Crack type artificial rock core preparation device and method thereof

Abstract

The invention relates to a crack type artificial rock core preparation device, and relates to the field of petroleum oil and gas development technology, the crack type artificial rock core preparation device comprises a cutting tool and a rock core manufacturing mold, the top wall of the rock core manufacturing mold is open, and the cutting end of the cutting tool extends into the rock core manufacturing mold from the top end of the rock core manufacturing mold; a tool bit limiting assembly is arranged between the cutting tool and the rock core manufacturing mold, and the tool bit limiting assembly is used for guiding the moving direction of the cutting tool. The method has the advantages that the situation that the opening degree of the crack is large is reduced, and the effect of fine simulation of the crack is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil and gas development technology, in particular to a fracture type artificial core preparation device and method thereof. BACKGROUND

[0002] The core is an important material for oil and gas reservoir description, and plays an irreplaceable role in studying the microstructure, physical parameters and percolation capacity of the reservoir. In the development process of fracture type oil and gas reservoir, due to the constraints of geological conditions, there may be problems such as that the obtained core is easy to break and the core is damaged during coring. Even if the complete core can be obtained, it cannot represent the actual situation of the reservoir, and the repeated utilization rate of the natural fracture core is very low, which is very unfavorable for the experimental work of the fracture core. Therefore, it is necessary to develop a man-made fracture core.

[0003] The current man-made fracture core technology mainly includes three types: pressure seam method, cutting seam method and filling seam method, but all have certain shortcomings. The pressure seam method is to generate cracks in the core by applying external force, but the direction and size of the cracks cannot be controlled, and the repeatability is low, so it is difficult to mass-produce. The cutting seam method is to cut the device in the core to form a seam, but the opening of the seam is large, the fine simulation of the micro crack cannot be realized, the seam is exposed outside the core, the non-penetrating seam cannot be simulated, the inner wall of the seam is smooth, the actual percolation capacity of the core is increased, and the actual situation is not met. The filling seam method is to pre-fill solid support in the core, and then dissolve the filler by chemical or physical means to obtain a crack, but there are problems such as residual filler and influence of chemical means on the physical properties of the core.

[0004] According to the related technology in the above, the inventors believe that the traditional cutting seam method leads to a large crack opening and a smooth inner wall of the seam. SUMMARY

[0005] In order to reduce the large crack opening and realize fine simulation of the crack, the present application provides a fracture type artificial core preparation device and method thereof.

[0006] The fracture type artificial core preparation device provided by the present application adopts the following technical scheme:

[0007] A fracture type artificial core preparation device, comprising a cutting tool and a core making mold, the top wall of the core making mold is open, the cutting end of the cutting tool extends into the top end of the core making mold, a tool bit limiting assembly is arranged between the cutting tool and the core making mold, and the tool bit limiting assembly guides the moving direction of the cutting tool.

[0008] Optionally, the cutting tool comprises a cutting head, the cutting head comprises a connecting portion at the upper portion and a cutting portion at the bottom end of the connecting portion, the cutting surface of the cutting portion extends into the inside of the core making mold, and the side of the cutting portion away from the cutting surface is provided with a concave-convex structure.

[0009] Optionally, the cutting tool further comprises a cutting handle, a connecting assembly is arranged between the bottom end of the cutting handle and the cutting head, the outer side of the cutting handle is provided with a cutting shell, the cutting shell is in sliding connection with the cutting handle, and a locking assembly is arranged between the cutting shell and the cutting handle.

[0010] Optionally, the connecting assembly comprises a connecting plate fixed on the cutting handle, a head clamping block is fixedly connected on the connecting plate, a head clamping groove is horizontally arranged on the cutting head, the head clamping block is clamped in the inside of the head clamping groove, a head fixer is arranged at the position of the bottom end of the cutting handle relative to the head clamping block, the head fixer is in elastic structure, and the side wall of the head fixer is in abutment with the side wall of the head clamping block.

