Description

[0056] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0057] Figure 1 is a structural block diagram of the rock mechanics testing system provided in an embodiment of the present invention;

[0058] Figure 2 is a structural schematic diagram of the sealed compartment provided in an embodiment of the present invention;

[0059] Figure 3 is a schematic diagram of the mechanical simulation device provided in an embodiment of the present invention;

[0060] Figure 4 is a schematic diagram of the dual heating system provided in this embodiment of the invention;

[0061] Figure 5 is a structural schematic diagram of the pressure control device provided in an embodiment of the present invention;

[0062] Figure 6 is a schematic diagram of the cooling device provided in an embodiment of the present invention;

[0063] Figure 7 is a schematic diagram of the ultrasonic monitoring device provided in an embodiment of the present invention;

[0064] Figure 8 is a structural block diagram of the internal damage monitoring device provided in an embodiment of the present invention.

[0065] Explanation of reference numerals in the attached diagram: 01-Sealed chamber, 02-Hydraulic lifting door, 03-Induction probe, 04-Hydraulic tank, 05-Operating button, 06-Remote control panel for lifting door, 11-Temperature sensor, 12-High-temperature resistant elastomer alloy sealing ring, 13-Electromagnetic heating unit, 14-Simulation shell, 15-Heating rod, 16-Solid thermal conductive layer, 21-Resistance extensometer, 22-Differential transformer type displacement sensor, 23-Fiber optic monitor, 24-Strain control upper pressure head, 25-Strain control lower pressure head, 26-Test bench, 31-First intensifier automatic valve, 32-Second intensifier automatic valve, 33-Second oil tank automatic valve Valves, 34-First oil tank automatic valve, 35-First booster, 36-Second booster, 37-Containing pressure oil tank, 40-Coolant pump injection module, 41-Top cooling loop, 42-Bottom cooling loop, 43-Containing pressure oil cooler, 44-Cooling medium cooler, 45-Cooling pipe, 46-Freon module, 47-Cooling medium flow channel, 48-Containing pressure oil flow channel, 49-Air-cooled heat dissipation unit, 51-Universal coupling, 52-Ultrasonic transmitter, 53-Ultrasonic pressure head automatic opening and closing mechanism, 54-Coupled agent storage mechanism, 55-Coupled agent pump, 56-Coupled agent nozzle, 57-Core sample to be tested. Detailed Implementation

[0066] To make the technical solutions and advantages of the embodiments of the present invention clearer, the exemplary embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0067] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0068] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0069] In this invention, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0070] In the process of developing this invention, the inventors discovered that the depth of oil and gas resource exploration and development is gradually moving towards deep and ultra-deep formations. In these deep and ultra-deep formations, the formation temperature and stress environment become extremely harsh, posing new challenges to well engineering operations such as drilling, completion, and reservoir stimulation. Rock mechanics is the fundamental problem causing complex downhole accidents. Currently, the constitutive and fracture mechanisms of rocks under ultra-high temperature and ultra-high stress conditions are not well understood, and existing experimental capabilities cannot meet the needs of in-situ rock mechanics research in ultra-deep formations.

[0071] Existing rock mechanics instruments cannot accurately monitor rock deformation under extreme conditions of ultra-high temperature and ultra-high pressure. They face many challenges such as easy failure of seals and low accuracy of strain gauge monitoring, making it difficult to carry out rock mechanics tests under extreme conditions effectively.

[0072] To address the aforementioned problems, this invention provides a rock mechanics testing system, comprising: a sealed chamber, and a mechanical simulation device, a temperature control device, and a deformation monitoring device disposed within the sealed chamber. The deformation monitoring device includes: a resistance monitoring unit and a differential transformer displacement sensing unit. A test bench is provided within the sealed chamber, and the mechanical simulation device is disposed on the test bench. The core sample to be tested is placed inside the mechanical simulation device, which provides confining pressure to the core sample. The temperature control device provides a first temperature environment, a second temperature environment, or a third temperature environment to the sealed chamber, wherein the first temperature environment... The temperature value of the first ambient temperature is lower than the temperature value of the second ambient temperature, and the temperature value of the second ambient temperature is lower than the temperature value of the third ambient temperature. The resistive monitoring unit is used to monitor the deformation characteristics of the core sample under confining pressure when the sealed chamber is in the first temperature environment. The differential transformer displacement sensing unit is used to monitor the deformation characteristics of the core sample under confining pressure when the sealed chamber is in the second temperature environment. When the sealed chamber is in the third temperature environment, the resistive monitoring unit and the differential transformer displacement sensing unit simultaneously monitor the deformation characteristics of the core sample under confining pressure. The deformation monitoring device in the rock mechanics testing system provided by this invention includes a resistance monitoring unit and a differential transformer displacement sensing unit. The resistance monitoring unit monitors the deformation characteristics of the core sample under confining pressure when the sealed chamber is in a first temperature environment. The differential transformer displacement sensing unit monitors the deformation characteristics of the core sample under confining pressure when the sealed chamber is in a second temperature environment. Furthermore, the resistance monitoring unit and the differential transformer displacement sensing unit simultaneously monitor the deformation characteristics of the core sample under confining pressure when the sealed chamber is in a third temperature environment. By employing different monitoring methods to monitor the deformation characteristics of the core sample under different temperature environments, accurate monitoring data can be obtained, improving monitoring precision.

