CN109781606B - A core holder for in-situ seepage CT scanning - Google Patents

Abstract

The invention discloses a core holder for in-situ seepage CT scanning, which comprises a core fixing system, a seepage system, a confining pressure loading system and a supporting base, wherein the core fixing system comprises a hollow plug body and a sleeve, the sleeve is used for fixing a core sample, and two ends of the sleeve are respectively provided with an upper plug and a lower plug; the seepage liquid inlet flow pump of the seepage system is connected with the bottom end of the lower plug through a seepage liquid inlet pipe, and the seepage liquid outlet flow pump is connected with the top end of the upper plug through a seepage liquid outlet pipe; the confining pressure cover of the confining pressure loading system is reversely buckled outside the hollow plug body, the confining pressure liquid inlet flow pump is connected with one side of the confining pressure cover through a confining pressure liquid inlet pipe, and the confining pressure liquid outlet flow pump is connected with the other side of the confining pressure cover through a confining pressure liquid outlet pipe. The invention has simple and compact structure and low manufacturing cost, can effectively reduce leakage points by arranging the covering confining pressure loading system, and can realize the seepage experiment of external confining pressure while carrying out in-situ CT scanning, thereby having strong operability.

Description

A core holder for in-situ seepage CT scanning

Technical Field

The invention relates to a seepage experimental device for in-situ CT scanning, in particular to a core holder for in-situ seepage CT scanning.

Background Art

In-situ CT scanning refers to real-time CT scanning of samples while maintaining the experimental temperature and pressure conditions. Currently, most of the existing seepage experimental equipment uses lightweight aluminum-carbon fiber composite material clamps, because lightweight aluminum-carbon fiber composite materials allow CT scanning X-rays to pass through and will not have a great impact on the CT scanning process. Therefore, lightweight aluminum-carbon fiber composite material clamps can be used as components for clamping samples in seepage experiments that require in-situ CT scanning. However, this lightweight aluminum-carbon fiber composite material clamp is not only expensive, but also has a complex structure, many interfaces, and is prone to leakage. The clamp must be modified to match the CT scanner, and it is impossible to directly conduct a real-time seepage experiment of fluid passing through the core sample in the CT scanner.

Summary of the invention

The object of the present invention is to provide a core holder for in-situ seepage CT scanning which has a simple structure, is not prone to leakage, and is compatible with a micrometer CT scanner.

To achieve the above object, the present invention provides the following solutions:

The present invention provides a core holder for in-situ seepage CT scanning, comprising a core fixing system, a seepage system, a confining pressure loading system and a supporting base, wherein the core fixing system comprises a hollow plug body and a sleeve, wherein the hollow plug body is vertically fixed on the supporting base, wherein the sleeve is fixed on the inner top of the hollow plug body, wherein the sleeve is used to fix the core sample, wherein the top and bottom of the sleeve are respectively provided with an upper plug and a lower plug; wherein the seepage system comprises a seepage liquid inlet flow pump and a seepage liquid outlet flow pump, wherein the seepage liquid inlet flow pump is connected to the supporting base; ... The seepage liquid inlet pipe is connected to the bottom end of the lower plug, and the seepage liquid outlet flow pump is connected to the top end of the upper plug through the seepage liquid outlet pipe; the confining pressure loading system includes a confining pressure cover, a confining pressure liquid inlet flow pump and a confining pressure liquid outlet flow pump, the confining pressure cover is inverted on the outside of the hollow plug body, and the opening of the confining pressure cover is sealed and connected to the upper surface of the supporting base, the confining pressure liquid inlet flow pump is connected to one side of the confining pressure cover through the confining pressure liquid inlet pipe, and the confining pressure liquid outlet flow pump is connected to the other side of the confining pressure cover through the confining pressure liquid outlet pipe.

Optionally, the hollow plug body is an alumina ceramic hollow plug body.

Optionally, the confining pressure hood is an alumina ceramic confining pressure hood, and an exhaust port is provided at the top of the confining pressure hood.

Optionally, the sleeve is a rubber sleeve or a polyetheretherketone resin (PEEK) sleeve.

Optionally, the support base is a two-step boss-type base, and the hollow plug body is fixedly connected to the center of the top end surface of the two-step boss-type base.

Optionally, the confining pressure cover is inverted on the outside of the top boss of the second-step boss-type base, and the confining pressure cover is threadedly connected to the second-step boss-type base.