[0011] Optionally, the locking assembly comprises a first locking block fixed on the inner side wall of the cutting shell, a plurality of first locking blocks are arranged along the height direction of the cutting shell, the side wall of the cutting handle is fixedly connected with a limiting block, a locking groove is arranged at the position of the limiting block relative to the first locking block, a second locking block is in sliding connection in the inside of the locking groove, the second locking block is provided with an elastic piece close to the groove bottom side of the locking groove, the first locking block is provided with a first locking surface and a second locking surface close to the second locking block, the first locking surface and the second locking surface are inclined surfaces with opposite inclined directions, and the second locking block is relatively provided with a fourth locking surface with the same inclined direction as the first locking surface and a third locking surface with the same inclined direction as the second locking surface relative to the side of the first locking block.

[0012] Optionally, the head limiting assembly comprises a limiting plate, a head limiting groove is vertically arranged on the limiting plate, the bottom end of the cutting handle is in abutment and sliding with the top wall of the limiting plate, and the cutting head extends into the inside of the head limiting groove.

[0013] Optionally, the head limiting assembly comprises two limiting plates arranged oppositely, a gasket is fixedly connected between the two limiting plates, a spacing is left between the two limiting plates to form a head limiting groove, the bottom end of the cutting handle is in abutment and sliding with the top wall of the limiting plate, and the cutting head extends into the inside of the head limiting groove.

[0014] Optionally, the abutting plate is fixedly connected to the cutter head fixer at a position abutting against the cutter head clamping block, and the setting direction of the abutting plate is the same as the setting direction of the cutting cutter head.

[0015] Optionally, the width of the cutter head limiting groove is 1-2mm larger than the width of the cutting cutter head.

[0016] The application also provides a preparation method of the fracture type artificial core, which is applied to the fracture type artificial core preparation device and comprises the following steps:

[0017] S01: the thickness and the telescopic length of the cutting cutter head are selected as required; the core making mold is assembled; the parameters of the fracture are designed as required; and the upper surfaces of the front and rear baffles and the left and right baffles are marked to mark the fracture position information;

[0018] S02: the release agent is evenly applied to the inner wall of the core making mold space; then the diagenetic mixture is placed in the core making mold; after being scraped flat, the diagenetic mixture is placed in the press to be pressed and formed under a certain pressure, which is the first pressing, and the pressure is recorded as the first pressure;

[0019] S03: after the pressing and forming, the core making mold is taken out of the press; the upper wall plate is opened; the cutter head limiting assembly is placed according to the designed fracture position; the cutting cutter head is inserted into the core through the cutter head limiting groove on the cutter head limiting assembly to start the fracture; the cutting cutter head is inserted into the designed depth for multiple times in the production process; the fracture is repeatedly cut according to the designed fracture length; and the production of all fractures is sequentially performed from the middle of the formed core to the two sides;

[0020] S04: after the production of all fractures is completed, the cutting cutter head and the cutter head limiting assembly are taken out of the core making mold; a certain amount of diagenetic mixture is placed on the fracture according to the opening and the depth of the fracture; the diagenetic mixture is scraped flat by a scraper; and the diagenetic mixture is placed into the press to be pressed again, which is the second pressing, and the pressure is recorded as the second pressure, and the second pressure is smaller than the first pressure;

[0021] S05: after the second pressing and forming, the diagenetic mixture is subjected to pressing and curing treatment; the cured core block is taken out of the core making mold; the part of the core block adhered to the release agent around the core block is removed; and the complete cylindrical artificial fracture core with a predetermined diameter is drilled.

[0022] In summary, the application has at least one of the following beneficial technical effects:

[0023] 1. In the production of the fracture cutter, the back part of the cutter is not a flat surface; and the diagenetic mixture is added for the second time in the production process and the pressing process, so that the inner wall of the fracture is irregular and not smooth.

