Hot dry rock fracturing simulation experiment device and test method thereof

Abstract

The invention discloses a hot dry rock fracturing simulation experiment device which comprises a pressure chamber, a rotating assembly, a first pressurizing assembly and the like, the pressure chamber is installed on the rotating assembly, and the rotating assembly is used for driving the pressure chamber to rotate; the first pressurizing assembly is arranged on the peripheral side of the pressure chamber and communicates with the interior of the pressure chamber so as to provide temperature and pressure for the pressure chamber. The third pressurizing assembly is arranged on the peripheral side of the pressure chamber and communicated with the interior of the pressure chamber so as to be used for impacting cracks of the rock sample and fracturing; the imaging assembly is arranged on the peripheral side of the rotating assembly and is used for acquiring an image of the rock sample in the pressing process. According to the technical scheme, the rock sample is subjected to fracturing treatment, and the three-dimensional structure in the rock sample is reconstructed for the fractured sample through the imaging assembly, so that artificial fractured cracks can be evaluated and analyzed conveniently, and design support is provided for subsequent continuous development of geothermal resources.

Description

Technical Field

[0001] The present invention relates to the technical field of hot dry rock experiments, and particularly to a hot dry rock fracturing simulation experiment device and a testing method thereof. Background Art

[0002] Geothermal resources are a new type of clean and renewable energy. A large amount of geothermal energy is stored in the deep hot dry rock formations, and reservoir stimulation technologies such as hydraulic fracturing are required to form water flow channels, and injection-production well networks are formed to increase the heat exchange area to realize the development of geothermal resources. However, due to the long-term interaction between reservoir water and rock, the reservoir permeability is changed, affecting the long-term exploitation of geothermal resources.

[0003] Currently, the existing hydraulic fracturing experimental devices cannot meet the simulation of hot dry rock fracturing injection-production integration. During the experiment, the change process of artificial fractures cannot be accurately obtained, and the influence of water-rock interaction on reservoir artificial fracturing fractures cannot be evaluated in a timely manner, making it impossible to provide comprehensive and reliable verification data during actual exploitation, nor to know parameter adjustment during actual exploitation. Summary of the Invention

[0004] The main object of the present invention is to propose a hot dry rock fracturing simulation experiment device and a testing method thereof, aiming to perform fracturing treatment on a rock sample by setting a pressure chamber, a rotating assembly, a first pressurizing assembly, etc., and reconstruct the three-dimensional structure inside the rock sample after fracturing through an imaging assembly, so as to facilitate the evaluation and analysis of artificial fracturing fractures, thereby providing design support for the subsequent continuous and efficient development of geothermal resources.

[0005] To achieve the above object, the hot dry rock fracturing simulation experiment device proposed by the present invention includes:

[0006] A pressure chamber for placing a rock sample;

[0007] A rotating assembly, the pressure chamber is installed on the rotating assembly, and the rotating assembly is used to drive the pressure chamber to rotate;

[0008] A first pressurizing assembly provided on the outer peripheral side of the pressure chamber and communicating with the inside of the pressure chamber to provide temperature and pressure for the pressure chamber;

[0009] A second pressurizing assembly installed inside the pressure chamber and used to press against the rock sample to provide an axial force for the rock sample;

[0010] A third pressurizing assembly provided on the outer peripheral side of the pressure chamber and communicating with the inside of the pressure chamber to fracture the rock sample;

[0011] An imaging assembly, which is disposed on the outer peripheral side of the rotating assembly for acquiring an image of the rock sample during the compression process; and

[0012] A controller, which is electrically connected to the rotating assembly, the first pressurizing assembly, the second pressurizing assembly, and the imaging assembly respectively.

[0013] In an alternative embodiment, the pressure chamber includes a first housing and a second housing. The first housing is mounted on the rotating assembly, the second housing is mounted within the first housing, the second housing is for placing the rock sample, the second pressurizing assembly is mounted within the first housing and is drivingly connected to the second housing, the first pressurizing assembly communicates with the first housing, and the third pressurizing assembly communicates with the second housing.

[0014] In an alternative embodiment, the rotating assembly includes a driving member, a rotating platform, and a fixed seat. The first housing is mounted on the rotating platform, the driving member is mounted on the fixed seat, and the output shaft of the driving member is drivingly connected to the rotating platform to drive the rotating platform to rotate relative to the fixed seat.

[0015] In an alternative embodiment, the imaging assembly includes a radiation source and a planar array detector. The radiation source and the planar array detector are electrically connected to the controller respectively. The radiation source and the planar array detector are disposed on opposite sides of the pressure chamber. The radiation source is for emitting radiation, the planar array detector is for receiving the attenuated radiation, and the controller is for displaying the internal three-dimensional structure of the rock sample during the fracturing process according to the signal received by the planar array detector.

[0016] In an alternative embodiment, the hot dry rock fracturing simulation experimental device further includes a packaging assembly. The packaging assembly includes a first cushion block, a water-permeable cushion block, and a second cushion block arranged in sequence. The first cushion block, the water-permeable cushion block, and the second cushion block are disposed on the second housing and are spaced apart in the axial direction of the second housing. The rock sample is disposed between the first cushion block and the water-permeable cushion block. One side of the third pressurizing assembly passes through the first cushion block and is for inserting into the rock sample, and the other side of the third pressurizing assembly passes through the second cushion block and is for inserting into the water-permeable cushion block.

[0017] In an alternative embodiment, the packaging assembly further includes a leveling member. The leveling member is mounted outside the second housing and is located on the side of the second cushion block away from the water-permeable cushion block. The leveling member is for flattening the rock sample within the second housing.

