Rock indentation hardness testing device and method under ultra-deep high temperature and high pressure environment

Abstract

The application discloses a rock indentation hardness testing device and method under an ultra-deep high-temperature and high-pressure environment, relates to the technical field of rock mechanics testing, and is characterized in that a sample bin is arranged on a frame, a sample of rock to be detected is placed in the bin, the sample bin can inject a medium providing confining pressure for the sample, further comprises a heating device capable of maintaining the temperature in the sample bin, the upper end of the sample bin is provided with a detection head in contact with the sample, and the lower end of the sample bin is provided with a pressurizing device capable of loading axial pressure and confining pressure on the sample; a static load module for applying a static load to the detection head and a dynamic load module for applying a high-frequency dynamic load to the detection head are arranged on the frame. The dynamic and static coupling loading of the device is highly similar to the drilling working condition, can be more in line with the actual situation of construction, and greatly improves the guiding value of the experiment on engineering.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rock mechanics testing, in particular to a rock indentation hardness testing device and method under super-deep high-temperature and high-pressure environment. BACKGROUND

[0002] Deep and super-deep oil and gas reservoirs have become the focus of global oil and gas exploration and development. However, deep strata are characterized by long age, large burial depth, super-high temperature, super-high pressure and complex skeleton structure, and the dynamic and static mechanical responses of deep strata under high temperature and high pressure conditions are still lacking systematic understanding due to the superposition of multiple factors. Rock indentation hardness testing, which involves pressing a rock sample with a known geometric indenter under controlled load and recording the load-displacement curve in real time, has been widely used for formation drillability evaluation. However, existing indentation hardness devices generally work at normal temperature and pressure and low loading rate, and can only provide quasi-static data, making it difficult to simulate the high temperature, high pressure and high strain rate environment of super-deep drilling, resulting in significant deviation between the obtained rock mechanical properties and actual working conditions.

[0003] Patent No. CN 113092295 B discloses a rock hardness detection device, which includes a support frame, a loading mechanism and a detection mechanism. The loading mechanism includes a dynamic load generator, a fulcrum adjusting block, a lever and a first displacement sensor. The dynamic load generator is fixed on the support frame, the fulcrum adjusting block is slidably installed on the support frame, the first end of the lever is connected with the force applying part of the dynamic load generator, the middle part of the lever is in sliding cooperation with the fulcrum adjusting block, the sliding direction of the fulcrum adjusting block is the same as the length direction of the lever, the fulcrum adjusting block is located between the lever and the support frame, one end of the first displacement sensor is fixed on the support frame, and the other end of the first displacement sensor is fixed on the second end of the lever. The detection mechanism includes a test indenter, a tension and compression force sensor and a temperature control box, and the temperature control box is fixed on the support frame.

[0004] However, the device has the following problems: it cannot implement dynamic and static load loading, it does not have microsecond-level impact dynamic load, the loading condition is relatively single, it cannot be closer to the real drilling conditions, and it does not have pressure and displacement synchronous acquisition function when the hard sharp indenter is pressed. SUMMARY

[0005] To solve the above problems in the prior art, the present application provides a rock indentation hardness testing device and method under super-deep high-temperature and high-pressure environment.

[0006] The technical solution adopted by the present application to solve its technical problems is:

[0007] The application provides a rock indentation hardness testing device under an ultra-deep high-temperature and high-pressure environment, which comprises a frame, wherein a sample bin is arranged on the frame, a sample of the rock to be detected is placed in the bin, the sample bin can be filled with a medium to provide confining pressure for the sample, a heating device capable of maintaining the temperature in the sample bin is further arranged, a detection head in contact with the sample is arranged at the upper end of the sample bin, and a pressurizing device capable of loading axial pressure and confining pressure on the sample is arranged at the lower end of the sample bin; a static load module for applying static load to the detection head and a dynamic load module for applying high-frequency dynamic load to the detection head are arranged on the frame.