[0073] Figure 1 is a structural block diagram of the rock mechanics testing system provided in an embodiment of the present invention. As shown in Figure 1, the rock mechanics testing system provided in this embodiment includes: a sealed chamber 01, and a mechanical simulation device, a temperature control device, a deformation monitoring device, a pressure control device, a cooling device, a crack monitoring device, an ultrasonic monitoring device, a coupling agent replenishment device, and an internal damage monitoring device disposed within the sealed chamber 01.

[0074] The temperature and pressure control devices are used to provide an extreme high-temperature and high-pressure environment inside the sealed chamber 01. The core sample 57 to be tested undergoes rock mechanics testing within this extreme environment. The rock mechanics testing includes: conducting a confining pressure simulation test on the core sample 57 under ultra-high temperature and ultra-high pressure using a mechanical simulation device; monitoring the deformation characteristics of the core sample 57 during the confining pressure simulation test using a deformation monitoring device; monitoring the crack characteristics of the core sample 57 during the confining pressure simulation test using a crack monitoring device; and monitoring the internal damage characteristics of the core sample 57 during the confining pressure simulation test using an internal damage monitoring device. An ultrasonic anisotropy test is also conducted on the core sample under ultra-high temperature and ultra-high pressure to obtain anisotropic characteristics of the core sample 57 under extreme conditions.

[0075] Figure 2 is a structural schematic diagram of the sealed compartment 01 provided in an embodiment of the present invention. As shown in Figure 2, in this embodiment, the sealed compartment 01 is provided with a test bench 26. More specifically, the sealed compartment 01 includes: a compartment body, a hydraulic lifting door 02, a sensor probe 03, a hydraulic tank 04, an operation button 05, and a remote control console 06 for the lifting door. The sensor probe 03 is installed on the hydraulic lifting door 02 and is used to monitor environmental information within a preset range outside the hydraulic lifting door 02, obtain environmental monitoring signals, and send the environmental monitoring signals to the controller of the hydraulic lifting door 02. The controller of the hydraulic lifting door 02 selects to connect to the remote control console 06 or the operation button 05 according to the environmental monitoring signals, and is used to lift or lower according to the control commands of the remote control console 06 or the operation button 05. The hydraulic tank 04 is connected to the hydraulic lifting door 02 and is used to provide the hydraulic lifting door 02 with the power to lift and lower, so as to close the compartment body.

[0076] In this embodiment, the sensing probe 03 is installed on the hydraulic lifting door 02 to detect personnel movement within a five-meter radius outside the hydraulic lifting door 02. Specifically, the sensing probe 03 sets a danger limit of 0.5 meters outside the hydraulic lifting door 02. When the sensing probe 03 detects personnel entering the danger limit, the lifting control of the hydraulic lifting door 02 switches to button operation. The operator needs to continuously press the button to control the lifting of the hydraulic lifting door 02. One set of operation buttons 05 is located on the frame of the body, and the other set is led out through hydraulic lines for remote operation on the lifting door remote control console 06, ensuring safety and operability. Furthermore, the hydraulic lifting door 02 is made of Incoloy 800 nickel-based alloy material. Under the combined action of the hydraulic lifting door 02 and the hydraulic tank 04, the hydraulic lifting door 02 can lift quickly and smoothly, achieving complete sealing of the enclosed body 01.