[0024] 2. On the selection of the crack making, the crack depth and opening can be controlled by changing the thickness of the cutter head and the extension length; the crack inclination angle, crack length and crack position can be controlled by controlling the placement position of the crack mold, so that the crack parameters can be personalized designed and the crack can be finely simulated.

[0025] 3. The method for making the crack core has the characteristics of simple operation, low requirement for equipment and repeatable batch production. The crack making is completely in the core making and forming process, has no influence on the core strength, is a pure physical process, has no damage to the core and has no influence on the core physical property. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a schematic diagram of the overall structure of a crack type artificial core preparation device in the embodiments of the present application.

[0027] Figure 2 is a schematic diagram of the structure of a cutting tool of a crack type artificial core preparation device in the embodiments of the present application.

[0028] Figure 3 is a schematic diagram of the structure of a connecting assembly of a cutting tool of a crack type artificial core preparation device in the embodiments of the present application.

[0029] Figure 4 is a sectional view of a cutting tool of a crack type artificial core preparation device in the embodiments of the present application.

[0030] Figure 5 is Figure 4 is an enlarged view of

[0031] Figure 6 is a schematic diagram of the structure of a cutter head limiting assembly in the first embodiment of a crack type artificial core preparation device in the embodiments of the present application.

[0032] Figure 7 is a schematic diagram of the structure of a cutter head limiting assembly in the second embodiment of a crack type artificial core preparation device in the embodiments of the present application.

[0033] Figure 8 is a schematic diagram of the structure of a core making mold of a crack type artificial core preparation device in the embodiments of the present application.

[0034] Explanation of reference signs: 1, cutting tool; 11, cutting shell; 12, cutting handle; 121, limiting block; 122, locking groove; 123, second locking block; 124, spring; 13, locking assembly; 131, first locking block; 14, cutting bit; 141, bit clamping groove; 15, connecting assembly; 151, connecting plate; 152, bit clamping block; 153, bit fixer; 154, abutting plate; 2, core making mold; 21, side wall plate; 22, bottom wall plate; 23, upper wall plate; 3, bit limiting assembly; 31, limiting plate; 32, bit limiting groove; 33, gasket. DETAILED DESCRIPTION

[0035] In order to enable the above-mentioned objects, features and advantages of the present application to be more clearly understood and to be put into practical use, the present application will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0036] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and therefore the scope of protection of the present application is not limited by the specific embodiments disclosed below.

[0037] The following will be described in detail with reference to the accompanying drawings. Figures 1-8 The present application will be further described in detail.

[0038] The embodiments of the present application disclose a fracture type artificial core preparation device. Referring to Figure 1 , Figure 2 A fracture type artificial core preparation device comprises a cutting tool 1, a core making mold 2 is arranged below the cutting tool 1, a bit limiting assembly 3 is arranged above the core making mold 2, the bottom wall of the bit limiting assembly 3 abuts against the top wall of the core making mold 2, and the movement of the cutting tool 1 inside the core making mold 2 is guided and limited by the bit limiting assembly 3.

[0039] Referring to Figure 2 , Figure 3 The cutting tool 1 comprises a cutting shell 11, a cutting handle 12 is arranged inside the cutting shell 11, the cutting handle 12 is in sliding connection with the cutting shell 11, and the cutting handle 12 slides in the height direction inside the cutting shell 11.

[0040] Referring to Figure 2 , Figure 4A locking component 13 is located inside the cutting housing 11 at a position relative to the cutting handle 12. When the cutting handle 12 is moved into place, the locking component 13 locks the cutting handle 12 in its position inside the cutting housing 11. A cutting head 14 is located at the bottom of the cutting handle 12. The cutting head 14 is detached and installed from the cutting handle 12 via a connecting component 15, allowing for the selection and replacement of different cutting heads 14 according to different operational needs.