[0008] Preferably, the static load module comprises a plurality of static load cylinders fixed to the frame, the static load cylinders are connected with a controller, the upper end of the static load cylinder is connected with a cross beam, the lower end of the cross beam is in contact with the detection head, and the cross beam provides a continuous downward static load for the detection head; the dynamic load module comprises an impact piece arranged on the cross beam, an impact head is connected to the detection head, a through hole is formed in the cross beam and used for allowing the impact head to freely penetrate, and the impact head is used for receiving instantaneous impact load from the impact piece.

[0009] Preferably, a pressure sensor is fixedly connected to the lower end of the detection head and arranged along the loading axis, and the lower end of the pressure sensor is connected with a pressure die in contact with the sample.

[0010] Preferably, a displacement sensor is arranged on the frame, a transmission rod is fixed to the detection head, the transmission rod can drive the displacement sensor to move and measure, so that the displacement of the detection head in the loading process can be measured in real time, and the pressure sensor and the displacement sensor are both connected with a controller.

[0011] Preferably, the pressurizing device comprises an axial pressure cylinder fixed to the frame, the axial pressure cylinder is connected with a controller, an axial pressure rod is slidably arranged in the axial pressure cylinder, a bushing is fixedly connected to the frame, the bushing is provided with a through hole for the axial pressure rod to penetrate, a top cover is connected to the upper end of the bushing, the top cover is provided with a through hole for the detection head to insert, and the axial pressure rod, the bushing and the top cover form the sample bin for containing the confining pressure medium.

[0012] Preferably, a sample base is fixed to the front end of the axial pressure rod, a soft material is coated on the side surface of the sample and placed on the sample base, and the upper and lower ends of the sample are in contact with the sample base and the top cover respectively, so that the confining pressure medium can wrap the soft material, a plurality of interfaces are arranged on the side edge of the bushing and connected with the sample bin, and the interfaces are connected with a confining pressure system through pipelines.

[0013] Preferably, the heating device comprises an electric heating wire arranged on the inner wall of the sample bin, a heat insulation layer is coated on the surface of the electric heating wire, a thermocouple sensor for measuring the temperature of the sample is arranged in the sample bin, and the thermocouple sensor is connected with a controller.

[0014] A rock indentation hardness testing method under an ultra-deep high temperature and high pressure environment, adopts the rock indentation hardness testing device under an ultra-deep high temperature and high pressure environment, and is characterized by comprising the following steps:

[0015] S1: opening the sample bin, placing the sample in the sample bin, then closing the sample bin, starting the pressure device to apply axial pressure to the sample, and the pressure device drives the sample to be close to the inner surface of the sample bin;

[0016] S2: the heating device heats the confining pressure medium in the sample bin to a preset temperature, the pressure device is started to cyclically and gradiently load the axial pressure and the confining pressure of the sample in turn, until the axial pressure and the confining pressure reach the preset pressure of the test at the same time;

[0017] S3: after the temperature and pressure loading are completed, the system runs the data, and records the initial baseline value;

[0018] S4: the controller controls the static load module to stably press down to generate a constant axial static force load on the sample, the controller controls the dynamic load module to apply a transient impact load once, so that the impact load and the static load are superimposed on the upper end surface of the sample, and the displacement sensor records the displacement data in the loading process, and the pressure sensor synchronously records the axial load signal in the loading process;

[0019] S5: after the loading is completed, the device is sequentially disassembled, the dynamic load module is first closed, the controller controls the static load module to push up, the pressure device sequentially unloads the axial pressure and the confining pressure according to the gradient, until the pressure is zero, the pressure device is closed, the sample bin is opened, and the sample is taken out, and the whole test process is completed.

[0020] Preferably, in S3, the axial pressure is first applied to the sample, the loading amount is P1 each time, after the axial pressure is loaded to P1, the confining pressure medium is injected into the sample bin, so that the confining pressure of the sample reaches P1, and the above steps are repeated until the axial pressure and the confining pressure reach the experimental preset pressure Pn.