[0018] In an alternative embodiment, the third pressurizing assembly includes a fluid injector, a water inlet pipeline, and a drainage pipeline. The fluid injector is electrically connected to the controller. One side of the fluid injector is connected to the water inlet pipeline, and the other side of the fluid injector is connected to the drainage pipeline. The other side of the water inlet pipeline communicates with the first cushion block, and the other side of the drainage pipeline communicates with the second cushion block.

[0019] In an alternative embodiment, the first pressurizing assembly includes a circulation pump, an air inlet pipeline, and an exhaust pipeline. The circulation pump is electrically connected to the controller. One side of the air inlet pipeline is connected to the circulation pump, and the other side of the air inlet pipeline is connected to the first housing. One side of the exhaust pipeline is connected to the circulation pump, and the other side of the exhaust pipeline communicates with the first housing.

[0020] In an alternative embodiment, the fixed seat is provided with a conductive slip ring, the conductive slip ring is electrically connected to the controller, and the rotating platform is provided with a brush.

[0021] The hot dry rock fracturing simulation experimental device further includes a temperature sensor and a pressure sensor. The temperature sensor and the pressure sensor are respectively electrically connected to the brush. The pressure sensor is disposed on the outer bottom wall of the second housing, and the temperature sensor is disposed inside the first housing. During the rotation of the rotating platform, the brush is electrically connected to the conductive slip ring to transmit the signals of the temperature sensor and the pressure sensor to the controller.

[0022] The present invention further provides a testing method for a hot dry rock fracturing simulation experimental device based on any one of the above, which is characterized by including the following steps:

[0023] Place the rock sample in the pressure chamber, and a fracturing hole is opened at the central position of the rock sample.

[0024] Control the rotating assembly to drive the pressure chamber to rotate continuously.

[0025] Control the first pressurizing assembly to provide a preset temperature field and pressure field for the pressure chamber.

[0026] Control the second pressurizing assembly to apply an axial force to the rock sample, and control the third pressurizing assembly to inject high-pressure water into the fracturing hole of the rock sample in the pressure chamber.

[0027] Control the imaging assembly to continuously scan the rock sample, observe the process of hydraulic fracturing crack propagation through the imaging assembly, and reconstruct the crack morphology.

[0028] Receive the signal of the imaging assembly and display the reconstructed crack morphology.

[0029] The dry hot rock fracturing simulation experiment device of the technical solution of the present invention includes a pressure chamber, a rotating assembly, a first pressurizing assembly, a second pressurizing assembly, a third pressurizing assembly, an imaging assembly and a controller. The pressure chamber is used to place a rock sample; the pressure chamber is installed on the rotating assembly, and the rotating assembly is used to drive the pressure chamber to rotate, so that the imaging assembly can continuously perform three-dimensional structure imaging on the rock sample, increasing the credibility of the experiment; the first pressurizing assembly is arranged on the outer peripheral side of the pressure chamber and communicates with the inside of the pressure chamber to provide temperature and pressure to the pressure chamber to simulate the temperature and pressure that the rock is subjected to in the real environment; the second pressurizing assembly is installed inside the pressure chamber and is used to press against the rock sample to provide an axial force to the rock sample, so that the rock sample can be uniformly and reliably stressed, ensuring the simulation of dry hot rock in a high-pressure environment; the third pressurizing assembly is arranged on the outer peripheral side of the pressure chamber and communicates with the inside of the pressure chamber to fracture the rock sample and inject circulating water into the fractured rock sample to create artificial fractures in the rock sample and continuously inject high-pressure water into the fractured rock sample to form stable circulating water in the artificial fracturing fractures. During this process, the imaging assembly is continuously used to scan and reconstruct the fracture morphology to observe the influence of the water-rock interaction on the fracture morphology; the imaging assembly is arranged on the outer peripheral side of the rotating assembly to obtain images of the rock sample during the pressurization process, and then facilitate the fracture analysis of the fractured rock sample. The controller is electrically connected to the rotating assembly, the first pressurizing assembly, the second pressurizing assembly and the imaging assembly respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0031] Figure 1 It is a schematic structural diagram of an embodiment of the dry hot rock fracturing simulation experiment device of the present invention;

[0032] Figure 2 is Figure 1 a schematic structural diagram of the pressure chamber in the dry hot rock fracturing simulation experiment device shown;

[0033] Figure 3 is Figure 2 a schematic installation structure diagram of the second housing and the encapsulation assembly in the dry hot rock fracturing simulation experiment device shown;

[0034] Figure 4 is Figure 3 an enlarged view of part A in

[0035] Figure 5 isFigure 1 Schematic diagram of the structure of the rotating assembly in the dry hot rock fracturing simulation experiment device shown;

[0036] Figure 6 is Figure 5 Enlarged view at position B in

[0037] Figure 7 Flow chart of the test method based on the dry hot rock fracturing simulation experiment device of the present invention.

[0038] Explanation of the reference numerals in the drawings:

[0039]

[0040] The realization of the object, functional features and advantages of the present invention will be further described with reference to the embodiments and the accompanying drawings. Specific embodiments

[0041] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0042] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0043] In the present invention, unless otherwise clearly defined and limited, the terms "connection", "fixation", etc. shall be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0044] In addition, in the present invention, descriptions such as "first" and "second" are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments may be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0045] The present invention provides a dry hot rock fracturing simulation experimental device and a testing method thereof, aiming to perform fracturing treatment on a rock sample by providing a pressure chamber, a rotating assembly, a first pressurizing assembly, etc., and reconstructing the three-dimensional structure inside the rock sample through an imaging assembly after fracturing, so as to facilitate the evaluation and analysis of the fractures formed by artificial fracturing, thereby providing design support for the subsequent continuous and efficient development of geothermal resources.