[0077] Figure 3 is a schematic diagram of the mechanical simulation device provided in an embodiment of the present invention. As shown in Figure 3, the mechanical simulation device is disposed on the test bench 26, and the core sample 57 to be tested is placed inside the mechanical simulation device. The mechanical simulation device is used to provide confining pressure to the core sample. Specifically, the mechanical simulation device includes: a strain-controlled upper pressure head 24, a strain-controlled lower pressure head 25, a first heating module, and a simulation shell 14; the strain-controlled upper pressure head 24 penetrates through the top of the simulation shell 14 and is movably disposed inside the simulation shell 14, used to apply downward confining pressure to the core sample 57 to be tested; the strain-controlled lower pressure head 25 is movably disposed inside the simulation shell 14, used to apply upward confining pressure to the core sample 57 to be tested; the first heating module is disposed inside the simulation shell 14, used to provide a high-temperature environment for the mechanical simulation device. In this embodiment, the mechanical simulation device provides three-dimensional confining pressure to the core sample 57 to be tested. The strain-controlled upper pressure head 24 and the strain-controlled lower pressure head 25 provide axial confining pressure to the core sample 57 to be tested. The pressure control module provides circumferential confining pressure to the core sample 57 to be tested, excluding the axial direction. Applying three-dimensional confining pressure to the periphery of the core sample 57 causes deformation, cracking, and internal damage to the sample. Furthermore, the first heating module provides a temperature environment for the core sample 57 to be tested. The first heating module includes a heating rod 15 and a solid thermally conductive layer 16; the solid thermally conductive layer 16 is attached to the inner wall of the simulation shell 14; the heating rod 15 is disposed inside the simulation shell 14.

[0078] In this embodiment, the temperature control device is used to provide a first temperature environment, a second temperature environment, or a third temperature environment for the sealed compartment 01, wherein the temperature value of the first temperature environment is lower than the temperature value of the second ambient temperature, and the temperature value of the second ambient temperature is lower than the temperature value of the third ambient temperature. The temperature control device includes a temperature sensor 11 and a second heating module; the second heating module is used to heat the internal environment of the sealed compartment 01 to place the sealed compartment 01 in the first temperature environment, the second temperature environment, or the third temperature environment; the temperature sensor 11 is used to monitor the temperature value inside the sealed compartment 01.

[0079] Figure 4 is a schematic diagram of the dual heating system provided in this embodiment of the invention. As shown in Figure 4, in this embodiment, the first heating module of the mechanical simulation device and the second heating module of the temperature control device constitute a dual heating system, which provides the temperature environment during the test of the core sample 57. Specifically, after the experiment is started, the electromagnetic heating unit 13 is turned on and the target temperature of the electromagnetic heating unit 13 is set. When the required temperature is below 200°C, the experiment begins after the electromagnetic heating unit 13 heats up to the target temperature. When the required temperature exceeds 200°C, the electromagnetic heating unit 13 maintains the temperature at 200°C when the electromagnetic heating temperature reaches 200°C. The heating mode is automatically switched to the first heating module for local heating of the core sample 57. The first heating module includes a heating rod 15 and a solid heat-conducting layer 16. During the heating process of the electromagnetic heating unit 13, the temperature inside the mechanical simulation device is transferred through the solid heat-conducting layer 16, and the temperature inside the simulation shell 14 is raised. When the heating is switched to the heating rod 15 for local heating of the simulation shell 14, the heating is performed by the heating rod 15 and continues to heat to the target temperature. The dual heating system ensures that extreme temperatures remain within or near the mechanical simulation device, reducing the impact of extreme temperatures on the sealed compartment 01 and the components of the pressurization chamber. During the heating process, temperature sensor 11 continuously monitors the temperature.

[0080] In this embodiment, the temperature control device further includes a high-temperature resistant elastomer alloy sealing ring 12, which is attached to the temperature contact surface inside the sealed compartment 01. The high-temperature resistant elastomer alloy sealing ring changes volume with temperature to enhance the sealing effect and compensate for the small gaps caused by temperature changes.

[0081] Furthermore, in this embodiment, when the temperature sensor 11 detects that the temperature inside the sealed compartment 01 reaches 80% of the preset value, the temperature control device automatically switches to more precise analog quantity control and starts the constant temperature insulation unit to avoid overheating and protect key components such as the pressure chamber and the booster from high temperature.

[0082] In this embodiment, the resistive monitoring unit is used to monitor the deformation characteristics of the core sample 57 under confining pressure when the sealed chamber 01 is in a first temperature environment; the differential transformer displacement sensing unit is used to monitor the deformation characteristics of the core sample 57 under confining pressure when the sealed chamber 01 is in a second temperature environment; and the resistive monitoring unit and the differential transformer displacement sensing unit simultaneously monitor the deformation characteristics of the core sample under confining pressure when the sealed chamber 01 is in a third temperature environment.