[0021] Preferably, in S4, the collected data is converted into a digital signal through an analog signal and input to an integrated data acquisition card, and the sampling rate range is 10kHz-5MHz.

[0022] Compared with the prior art, the beneficial effects of the present application are:

[0023] 1. The present application is provided with a static load module and a dynamic load module, the static load module applies a constant static load to the sample, the sample is stably pressed down, the dynamic load module applies a microsecond-level transient impact load to the sample through an impact piece, the dynamic load module and the static load module transmit the dynamic and static loads to the end surface of the sample through a detection head, realize the indentation process under the dynamic and static coupling effect, the dynamic and static coupling loading is highly similar to the drilling working condition, can be more in line with the actual situation of construction, and greatly improves the guiding value of the experiment on the project.

[0024] 2. The application sets shaft pressure cylinder and interface, the shaft pressure cylinder applies axial static load to the sample, the interface injects surrounding pressure medium to apply uniform confining pressure to the sample, the shaft pressure cylinder and the interface perform cyclic gradient loading pressure, so that the sample axial pressure and confining pressure are alternately raised, the stress superposition caused by the simultaneous rise of the axial pressure and the confining pressure is reduced, or the stress distortion caused by the improper matching of the axial pressure and the confining pressure is reduced, the stability is greatly increased, and the heating device in the sample bin can accurately simulate the real high temperature and high pressure environment of deep rock.

[0025] 3. The lower end of the detection head is embedded with a pressure sensor, and a transmission rod cooperating with a displacement sensor is fixed on the side surface of the detection head, so that the synchronous acquisition of pressure and displacement can track the load size and deformation amount at the corresponding moment in real time, accurately capture the change of rock under complex load, and be beneficial to subsequent analysis. BRIEF DESCRIPTION OF DRAWINGS

[0026] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

[0027] Figure 1 is a front view of the present application;

[0028] Figure 2 is Figure 1 is a local enlarged view of part A in figure 1;

[0029] Figure 3 is a side view of the present application;

[0030] Figure 4 is a top view of the present application;

[0031] Figure 5 is a schematic view of the detection head of the present application.

[0032] BRIEF DESCRIPTION OF DRAWINGS

[0033] 1, frame; 2, sample bin; 3, sample; 4, impact head; 5, detection head; 6, axial pressure rod; 7, bushing; 8, top cover; 9, static load cylinder; 10, cross beam; 11, copper sleeve; 12, pressure sensor; 13, pressure die; 14, displacement sensor; 15, transmission rod; 16, interface; 17, guide rod; 18, drop hammer; 19, column; 20, support table. DETAILED DESCRIPTION

[0034] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0035] Reference Figures 1-5 As shown in the figure, a rock indentation hardness testing device under super-deep high temperature and high pressure environment comprises a frame 1, a sample bin 2 is arranged on the frame 1, a sample 3 of rock to be detected is placed in the bin, the sample bin 2 can inject a medium providing confining pressure for the sample 3, further comprising a heating device capable of maintaining the temperature in the sample bin 2, the upper end of the sample bin 2 is placed with a detection head 5 in contact with the sample 3, and the lower end of the sample bin 2 is provided with a pressurizing device capable of loading axial pressure and confining pressure on the sample 3; the frame 1 is provided with a static load module for applying static load to the detection head 5, and a dynamic load module for applying high-frequency dynamic load to the detection head 5.

[0036] By injecting confining pressure medium into the sample bin 2, confining pressure is applied to the sample 3, and then by the pressurizing device, axial pressure is provided to the sample 3, while cooperating with the heating device in the sample bin, the real high temperature and high pressure environment of the deep rock can be accurately simulated, the static load module applies constant static load to the sample, and the sample is stably pressed down, the dynamic load module applies microsecond high-frequency instantaneous impact load to the sample through the impact piece, the dynamic load module and the static load module transmit the dynamic and static loads to the sample end face through the detection head, and realize the indentation process under the dynamic and static coupling effect, the dynamic and static coupling loading is highly similar to the drilling working condition, which can better fit the actual situation of construction, and greatly improves the guiding value of the experiment to the project.