[0046] Please refer to Figures 1 to 7 , and the specific structure of the dry hot rock fracturing simulation experimental device 100 proposed by the present invention will be described in specific embodiments below. In an embodiment of the present invention, the dry hot rock fracturing simulation experimental device 100 includes:

[0047] A pressure chamber 1 for placing a rock sample 2;

[0048] A rotating assembly 3, the pressure chamber 1 is installed on the rotating assembly 3, and the rotating assembly 3 is used to drive the pressure chamber 1 to rotate;

[0049] A first pressurizing assembly 4, which is provided on the outer peripheral side of the pressure chamber 1 and is in communication with the inside of the pressure chamber 1 to provide temperature and pressure for the pressure chamber 1;

[0050] A second pressurizing assembly 5, which is installed inside the pressure chamber 1 and is used to press against the rock sample 2 to provide an axial force for the rock sample 2;

[0051] A third pressurizing assembly 6, which is provided on the outer peripheral side of the pressure chamber 1 and is in communication with the inside of the pressure chamber 1 to fracture the rock sample 2;

[0052] An imaging assembly 8, which is provided on the outer peripheral side of the rotating assembly 3 to obtain images of the rock sample 2 during the compression process; and

[0053] A controller, which is electrically connected to the rotating assembly 3, the first pressurizing assembly 4, the second pressurizing assembly 5, and the imaging assembly 8 respectively.

[0054] In this embodiment, the hot dry rock fracturing simulation experimental device 100 includes a pressure chamber 1, a first pressurizing assembly 4, a second pressurizing assembly 5, and a third pressurizing assembly 6. Among them, the rock sample 2 is placed in the pressure chamber 1. It can be understood that the pressure chamber 1 is a sealed space to ensure the smooth progress of the experiment. And the first pressurizing assembly 4 is used to provide temperature and pressure to the pressure chamber 1 to simulate the circumferential temperature and pressure borne by the rock in reality. The second pressurizing assembly 5 is installed in the pressure chamber 1 and is used to press against the rock sample 2 to provide an axial force to the rock sample 2, so that the rock sample 2 can be uniformly and reliably stressed, ensuring the simulation of hot dry rock in a high-pressure environment. The third pressurizing assembly 6 is used to provide high-pressure water to the pressure chamber 1 to fracture the rock sample 2 in the pressure chamber 1. And after fracturing the rock sample 2, circulating flowing water is injected into the fractured rock sample 2 to obtain the path of crack propagation of the fractured rock sample 2, thereby obtaining accurate and effective hot dry rock fracturing data, providing technical support for actual fracturing work, enabling refined fracturing description of hot dry rock formations, and saving a large amount of manpower and material costs in actual fracturing work.

[0055] Specifically, in order to obtain accurate fracturing data, the hot dry rock fracturing simulation experimental device 100 further includes a controller, a rotating assembly 3, and an imaging assembly 8. The pressure chamber 1 is arranged on the rotating assembly 3 and, driven by the rotating assembly 3, realizes continuous rotation. And the imaging assembly 8 is arranged on the outer peripheral side of the rotating assembly 3. Furthermore, while the pressure chamber 1 is continuously rotating, the imaging assembly 8 can accurately scan the changes in the internal structure of the rock sample 2 during the experiment, and thus can obtain fracturing crack parameters in real time, thereby obtaining effective hot dry rock fracturing data, providing technical support for actual fracturing work, enabling refined fracturing description of hot dry rock formations, and saving a large amount of manpower and material costs in actual fracturing work.

[0056] It should be noted that the third pressurizing assembly 6 is a hydraulic transmission device, and the hydraulic transmission device is a prior art, so this application will not elaborate on it here.

[0057] Please refer to Figure 1 and Figure 2 , in an optional embodiment, the pressure chamber 1 includes a first housing 11 and a second housing 12. The first housing 11 is installed on the rotating assembly 3, the second housing 12 is installed in the first housing 11, the second housing 12 is used to place the rock sample 2, the second pressurizing assembly 5 is installed in the first housing 11 and is drivingly connected to the second housing 12, the first pressurizing assembly 4 communicates with the first housing 11, and the third pressurizing assembly 6 communicates with the second housing 12. Furthermore, through the combined action of the first pressurizing assembly 4, the second pressurizing assembly 5, and the third pressurizing assembly 6 on the pressure chamber 1, a simulation scenario is provided for the rock sample 2 in the pressure chamber 1.

[0058] In this embodiment, to facilitate the cooperation between the first pressurizing assembly 4, the second pressurizing assembly 5, the third pressurizing assembly 6 and the pressure chamber 1, the pressure chamber 1 includes a first housing 11 and a second housing 12. Among them, the first housing 11 is installed on the rotating assembly 3, and the second housing 12 is installed inside the first housing 11. Thus, driven by the rotating assembly 3, the first housing 11 and the second housing 12 can be driven to rotate continuously at the same time. Among them, a rock sample 2 for fracturing is placed inside the second housing 12, and the first pressurizing assembly 4 is communicated with the first housing 11 to provide temperature and pressure for the rock sample 2 inside the second housing 12, so as to simulate the circumferential temperature and pressure borne by real rocks. The second pressurizing assembly 5 is arranged inside the first housing 11 and is drivingly connected to the second housing 12. Thus, the second pressurizing assembly 5 provides an axial driving force for the rock sample 2 inside the second housing 12 to simulate the circumferential stress borne by real rocks. The third pressurizing assembly 6 is communicated with the second housing 12 to provide high-pressure water for the rock sample 2 inside the second housing 12 to fracture the rock sample 2, thereby creating an artificial fracture, and injecting circulating flowing water into the artificial fracture, so that the imaging assembly 8 can scan the rock sample 2, thereby facilitating the acquisition of the change process of the artificial fracture and calculating the change of the reservoir permeability, quantitatively evaluating the influence of water-rock interaction on the heat exchange effect, so as to realize the refined fracturing description of the hot dry rock formation, saving a large amount of manpower and material costs in actual fracturing work.