[0083] In this embodiment, the deformation monitoring device includes: a resistive monitoring unit and a differential transformer displacement sensing unit; the resistive monitoring unit includes: a resistive strain gauge and a resistance extensometer 21, and the differential transformer displacement sensing unit includes: a differential transformer displacement strain gauge and a differential transformer displacement sensor 22. Specifically, the resistive strain gauge is installed on the core sample 57 to be tested, and is used to monitor the characteristic information of the deformation of the core sample 57 under confining pressure when the sealed chamber 01 is in a first temperature environment; the differential transformer displacement strain gauge is installed on the core sample 57 to be tested, and is used to monitor the characteristic information of the deformation of the core sample 57 under confining pressure when the sealed chamber 01 is in a second temperature environment; the resistance extensometer 21... The probes are placed on both sides of the core sample 57 to be tested. The probe of the differential transformer displacement sensor 22 is placed at the end of the strain control pressure head 24 located outside the simulation shell 14. The measuring bodies of the resistance extensometer 21 and the differential transformer displacement sensor 22 are placed outside the simulation shell 14. When the sealed chamber 01 is in the third temperature environment, the resistance extensometer 21 and the differential transformer displacement sensor 22 monitor the characteristic information of the deformation of the core sample 57 under the action of confining pressure.

[0084] In this embodiment, the resistive monitoring unit uses strain gauge self-compensation. By selecting a suitable strain gauge material, the resistance change caused by temperature variation cancels out the resistance change caused by mechanical deformation, thus achieving temperature compensation. The differential transformer displacement sensing unit has a certain degree of temperature stability and can adapt to temperature changes within a certain range.

[0085] In this embodiment, the first temperature environment is: the experimental temperature is less than 100°C; the second temperature environment is: the experimental temperature is within the range of [100°C, 200°C]; and the third temperature environment is: the experimental temperature is greater than 200°C.

[0086] When the ambient temperature is the third temperature environment, the strain monitoring of the core sample 57 under test is realized through the mechanical transmission of the probe of the resistance extensometer 21 and the probe of the differential transformer displacement sensor 22, which effectively avoids the influence of extreme temperature on the accuracy of strain testing.

[0087] Figure 5 is a schematic diagram of the pressure control device provided in an embodiment of the present invention. As shown in Figure 5, in this embodiment, the pressure control device is used to provide an extreme pressure environment for the sealed chamber 01 and to provide circumferential confining pressure for the mechanical simulation device. Specifically, the pressure control device includes: a confining pressure sensor, a confining pressure oil tank 37, a first booster 35, a second booster 36, a first booster automatic valve 31, a second booster automatic valve 32, a first oil tank automatic valve 34, and a second oil tank automatic valve 33; the confining pressure sensor is disposed inside the sealed chamber 01 and is used to monitor the pressure value inside the sealed chamber 01; the first booster 35 or the second booster 36 is used to apply circumferential confining pressure to the sealed chamber 01 and the mechanical simulation device individually; the confining pressure oil tank 37 is connected to the first booster 35 and the second booster 36 respectively, and is used to provide the confining pressure oil required to generate pressure for the first booster 35 and the second booster 36.

[0088] During the experiment, when it is necessary to pressurize the sealed chamber 01 or the mechanical simulation device, the first pressurizer automatic valve 31 is opened, and the first pressurizer 35 is started to pressurize the sealed chamber 01. At this time, the second pressurizer automatic valve 32, the first oil tank automatic valve 34, and the second oil tank automatic valve 33 are all closed. After the first pressurizer 35 finishes pressurizing, the first pressurizer automatic valve 31 closes, and the first oil tank automatic valve 34 opens to replenish oil and pressurize the first pressurizer 35. At this time, the second pressurizer automatic valve 32 automatically opens, and the second pressurizer 36 pressurizes the confining chamber. The second oil tank automatic valve 33 is closed. After the second pressurizer 36 finishes pressurizing, the second pressurizer automatic valve 32 closes, and the second oil tank automatic valve 33 opens to replenish oil and pressurize the second pressurizer 36. At this time, the first pressurizer automatic valve 31 automatically opens, and the first pressurizer 35 pressurizes the confining chamber. The first oil tank automatic valve 34 is closed. This process is repeated to achieve automatic boosting in parallel between the first booster 35 and the second booster 36.