[0037] The static load module comprises a static load cylinder 9 fixed with the frame 1, the static load cylinder 9 is connected with a controller, the upper end of the static load cylinder 9 is connected with a cross beam 10, the lower end of the cross beam 10 is in contact with the detection head 5, and the detection head 5 is provided with continuous downward static load; the dynamic load module comprises an impact piece arranged on the cross beam 10, the detection head 5 is connected with an impact head 4, the cross beam 10 is provided with a through hole for the impact head 4 to freely penetrate, and the impact head 4 is used for receiving instantaneous impact load from the impact piece.

[0038] The impact piece is a drop hammer 18, a guide bracket is fixed on the cross beam 10, a small cross beam is fixedly connected on the guide bracket, a guide rod 17 is fixedly connected on the small cross beam, the drop hammer 18 is slidably sleeved on the guide rod 17, the guide rod 17 has a gap with the impact head 4, and the mass and height of the drop hammer 18 are adjustable, which can be realized by replacing drop hammers of different sizes or fixing weights of different masses on the drop hammer to realize adjustment, so as to realize dynamic load input of different amplitudes, and it can also be suitable for different experimental objects.

[0039] The impact piece is a high-speed hydraulic cylinder, the high-speed hydraulic cylinder is detachably connected with the cross beam 10, the high-speed hydraulic cylinder piston rod can impact the impact head 4, and the high-speed hydraulic cylinder is connected with a hydraulic station and a controller.

[0040] The static load module is used for applying controllable constant static load, and the dynamic load module is used for applying high-frequency transient dynamic load. The dynamic load part is guided by the guide rod 17, and the drop hammer 18 can freely fall along the axial direction at the moment of release. The impact head 4 and the detection head 5 are vertically inserted along the axial direction, so as to ensure that the impact force can be accurately transmitted to the upper end surface of the sample 3. The static load part is connected with the external high-pressure oil source through the two static load cylinders 9 arranged on the left and right, so as to realize the downward pressing of the cross beam 10 and generate constant axial static force load through the cooperative action of the two cylinders.

[0041] The lower end of the detection head 5 is fixedly connected with the pressure sensor 12, which is arranged along the loading axis direction. The lower end of the pressure sensor 12 is connected with the pressure die 13 in contact with the sample 3.

[0042] The pressure sensor 12 is selected from a high-temperature piezoelectric load sensor of FCL1005 type, which has a measurement range of -200-1260℃ and a measurement accuracy of ±0.75℃, is suitable for long-term work under high temperature, can record the dynamic and static coupling load applied on the top of the sample 3 in real time, has a maximum range of 10kN, a sensitivity of 4pC / N, a frequency response bandwidth of more than 75kHz, a linear error of less than ±1%FS, and a hysteresis and repeatability error of less than 1%FS, and is suitable for dynamic mechanical monitoring of high-frequency impact process.

[0043] A through hole is formed in the center of the pressure sensor 12, and a sliding rod fixed with the detection head 5 is arranged in the through hole. A connecting rod abutting against the pressure sensor 12 is sleeved on the sliding rod. The lower end of the connecting rod is fixed with the pressure die 13. The pressure die 13 is made of high-strength alloy and has good impact resistance and wear resistance.

[0044] The upper end of the detection head 5 is a static load loading end surface, which is in contact with the loading members (i.e. the cross beam 10) of the two static load cylinders 9. The static load cylinder 9 applies constant static load to the static load loading end surface of the detection head 5 through the cross beam 10. The detection head 5 transmits the constant static load to the sample 3. The impact head 4 is screwed into the upper part of the detection head 5. The upper end surface of the impact head 4 is a dynamic load loading end surface, which is used for receiving the transient impact load generated by the free falling of the drop hammer 18.