[0059] It should be noted that the first housing 11 includes a surrounding plate 111 and a base 112. The surrounding plate 111 and the base 112 are connected and enclosed to form an accommodating cavity 11a. Among them, the second pressurizing assembly 5 is installed inside the base 112, and the second housing 12 is placed on the base 112. Thus, when the drive shaft of the second pressurizing assembly 5 can jack up the second housing 12 at any time. It can be understood that a perforation for the piston to pass through is provided on the base 112, and the second housing 12 is installed directly above the perforation. Thus, when the second pressurizing assembly 5 is not working, the second housing 12 can be stably placed inside the accommodating cavity 11a.

[0060] Please refer to Figure 5 and Figure 6 , in an alternative embodiment, the rotating assembly 3 includes a driving member, a rotating platform 31 and a fixed seat 32. The first housing 11 is installed on the rotating platform 31, the driving member is installed on the fixed seat 32, and the output shaft of the driving member is drivingly connected to the rotating platform 31 to drive the rotating platform 31 to rotate relative to the fixed seat 32. Driven by the driving member, the pressure chamber 1 realizes connected rotation, so as to facilitate the continuous scanning of the rock sample 2 inside the pressure chamber 1 by the forming assembly to obtain accurate experimental data of hot dry rock fracturing.

[0061] In this embodiment, to facilitate the rotation assembly 3 to drive the pressure chamber 1 to rotate, the rotation assembly 3 includes a driving member, a driving platform, and a fixed seat 32. The first housing 11 is mounted on the rotating platform 31, and the driving member is mounted on the fixed seat 32. The output shaft of the driving member is drivingly connected to the rotating platform 31, thereby driving the rotating plate platform to rotate relative to the fixed part, and then driving the pressure chamber 1 to rotate through the rotating platform 31. It should be noted that the first housing 11 can be mounted on the rotating platform 31 by welding or other means. The driving member can be a common rotating motor, which is not claimed in this application.

[0062] Please refer to Figure 1 , in an alternative embodiment, the imaging assembly 8 includes a radiation source 81 and a planar array detector 82. The radiation source 81 and the planar array detector 82 are respectively electrically connected to the controller. The radiation source 81 and the planar array detector 82 are arranged on opposite sides of the pressure chamber 1. The radiation source 81 is used to emit radiation, and the planar array detector 82 is used to receive the attenuated radiation. The controller is used to display the internal three-dimensional structure during the fracturing process of the rock sample 2 according to the signal received by the planar array detector 82, and then can perform three-dimensional CT imaging on the rock sample 2 during the fracturing process in real time, reconstruct the fracture morphology of the rock sample 2, and observe the influence of water-rock interaction on the fracture morphology.

[0063] In this embodiment, the imaging assembly 8 includes a radiation source 81 and a planar array detector 82. The radiation source 81 and the planar array detector 82 are relatively arranged on both sides of the pressure chamber 1. It can be understood that both the radiation source 81 and the planar array detector 82 are fixed. During the rotation of the pressure chamber 1, the radiation source 81 can emit radiation, and the radiation can accurately irradiate the pressure chamber 1. After passing through the rock sample 2, the radiation is attenuated, and the attenuated radiation is received by the planar array detector 82. Since both the radiation source 81 and the planar array detector 82 are electrically connected to the controller, the planar array detector 82 transmits the received signal to the controller, and the controller reconstructs the internal three-dimensional structure of the rock sample 2, thereby obtaining the change process of the artificial fracture and calculating the change of the reservoir permeability, quantitatively evaluating the influence of water-rock interaction on the heat exchange effect, so as to realize the refined fracturing description of the hot dry rock formation, saving a large amount of manpower and material resources in the actual fracturing work. It should be noted that the radiation source 81, the planar array detector 82, and the controller are all prior arts, and are not elaborated in this application.

[0064] Please refer to Figure 3 and Figure 4, In an alternative embodiment, the hot dry rock fracturing simulation experimental device 100 further includes a packaging assembly 7. The packaging assembly 7 includes a first cushion block 71, a water-permeable cushion block 72, and a second cushion block 73 arranged in sequence. The first cushion block 71, the water-permeable cushion block 72, and the second cushion block 73 are disposed in the second housing 12 and are spaced apart in the axial direction of the second housing 12. The rock sample 2 is disposed between the first cushion block 71 and the water-permeable cushion block 72. One side of the third pressurizing assembly 6 passes through the first cushion block 71 and is used to be inserted into the rock sample 2. The other side of the third pressurizing assembly 6 passes through the second cushion block 73 and is used to plug into the water-permeable cushion block. By providing the packaging assembly 7, the rock sample 2 can be stably placed in the second housing 12, and it is ensured that the third pressurizing assembly 6 can smoothly fracture the rock sample 2.

[0065] In this embodiment, in order to ensure the smooth progress of the third pressurizing assembly 6, a packaging assembly 7 is further included. Among them, the packaging assembly 7 includes a first cushion block 71, a water-permeable cushion block 72, and a second cushion block 73 arranged in sequence. And the first cushion block 71, the water-permeable cushion block 72, and the second cushion block 73 are all installed in the second housing 12 and are spaced apart in the axial direction of the second housing 12. It should be noted that in order to facilitate the placement of the packaging assembly 7 and the rock sample 2 in the second housing 12, the second housing 12 can form a placement cavity with one end open. Then, the first cushion block 71 is arranged at the bottom layer of the placement cavity, the rock sample 2 is arranged above the first cushion block 71, and the water-permeable cushion block 72 is arranged on the side of the rock sample 2 away from the first cushion block 71, while the second cushion block 73 is arranged on the side of the water-permeable cushion block 72 away from the rock sample 2, so as to encapsulate the rock sample 2 in the second housing 12.