[0041] Reference Figure 4 , Figure 5 The locking assembly 13 includes a first locking block 131 fixed to the inner wall of the cutting housing 11. The first locking block 131 is positioned at both ends along the direction of movement of the cutting housing 11, and is fixedly connected to the inner wall of the cutting housing 11. The first locking block 131 has a triangular structure and includes a first locking surface at the top and a second locking surface at the bottom. The first locking surface is inclined, gradually tilting downwards from the side opposite to the center of the cutting housing 11 to the side closer to the center. The second locking surface is also inclined, gradually tilting upwards from the side opposite to the center of the cutting housing 11 to the side closer to the center. Multiple first locking blocks 131 are equidistantly arranged along the height direction of the cutting housing 11.

[0042] A limiting block 121 is fixedly connected to the outer wall of the cutting handle 12. The limiting block 121 has a rectangular structure. Locking grooves 122 are respectively opened on the two side walls of the limiting block 121 opposite to the first locking block 131. A second locking block 123 is horizontally slidably connected inside the locking groove 122. A spring 124 is horizontally arranged on the side of the second locking block 123 near the bottom of the locking groove 122. One end of the spring 124 is fixedly connected to the limiting block 121, and the other end of the spring 124 is fixedly connected to the second locking block 123.

[0043] The second locking block 123 has a triangular structure on the side closest to the first locking block 131, and the second locking block 123 includes a third locking surface located above and a fourth locking surface located below. The inclination direction of the third locking surface is the same as that of the second locking surface, and the inclination direction of the fourth locking surface is the same as that of the first locking surface.

[0044] When the spring 124 is compressed, the second locking block 123 extends into the interior of the locking groove 122, and the projection of the end of the first locking block 131 near the second locking block 123 and the end of the second locking block 123 near the first locking block 131 along the height direction is spaced, so that the cutting handle 12 can move freely up and down inside the cutting housing 11.

[0045] When the spring 124 is in a free state, the second locking block 123 extends into the position between the two adjacent first locking blocks 131, and the position of the second locking block 123 is restricted by the two adjacent first locking blocks 131, thereby restricting the position of the cutting handle 12 inside the cutting housing 11.

[0046] Reference Figure 2 , Figure 3 The connecting assembly 15 includes a connecting plate 151 fixed to the bottom end of the cutting handle 12. The connecting plate 151 is vertically arranged, and a blade head retainer 152 is fixedly connected to the side of the bottom end of the connecting plate 151 near the center of the cutting handle 12. The blade head retainer 152 may be an elliptical structure. A blade head retainer 153 is also fixedly connected to the side of the bottom end of the cutting handle 12 away from the connecting plate 151. The blade head retainer 153 is an elastically deformable structure. The top end of the blade head retainer 153 is connected to the bottom end of the cutting handle 12, and an abutment plate 154 is fixedly connected to the bottom end of the blade head retainer 153. The abutment plate 154 is a vertically arranged plate. When the blade head retainer 153 is in a free state, the side wall of the abutment plate 154 abuts against the side wall of the blade head retainer 152, so that a sealed space is formed by the upper part of the blade head retainer 152, the cutting handle 12, the blade head retainer 153, and the abutment plate 154. When the cutter head retainer 153 deforms away from the cutter head retainer block 152, the tip of the cutting blade can enter the sealed space through the gap between the cutter head retainer 153 and the cutter head retainer block 152.

[0047] The sidewall of the cutting head 14 is horizontally provided with a cutting head groove 141 relative to the position of the cutting head retainer 152. The cutting head groove 141 completely penetrates the sidewall of the cutting head, and the shape of the cutting head groove 141 is adapted to the shape of the cutting head retainer 152. When the tip of the cutting head 14 extends into the interior of the sealed space, the cutting head retainer 152 and the cutting head groove 141 are aligned, and the cutting head 14 is mounted on the cutting head retainer 152. The cutting head 14 is fixed and removed by the sidewall of the abutment plate 154 of the cutting head retainer 153 being aligned with the sidewall of the cutting head retainer 152. The thickness of the cutting head 14 determines the opening of the crack, and can be customized according to the crack opening. It can be as thin as 0.1mm and can be used to create cracks larger than 100μm. The extension length of the cutting head 14 determines the depth of the crack. The actual depth of the crack is the extension length of the cutting head 14 minus the thickness of the crack creation model.