[0045] A displacement sensor 14 is arranged on the frame 1. A transmission rod 15 is fixed on the detection head 5, which can drive the displacement sensor 14 to move and measure, so as to realize real-time measurement of the displacement of the detection head 5 during the loading process. The pressure sensor 12 and the displacement sensor 14 are both connected with a controller.

[0046] The displacement sensor 14 is a high-temperature rebound LVDT displacement sensor. The moving shaft of the displacement sensor is in contact with the transmission rod 15. At the same time, the displacement sensor is fixed on the top cover 8 through an adjustable structure. Before measurement, the initial contact accuracy is ensured through manual adjustment. The measurement range of the displacement sensor 14 is ±50mm, which is suitable for the measurement requirements of high-frequency vibration and small displacement response.

[0047] The adjustable structure adopts a self-locking connecting rod or an adjusting mechanism formed by a bolt and a threaded lifting plate to adjust the position of the displacement sensor 14, facilitating calibration.

[0048] The pressurizing device comprises a shaft press cylinder fixed on the frame 1, a controller connected to the shaft press cylinder, a shaft press rod 6 slidingly arranged in the shaft press cylinder, a bushing 7 fixedly connected to the frame 1, a through hole provided in the bushing 7 for the shaft press rod 6 to pass through, a top cover 8 connected to the upper end of the bushing 7, a through hole provided in the top cover 8 for the detection head 5 to insert into, and a sample chamber 2 formed between the shaft press rod 6, the bushing 7 and the top cover 8 for accommodating the confining medium.

[0049] Six stand columns 19 are fixed on the frame 1, and a support table 20 is fixed to the top end of each stand column 19 by a bolt.

[0050] The top cover 8 is threadedly connected to the bushing 7, and the top cover 8 is a thick-walled cylindrical pressure container made of high-temperature and high-pressure alloy steel. A through hole is provided in the top cover 8 for the detection head 5 to pass through and contact the end surface of the sample 3. An axial seal is achieved between the inner wall of the through hole and the detection head 5 by a perfluoroether FFKMO type sealing ring, and the sealing ring can withstand a hydrostatic pressure of 250 MPa.

[0051] A sample base is fixed to the front end of the shaft press rod 6, and a soft material is wrapped around the side surface of the sample 3 and placed on the sample base. The upper and lower ends of the sample 3 are in contact with the sample base and the top cover 8, respectively, so that the confining medium wraps the soft material. A plurality of interfaces 16 are provided in the side edge of the bushing 7 and are in communication with the sample chamber 2. The interfaces 16 are connected to a confining system through a pipeline.

[0052] The soft material is a copper sleeve 11. After the shaft press rod 6 pushes the sample 3 upward and tightly presses the sample 3 against the top cover 8, the copper sleeve 11, the sample base and the top cover 8 wrap the sample 3 to prevent the sample from directly contacting the hydraulic oil.

[0053] The interface 16 located in the middle is connected to the confining system through a high-temperature and high-pressure hydraulic pipeline, and is used to inject the confining medium into the sample chamber 2 to establish a uniform radial hydrostatic pressure in the cavity.

[0054] The confining system is generally a high-temperature hydraulic station.

[0055] The shaft press rod 6 can push the sample base upward to send the sample 3 to a designated position in the sample chamber 2 and apply an axial static load to the end surface of the sample 3. At the same time, the confining medium is injected into the sample chamber 2 through the interface 16 to establish and maintain a uniform radial (hydrostatic) confining pressure in the sample chamber 2, so as to realize a three-way confining pressure condition of up to 250 MPa and accurately simulate the real high-pressure environment of deep rock.

[0056] The heating device comprises a resistance heating wire arranged on the inner wall of the sample chamber 2, and a thermal insulation layer is arranged on the surface of the resistance heating wire; a thermocouple sensor for measuring the temperature of the sample 3 is arranged in the sample chamber 2, and the thermocouple sensor is connected with a controller.

[0057] The inner wall of the sample chamber 2 generally refers to the inner wall of the bushing 7.