[0066] Specifically, in order to facilitate the connection between the third pressurizing assembly 6 and the second housing 12 so that the third pressurizing assembly 6 can fracture the rock sample 2, one side of the third pressurizing assembly 6 passes through the first cushion block 71 and is used to be inserted into the rock sample 2, and the other side of the third pressurizing assembly 6 passes through the second cushion block 73 and is used to plug into the water-permeable cushion block. Then, by injecting high-pressure water into the rock sample 2 through the third pressurizing assembly 6, the rock sample 2 is fractured to create artificial fractures, and circulating flowing water is injected into the artificial fractures, so that the imaging assembly 8 can scan the rock sample 2, and thus it is convenient to obtain the change process of the artificial fractures.

[0067] Further, to prevent water from flowing out of the second housing 12 into the first housing 11, the encapsulation assembly 7 further includes a sealing ring 75. In this embodiment, there are two sealing rings 75. One sealing ring 75 is disposed on the outer peripheral wall of the first spacer 71 to form a sealed connection between the first spacer 71 and the inner peripheral wall of the second housing 12. The other sealing ring 75 is disposed on the outer peripheral wall of the second spacer 73 to form a sealed connection between the second spacer 73 and the inner peripheral wall of the second housing 12, thereby effectively preventing the water that has entered the second housing 12 from flowing out.

[0068] It should be noted that the second housing 12 is cylindrical, and the rock sample 2 is also cylindrical.

[0069] Please refer to Figure 3 and Figure 4 In an alternative embodiment, the encapsulation assembly 7 further includes a leveling member 74. The leveling member 74 is installed on the second housing 12 and is located on the side of the second spacer 73 away from the water-permeable spacer 72. The leveling member 74 is used to flatten the rock sample 2 in the second housing 12, thereby effectively adjusting the rock sample 2 to avoid uneven local stress caused by uneven end faces.

[0070] In this embodiment, to further encapsulate the rock sample 2 in the second housing 12, the encapsulation assembly 7 further includes a leveling member 74. The leveling member 74 is installed on the second housing 12 and is located on the side of the second spacer 73 away from the water-permeable spacer 72. By rotating the leveling member 74, the rock sample 2 is further fixedly encapsulated in the second housing 12 so that the impact force received by the rock sample 2 is more uniform, and thus the experimental data obtained is more accurate. It should be noted that the leveling member 74 is a ball hinge in the prior art, that is, the leveling member 74 includes an upper ball hinge 741 and a lower ball hinge 742. Both the upper ball hinge 741 and the lower ball hinge 742 have arc surfaces. It can be understood that one side of the lower ball hinge 742 is installed on the second spacer 73, and the mutually approaching surfaces of the lower ball hinge 742 and the upper ball hinge 741 are arc surfaces. By rotating the upper ball hinge 741, the lower ball hinge 742 presses the rock sample 2 and the like tightly in the second housing 12.

[0071] Please refer to Figures 1 to 6 In an alternative embodiment, the first pressurization assembly 4 includes a circulation pump, an intake pipeline 41, and an exhaust pipeline 42. The circulation pump is electrically connected to the controller. One side of the intake pipeline 41 is connected to the circulation pump, and the other side of the intake pipeline 41 is connected to the first housing 11. One side of the exhaust pipeline 42 is connected to the circulation pump, and the other side of the exhaust pipeline 42 communicates with the first housing 11. Thus, a gas at a certain temperature and a certain pressure can be filled into the first housing 11 through the circulation pump, thereby providing a realistic circumferential temperature and pressure for the rock sample 2 to withstand.

[0072] In this embodiment, the first pressurizing assembly 4 includes a circulation pump, an intake pipeline 41, and an exhaust pipeline 42. Among them, one side of the intake pipeline 41 is connected to the circulation pump, and the other side of the intake pipeline 41 communicates with the first housing 11. Similarly, one side of the exhaust pipeline 42 is connected to the circulation pump, and the other side of the exhaust pipeline 42 is connected to the circulation pump. Thus, through the circulation pump and the intake pipeline 41, gas with a certain temperature and a certain pressure can be filled into the first housing 11 to provide a temperature field and a pressure field for the rock sample 2. And after the experiment is over, the gas in the first housing 11 is discharged from the first housing 11 through the exhaust pipeline 42. It should be noted that in order to generate gas with a certain temperature and a certain pressure, the first pressurizing assembly 4 further includes a high-temperature and high-pressure gas generator. The high-temperature and high-pressure gas generator is connected to the circulation pump and discharges the high-temperature and high-pressure gas to the first housing 11 through the circulation pump. The high-temperature and high-pressure gas generator is a prior art, and this application does not make any limitation here.