[0089] Figure 6 is a schematic diagram of the cooling device provided in an embodiment of the present invention. As shown in Figure 6, in this embodiment, the cooling device includes: a coolant pump injection module 40, a cooling pipe 45, a cooling medium cooler 44, a confining pressure oil cooler 43, a top cooling loop 41, and a bottom cooling loop 42.

[0090] The output end of the coolant pumping module 40 is connected to the coolant input end of the cooling medium cooler 44 through the cooling pipe 45. The coolant output end of the cooling medium cooler 44 is connected to the coolant input end of the confining pressure oil cooler 43. The coolant output end of the confining pressure oil cooler 43 is connected to the input end of the top cooling loop 41. The output end of the top cooling loop 41 is used to connect to the input end of the bottom cooling loop 42. The output end of the bottom cooling loop 42 is connected to the input end of the coolant pumping module 40.

[0091] Specifically, when it is necessary to lower the temperature of the confining pressure chamber or related sealing components during the experiment, the coolant pump module 40 is first turned on, allowing the cooling medium to flow sequentially through the cooling pipe 45 to the cooling medium cooler 44, the confining pressure oil cooler 43, the top cooling loop 41, and the bottom cooling loop 42. The flow of the cooling medium achieves the purpose of cooling the bottom cooling loop 42, the top cooling loop 41, and the confining pressure oil. The bottom cooling loop 42 continuously cools the static seal between the base and the confining pressure chamber. The top cooling loop 41 continuously cools the dynamic seal contact position between the top of the confining pressure chamber and the lower pressure probe, effectively preventing seal failure. Simultaneously, the confining pressure oil cooler 43 includes a cooling medium flow channel 47 and a confining pressure oil flow channel 48. When the coolant flows through the cooling medium flow channel 47 in the confining pressure oil cooler 43, it continuously cools the confining pressure oil flowing in the confining pressure oil flow channel 48, thus achieving cooling of the confining pressure oil. The cooling medium cooler 44 includes a cooling medium flow channel 47 and a Freon module 46. The coolant is cooled by the Freon module 46 in the cooling medium flow channel 47 of the cooling medium cooler 44, thereby achieving cooling of the cooling medium and realizing multi-stage cooling. After the experiment, the coolant can be discharged according to the coolant pumping module 40.

[0092] In this embodiment, the cooling device further includes a wind-cooled heat dissipation unit 49, which is installed on the inner wall of the sealed chamber 01. The wind-cooled heat dissipation unit 49 can be opened to quickly cool down the sealed chamber 01 after the experiment.

[0093] In this embodiment, the crack monitoring device includes: an optical fiber monitor 23; the optical fiber monitor 23 is installed on the core sample 57 to be tested and is used to monitor the characteristic information of cracks generated in the core sample 57 under confining pressure.

[0094] Figure 7 is a schematic diagram of the ultrasonic monitoring device provided in an embodiment of the present invention. As shown in Figure 7, in this embodiment, the ultrasonic monitoring device is installed on the core sample 57 to be tested and is used to emit ultrasonic signals in different directions to the core sample 57 to be tested. The ultrasonic signals propagate from one end of the core sample 57 to the other end and are received by the ultrasonic monitoring device at the other end of the core sample 57. The ultrasonic monitoring device determines the anisotropic characteristic information of the core sample 57 to be tested based on the received ultrasonic signals. Specifically, the ultrasonic monitoring device includes: an ultrasonic transmitter 52, an ultrasonic receiver, an ultrasonic probe, and a universal coupling 51. The ultrasonic transmitter 52 is used to generate ultrasonic transmission signals and transmit the ultrasonic transmission signals to the ultrasonic probe. The ultrasonic probe is installed on the universal coupling 51 and is used to send the ultrasonic signals to one end of the core sample 57 to be tested according to a preset direction. The ultrasonic probe is also used to receive ultrasonic signals from the other end of the core sample 57 to be tested and transmit the received ultrasonic signals to the ultrasonic receiver.

[0095] In this embodiment, the coupling agent replenishment device includes a coupling agent storage mechanism 54, a coupling agent pump 55, and a coupling agent nozzle 56. The ultrasonic monitoring device further includes an ultrasonic indenter automatic opening and closing mechanism 53. The coupling agent pump 55 is used to inject the coupling agent stored in the coupling agent storage mechanism 54 onto the core sample 57 to be tested through the coupling agent nozzle 56. The ultrasonic indenter automatic opening and closing mechanism 53 is disposed between the coupling agent replenishment device and the core sample 57 to be tested. The ultrasonic indenter automatically opens when the ultrasonic monitoring device is working, so that the coupling agent replenishment device automatically injects the coupling agent onto the core sample 57 to be tested.