[0058] The temperature measurement adopts a K-type armored thermocouple sensor, which is installed on the inner wall of the sample chamber 2 and close to the sample 3 to obtain the true temperature.

[0059] The resistance heating wire on the inner wall of the sample chamber 2 and the high-efficiency thermal insulation layer on the surface thereof are rapidly heated under closed-loop control, and the temperature required for the test is stably maintained; the highest working temperature is 250℃, and the temperature control accuracy is ±0.5℃.

[0060] The heating device, the pressurizing device and the confining medium can simulate the deep geological environment conditions in the closed sample chamber 2, and can realize a heating temperature of up to 250℃ and a three-way confining pressure of up to 250MPa, so as to reproduce the thermal and pressure state of the sample 3 under the ultra-deep geological conditions, and realize the dynamic penetration hardness test working condition through the synergistic action of the static load module and the dynamic load module; meanwhile, the key test parameters such as the temperature of the sample 3, the load of the detection head 5 and the displacement are synchronously acquired through the sensors, so as to ensure the data integrity and accuracy in the experimental process.

[0061] A rock penetration hardness test method under an ultra-deep high-temperature and high-pressure environment, which adopts the rock penetration hardness test device under an ultra-deep high-temperature and high-pressure environment, and comprises the following steps:

[0062] S1: opening the sample chamber 2, placing the sample 3 in the sample chamber, then closing the sample chamber 2, starting the pressurizing device to apply axial pressure to the sample 3, and driving the sample 3 to tightly contact the inner surface of the sample chamber 2;

[0063] S2: the heating device heats the confining medium in the sample chamber 2 to a preset temperature, and the pressurizing device cyclically and gradiently loads the axial pressure and the confining pressure of the sample 3 in sequence until the axial pressure and the confining pressure simultaneously reach the preset pressure of the test;

[0064] S3: after the temperature and pressure loading are completed, the data of the system is run, and the initial baseline value is recorded;

[0065] S4: the controller controls the static load module to stably press down to generate a constant axial static load on the sample, the controller controls the dynamic load module to apply a transient impact load, the impact load and the static load are superimposed on the upper end surface of the sample 3, the displacement sensor 14 records the displacement data in the loading process, and the pressure sensor 12 synchronously records the axial load signal in the loading process;

[0066] S5: After loading is completed, the device is sequentially disassembled, first the dynamic load module is closed, the controller controls the static load module to push up, the pressurizing device sequentially unloads the axial pressure and confining pressure according to the gradient, until the pressure is zero, the pressurizing device is closed, the sample chamber 2 is opened to take out the sample 3, and the whole test process is completed.

[0067] In S2, first, the axial pressure is applied to the sample 3, and the loading amount is P1 each time. After the axial pressure is loaded to P1, the confining pressure medium is injected into the sample chamber 2, so that the confining pressure of the sample 3 reaches P1. The above steps are repeated until the axial pressure and the confining pressure reach the preset pressure Pn of the experiment.

[0068] In S4, the collected data is converted into a digital signal through an analog signal and input to an integrated data acquisition card, and the sampling rate ranges from 10 kHz to 5 MHz.

[0069] First, the sample chamber top cover 8 is removed, the axial pressure rod 6 of the axial pressure cylinder is completely retracted, the prepared sample 3 is wrapped around the side surface through a soft copper sleeve, and then placed on the sample base. Subsequently, the sample chamber top cover 8 is screwed and connected to the guide bushing 7, thereby closing the sample chamber 2. At this time, the axial pressure rod 6 is pushed up, so that the upper end surface of the sample 3 is tightly attached to the inner surface of the top cover 8, and an initial contact pressure of about 0.1 MPa is established through the control system.