[0073] Specifically, to facilitate the smooth supply of gas and liquid during the rotation of the pressure chamber 1, a first channel 311, a second channel 312, a third channel 313, a fourth channel 314, a fifth channel 315, and a sixth channel 316 are provided on the rotating platform 31. Among them, the first channel 311 and the fifth channel 315 are located on one side of the rotating platform 31, while the second channel 312, the third channel 313, the fourth channel 314, and the sixth channel 316 are located on the other side of the rotating platform 31. And first annular grooves 321, second annular grooves 322, third annular grooves 323, fourth annular grooves 324, fifth annular grooves 325, and sixth annular grooves 326 that are respectively communicated with the first channel 311, the second channel 312, the third channel 313, the fourth channel 314, the fifth channel 315, and the sixth channel 316 are also provided on the fixed seat 32. A pair of first annular grooves 321, second annular grooves 322, third annular grooves 323, fourth annular grooves 324, fifth annular grooves 325, and sixth annular grooves 326 are provided, and one first annular groove 321, one second annular groove 322, one third annular groove 323, one fourth annular groove 324, one fifth annular groove 325, and one sixth annular groove 326 are arranged at intervals on one side of the fixed seat 32, and the other first annular groove 321, the other second annular groove 322, the other third annular groove 323, the other fourth annular groove 324, the other fifth annular groove 325, and the other sixth annular groove 326 are arranged at intervals on the other side of the fixed seat 32. Among them, the end of the intake pipeline 41 away from the first housing 11 passes through the first channel 311 and the first annular groove 321 and is connected to the circulation pump, and the end of the exhaust pipeline 42 away from the first housing 11 passes through the second channel 312 and the second annular groove 322 and is connected to the circulation pump. Thus, when the rotating platform 31 drives the pressure chamber 1 to rotate, stable gas supply can also be achieved. It should be noted that both the rotating platform 31 and the fixed seat 32 are circular. Thus, during the rotation of the rotating platform 31, the first channel 311, the second channel 312, the third channel 313, the fourth channel 314, the fifth channel 315, and the sixth channel 316 can be respectively communicated with the first annular groove 321, the second annular groove 322, the third annular groove 323, the fourth annular groove 324, the fifth annular groove 325, and the sixth annular groove 326.

[0074] Please refer to Figures 1 to 6, In an alternative embodiment, the third pressurizing assembly 6 includes a fluid injector, a water inlet pipe 61, and a drain pipe 62. The fluid injector is electrically connected to the controller. One side of the fluid injector is connected to the water inlet pipe 61, and the other side of the fluid injector is connected to the drain pipe 62. The other side of the water inlet pipe 61 communicates with the first cushion block 71, and the other side of the drain pipe 62 communicates with the second cushion block 73. Through the fluid injector, high-pressure water is injected into the second housing 12 through the water inlet pipe 61 to fracture the rock sample 2, and the water in the second housing 12 flows back to the fluid injector through the drain pipe 62.

[0075] In this embodiment, the third pressurizing assembly 6 further includes a fluid injector, a water inlet pipe 61, and a drain pipe 62. Among them, one side of the fluid injector is connected to the water inlet pipe 61, and the other side of the fluid injector is connected to the drain pipe 62. And the other side of the water inlet pipe 61 communicates with the first cushion block 71, while the other side of the drain pipe 62 passes through the second cushion block 73 and communicates with the permeable cushion block 72. It should be noted that a water injection channel 711 can be opened on the first cushion block 71 to connect the water inlet pipe 61 to the first cushion block 71, and the water injection channel 711 is connected to the fracturing hole 21 of the rock sample 2 on the side away from the first cushion block 71, so that high-pressure water can smoothly pass through the water inlet pipe 61 and the water injection channel 711 in sequence and be injected into the fracturing hole 21 on the rock sample 2. Further, it should be noted that a drain channel 731 can be opened on the second cushion block 73, so that the drain pipe 62 communicates with the second cushion block 73, so that the high-pressure water in the second housing 12 can smoothly pass through the permeable cushion block 72 and the second cushion block 73 and be discharged to the second housing 12.

[0076] Specifically, in order to enable the high-pressure water in the second housing 12 to smoothly pass through the permeable cushion block 72 and be discharged to the drain channel 731, the permeable cushion block 72 in this embodiment is cylindrical, and a permeable hole 721 and a permeable groove 722 are provided in the permeable cushion block 72. The permeable cushion block 72 is provided with a permeable hole 721 on the side facing the second cushion block 73. The permeable groove 722 communicates with the permeable hole 721, and the permeable hole 721 communicates with the drain channel 731. The permeable groove 722 is formed on the outer peripheral side of the permeable cushion block 72, so that the high-pressure water in the second housing 12 is discharged from the permeable groove 722 to the permeable hole 721, and finally discharged to the drain pipe 62 through the drain channel 731.

[0077] Furthermore, in order to facilitate the smooth supply of liquid during the rotation of the pressure chamber 1, the water inlet pipe 61 is sequentially connected to the third channel 313 and the third annular groove 323 on the side away from the first cushion block 71, and the drain pipe 62 is sequentially connected to the fourth channel 314 and the fourth annular groove 324 on the side away from the second cushion block 73. Thus, when the rotating platform 31 drives the pressure chamber 1 to rotate, stable liquid supply can also be achieved.

[0078] It should be noted that the fluid injector is used to control the injection of high-pressure water and is a prior art, so this application will not elaborate on it here.

[0079] Please refer to Figure 5 and Figure 6 , in an optional embodiment, the fixed seat 32 is provided with a conductive slip ring 34, the conductive slip ring 34 is electrically connected to the controller, and the rotating platform 31 is provided with a brush 33;

[0080] The hot dry rock fracturing simulation experimental device 100 further includes a temperature sensor 9 and a pressure sensor 10. The temperature sensor 9 and the pressure sensor 10 are respectively electrically connected to the brush 33. The pressure sensor 10 is arranged on the outer bottom wall of the second housing 12, and the temperature sensor 9 is arranged inside the first housing 11. During the rotation of the rotating platform 31, the brush 33 is electrically connected to the conductive slip ring 34 to transmit the signals of the temperature sensor 9 and the pressure sensor 10 to the controller. Furthermore, when the rotating platform 31 drives the pressure chamber 1 to rotate continuously, the temperature and pressure inside the pressure chamber 1 can both achieve signal transmission through the brush 33 and the conductive slip ring 34, facilitating the real-time and timely control of the temperature and pressure inside the pressure chamber 1.