Optionally, the seepage liquid inlet flow pump and the seepage liquid outlet flow pump are symmetrically distributed on the periphery of the confining pressure hood, and the seepage liquid inlet pipe penetrates the interior of the second-step boss type base and enters the hollow plug body from the bottom end of the hollow plug body; the seepage liquid outlet pipe penetrates the interior of the second-step boss type base and enters the hollow plug body from the top end of the hollow plug body.

Optionally, the confining pressure liquid inlet flow pump and the confining pressure liquid outlet flow pump are symmetrically distributed on the periphery of the confining pressure cover, and the top surface of the second-step boss type base is provided with a confining pressure liquid inlet valve and a confining pressure liquid outlet valve, the confining pressure liquid inlet pipe passes through the interior of the second-step boss type base and is connected to the confining pressure liquid inlet valve; the seepage liquid outlet pipe passes through the interior of the second-step boss type base and is connected to the confining pressure liquid outlet valve.

Optionally, a back pressure valve is provided on the seepage liquid outlet pipe, and the back pressure valve is used to adjust the flow rate of the seepage liquid.

Compared with the prior art, the present invention has achieved the following technical effects:

The core holder for in-situ seepage CT scanning proposed by the present invention has a simple and compact structure and is compatible with a variety of seepage systems. It can realize online real-time scanning of the seepage process and can also be separated from the seepage system to realize offline pressure-maintaining scanning. At the same time, by setting up a novel structured covering confining pressure loading system, not only the confining pressure is evenly loaded, but also the leakage of the confining pressure fluid can be effectively reduced, the leakage points can be effectively reduced, and the leakage risk is low. The entire holder can be placed inside the CT scanner, and a seepage experiment with an external confining pressure can be performed while performing an in-situ CT scan, thereby achieving the purpose of performing in-situ seepage CT scanning while the fluid passes through the core sample, and the operability is strong.

In addition, the covering confining pressure cover and the hollow plug body in the present invention are made of high-strength alumina ceramics. The alumina ceramic material not only has a low absorption degree of X-rays and does not interfere with the scanning process, but also can greatly reduce the cost of the core clamp. In addition, in the core clamp of the present invention, each valve, pipeline and flow pump are centrally arranged on the upper surface of the support base, which is not only convenient for operation and replacement, but also can reduce the space occupied by the clamp in the CT scan, and has strong practicality.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

FIG1 is a top view of a core holder for in-situ seepage CT scanning proposed by the present invention;

Fig. 2 is a schematic cross-sectional view taken along line A-A of Fig. 1;

Fig. 3 is a schematic cross-sectional view taken along line B-B of Fig. 1;

FIG4 is an enlarged view of the top structure of the hollow plug body of the present invention;

Among them, the accompanying drawings are marked as follows: 1. support base; 2. hollow plug body; 3. sleeve; 4. seepage liquid inlet flow pump; 5. seepage liquid outlet flow pump; 6. seepage liquid inlet pipe; 7. seepage liquid outlet pipe; 8. confining pressure cover; 9. confining pressure liquid inlet flow pump; 10. confining pressure liquid outlet flow pump; 11. confining pressure liquid inlet pipe; 12. confining pressure liquid outlet pipe; 13. exhaust port; 14. X-ray source; 15. X-ray receiver; 16. core sample; 17. confining pressure liquid; 18. upper plug; 19. lower plug.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

The object of the present invention is to provide a core holder for in-situ seepage CT scanning which has a simple structure, is not prone to leakage, and is compatible with a micrometer CT scanner.

Based on this, the present invention provides a core holder for in-situ seepage CT scanning, including a core fixing system, a seepage system, a confining pressure loading system and a support base. The core fixing system includes a hollow plug body and a sleeve. The hollow plug body is vertically fixed on the support base, and the sleeve is fixed to the inner top of the hollow plug body. The sleeve is used to fix the core sample. The top and bottom of the sleeve are respectively provided with an upper plug and a lower plug; the seepage system includes a seepage liquid inlet flow pump and a seepage liquid outlet flow pump. The seepage liquid inlet The liquid flow pump is connected to the bottom end of the lower plug through the seepage liquid inlet pipe, and the seepage liquid outlet flow pump is connected to the top end of the upper plug through the seepage liquid outlet pipe; the confining pressure loading system includes a confining pressure cover, a confining pressure liquid inlet flow pump and a confining pressure liquid outlet flow pump, the confining pressure cover is inverted on the outside of the hollow plug body, and the opening of the confining pressure cover is sealed and connected to the upper surface of the supporting base, the confining pressure liquid inlet flow pump is connected to one side of the confining pressure cover through the confining pressure liquid inlet pipe, and the confining pressure liquid outlet flow pump is connected to the other side of the confining pressure cover through the confining pressure liquid outlet pipe.

