A test device for rock coring behavior in a deep simulated environment

Abstract

This invention belongs to the field of rock coring simulation technology and provides a testing device for rock coring behavior under a deep simulated environment. A crossbeam is installed above the base, and the crossbeam is fixedly connected to the base via a bracket. A moving platform is installed on the top of the base, and a pore pressure loading component is installed on the moving platform. An in-situ chamber is installed on top of the pore pressure loading component, and the in-situ chamber is used to place the sample. A confining pressure chamber is used to fit over the in-situ chamber and form confining pressure on the sample around the in-situ chamber. An axial load loading component is placed above the sample to apply axial pressure to the sample. The pore pressure loading component is used to generate pore water pressure from bottom to top. A coring drill rod is placed above the sample. This invention completes the indoor simulation of deep rock coring behavior. This testing device is the first to realize the abrupt change of the rock core from a state of high temperature, high pressure, and high pore pressure in deep rock to a state of normal temperature and pressure during the coring process, and can quantitatively evaluate the influence of deep coring behavior on the physical and mechanical characteristics of deep rocks.

Description

Technical Field

[0001] This invention belongs to the field of rock coring simulation technology, specifically relating to a test device for rock coring behavior in a deep simulated environment. Background Technology

[0002] With the deepening of resource development, the impact of extreme environments such as high stress, high pore pressure, and high temperature on rocks is becoming increasingly prominent. Accurately assessing the physical and mechanical parameters of deep rocks is a crucial prerequisite for deep resource development. Due to abrupt changes in the rock's environment and the disturbance caused by the drill bit during coring, the coring process causes varying degrees of damage to the rocks. Assessing the extent of rock damage during this process is of great significance for the accurate testing of the physical and mechanical properties of deep rocks. Currently, deep coring processes are mainly recreated through laboratory experiments and numerical simulations. However, existing laboratory experimental methods do not simultaneously consider the three extreme conditions of high stress, high pore pressure, and high geothermal temperature at depth, while numerical simulation methods deviate significantly from reality. Therefore, this invention addresses these issues by designing a rock coring behavior testing device based on a simulated deep environment. This device can apply confining pressure and pore pressure, and achieve high-temperature loading of the pressure chamber through a high-temperature heating belt, enabling coring drilling under high pore pressure and high confining pressure. Finally, the difference in the physical and mechanical properties of the samples is compared to test the degree of rock damage caused by the coring process. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a testing device for rock coring behavior under a deep simulated environment, thereby resolving the issues in the prior art. The technical solution adopted by this invention is as follows: A test device for testing rock coring behavior in a deep simulated environment includes a base, a moving platform, a crossbeam, an in-situ chamber, a confining pressure chamber, a pore pressure loading component, an axial load loading component, and a coring drill rod. The crossbeam is positioned above the base and is fixedly connected to the base via a bracket. A mobile platform is mounted on top of the base, and a pore pressure loading assembly is mounted on the mobile platform. An in-situ chamber is mounted on top of the pore pressure loading assembly, and the in-situ chamber is used to place the sample. A confining pressure chamber is fitted over the in-situ chamber and forms confining pressure around the sample. An axial load loading assembly is positioned above the sample and is used to apply axial pressure to the sample. The pore pressure loading assembly is used to generate pore water pressure from bottom to top. A coring drill rod is positioned above the sample and is used for coring.

[0004] Furthermore, the ballast chamber includes a steel cylinder, an oil inlet pipe, an oil return pipe, and a first linear drive device; The steel cylinder is fitted onto the in-situ chamber, and a confining pressure cavity is formed between the inner side of the steel cylinder and the outer side of the in-situ chamber. An oil inlet pipe and an oil return pipe are fixedly installed on the steel cylinder, which communicate with the confining pressure cavity. The oil inlet pipe is used to input confining pressure oil into the confining pressure cavity to form a surrounding hydraulic pressure on the in-situ chamber within the confining pressure cavity. The oil return pipe is used to discharge the confining pressure oil. The first linear drive device is installed on the crossbeam, and the bottom of the first linear drive device is fixedly connected to the top of the steel cylinder for raising and lowering the steel cylinder. The in-situ chamber includes an inner cylinder and an elastic pressure plate. The inner cylinder has a hollow structure with multiple openings on its wall. The elastic pressure plate is fixedly connected to the openings. The confining pressure oil in the confining pressure chamber squeezes the elastic pressure plate inward, thereby forming confining pressure on the sample.