[0096] Figure 8 is a structural block diagram of the internal damage monitoring device provided in an embodiment of the present invention. As shown in Figure 8, in this embodiment, the internal damage monitoring device includes: an acoustic emission monitoring device, which is used to receive the acoustic wave signal generated by the core sample 57 under confining pressure, and obtain characteristic information of the internal damage generated by the core sample 57 under confining pressure based on the acoustic wave signal. The internal damage monitoring device also includes: an environmental monitoring module and a noise reduction processing module; the environmental monitoring module is used to monitor the environmental noise signal inside the sealed chamber 01; the noise reduction processing module is connected to the environmental monitoring module, and is used to receive the environmental noise signal, identify the noise decibel value of the environmental noise signal, and perform noise reduction processing on the acoustic wave signal received by the acoustic emission monitoring device based on the identified noise decibel value of the environmental noise signal. After the experiment starts, the environmental monitoring module is activated to monitor the environmental noise and system interference in real time. The data of the benchmark point are compared and analyzed to identify and record the characteristics of environmental noise and system interference, and the data is collected to the noise reduction processing system. The acoustic emission monitoring device is used to collect acoustic emission signals and record the data. The collected acoustic emission signals are input into the noise reduction processing system. Based on data from the environmental monitoring module, the noise reduction processing system identifies and removes environmental noise and system interference.

[0097] In this embodiment, specifically, the internal damage monitoring device further includes: an electrostatic connection cable and an independent grounding device. The electrostatic connection cable is used to electrostatically connect the mechanical simulation device, temperature control device, deformation monitoring device, pressure control device, cooling device, crack monitoring device, ultrasonic monitoring device, and coupling agent replenishment device together, and connects them to the independent grounding device.

[0098] In this embodiment, the system further includes a pore pressure monitoring device, which includes an EDC controller, a pore pressure sensor, and connecting pipes and valves.

[0099] In this embodiment, the system further includes a seepage monitoring device, which includes a pressure chamber, a seepage device, a hydraulic system, a measurement and control system, a sample clamp, and other auxiliary components.

[0100] In this embodiment, the system further includes a hydraulic power source device, which includes: a high-pressure plunger pump assembly, a relief valve, a precision oil filter, a temperature sensor 11 and a cooler, a low-pressure gear pump, an accumulator, an oil tank, pipelines and connectors.

[0101] This invention achieves complete sealing of the confining pressure chamber by setting up a sealed chamber 01 and a hydraulic lifting door 02, thus ensuring safety during the high temperature and high pressure test process.

[0102] This invention, through the design of a deformation monitoring device, enables the selection of different deformation monitoring methods under multi-level temperature conditions. In particular, it provides a technical means for accurately monitoring rock deformation under extreme temperature conditions by combining a resistance monitoring unit with a differential transformer displacement sensing unit to monitor the core sample 57 under ultra-high temperature conditions above 200℃. Simultaneously, the fiber optic monitoring device designed in this invention also provides feasibility for analyzing the dynamic evolution of cracks and pressure distribution characteristics in rock mechanics experiments.

[0103] This invention combines the second heating module of the temperature control device and the first heating module of the mechanical simulation device to form a dual heating system design, which realizes local ultra-high temperature heating of the rock core and avoids the thermal damage to key components of the confining pressure chamber caused by ultra-high temperature in existing devices.

[0104] This invention achieves continuous cooling of critical sealing locations by the coolant through the design of the cooling device, and also achieves rapid cooling of high-temperature confining oil, thus avoiding the impact of temperature failure on critical locations such as seals under ultra-high temperature conditions.

[0105] This invention achieves automatic and continuous pressurization without human intervention by designing a parallel automatic booster for the pressure control module, thus avoiding the problem of repeated manual operation required in existing equipment.

[0106] This invention achieves automatic control of high-temperature and high-pressure equipment through a distributed, factory-based layout of the control system.

[0107] This invention avoids the influence of environmental noise and static electricity on the acoustic emission experimental results by adding electrostatic connection cables, independent grounding devices, environmental monitoring modules, and noise reduction modules to the acoustic emission system.

[0108] This invention achieves automatic injection of coupling agent through a coupling agent replenishment device, avoiding the problems of repeated manual injection of coupling agent and manual change of probe test direction required in existing acoustic wave testing experiments.