The core holder for in-situ seepage CT scanning proposed by the present invention has a simple and compact structure and is compatible with a variety of seepage systems. It can realize online real-time scanning of the seepage process and can also be separated from the seepage system to realize offline pressure-maintaining scanning. At the same time, by setting up a novel structured covering confining pressure loading system, not only the confining pressure is evenly loaded, but also the leakage of the confining pressure fluid can be effectively reduced, the leakage points can be effectively reduced, and the leakage risk is low. The entire holder can be placed inside the CT scanner, and a seepage experiment with an external confining pressure can be performed while performing an in-situ CT scan, thereby achieving the purpose of performing in-situ seepage CT scanning while the fluid passes through the core sample, and the operability is strong.

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

Embodiment 1:

As shown in FIGS. 1 to 4 , this embodiment provides a core holder for in-situ seepage CT scanning, including a core fixing system, a seepage system, a confining pressure loading system and a support base 1. The core fixing system includes a hollow plug body 2 and a sleeve 3. The hollow plug body 2 is vertically fixed to the top surface of the support base 1, and the sleeve 3 is fixed to the inner top of the hollow plug body 2. The sleeve 3 is used to fix the core sample 16. As shown in FIG. 4 , the top and bottom ends of the sleeve 3 are respectively provided with upper plugs 18 The upper plug 18 and the lower plug 19 are used to seal the core sample 16 in the sleeve 3, wherein the upper plug 18 and the lower plug 19 are preferably a rubber pad structure with a sealing effect, which has good sealing performance and is easy to disassemble and assemble; the seepage system includes a seepage liquid inlet flow pump 4 and a seepage liquid outlet flow pump 5, one end of the seepage liquid inlet flow pump 4 is connected to the bottom center of the lower plug 19 through the seepage liquid inlet pipe 6, and the other end is connected to the seepage liquid source, so as to pump the seepage liquid into the sleeve 3, and accordingly, the seepage liquid outlet flow pump 5 is connected to the seepage liquid source. One end of the pump 5 is connected to the top of the upper plug 18 through the seepage liquid outlet pipe 7, and the other end is connected to the seepage liquid collecting device, so as to pump the seepage liquid from the sleeve 3 to the seepage liquid collecting device, wherein the seepage liquid source and the seepage liquid collecting device can be the same device or different devices; as shown in Figures 2 and 3, the confining pressure loading system includes a confining pressure cover 8, a confining pressure liquid inlet flow pump 9 and a confining pressure liquid outlet flow pump 10, and the confining pressure cover 8 is inverted on the outside of the hollow plug body 2, and the confining pressure cover 8 The opening is sealed and connected to the upper surface of the support base 1, thereby forming a covered confining pressure loading system. One end of the confining pressure liquid inlet flow pump 9 is connected to one side of the confining pressure cover 8 through the confining pressure liquid inlet pipe 11, and the other end is connected to the confining pressure liquid source. Correspondingly, one end of the confining pressure liquid outlet flow pump 10 is connected to the other side of the confining pressure cover 8 through the confining pressure liquid outlet pipe 12, and the other end can be connected to a confining pressure liquid collecting device, wherein the confining pressure liquid source and the confining pressure liquid collecting device can be the same device or different devices. During the test, the seepage liquid inlet flow pump 4 is first opened to pump the seepage liquid into the core sample 16 wrapped in the sleeve 3 until the pore pressure required for the test is reached in the sleeve 3, and then the confining pressure liquid inlet flow pump 9 is opened to pump the confining pressure liquid 17 into the confining pressure cover 8 until the system reaches the confining pressure required for the test. In this embodiment, the confining pressure liquid 17 is preferably oil or water.