[0005] Furthermore, it also includes a heating device, which is arranged in a ring around the steel cylinder.

[0006] Furthermore, the orifice pressure loading assembly includes a base, a floating plate, a sliding column, a top pressure ring, a central tube, a guide block, and an orifice pressure plate; The base is provided with a pressure chamber, the float is disposed in the pressure chamber and divides the pressure chamber into upper and lower chambers, the side of the base is provided with a water inlet pipe communicating with the lower chamber, the top of the float is fixedly connected to the sliding column, the sliding column can slide up and down through the top of the base, and the top of the sliding column is fixedly connected to the top pressure ring; The base is fixedly connected to the central tube at the top, and the bottom of the central tube passes through the top surface of the base and the float plate in sequence. The bottom of the inner cylinder is sleeved on the guide block, and the top of the guide block is fixedly connected to the perforated pressure plate. The top of the guide block is provided with an opening, which forms a flow divider cavity with the perforated pressure plate. The perforated pressure plate is provided with a through hole communicating with the flow divider cavity, and the perforated pressure plate supports the bottom of the sample. The top of the central tube passes through the guide block and communicates with the flow divider cavity. The liquid input through the water inlet pipe enters the central tube from the lower chamber, and then enters the flow divider cavity from the central tube. Finally, the liquid enters the through hole from the flow divider cavity, and the liquid is output from the through hole, forming a pore water pressure on the sample from bottom to top. The top of the pressure ring is provided with an annular protrusion, and the bottom of the steel cylinder is provided with an annular groove adapted to the annular protrusion. The annular protrusion is used to insert into the annular groove to form a seal. A first stepped structure for sealing is provided between the inner side of the pressure ring and the outer side of the bottom of the inner cylinder. The float is used to rise under the water pressure of the lower chamber, so that the annular protrusion and the groove fit tightly together, and the first stepped structure between the pressure ring and the inner cylinder fits tightly together, forming a bottom seal for the confining pressure cavity.

[0007] Furthermore, the axial load loading assembly includes an axial pressure block, a second linear drive device, and a sealing ring sleeve; The axial pressure block is adapted to the interior of the inner cylinder. The top of the axial pressure block is fixedly connected to the bottom of the second linear drive device. The second linear drive device is installed on the crossbeam. The bottom of the axial pressure block is used to apply axial pressure to the sample. The axial pressure block has an annular groove in its circumference, and a sealing ring sleeve is fitted inside the annular groove and placed on the axial pressure block. An elastic sealing ring is provided between the top of the sealing ring sleeve and the annular groove. The outer diameter of the sealing ring sleeve is larger than the outer diameter of the axial pressure block. The bottom of the sealing ring sleeve has a sealing groove for the top of the inner cylinder to be inserted. A second stepped structure is provided between the outer side of the sealing ring sleeve and the inner side of the top of the steel cylinder to form a top seal for the confining pressure cavity.

[0008] Furthermore, the axial pressure block has a hollow structure and is sleeved on the core drill rod, with the top of the core drill rod connected to the output end of the rotating device.

[0009] Furthermore, the top of the coring drill rod is rotatably connected to the output of the third linear drive device via a connecting ring. The third linear drive device is mounted on the crossbeam. A transmission rod is provided inside the coring drill rod. The transmission rod is splined with the coring drill rod. The top of the transmission rod is fixedly connected to the output end of the rotating device. The rotating device is mounted on the fourth linear drive device, which is also mounted on the crossbeam. The bottom of the drive rod and the core drill rod are flush with the bottom of the axial pressure block to form a sealed space at the top of the sample; after the core is extracted by the core drill rod, the drive rod is used to move downward to push out the core sample.