[0048] The cutting blade includes a connecting part with a blade head slot 141 and a cutting part located below it. The side of the cutting part facing the cutting direction is the cutting surface, and the side wall of the cutting part facing away from the cutting surface has an uneven structure. By moving the cutting head 14 along the cutting direction, the uneven cutting of the cutting head 14 creates scratches on the cutting surface, reducing the impact of an overly flat cutting surface that does not conform to reality.

[0049] Reference Figure 6 , Figure 7 In some embodiments, the cutter head limiting assembly 3 includes a limiting plate 31, which is a rectangular structure. A cutter head limiting groove 32 is vertically formed on the upper surface of the limiting plate 31. The width of the cutter head limiting groove 32 is 1-2 mm larger than the width of the cutting cutter head 14. The cutting cutter head 14 can extend into the interior of the cutter head limiting groove 32. The bottom wall of the cutting shell 11 and the top wall of the limiting plate 31 are in contact and slide relative to each other. The bottom end of the cutting cutter head 14 extends out from the lower surface of the limiting plate 31 and extends into the core to be cut. By sliding the cutting shell 11 on the surface of the limiting plate 31, the cutting cutter head 14 is driven to cut the core to be cut.

[0050] In some other embodiments, the cutter head limiting assembly 3 includes two opposing limiting plates 31. A shim 33 is provided at the ends of the relatively close sidewalls of the two limiting plates 31, and the shims 33 are fixedly connected to the limiting plates 31. A cutter head limiting groove 32 is formed by the opposing limiting plates 31 and the opposing shims 33 at the ends. The width of the cutter head limiting groove 32 is 1-2 mm greater than the width of the cutting cutter head 14. The width of the cutter head limiting groove 32 can be adjusted by adjusting the width of the shims 33, and the specific width depends on the set thickness of the cutting cutter head 14. The cutting cutter head 14 can extend into the interior of the cutter head limiting groove 32, and the bottom wall of the cutting shell 11 slides against the top wall of the limiting plate 31. The bottom end of the cutting cutter head 14 extends from the lower surface of the limiting plate 31 and into the core to be cut. By sliding the cutting shell 11 on the surface of the limiting plate 31, the cutting cutter head 14 is driven to cut the core to be cut.

[0051] Reference Figure 1 , Figure 8 The core preparation mold 2 is a rectangular hollow mold. The core preparation mold 2 includes a side wall plate 21 for forming the four side walls, a bottom wall plate 22 for forming the bottom wall, and an upper wall plate 23 for forming the upper wall. The side wall plate 21 and the bottom wall plate 22 are fixedly connected. The upper wall plate 23 is located inside the side wall plate 21, and the four side walls of the upper wall plate 23 are slidably connected to the side wall plate 21.

[0052] In some embodiments, the side wall panel 21 includes two front and rear baffles and two left and right baffles arranged opposite each other. The front and rear baffles have a first groove vertically formed at a position relative to the left and right baffles, allowing the ends of the left and right baffles to extend into the interior of the front and rear baffles through the first groove. Bolts are horizontally arranged inside the left and right baffles, with the ends of the bolts extending from the sidewalls of the left and right baffles and threadedly connected to the front and rear baffles for fixation. The upper surface of the bottom wall panel 22 has a second groove at a position relative to the front and rear baffles and the left and right baffles, allowing the front and rear baffles and the left and right baffles to extend into the interior of the bottom wall panel 22 for fixation.