Further, in this embodiment, the hollow plug body 2 is preferably an alumina ceramic hollow plug body. The alumina ceramic material not only has a very low absorption degree of X-rays and does not interfere with the scanning process, but also can greatly reduce the cost of the core clamp compared to the use of lightweight aluminum-carbon fiber composite materials. At the same time, the confining pressure cover 8 is also preferably made of alumina ceramics. The alumina ceramic confining pressure cover not only has a very low absorption degree of X-rays and does not interfere with the scanning process, but also has a low cost. At the same time, the alumina ceramic confining pressure cover can effectively reduce the leakage of the confining pressure liquid, effectively reduce the leakage point, and have a low risk of leakage, so that the entire clamp can be placed inside the CT scanner, and can realize the seepage experiment of the external confining pressure while performing the in-situ CT scanning, so as to achieve the purpose of performing in-situ seepage CT scanning while the fluid passes through the core sample. As shown in Figures 2 to 3, in this embodiment, the top surface and side wall of the preferred confining pressure cover 8 are set with a rounded transition, which can reduce the pressure load on the confining pressure cover and effectively reduce the risk of leakage of the confining pressure liquid.

Furthermore, as shown in FIGS. 2-3 , an exhaust port 13 is provided at the top end of the confining pressure cover 8 .

Furthermore, in this embodiment, the sleeve 3 is preferably a rubber sleeve or polyetheretherketone (PEEK) sleeve with good elasticity and cylindrical shape. The core sample 16 is used to be inserted into the sleeve 3, and then the upper plug 18 and the lower plug 19 are respectively installed at the upper and lower ends of the sleeve 3 to fix the core sample 16. Among them, the upper plug 18 and the lower plug 19 are preferably rubber pad structures with sealing effects, and the seepage liquid inlet pipe 6 and the seepage liquid outlet pipe 7 are preferably connected to the inside of the sleeve 3 through the middle of the rubber pad structure, and the upper plug 18 and the lower plug 19 are respectively sealed and connected to the seepage liquid outlet pipe 7 and the seepage liquid inlet pipe 6 to prevent leakage of the seepage liquid.

Further, as shown in Figures 2 and 3, the support base 1 is preferably configured as a two-step boss type base, that is, the two-step boss type base includes an upper boss and a lower base, the upper boss is fixed at the center of the lower base, and the area of the upper boss is smaller than the area of the lower base. In this embodiment, as shown in Figure 1, the upper boss and the lower base are preferably coaxial cylindrical structures with different diameters. This two-step boss type base is a common boss structure in the prior art center, and will not be described in detail here. Among them, the hollow plug body 2 is fixedly connected to the center of the top surface of the two-step boss type base. In this embodiment, the hollow plug body 2 and the two-step boss type base can be preferably set as a whole.

Furthermore, as shown in Figures 2 and 3, the confining pressure cover 8 is inverted on the outside of the top boss of the two-step boss type base. Preferably, the confining pressure cover 8 is inverted on the outside of the above-mentioned upper boss, and preferably, the confining pressure cover 8 is threadedly connected to the outer side wall of the upper boss of the two-step boss type base, which is convenient for disassembly and assembly and can ensure the sealing inside the confining pressure cover 8.

Further, as shown in Figs. 1 and 2, the seepage liquid inlet flow pump 4 and the seepage liquid outlet flow pump 5 are symmetrically distributed on the outer periphery of the confining pressure cover 8, the seepage liquid inlet pipe 6 penetrates the interior of the second-step boss-type base and enters the hollow plug body 2 from the bottom end of the hollow plug body 2; the seepage liquid outlet pipe 7 penetrates the interior of the second-step boss-type base and enters the hollow plug body 2 from the top end of the hollow plug body 2. Correspondingly, the confining pressure liquid inlet flow pump 9 and the confining pressure liquid outlet flow pump 10 are symmetrically distributed on the outer periphery of the confining pressure cover 8, the top surface of the second-step boss-type base is provided with a confining pressure liquid inlet valve and a confining pressure liquid outlet valve, the confining pressure liquid inlet pipe 11 penetrates the interior of the second-step boss-type base and is connected to the confining pressure liquid inlet valve; the seepage liquid outlet pipe 12 penetrates the interior of the second-step boss-type base and is connected to the confining pressure liquid outlet valve. In this embodiment, as shown in Figure 1, the seepage liquid inlet flow pump 4, the seepage liquid outlet flow pump 5, the confining pressure liquid inlet flow pump 9 and the confining pressure liquid outlet flow pump 10 are preferably arranged at intervals and cross-arranged on the upper surface of the lower base of the two-step boss type base. At the same time, the seepage liquid inlet pipe 6, the seepage liquid outlet pipe 7, the confining pressure liquid inlet pipe 11 and the seepage liquid outlet pipe 12 are connected to the upper seepage system and/or the confining pressure loading system in a manner of penetrating the interior of the two-step boss type base. All flow pumps and pipelines are arranged at the bottom of the clamp, which is different from the design of the traditional clamp valves distributed at the upper and lower ends of the clamp. It is not only easy to operate and replace, but also can reduce the space occupied by the clamp in the CT scan, and is also beneficial to the protection of each pipeline, and is extremely practical.