[0010] The present invention has the following beneficial effects: The present invention realizes the synergistic simulation of multiple physical fields in the deep environment, namely confining pressure, pore pressure, and axial pressure, and the simulation parameter range can cover geological environments at a certain depth; the core sampling test is carried out in a simulated environment, and the test data has a small deviation from the actual deep core sampling behavior, providing an accurate reference for the design of deep drilling equipment; the present invention completes the indoor simulation of deep rock core sampling behavior. This testing device realizes for the first time the abrupt change of the rock core from the state of high temperature, high pressure and high pore pressure in the deep environment to the state of normal temperature and pressure during the core sampling process, and can quantitatively evaluate the influence law of deep rock physical and mechanical characteristics on deep core sampling behavior. Attached Figure Description

[0011] Figure 1 This is an overall structural diagram of the present invention; Figure 2 yes Figure 1 Enlarged view of point A in the middle; Figure 3 This is a diagram illustrating the core extraction process; Figure 4 This is a schematic diagram of the confining chamber rising and separating from its original compartment. Figure 5 This is a schematic diagram of the core drill rod detaching from the sample; Figure 6 This is a schematic diagram of a collection container collecting samples. Detailed Implementation

[0012] The following will be based on embodiments of the present invention. Figures 1-6 The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0013] like Figure 1 A test device for testing rock coring behavior in a deep simulated environment includes a base 1, a mobile platform 2, a crossbeam 10, an in-situ chamber 5, a confining pressure chamber 4, a pore pressure loading component 3, an axial load loading component, and a coring drill rod 14. The crossbeam 10 is disposed above the base 1, and the crossbeam 10 is fixedly connected to the base 1 by a bracket. The moving platform 2 is installed on the top of the base 1, and the pore pressure loading assembly 3 is disposed on the moving platform 2. The in-situ chamber 5 is installed on the top of the pore pressure loading assembly 3, and the in-situ chamber 5 is used to place the sample 16. The confining pressure chamber 4 is used to fit on the in-situ chamber 5 and form confining pressure on the sample 16 around the in-situ chamber 5. The axial load loading assembly is disposed above the sample 16 and is used to apply axial pressure to the sample 16. The pore pressure loading assembly 3 is used to form pore water pressure from bottom to top. The coring drill rod 14 is disposed above the sample 16 and is used for coring.

[0014] Before testing, sample 16 is prepared, and its size is adapted to the in-situ chamber 5. Then, sample 16 is placed in the in-situ chamber 5. The horizontal position of the pore pressure loading component 3 and the in-situ chamber 5 is moved by the moving platform 2 so that sample 16 is directly below the coring drill rod 14, and the confining pressure chamber 4 and the in-situ chamber 5 are coaxial. Then, the confining pressure chamber 4 is fitted onto the in-situ chamber 5 and confining pressure is applied. The pore pressure loading component 3 applies pore water pressure from the bottom of sample 16, and the axial load loading component applies axial pressure from the top of sample 16 to simulate the mechanical and environmental parameters of the deep environment. After the test device is stationary and the parameters are stable, the coring drill rod 14 is lowered and rotated to perform coring operation on sample 16, completing the coring behavior test.

[0015] Three copies of initial sample 16 can be prepared. Core sampling can be performed twice. The first time, under conditions of high temperature, high confining pressure, and high pore pressure, simulates the core sampling behavior in a deep environment, serving as the experimental group. The second time, using another sample 16, but with reduced confining pressure, pore pressure, and axial pressure, returning to a normal temperature and pressure state, serves as the control group, simulating the abrupt change in core sample conditions from high temperature, high pressure, and high pore pressure to normal temperature and pressure during drilling. The remaining sample 16 serves as the blank group.

[0016] After coring, the three samples 16 were dried, and then uniaxial mechanical tests, porosity and permeability tests were conducted on the three samples 16. By comparing the physical and mechanical properties of the three samples 16, the degree of damage to the physical and mechanical properties of the rock core caused by the deep simulated environment coring behavior can be reflected.

[0017] This invention simulates the confining pressure (radial pressure), pore water pressure (internal permeability pressure), and axial pressure (vertical stress) of deep rocks using a confining pressure chamber 4, a pore pressure loading component 3, and an axial load loading component, respectively, constructing a mechanical field consistent with the actual deep environment. The core drilling rod 14 performs core sampling in this simulated environment, accurately reflecting the core sampling response of deep rocks, such as fracture morphology and core sampling resistance. This invention achieves coordinated simulation of multiple physical fields in the deep environment, namely confining pressure, pore pressure, and axial pressure, with simulation parameters covering geological environments at certain depths. Core sampling tests are conducted in a simulated environment, and the test data shows minimal deviation from actual deep core sampling behavior, providing accurate reference for the design of deep drilling equipment. This invention completes indoor simulation of deep rock core sampling behavior. This testing device is the first to realize the abrupt change in the rock core from a state of high temperature, high pressure, and high pore pressure in deep rock to a state of normal temperature and pressure during core sampling, enabling quantitative evaluation of the influence of deep core sampling behavior on the physical and mechanical characteristics of deep rocks.