[0081] In this embodiment, in order to monitor the specific data of the temperature and pressure inside the pressure chamber 1 in real time, a conductive slip ring 34 is arranged on the fixed seat 32, and a brush 33 is arranged on the rotating platform 31. During the rotation of the rotating platform 31, the brush 33 is electrically connected to the conductive slip ring 34. The brush 33 is respectively connected to the temperature sensor 9 and the pressure sensor 10 through wires. The pressure sensor 10 is arranged on the second housing 12 to detect the axial force received by the rock sample 2. It should be noted that the pressure sensor 10 is arranged on the outer bottom wall of the second housing 12. When the driving shaft of the second pressurizing assembly 5 extends out, it first lifts the pressure sensor 10 and then lifts the second housing 12. Thus, the pressure sensor 10 can monitor the pressure received by the second housing 12 in real time. The temperature sensor 9 is arranged inside the first housing 11 to detect the temperature change inside the first housing 11 in real time. Therefore, the temperature change and pressure change inside the pressure chamber 1 can be transmitted to the controller through the brush 33 and the conductive slip ring 34.

[0082] Specifically, one end of the wire is connected to the brush 33, and the other end of the wire passes through the fifth channel 315 and is respectively connected to the temperature sensor 9 and the pressure sensor 10. And an electric wire is connected to the conductive slip ring 34, and the electric wire passes through the sixth channel 316 and the sixth annular groove 326 and is connected to an external power supply.

[0083] The present invention further provides a testing method for the hot dry rock fracturing simulation experimental device 100 based on any one of the above, characterized in that it includes the following steps:

[0084] Place the rock sample 2 in the pressure chamber 1. A fracturing hole 21 is provided at the central position of the rock sample 2. It should be noted that before the experiment starts, a fracturing hole 21 needs to be drilled in the rock sample 2, and then the rock sample 2 is placed in sequence.

[0085] Control the rotation assembly 3 to drive the pressure chamber 1 to rotate continuously. At this time, the imaging assembly 8 also starts to work and continuously performs three-dimensional structure imaging on the rock sample 2.

[0086] Control the first pressurizing assembly 4 to provide a preset temperature field and pressure field for the pressure chamber 1 to simulate the temperature and pressure that the rock is subjected to in the real environment.

[0087] Control the second pressurizing assembly 5 to apply an axial force to the rock sample 2 so that the rock sample 2 can be uniformly and reliably stressed, ensuring the simulation of the hot dry rock in a high-pressure environment. Control the third pressurizing assembly 6 to inject high-pressure water into the fracturing hole 21 of the rock sample 2 in the pressure chamber 1 to fracture the rock sample 2, and continuously inject high-pressure water into the fractured rock sample 2 to form a stable circulating flow of water in the artificial fracturing cracks.

[0088] Control the imaging assembly 8 to continuously scan the rock sample 2, observe the process of hydraulic fracturing crack propagation through the imaging assembly 8, and reconstruct the crack morphology. The imaging assembly 8 is provided on the outer peripheral side of the rotation assembly 3 for obtaining images of the rock sample 2 during the compression process.

[0089] Receive the signal from the imaging assembly 8 and display the reconstructed crack morphology, thereby facilitating the staff to analyze the cracks of the fractured rock sample 2 and observe the influence of water-rock interaction on the crack morphology.

[0090] Specifically, before starting the experiment, in order to facilitate the fracturing treatment of the rock sample 2, a fracturing hole 21 needs to be drilled in the rock sample 2 first. When starting the experiment, the rock sample 2 needs to be placed in the second housing 12, and the encapsulation assembly 7 is used to stably place the rock sample 2 in the second housing 12, and ensure the smooth fracturing of the rock sample 2 by the third pressurizing assembly 6. After encapsulation, the driving member drives the rotating platform 31 to rotate, and then drives the pressure chamber 1 to rotate. Subsequently, the first pressurizing assembly 4 provides a preset temperature field and pressure field to the pressure chamber 1. It should be noted that the first pressurizing assembly 4 supplies air with a certain temperature and a certain pressure into the pressure chamber 1 to real-time simulate the circumferential temperature and pressure borne by the rock sample 2 in reality. Subsequently, the second pressurizing assembly 5 is started, and the drive shaft of the second pressurizing assembly 5 jacks up the second housing 12. When the second housing 12 is jacked up to the inner top wall of the first housing 11, the second housing 12 begins to be subjected to the axial force of the second pressurizing assembly 5. At this time, the pressure sensor 10 provided on the second housing 12 can detect the driving force output by the second pressurizing assembly 5. Subsequently, the third pressurizing assembly 6 is started. Among them, the water inlet pipeline 61 in the third pressurizing assembly 6 injects a certain amount of high-pressure water into the fracturing hole 21 of the rock sample 2 to cause cracks in the rock sample 2, and continuously injects water to enable the rock sample 2 to clearly observe the flow direction of water in the cracks through the imaging assembly 8 while generating cracks. During the operation of the first pressurizing assembly 4, the second pressurizing assembly 5 and the third pressurizing assembly 6, the imaging assembly 8 is continuously used to scan, reconstruct the crack morphology, observe the influence of the water-rock interaction on the crack morphology, and display the reconstructed crack morphology through the controller, so as to facilitate the staff to analyze the cracks of the fractured rock sample 2, and then facilitate the acquisition of the change process of the artificial cracks, calculate the change of the reservoir permeability, quantitatively evaluate the influence of the water-rock interaction on the heat exchange effect, and realize the refined fracturing description of the hot dry rock formation, saving a large amount of manpower and material costs in the actual fracturing work.