[0053] In some embodiments, the aforementioned cutter head limiting component 3 and cutting cutter head 14 are made of steel, and the core forming mold 2 is made of Hastelloy.

[0054] This application also provides a method for preparing fractured artificial rock cores, applied to the aforementioned fractured artificial rock core preparation apparatus, the method comprising:

[0055] S01: Select the thickness and extension length of the cutting head 14 as required; assemble the core preparation mold 2, design the location, inclination angle, length and other parameters of the crack as required, and mark the upper surface of the front, back and left and right baffles of the core preparation mold 2 to mark the crack location information;

[0056] S02: Use methyl silicone oil as a release agent. Apply the release agent evenly to the inner wall of the core making mold 2. Then place the rock-forming mixture (the materials required for the core and inorganic binders, etc.) into the core making mold 2. After smoothing, put it into a press and apply a certain pressure to press it into shape. This is the first pressing. The pressure used is called the first pressure.

[0057] S03: After pressing and molding, remove the core making mold 2 from the press, open the upper wall plate 23, place the cutter head limiting component 3 according to the designed crack position, insert the cutting cutter head 14 into the core through the cutter head limiting groove 32 on the cutter head limiting component 3 to start making the crack. The production process requires inserting the cutting cutter head 14 to the designed depth multiple times and repeatedly cutting according to the designed crack length. The production of all cracks is carried out from the middle of the formed core to both sides in sequence.

[0058] S04: After all the cracks are made, the cutting head 14 and the cutting head limiting component 3 are taken out from the core making mold 2. According to the opening and depth of the crack, a certain amount of rock-forming mixture is placed on the crack, scraped flat with a scraper, and then put into the press again for pressing. This is the second pressing. The pressure used is recorded as the second pressure. The second pressure is much smaller than the first pressure.

[0059] S05: After the second pressing and molding, the rock-forming mixture is pressed and solidified. The solidified rock core block is taken out from the rock core making mold 2, the part of the release agent adhering around the rock core block is removed, and a complete cylindrical artificial crack rock core of a predetermined diameter is drilled.

[0060] In this application, the term "multiple" refers to at least two or more, unless otherwise expressly defined. The terms "installed," "connected," "linked," and "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "linked" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0061] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A device for preparing fractured artificial rock cores, characterized in that: It includes a cutting tool (1) and a core making mold (2). The top wall of the core making mold (2) is open. The cutting end of the cutting tool (1) extends into the top of the core making mold (2). A cutting head limiting component (3) is provided between the cutting tool (1) and the core making mold (2). The cutting head limiting component (3) guides the movement direction of the cutting tool (1).

2. The fractured artificial rock core preparation device according to claim 1, characterized in that: The cutting tool (1) includes a cutting head (14), which includes a connecting part located at the upper part and a cutting part located at the bottom end of the connecting part. The cutting surface of the cutting part extends into the interior of the core making mold (2), and the side of the cutting part away from the cutting surface is provided with a concave-convex structure.

3. The fractured artificial rock core preparation device according to claim 2, characterized in that: The cutting tool (1) also includes a cutting handle (12), a connecting component (15) is provided between the bottom end of the cutting handle (12) and the cutting head (14), a cutting shell (11) is provided on the outside of the cutting handle (12), the cutting shell (11) is slidably connected to the cutting handle (12), and a locking component (13) is provided between the cutting shell (11) and the cutting handle (12).

4. The fractured artificial rock core preparation device according to claim 3, characterized in that: The connecting assembly (15) includes a connecting plate (151) fixed on the cutting handle (12), a blade holder (152) is fixedly connected to the connecting plate (151), a blade holder groove (141) is horizontally opened on the cutting blade (14), the blade holder (152) is engaged inside the blade holder groove (141), a blade retainer (153) is provided at the bottom end of the cutting handle (12) relative to the blade holder (152), the blade retainer (153) is an elastic structure, and the side wall of the blade retainer (153) abuts against the side wall of the blade holder (152).