[0018] like Figure 2 The ballast chamber 4 includes a steel cylinder 401, an oil inlet pipe 404, an oil return pipe 403, and a first linear drive device 6; The steel cylinder 401 is sleeved on the in-situ chamber 5, and a confining pressure cavity is formed between the inner side of the steel cylinder 401 and the outer side of the in-situ chamber 5. The oil inlet pipe 404 and the oil return pipe 403, which communicate with the confining pressure cavity, are fixedly installed on the steel cylinder 401. The oil inlet pipe 404 is used to input confining pressure oil 405 into the confining pressure cavity to form a surrounding hydraulic pressure on the in-situ chamber 5 within the confining pressure cavity. The oil return pipe 403 is used to discharge the confining pressure oil 405. The first linear drive device 6 is installed on the crossbeam 10. The bottom of the first linear drive device 6 is fixedly connected to the top of the steel cylinder 401 for raising and lowering the steel cylinder 401. The in-situ chamber 5 includes an inner cylinder 501 and an elastic pressure plate 503. The inner cylinder 501 has a hollow structure and multiple openings 502 are provided on its wall. The elastic pressure plate 503 is fixedly connected inside the openings 502. The confining pressure oil 405 in the confining pressure chamber squeezes the elastic pressure plate 503 inward, thereby forming confining pressure on the sample 16.

[0019] In practice, the first linear drive device 6 extends, causing the steel cylinder 401 to descend and be fitted onto the outside of the inner cylinder 501 of the in-situ chamber 5, forming a confining pressure chamber. The oil inlet pipe 404 injects confining pressure oil 405 into the confining pressure chamber, creating uniform hydraulic pressure within the chamber. This pressure oil 405 compresses the elastic pressure plate 503 at the opening 502 of the inner cylinder 501, causing the elastic pressure plate 503 to deform and press inward against the sample 16, thus applying confining pressure. After the test, the oil return pipe 403 discharges the confining pressure oil 405, and the first linear drive device 6 retracts, causing the steel cylinder 401 to rise and detach from the in-situ chamber 5. The elastic pressure plate 503 is a prior art material, such as a rubber plate or spring steel plate, and its material and thickness can be selected according to actual testing requirements. The oil inlet pipe 404 and the oil return pipe 403 connect to a pump body and an oil tank (not shown in the figure).

[0020] In this invention, the hydraulic pressure of the confining oil 405 is constrained by the rigid wall of the steel cylinder 401 and converted into a uniformly distributed pressure on the elastic pressure plate 503. The elastic pressure plate 503 is made of elastic material, and its deformation energy can uniformly transmit the hydraulic pressure to the surface of the sample 16, forming radial confining pressure. The first linear drive device 6 realizes the rapid docking and separation of the confining chamber 4 and the in-situ chamber 5 through the lifting steel cylinder 401. The cylinder 501 can be a hollow circular cylinder or a square cylinder.

[0021] Furthermore, it also includes a heating device 402, which is annularly sleeved on the steel cylinder 401.

[0022] The heating device 402 uniformly heats the steel cylinder 401 through a ring structure. The heat is conducted through the steel cylinder 401 to the confining pressure oil 405. After the confining pressure oil 405 heats up, it heats the inner cylinder 501 of the in-situ chamber 5 and the internal sample 16 through heat conduction. According to the simulation depth requirements, the heating power is adjusted to stabilize the temperature of the sample 16 at the target value to simulate the high-temperature environment at depth. The heating device 402 is existing technology, such as resistance heating wire or heating belt.