Furthermore, a back pressure valve is provided on the seepage liquid outlet pipe 7, and the back pressure valve is used to adjust the pressure at the seepage liquid outflow end in the seepage liquid outlet pipe 7, thereby adjusting the flow rate of the seepage liquid.

The following uses the core holder for in-situ seepage CT scanning of this embodiment in conjunction with a Zeiss Xradia 410 micrometer CT scanner as an example to specifically explain the use of this embodiment.

First, when loading the sample, the core sample 16 is inserted into the sleeve 3, and then the upper plug 18 and the lower plug 19 are sealed at the upper and lower ends of the sleeve 3 respectively, and then the confining pressure cover 8 is turned upside down on the second-order boss type base, and is sealed and connected with the upper raised thread of the second-order boss type base, as shown in Figures 1 to 4. At this time, the hollow plug body 2, the sleeve 3, the upper plug 18 and the lower plug 19 are all located inside the confining pressure cover 8.

Then, the seepage test is carried out: first, the entire clamp is fixed on the sample tray of the Zeiss Xradia 410 micrometer CT scanner. At this time, as shown in FIG2 , the clamp is located between the X-ray source 14 and the X-ray receiver 15. First, the confining pressure liquid inlet flow pump 9 is turned on to pump the confining pressure liquid 17 into the confining pressure cover 8 until the relevant pressure measuring components in the system detect that the confining pressure in the confining pressure cover 8 reaches the confining pressure required for the test. The confining pressure liquid inlet flow pump 9 itself has the function of detecting and displaying the confining pressure. The confining pressure liquid inlet flow pump 9 is a conventional flow pump structure, and its specific structure and working principle are not repeated here. After that, the seepage fluid inlet flow pump 4 is turned on to allow the seepage fluid to flow from the lower left of the system into the core sample 16 wrapped in the sleeve 3 until the relevant pressure measuring component detects that the pore pressure required for the test is reached in the sleeve 3; the pore pressure here is measured by the seepage fluid inlet flow pump 4, which itself has the function of detecting and displaying the pore pressure, wherein the seepage fluid inlet flow pump 4 is a conventional flow pump structure, and its specific structure and working principle are not repeated here. The above-mentioned confining pressure value and pore pressure value are determined by the specific experimental requirements, generally the maximum pore pressure is 30MPa, and the maximum confining pressure is 35MPa.

After that, the back pressure valve on the seepage outlet pipe 7 can be used to adjust the pressure at the lower right side of the system, that is, the pressure at the seepage outlet end of the seepage outlet pipe 7, to adjust the fluid flow. When the seepage flow is stable, the power supply of the Zeiss Xradia 410 micrometer CT scanner can be turned on to perform micrometer CT scanning. The X-ray source 14 of the Zeiss Xradia 410 micrometer CT scanner faces the clamp, receives the X-rays passing through the core sample 16 through the X-ray receiver 15, and analyzes the attenuation degree of the X-ray signal through the signal analysis system of the scanner, thereby realizing the three-dimensional visualization of the internal structure of the core sample 16 under the test condition of the external confining pressure. It should be noted that the X-ray emission principle of the X-ray source 14, the structural principle of the X-ray receiver 15, and the analysis principle of the system for the attenuation degree of the X-ray signal in the above-mentioned Zeiss Xradia 410 micrometer CT scanner are all well known in the art, and the specific structure and working principle of each component in the scanner will not be repeated here.