[0109] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0110] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

[0111] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details described above. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention. Furthermore, it should be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. As long as such combination does not violate the spirit of the embodiments of the present invention, it should also be considered as the content disclosed by the embodiments of the present invention.

Claims

1. A rock mechanics testing system, characterized in that, include: A sealed compartment, and a mechanical simulation device, a temperature control device, and a deformation monitoring device installed inside the sealed compartment, wherein the deformation monitoring device includes a resistive monitoring unit and a differential transformer displacement sensing unit. The sealed chamber is equipped with a test bench, and the mechanical simulation device is set on the test bench. The core sample to be tested is placed inside the mechanical simulation device, which is used to provide confining pressure for the core sample. The temperature control device is used to provide a first temperature environment, a second temperature environment, or a third temperature environment for the sealed compartment, wherein the temperature value of the first temperature environment is lower than the temperature value of the second ambient temperature, and the temperature value of the second ambient temperature is lower than the temperature value of the third ambient temperature. The resistive monitoring unit is used to monitor the characteristic information of the deformation of the core sample under confining pressure when the sealed chamber is in the first temperature environment. The differential transformer displacement sensing unit is used to monitor the deformation characteristics of the core sample under confining pressure when the sealed chamber is in a second temperature environment. When the sealed chamber is in a third temperature environment, the resistive monitoring unit and the differential transformer displacement sensing unit simultaneously monitor the characteristic information of the deformation of the core sample under the confining pressure.

2. The rock mechanics testing system according to claim 1, characterized in that, The mechanical simulation device includes: a strain-controlled upper pressure head, a strain-controlled lower pressure head, a first heating module, and a simulation shell; The strain control pressure head penetrates the top of the simulation shell and is movably disposed inside the simulation shell to apply downward confining pressure to the core sample to be tested; The strain-controlled indenter is movably disposed within the simulation shell and is used to apply an upward confining pressure to the core sample to be tested. The first heating module is disposed inside the simulation housing and is used to provide a high-temperature environment for the mechanical simulation device.

3. The rock mechanics testing system according to claim 2, characterized in that, The first heating module includes: a heating rod and a solid heat-conducting layer; The solid thermally conductive layer is attached to the inner wall of the simulated shell; The heating rod is located inside the simulated housing.

4. The rock mechanics testing system according to claim 2, characterized in that, The resistive monitoring unit includes a resistive monitoring strain gauge and a resistance extensometer; the differential transformer displacement sensing unit includes a differential transformer displacement strain gauge and a differential transformer displacement sensor. The resistance strain gauge is installed on the core sample to be tested. The resistance strain gauge is used to monitor the characteristic information of the deformation of the core sample under confining pressure when the sealed chamber is in the first temperature environment. The differential transformer type displacement strain gauge is installed on the core sample to be tested. The differential transformer type displacement strain gauge is used to monitor the characteristic information of the deformation of the core sample under confining pressure when the sealed chamber is in a second temperature environment. The probes of the resistance extensometer are placed on both sides of the core sample to be tested, and the probes of the differential transformer displacement sensor are placed at the end of the strain control pressure head located outside the simulation shell. The measuring bodies of the resistance extensometer and the differential transformer displacement sensor are placed outside the simulation shell. When the sealed chamber is in a third temperature environment, the resistance extensometer and the differential transformer displacement sensor monitor the characteristic information of the deformation of the core sample under confining pressure.

5. The rock mechanics testing system according to claim 1, characterized in that, The sealed compartment includes: the compartment body, the hydraulic lifting door, the sensor probe, the hydraulic tank, the operation buttons, and the remote control console for the lifting door; The sensing probe is installed on the hydraulic lifting door to monitor environmental information within a preset range outside the hydraulic lifting door, obtain environmental monitoring signals, and send the environmental monitoring signals to the controller of the hydraulic lifting door; The controller of the hydraulic lifting door selects to connect to the remote control console or operation button of the lifting door according to the environmental monitoring signal, and is used to lift or lower according to the control command of the remote control console or the control command of the operation button. The hydraulic tank is connected to the hydraulic lifting door and is used to provide the hydraulic lifting door with the power to lift and lower, so as to close the body of the compartment.

6. The rock mechanics testing system according to claim 1, characterized in that, The temperature control device includes: a temperature sensor and a second heating module; The second heating module is used to heat the internal environment of the sealed compartment so that the sealed compartment is in a first temperature environment, a second temperature environment, or a third temperature environment. The temperature sensor is used to monitor the temperature inside the sealed compartment.