[0023] Furthermore, the orifice pressure loading assembly 3 includes a base 301, a float 302, a sliding column 303, a top pressure ring 304, a central tube 305, a flow guide block 306, and an orifice pressure plate 307. The base 301 is provided with a pressure chamber, the float 302 is disposed in the pressure chamber and divides the pressure chamber into upper and lower chambers, the side of the base 301 is provided with a water inlet pipe 305 communicating with the lower chamber, the top of the float 302 is fixedly connected to the sliding column 303, the sliding column 303 can slide up and down through the top of the base 301, and the top of the sliding column 303 is fixedly connected to the top pressure ring 304; The base 301 is fixedly connected to the top of the central tube 305. The bottom of the central tube 305 passes through the top surface of the base 301 and the float plate 302 in sequence. The bottom of the inner cylinder 501 is sleeved on the guide block 306. The top of the guide block 306 is fixedly connected to the perforated pressure plate 307. The top of the guide block 306 is provided with an opening, which forms a flow divider cavity with the perforated pressure plate 307. The perforated pressure plate 307 is provided with a through hole that connects to the flow divider cavity. The perforated pressure plate 307 supports the bottom of the sample 16. The top of the central tube 305 passes through the guide block 306 and connects to the flow divider cavity. The liquid input through the water inlet pipe 305 enters the central tube 305 from the lower chamber, and then enters the flow divider cavity from the central tube 305. Finally, the liquid enters the through hole from the flow divider cavity and is output from the through hole, forming a pore water pressure on the sample 16 from bottom to top. The top of the pressure ring 304 is provided with an annular protrusion, and the bottom of the steel cylinder 401 is provided with an annular groove that matches the annular protrusion. The annular protrusion is used to insert into the annular groove to form a seal. A first stepped structure for sealing is provided between the inner side of the pressure ring 304 and the outer side of the bottom of the inner cylinder 501. The float 302 is used to rise under the water pressure of the lower chamber, so that the annular protrusion and the groove fit tightly together, and the first stepped structure between the pressure ring 304 and the inner cylinder 501 fits tightly together, forming a bottom seal on the confining pressure cavity.

[0024] Liquid medium, such as water, is injected into the lower chamber through the inlet pipe 305. As the liquid medium enters the central pipe 305, the pressure in the lower chamber increases, causing the float 302 to rise. The float 302, through the sliding column 303, drives the top pressure ring 304 to rise until the annular protrusion of the top pressure ring 304 is fully inserted into the annular groove at the bottom of the steel cylinder 401, forming a mechanical seal. Simultaneously, as the amount of liquid medium in the lower chamber increases, the water pressure gradually increases, further pushing the float 302 upward, forming a self-sealing structure. The liquid in the lower chamber flows through the central pipe 305 into the diversion chamber of the guide block 306. From the diversion chamber, the liquid flows to multiple through holes in the pore pressure plate 307, where it seeps upward, applying pore water pressure to the bottom of the sample 16. This invention utilizes the self-sealing properties of liquid pressure. The water pressure in the lower chamber provides lift for the float 302 to achieve sealing and also serves as a power source for the pore water pressure, eliminating the need for an additional sealing drive device. The diversion chamber transforms the concentrated water flow from the central tube 305 into a uniformly distributed water flow from the pore pressure plate 307 through its cavity structure, ensuring that the pore water pressure is evenly distributed at the bottom of the sample 16. The double-sealing design of the first-step structure and the annular protrusion can withstand the pressure difference between the confining pressure chamber and the pore pressure system. The base 301 is also connected to a return water pipe (not shown in the figure), and the return water pipe and the inlet water pipe 305 are connected to the pump body and the water tank (not shown in the figure).

[0025] Furthermore, the axial load loading assembly includes an axial pressure block 13, a second linear drive device 7, and a sealing ring sleeve 18; The axial pressure block 13 is adapted to the interior of the inner cylinder 501. The top of the axial pressure block 13 is fixedly connected to the bottom of the second linear drive device 7. The second linear drive device 7 is installed on the crossbeam 10. The bottom of the axial pressure block 13 is used to axially pressurize the sample 16. The axial pressure block 13 has an annular groove in its circumference. A sealing ring 18 is sleeved on the axial pressure block 13 in the annular groove. An elastic sealing ring 17 is provided between the top of the sealing ring 18 and the annular groove. The outer diameter of the sealing ring 18 is larger than the outer diameter of the axial pressure block 13. The bottom of the sealing ring 18 has a sealing groove for the top of the inner cylinder 501 to be inserted. A second stepped structure is provided between the outer side of the sealing ring 18 and the inner side of the top of the steel cylinder 401 to form a top seal on the confining pressure cavity.