[0091] It should be noted that after the experiment, first unload the axial force of the second pressurizing assembly 5, and then gradually reduce the temperature and pressure in the pressure chamber 1 until the inside of the pressure chamber 1 returns to normal temperature and pressure, drain the water in the pressure chamber 1, then open the pressure chamber 1, and take out and disassemble the rock sample 2.

[0092] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A hot dry rock fracturing simulation experimental device, characterized in that: The hot dry rock fracturing simulation experimental device comprises: A pressure chamber, wherein the pressure chamber is used to place a rock sample; A rotating assembly, the pressure chamber is mounted on the rotating assembly, and the rotating assembly is used to drive the pressure chamber to rotate; A first pressurizing component, which is disposed on the outer peripheral side of the pressure chamber and communicated with the inside of the pressure chamber to provide temperature and pressure to the pressure chamber; a second pressurizing assembly installed in the pressure chamber and used to press against the rock sample to provide an axial force to the rock sample; a third pressurizing assembly, the third pressurizing assembly being disposed on the outer peripheral side of the pressure chamber and being connected to the inside of the pressure chamber for fracturing the rock sample; an imaging assembly, the imaging assembly being disposed on the outer peripheral side of the rotating assembly and being used to obtain an image of the rock sample during a compression process; and A controller is electrically connected to the rotating component, the first pressurizing component, the second pressurizing component and the imaging component respectively.

2. The hot dry rock fracturing simulation experimental device according to claim 1, characterized in that: The pressure chamber includes a first shell and a second shell, the first shell is installed on the rotating assembly, the second shell is installed in the first shell, the second shell is used to place the rock sample, the second pressurizing assembly is installed in the first shell and is drivingly connected to the second shell, the first pressurizing assembly is connected to the first shell, and the third pressurizing assembly is connected to the second shell.

3. The hot dry rock fracturing simulation experimental device according to claim 2, characterized in that: The rotating assembly includes a driving member, a rotating platform and a fixed seat. The first shell is installed on the rotating platform, the driving member is installed on the fixed seat, and the output shaft of the driving member is drivingly connected to the rotating platform to drive the rotating platform to rotate relative to the fixed seat.

4. The hot dry rock fracturing simulation experimental device according to any one of claims 1 to 3, characterized in that: The imaging component includes a ray source and an area array detector, which are electrically connected to the controller respectively. The ray source and the area array detector are arranged on opposite sides of the pressure chamber. The ray source is used to emit rays, and the area array detector is used to receive attenuated rays. The controller is used to display the internal three-dimensional structure of the rock sample during the fracturing process based on the signal received by the area array detector.

5. The hot dry rock fracturing simulation experimental device according to claim 2, characterized in that: The hot dry rock fracturing simulation experimental device also includes a packaging component, which includes a first pad, a permeable pad and a second pad arranged in sequence, the first pad, the permeable pad and the second pad are arranged in the second shell and are spaced apart in the axial direction of the second shell, the rock sample is arranged between the first pad and the permeable pad, one side of the third pressurizing component passes through the first pad and is used to be inserted into the rock sample, and the other side of the third pressurizing component passes through the second pad and is used to insert the permeable pad.

6. The hot dry rock fracturing simulation experimental device according to claim 5, characterized in that: The packaging assembly also includes a leveling member, which is installed outside the second shell and located on a side of the second pad away from the permeable pad. The leveling member is used to flatten the rock sample in the second shell.

7. The hot dry rock fracturing simulation experimental device according to claim 5, characterized in that: The third pressurizing component includes a fluid injector, a water inlet pipe and a drainage pipe, the fluid injector is electrically connected to the controller, one side of the fluid injector is connected to the water inlet pipe, the other side of the fluid injector is connected to the drainage pipe, the other side of the water inlet pipe is connected to the first pad, and the other side of the drainage pipe is connected to the second pad.

8. The hot dry rock fracturing simulation experimental device according to any one of claims 5 to 7, characterized in that: The first pressurizing component includes a circulation pump, an intake pipe and an exhaust pipe, the circulation pump is electrically connected to the controller, one side of the intake pipe is connected to the circulation pump, the other side of the intake pipe is connected to the first shell, one side of the exhaust pipe is connected to the circulation pump, and the other side of the exhaust pipe is connected to the first shell.

9. The hot dry rock fracturing simulation experimental device according to claim 3, characterized in that: The fixing seat is provided with a conductive slip ring, the conductive slip ring is electrically connected to the controller, and the rotating platform is provided with a brush; The hot dry rock fracturing simulation experimental device also includes a temperature sensor and a pressure sensor, wherein the temperature sensor and the pressure sensor are electrically connected to the brushes respectively, the pressure sensor is arranged on the outer bottom wall of the second shell, and the temperature sensor is arranged in the first shell. During the rotation of the rotating platform, the brush is electrically connected to the conductive slip ring to transmit the signals of the temperature sensor and the pressure sensor to the controller.

10. A test method for a hot dry rock fracturing simulation experimental device according to any one of claims 1 to 9, characterized in that: The following steps are involved: The rock sample is placed in the pressure chamber, and a fracturing hole is opened at the center of the rock sample; Controlling the rotating assembly to drive the pressure chamber to rotate continuously; Controlling the first pressurizing component to provide a preset temperature field and pressure field for the pressure chamber; Controlling the second pressurizing assembly to apply an axial force to the rock sample, and controlling the third pressurizing assembly to inject high-pressure water into the fracturing hole of the rock sample in the pressure chamber; Controlling the imaging assembly to continuously scan the rock sample, and observing the hydraulic fracturing crack expansion process through the imaging assembly, and reconstructing the crack morphology; The signal of the imaging component is received, and the reconstructed crack morphology is displayed.

Images