5. The fractured artificial rock core preparation device according to claim 3, characterized in that: The locking assembly (13) includes a first locking block (131) fixed to the inner sidewall of the cutting housing (11). Multiple first locking blocks (131) are arranged along the height direction of the cutting housing (11). A limit block (121) is fixedly connected to the sidewall of the cutting handle (12). A locking groove (122) is opened in the limit block (121) relative to the position of the first locking block (131). A second locking block (123) is slidably connected inside the locking groove (122). An elastic element is provided on the side of the second locking block (123) near the bottom of the locking groove (122). A first locking surface and a second locking surface are provided on the side of the first locking block (131) near the second locking block (123). The first locking surface and the second locking surface are inclined surfaces with opposite inclination directions. A fourth locking surface with the same inclination direction as the first locking surface and a third locking surface with the same inclination direction as the second locking surface are provided on the side of the second locking block (123) relative to the first locking block (131).

6. The fractured artificial rock core preparation device according to claim 3, characterized in that: The cutting head limiting assembly (3) includes a limiting plate (31), on which a cutting head limiting groove (32) is vertically provided. The bottom end of the cutting handle (12) slides against the top wall of the limiting plate (31), and the cutting head (14) extends into the interior of the cutting head limiting groove (32).

7. The fractured artificial core preparation device according to claim 3, characterized in that: The cutting head limiting assembly (3) includes two limiting plates (31) arranged opposite to each other. A gasket (33) is fixedly connected between the two limiting plates (31). A gap is left between the two limiting plates (31) to form a cutting head limiting groove (32). The bottom end of the cutting handle (12) slides against the top wall of the limiting plate (31). The cutting head (14) extends into the interior of the cutting head limiting groove (32).

8. The fractured artificial rock core preparation device according to claim 4, characterized in that: An abutment plate (154) is fixedly connected at the position where the cutter head retainer (153) abuts against the cutter head block (152), and the setting direction of the abutment plate (154) is the same as the setting direction of the cutting cutter head (14).

9. The fractured artificial core preparation device according to claim 7 or 8, characterized in that: The width of the blade limiting groove (32) is 1-2 mm larger than the width of the cutting blade (14).

10. A method for preparing fractured artificial rock cores, characterized in that, The method, applied to the fracture-type artificial core preparation apparatus according to any one of claims 1-9, comprises: S01: Select the thickness and extension length of the cutting head (14) as required; assemble the core making mold (2), design the parameters of the crack as required, and mark the upper surface of the front, back and left and right baffles of the core making mold (2) to mark the crack location information; S02: Apply the release agent evenly to the inner wall of the core making mold (2), then place the rock-forming mixture into the core making mold (2), smooth it out, and then put it into the press. Apply a certain pressure to press it into shape. This is the first pressing, and the pressure used is called the first pressure. S03: After pressing and molding, take the core making mold (2) out of the press, open the upper wall plate (23), place the cutter head limiting component (3) according to the designed crack position, insert the cutting cutter head (14) into the core through the cutter head limiting groove (32) on the cutter head limiting component (3) to start making the crack. The production process requires inserting the cutting cutter head (14) into the designed depth multiple times and repeatedly cutting according to the designed crack length. The production of all cracks is carried out from the middle of the formed core to both sides in sequence. S04: After all the cracks are made, take out the cutting head (14) and the cutting head limiting component (3) from the core making mold (2). According to the opening and depth of the crack, place a certain amount of rock-forming mixture on the crack, scrape it flat with a scraper, and put it into the press again for pressing. This is the second pressing. The pressure used is recorded as the second pressure. The second pressure is less than the first pressure. S05: After the second pressing and molding, the rock-forming mixture is pressed and solidified. The solidified rock core block is taken out from the rock core making mold (2), the part of the release agent adhering around the rock core block is removed, and a complete cylindrical artificial crack rock core of a predetermined diameter is drilled.

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