[0026] Specifically, the second linear drive device 7 extends, pushing the axial pressure block 13 downward into the inner cylinder 501, where its bottom contacts the sample 16 and applies axial pressure. Simultaneously, the sealing ring 18 descends with the axial pressure block 13, and the top of the inner cylinder 501 inserts into the sealing groove of the sealing ring 18. The elastic sealing ring 17 deforms under pressure, achieving a seal between the axial pressure block 13 and the sealing ring 18. The second stepped structure fits together to achieve a seal between the sealing ring 18 and the steel cylinder 401, together forming a seal at the top of the confining cavity. Furthermore, the axial pressure block 13 is a hollow structure, which is sleeved on the core drill rod 14, and the top of the core drill rod 14 is connected to the output end of the rotating device 12.

[0027] Furthermore, the top of the core drill rod 14 is rotatably connected to the output of the third linear drive device 8 via a connecting ring 15. The third linear drive device 8 is mounted on the crossbeam 10. A transmission rod 9 is provided inside the core drill rod 14. The transmission rod 9 is splinedly engaged with the core drill rod 14. The top of the transmission rod 9 is fixedly connected to the output end of the rotating device 12. The rotating device 12 is mounted on the fourth linear drive device 11. The fourth linear drive device 11 is mounted on the crossbeam 10. The bottom of the transmission rod 9 and the core drill rod 14 are flush with the bottom of the axial pressure block 13 to form a sealed space at the top of the sample 16; after the core drill rod 14 takes the core, the transmission rod 9 is used to move downward to push out the core sample.

[0028] The splined connection enables the transmission rod 9 to drive the core drill rod 14 to rotate without affecting the linear motion of the core drill rod 14. The transmission rod 9 simultaneously serves the functions of transmission and sample ejection. The third linear drive device 8 and the fourth linear drive device 11 control the lifting and rotation of the core drill rod 14, respectively.

[0029] The workflow of this invention is as follows: (1) Before core sampling, place sample 16 into the inner cylinder 501 of the in-situ chamber 5, ensuring that the bottom of sample 16 is stably placed on the pore pressure plate 307; adjust the horizontal position of the pore pressure loading assembly 3 and the in-situ chamber 5 by moving platform 2, so that the central axis of the in-situ chamber 5 is aligned with the central axis of the confining pressure chamber 4. Start the first linear drive device 6, so that its output end extends and drives the steel cylinder 401 to move downward until the steel cylinder 401 is fitted on the outside of the inner cylinder 501. At this time, the annular groove at the bottom of the steel cylinder 401 is initially aligned with the annular protrusion of the top pressure ring 304. The steel cylinder 401 does not interfere with other components during its movement. The second linear drive device 7 is activated, extending its output end and pushing the axial pressure block 13 downward into the inner cylinder 501 until the bottom of the axial pressure block 13 contacts the top of the sample 16; simultaneously, the sealing ring 18 is driven to descend, so that the top of the inner cylinder 501 is inserted into the sealing groove of the sealing ring 18, the elastic sealing ring 17 is deformed under pressure and the second stepped structure fits, completing the sealing of the top of the confining cavity; the third linear drive device 8 and the fourth linear drive device 11 work together to make the bottom of the core drill rod 14 and the transmission rod 9 flush with the bottom of the axial pressure block 13, forming a sealed space at the top of the sample 16.

[0030] Axial pressure is applied to the target value through the second linear drive device 7; liquid is injected into the lower chamber through the water inlet pipe 305, and the liquid pressure pushes the float plate 302 to move upward. The float plate 302 drives the top pressure ring 304 to rise through the sliding column 303, so that the annular protrusion is inserted into the annular groove and the first stepped structure fits tightly, completing the bottom sealing of the confining pressure chamber; at the same time, the liquid flows into the diversion chamber of the guide block 306 through the central pipe 305, and then seeps upward through the through hole of the pore pressure plate 307, applying pore water pressure to the bottom of the sample 16; confining pressure oil 405 is injected into the confining pressure chamber through the oil inlet pipe 404, and the confining pressure oil 405 squeezes the elastic pressure plate 503 and transfers it to the sample 16 to form radial confining pressure until the target confining pressure value is reached; the heating device 402 is started, and heat is conducted to the sample 16 through the steel cylinder 401 and the confining pressure oil 405, and the heating power is adjusted to stabilize the temperature of the sample 16.