It can be seen that the core holder for in-situ seepage CT scanning proposed by the present invention has a simple and compact structure and is compatible with a variety of seepage systems. It can realize online real-time scanning of the seepage process and can also be separated from the seepage system to realize offline pressure-maintaining scanning; at the same time, by setting up a novel covering confining pressure loading system, not only the confining pressure is loaded evenly, but also the leakage of the confining pressure fluid can be effectively reduced, the leakage points can be effectively reduced, and the leakage risk is low. The entire holder can be placed inside the CT scanner, and it is possible to perform a seepage experiment with an external confining pressure while performing an in-situ CT scan, thereby achieving the purpose of performing in-situ seepage CT scanning while the fluid passes through the core sample, and the operability is strong.

In addition, the covering confining pressure cover and the hollow plug body in the present invention are made of high-strength alumina ceramics. The alumina ceramic material not only has a low absorption degree of X-rays and does not interfere with the scanning process, but also can greatly reduce the cost of the core holder. In addition, in the core holder of the present invention, each flow pump is centrally arranged on the upper surface of the support base, which is not only convenient for operation and replacement, but also can reduce the space occupied by the holder in the CT scan, and has strong practicality.

It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any figure mark in the claims should not be regarded as limiting the claims involved.

The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims (6)

1. A core holder for in situ percolation CT scanning, characterized by: the core fixing system comprises a hollow plug body and a sleeve, wherein the hollow plug body is vertically fixed on the supporting base, the sleeve is fixed at the top end of the interior of the hollow plug body and is used for fixing a core sample, and an upper plug and a lower plug are respectively arranged at the top end and the bottom end of the sleeve; the seepage system comprises a seepage liquid inlet flow pump and a seepage liquid outlet flow pump, the seepage liquid inlet flow pump is connected with the bottom end of the lower plug through a seepage liquid inlet pipe, and the seepage liquid outlet flow pump is connected with the top end of the upper plug through a seepage liquid outlet pipe; the confining pressure loading system comprises a confining pressure cover, a confining pressure liquid inlet flow pump and a confining pressure liquid outlet flow pump, wherein the confining pressure cover is reversely buckled outside the hollow plug body, an opening of the confining pressure cover is in sealing connection with the upper surface of the supporting base, the confining pressure liquid inlet flow pump is connected with one side of the confining pressure cover through a confining pressure liquid inlet pipe, and the confining pressure liquid outlet flow pump is connected with the other side of the confining pressure cover through a confining pressure liquid outlet pipe; the hollow plug body is fixedly connected with the center of the top end surface of the second-order boss type base; the confining pressure cover is reversely buckled outside a top end boss of the second-order boss type base, and the confining pressure cover is in threaded connection with the second-order boss type base; the seepage liquid inlet flow pump and the seepage liquid outlet flow pump are symmetrically distributed on the periphery of the confining pressure cover, and the seepage liquid inlet pipe penetrates through the inside of the second-order boss type base and enters the hollow plug body from the bottom end of the hollow plug body; the seepage liquid outlet pipe penetrates through the interior of the second-order boss type base and enters the hollow plug body from the top end of the hollow plug body.

2. The core holder for in situ percolation CT scanning of claim 1, wherein: the hollow plug body is an alumina ceramic hollow plug body.

3. The core holder for in situ percolation CT scanning of claim 1, wherein: the confining pressure cover is an alumina ceramic confining pressure cover, and an exhaust port is arranged at the top end of the confining pressure cover.

4. The core holder for in situ percolation CT scanning of claim 1, wherein: the sleeve is a rubber sleeve or a polyether-ether-ketone resin sleeve.

5. The core holder for in situ percolation CT scanning of claim 1, wherein: the confining pressure liquid inlet flow pump and the confining pressure liquid outlet flow pump are symmetrically distributed on the periphery of the confining pressure cover, a confining pressure liquid inlet valve and a confining pressure liquid outlet valve are arranged on the top end surface of the second-order boss type base, and the confining pressure liquid inlet pipe penetrates through the inside of the second-order boss type base and is connected with the confining pressure liquid inlet valve; the seepage liquid outlet pipe penetrates through the inner part of the second-order boss type base and is connected with the confining pressure liquid outlet valve.

6. The core holder for in situ percolation CT scanning of claim 1, wherein: and the seepage liquid outlet pipe is provided with a back pressure valve, and the back pressure valve is used for adjusting the flow of seepage liquid.