[0070] During the temperature and pressure loading process, the hydraulic oil in the sample chamber 2 is heated to a preset temperature (such as 250°C) by the heating device arranged in the sample chamber 2, and the temperature is maintained stable through closed-loop control. Subsequently, the loading system is started, and the cyclic gradient loading is sequentially performed in the axial and radial directions. First, the axial pressure is applied by the axial pressure rod 6, and the loading increment is 5 MPa each time. When the axial pressure is loaded to 5 MPa, the axial pressure loading is stopped, the confining pressure medium is injected into the sample chamber 2 through the interface 16, so that the confining pressure reaches 5 MPa. The above steps are alternately repeated until the axial pressure and the confining pressure simultaneously reach the preset pressure of the experiment (such as 250 MPa).

[0071] After the temperature and pressure loading are completed, the detection head 5 is installed, the detection head 5 and the impact head 4 are placed in the reserved hole in the cross beam 10, the detection head 5 and the top of the sample 3 are in contact, the lower end of the cross beam 10 is in contact with the upper end of the static load loading end surface of the detection head 5, and then the impact head 4 is screwed into the detection head 5. The detection head 5 is provided with a through hole, a transmission rod 15 is fixed in the through hole, the transmission rod is in contact with the displacement sensor 14 installed outside the sample chamber top cover 8, and is used for displacement measurement during the loading process. The detection head 5 is also fixed with a pressure sensor 12 for synchronously recording the axial load signal during the loading process. The bottom end of the detection head 5 is provided with a high-strength alloy die 13, which is directly in contact with the sample 3.

[0072] Before dynamic load loading, start the data acquisition system, check the stability and response of the signal channels of displacement sensor 14, pressure sensor 12, thermocouple sensor and the like in turn, and record the initial baseline value. Subsequently, the left and right static load cylinders 9 are retracted, the pre-tightening force required for the test is applied to the static load loading end face on the detection head 5 through the cross beam 10, the drop hammer 18 is lifted to a predetermined height, released under the constraint of the guide rod 17, freely falls and hits the dynamic load loading end face on the impact head 4, so that the impact load and the original static load are superimposed on the upper end face of the sample 3, thereby completing the dynamic-static load composite loading.

[0073] After loading is completed, the device is sequentially disassembled, the drop hammer and guide rod 17 are first removed, the static load cylinder 9 is pushed up to release the load of the detection head, then the detection head 5 is removed and the impact head 4 is removed, then the axial compression and confining pressure are sequentially unloaded through the axial compression rod 6 and the interface 16 at a gradient of no more than 5 MPa each time until the pressure is zero, after the axial compression rod 6 is completely retracted, the sample chamber top cover 8 is removed, the sample 3 is taken out, and the entire test process is completed.

[0074] Although embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.

Claims

1. A rock indentation hardness testing device under ultra-deep high temperature and high pressure environment, comprising a frame (1), characterized in that, Frame (1) is provided with sample bin (2), the sample (3) of rock to be detected is placed in the bin, the sample bin (2) can inject the medium that provides confining pressure to the sample (3), also includes the heating device that can maintain the temperature in the sample bin (2), the upper end of the sample bin (2) is placed with the detection head (5) that contacts the sample (3), the lower end of the sample bin (2) is provided with the pressurizing device that can load axial pressure and confining pressure to the sample (3);The frame (1) is provided with static load module that applies static load to the detection head (5), and dynamic load module that applies high-frequency dynamic load to the detection head (5); Static load module includes static load cylinder (9) fixed with several frames (1), the static load cylinder (9) is connected with controller, the upper end of the static load cylinder (9) is connected with crossbeam (10), the lower end of the crossbeam (10) contacts the detection head (5), and the detection head (5) is provided with continuous downward static load;Dynamic load module includes impact piece arranged on the crossbeam (10), the detection head (5) is connected with impact head (4), the crossbeam (10) is provided with through hole for the free penetration of the impact head (4), and the impact head (4) is used to receive instantaneous impact load from the impact piece; The pressurizing device includes axial pressure cylinder fixed on the frame (1), the axial pressure cylinder is connected with controller, the axial pressure cylinder is slidably provided with axial pressure rod (6), the frame (1) is fixedly connected with bushing (7), the bushing (7) is provided with through hole for the penetration of the axial pressure rod (6), the upper end of the bushing (7) is connected with top cover (8), the top cover (8) is provided with through hole for the insertion of the detection head (5), the axial pressure rod (6), the bushing (7) and the top cover (8) are arranged to form the sample bin (2) for containing confining pressure medium; The heating device includes resistance heating wire arranged on the inner wall of the sample bin (2), the surface of the resistance heating wire is coated with heat insulation layer, the sample bin (2) is provided with thermocouple sensor for measuring the temperature of the sample (3), and the thermocouple sensor is connected with controller. 2.The rock indentation hardness testing device under ultra-deep high temperature and high pressure environment according to claim 1, characterized in that, The lower end of the detection head (5) is fixedly connected with pressure sensor (12), which is arranged along the loading axis direction, and the lower end of the pressure sensor (12) is connected with pressure die (13) in contact with the sample (3).