[0031] (2) During core extraction, the fourth linear drive device 11 pushes the rotating device 12 and the transmission rod 9 to descend. The transmission rod 9 drives the core drill rod 14 to rotate synchronously through the spline. At this time, the transmission rod 9 does not descend, while the core drill rod 14 is pushed down by the third linear drive device 8 to complete the cutting and core extraction. Figure 3 The state in.

[0032] (3) After core sampling, the confining chamber 4 rises to its highest point, forming Figure 4 The state is as follows: then the axial pressure block 13 rises, and at the same time the fourth linear drive device 11 and the third linear drive device 8 drive the transmission rod 9 and the core drill rod 14 to rise synchronously and be located above the in-situ chamber 5, forming... Figure 5The mobile platform 2 pushes the borehole pressure loading assembly 3 and the in-situ chamber 5 to displace, exposing the area below the coring drill rod 14. Then, the collection container 19 is manually placed below the coring drill rod 14. The fourth linear drive device 11 individually pushes the transmission rod 9 down, pushing the sample inside the coring drill rod 14 into the collection container 19 for collection. Afterward, another sample 16 is replaced in the in-situ chamber 5, all components are reset, and the process returns to normal. Figure 1 The status indicates that the next test is about to begin.

[0033] In this invention, the first linear drive device 6, the second linear drive device 7, the third linear drive device 8, the fourth linear drive device 11, the moving platform 2, and the rotating device 12 are all prior art. The first linear drive device 6, the second linear drive device 7, and the third linear drive device 8 can be hydraulic cylinders, electric cylinders, etc.; the fourth linear drive device 11 and the moving platform 2 can be electric linear guides; and the rotating device 12 can be hydraulic motors, electric motors, etc.

[0034] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications, alterations, substitutions, or variations made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A test device for rock core sampling behavior in a deep simulated environment, characterized in that, It includes a base (1), a mobile platform (2), a crossbeam (10), an in-situ chamber (5), a confining chamber (4), a pore pressure loading assembly (3), an axial load loading assembly, and a core drill rod (14). The crossbeam (10) is provided above the base (1), and the crossbeam (10) is fixedly connected to the base (1) by a bracket. The moving platform (2) is installed on the top of the base (1), and the pore pressure loading assembly (3) is provided on the moving platform (2). The in-situ chamber (5) is installed on the top of the pore pressure loading assembly (3), and the in-situ chamber (5) is used to place the sample (16). The confining pressure chamber (4) is used to be fitted on the in-situ chamber (5) and to form confining pressure on the sample (16) around the in-situ chamber (5). The axial load loading assembly is provided above the sample (16) and is used to apply axial pressure to the sample (16). The pore pressure loading assembly (3) is used to form pore water pressure from bottom to top. The core drill rod (14) is provided above the sample (16) and is used to perform core sampling. The ballast chamber (4) includes a steel cylinder (401), an oil inlet pipe (404), an oil return pipe (403), and a first linear drive device (6). The steel cylinder (401) is sleeved on the in-situ chamber (5), and a confining pressure cavity is formed between the inner side of the steel cylinder (401) and the outer side of the in-situ chamber (5). The oil inlet pipe (404) and the oil return pipe (403) communicating with the confining pressure cavity are fixedly installed on the steel cylinder (401). The oil inlet pipe (404) is used to input confining pressure oil (405) into the confining pressure cavity to form a surrounding hydraulic pressure on the in-situ chamber (5) in the confining pressure cavity. The oil return pipe (403) is used to discharge the confining pressure oil (405). The first linear drive device (6) is installed on the crossbeam (10). The bottom of the first linear drive device (6) is fixedly connected to the top of the steel cylinder (401) for raising and lowering the steel cylinder (401). The in-situ chamber (5) includes an inner cylinder (501) and an elastic pressure plate (503). The inner cylinder (501) is a hollow structure with multiple openings (502) on its wall. The elastic pressure plate (503) is fixedly connected inside the openings (502). The confining pressure oil (405) in the confining pressure chamber squeezes the elastic pressure plate (503) inward, thereby forming a confining pressure on the sample (16).

2. The device for testing rock coring behavior under a deep simulated environment according to claim 1, characterized in that, It also includes a heating device (402), which is annularly sleeved on the steel cylinder (401).