7. The rock mechanics testing system according to claim 6, characterized in that, The second heating module includes an electromagnetic heating unit, which is disposed on the outer wall of the sealed compartment.

8. The rock mechanics testing system according to claim 2, characterized in that, The system also includes a pressure control device for providing an extreme pressure environment for the sealed compartment and for providing circumferential confining pressure for the mechanical simulation device.

9. The rock mechanics testing system according to claim 8, characterized in that, The pressure control device includes: a confining pressure sensor, a confining pressure oil tank, a first booster, and a second booster; The confining pressure sensor is installed inside the sealed compartment to monitor the pressure value inside the sealed compartment. The first or second intensifier is used to apply circumferential confining pressure to the sealed compartment and the mechanical simulation device individually; The confining pressure oil tank is connected to the first intensifier and the second intensifier respectively, and is used to provide the confining pressure oil required to generate pressure for the first intensifier and the second intensifier.

10. The rock mechanics testing system according to claim 9, characterized in that, The system also includes a cooling device, which comprises a coolant pump module, a cooling pipe, a coolant medium cooler, a confining pressure oil cooler, a top cooling loop, and a bottom cooling loop. The output end of the coolant pumping module is connected to the coolant input end of the cooling medium cooler through the cooling pipe. The coolant output end of the cooling medium cooler is connected to the coolant input end of the confining pressure oil cooler. The coolant output end of the confining pressure oil cooler is connected to the input end of the top cooling loop. The output end of the top cooling loop is used to connect to the input end of the bottom cooling loop. The output end of the bottom cooling loop is connected to the input end of the coolant pumping module.

11. The rock mechanics testing system according to claim 1, characterized in that, The system also includes: a crack monitoring device, which includes: an optical fiber monitor; The fiber optic monitor is installed on the core sample to be tested and is used to monitor the characteristic information of the cracks generated in the core sample under confining pressure.

12. The rock mechanics testing system according to claim 1, characterized in that, The system also includes an ultrasonic monitoring device, which is installed on the core sample to be tested and is used to emit ultrasonic signals in different directions to the core sample to be tested. The ultrasonic signal propagates from one end of the core sample to the other end and is received by the ultrasonic monitoring device at the other end of the core sample. The ultrasonic monitoring device determines the anisotropic characteristic information of the core sample based on the received ultrasonic signal.

13. The rock mechanics testing system according to claim 12, characterized in that, The ultrasonic monitoring device includes: an ultrasonic transmitter, an ultrasonic receiver, an ultrasonic probe, and a universal coupling. The ultrasonic transmitter is used to generate an ultrasonic emission signal and transmit the ultrasonic emission signal to the ultrasonic probe. The ultrasonic probe is mounted on the universal coupling and is used to send the ultrasonic signal to one end of the core sample to be tested according to a preset direction. The ultrasonic probe is also used to receive ultrasonic signals from the other end of the core sample to be tested and to transmit the received ultrasonic signals to the ultrasonic receiver.

14. The rock mechanics testing system according to claim 13, characterized in that, The system also includes a coupling agent replenishment device, which includes a coupling agent storage mechanism, a coupling agent pump, and a coupling agent nozzle; the ultrasonic monitoring device also includes an automatic opening and closing mechanism for the ultrasonic pressure head. The coupling agent pump is used to inject the coupling agent stored in the coupling agent storage mechanism onto the core sample to be tested through the coupling agent nozzle; The ultrasonic indenter automatic opening and closing mechanism is located between the couplant replenishment device and the core sample to be tested. The ultrasonic indenter automatically opens when the ultrasonic monitoring device is working, so that the couplant replenishment device automatically injects couplant onto the core sample to be tested.

15. The rock mechanics testing system according to claim 1, characterized in that, The system further includes an internal damage monitoring device, which includes an acoustic emission monitoring device. The acoustic emission monitoring device is used to receive the acoustic wave signal generated by the core sample under test under confining pressure, and obtain the characteristic information of the internal damage generated by the core sample under test under confining pressure based on the acoustic wave signal.

16. The rock mechanics testing system according to claim 15, characterized in that, The internal damage monitoring device also includes: an environmental monitoring module and a noise reduction module; The environmental monitoring module is used to monitor the environmental noise signal inside the sealed compartment. The noise reduction processing module is connected to the environmental monitoring module and is used to receive the environmental noise signal, identify the noise decibel value of the environmental noise signal, and perform noise reduction processing on the sound wave signal received by the acoustic emission monitoring device according to the identified noise decibel value of the environmental noise signal.

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