3. The rock indentation hardness testing device under ultra-deep high temperature and high pressure environment according to claim 2, characterized in that, The frame (1) is provided with displacement sensor (14), and the detection head (5) is fixedly connected with transmission rod (15), which can drive the displacement sensor (14) to move and measure, so as to realize real-time measurement of the displacement of the detection head (5) in the loading process; The pressure sensor (12) and the displacement sensor (14) are connected with controller.

4. The rock indentation hardness testing device under ultra-deep high temperature and high pressure environment according to claim 1, characterized in that, The front end of the axial pressure rod (6) is fixed with sample base, the sample (3) is covered with soft material and placed on the sample base, and the upper and lower ends of the sample (3) are in contact with the sample base and the top cover (8) respectively, so that the confining pressure medium wraps the soft material, and the side edge of the bushing (7) is provided with a plurality of interfaces (16) connected with the sample bin (2), and the interfaces (16) are connected with the confining pressure system through pipeline.

5. A method for testing rock indentation hardness in an ultra-deep high temperature and high pressure environment, using the rock indentation hardness testing device in an ultra-deep high temperature and high pressure environment according to claim 3, characterized in that, The method comprises the following steps: S1: open the sample chamber (2), place the sample (3) in the sample chamber, then close the sample chamber (2), start the pressurizing device to apply axial pressure to the sample (3), the pressurizing device drives the sample (3) to tightly contact the inner surface of the sample chamber (2); S2: the heating device heats the confining pressure medium in the sample chamber (2) to a preset temperature, the pressurizing device is started to cyclically and gradiently load the axial pressure and the confining pressure of the sample (3) in turn, until the axial pressure and the confining pressure reach the preset pressure of the test at the same time; S3: after the temperature and pressure loading are completed, the system runs data and records the initial baseline value; S4: the controller controls the static load module to stably press down to generate a constant axial static force load on the sample, the controller controls the dynamic load module to apply a transient impact load once, so that the impact load and the static load are superimposed on the upper end surface of the sample (3), the displacement sensor (14) records the displacement data in the loading process, and the pressure sensor (12) synchronously records the axial load signal in the loading process; S5: after the loading is completed, the device is sequentially disassembled, the dynamic load module is first closed, the controller controls the static load module to push up, the pressurizing device sequentially unloads the axial pressure and the confining pressure according to the gradient, until the pressure is zero, the pressurizing device is closed, the sample chamber (2) is opened, and the sample (3) is taken out, and the whole test process is completed.

6. The method according to claim 5, wherein, In S2, first, the axial pressure is applied to the sample (3) with each loading amount of P1. After the axial pressure is loaded to P1, the confining pressure medium is injected into the sample chamber (2) to make the confining pressure of the sample (3) reach P1. The above steps are repeated until the axial pressure and the confining pressure reach the preset pressure P of the experiment n .

7. The method according to claim 5, wherein, In S4, the collected data is converted into a digital signal through an analog signal and input to an integrated data acquisition card, and the sampling rate range is 10 kHz-5 MHz.

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