3. The device for testing rock coring behavior under a deep simulated environment according to claim 1, characterized in that, The orifice pressure loading assembly (3) includes a second base (301), a float (302), a sliding column (303), a top pressure ring (304), a central tube (305), a guide block (306), and an orifice pressure plate (307). The second base (301) is provided with a pressure chamber, the float (302) is provided in the pressure chamber and divides the pressure chamber into upper and lower chambers. The side of the second base (301) is provided with a water inlet pipe (3011) that communicates with the lower chamber. The top of the float (302) is fixedly connected to the sliding column (303). The sliding column (303) can slide up and down through the top of the second base (301). The top of the sliding column (303) is fixedly connected to the top pressure ring (304). The top of the second base (301) is fixedly connected to the central tube (305), and the bottom of the central tube (305) passes through the top surface of the second base (301) and the float (302) in sequence. The bottom of the inner cylinder (501) is sleeved on the guide block (306), and the top of the guide block (306) is fixedly connected to the perforated pressure plate (307). The top of the guide block (306) is provided with an opening, and a flow-dividing cavity is formed between the opening and the perforated pressure plate (307). The sample (16) is provided with a through hole that connects to the flow distribution chamber. The pressure plate (307) supports the bottom of the sample (16). The top of the central tube (305) passes through the guide block (306) and connects to the flow distribution chamber. The liquid input through the water inlet pipe (3011) enters the central tube (305) from the lower chamber, and then enters the flow distribution chamber from the central tube (305). Finally, the liquid enters the through hole from the flow distribution chamber and is output from the through hole, forming a pore water pressure on the sample (16) from bottom to top. The top of the pressure ring (304) is provided with an annular protrusion, and the bottom of the steel cylinder (401) is provided with an annular groove that matches the annular protrusion. The annular protrusion is used to insert into the annular groove to form a seal. A first stepped structure for sealing is provided between the inner side of the pressure ring (304) and the outer side of the bottom of the inner cylinder (501). The float (302) is used to rise under the water pressure of the lower chamber, so that the annular protrusion and the groove fit tightly together, and the first stepped structure between the pressure ring (304) and the inner cylinder (501) fits tightly together, forming a bottom seal on the confining pressure cavity.

4. The rock coring behavior testing device based on a deep simulated environment according to claim 1, characterized in that, The axial load loading assembly includes an axial pressure block (13), a second linear drive device (7), and a sealing ring (18). The axial pressure block (13) is adapted to the interior of the inner cylinder (501). The top of the axial pressure block (13) is fixedly connected to the bottom of the second linear drive device (7). The second linear drive device (7) is installed on the crossbeam (10). The bottom of the axial pressure block (13) is used to axially pressurize the sample (16). The axial pressure block (13) is provided with an annular groove in its circumference. The sealing ring (18) is provided in the annular groove and is sleeved on the axial pressure block (13). An elastic sealing ring (17) is provided between the top of the sealing ring (18) and the annular groove. The outer diameter of the sealing ring (18) is larger than the outer diameter of the axial pressure block (13). The bottom of the sealing ring (18) is provided with a sealing groove for the top of the inner cylinder (501) to be inserted. A second stepped structure is provided between the outer side of the sealing ring (18) and the inner side of the top of the steel cylinder (401) to form a top seal for the confining pressure cavity.

5. A test device for rock coring behavior under a deep simulated environment according to claim 4, characterized in that, The axial pressure block (13) is a hollow structure and is sleeved on the core drill rod (14). The top of the core drill rod (14) is connected to the output end of the rotating device (12).

6. The device for testing rock coring behavior under a deep simulated environment according to claim 5, characterized in that, The top of the core drill rod (14) is rotatably connected to the output of the third linear drive device (8) via a connecting ring (15). The third linear drive device (8) is mounted on the crossbeam (10). A transmission rod (9) is provided inside the core drill rod (14). The transmission rod (9) is splined with the core drill rod (14). The top of the transmission rod (9) is fixedly connected to the output end of the rotating device (12). The rotating device (12) is mounted on the fourth linear drive device (11). The fourth linear drive device (11) is mounted on the crossbeam (10). The bottom of the transmission rod (9) and the core drill rod (14) are flush with the bottom of the axial pressure block (13) to form a sealed space at the top of the sample (16); after the core is taken by the core drill rod (14), the transmission rod (9) is used to move downward to push out the core sample.

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