Cutting device and cutting method for natural gas hydrate rock core

Abstract

The invention relates to a cutting device and a cutting method for a natural gas hydrate rock core, and the cutting device comprises a shell arranged on a base, and the shell is connected with a pressure maintaining device and a temperature adjusting device, so that the cutting sampling environment of a rock core sample in the shell is the same as or similar to the actual underground environment; a feeding pipe for a rock core sample to enter is arranged on the shell, and the feeding pipe is connected with pressure maintaining transfer equipment; the pushing mechanism is arranged in the shell and is configured to push the rock core samples to move rightwards, so that the moving distances of the rock core samples are the same; the rotating mechanism is arranged at the right end of the feeding pipe and is configured to drive the rock core sample to rotate; the cutting disc is located over the right side of the feeding pipe and is configured to cut a rock core sample, and a power assembly for driving the cutting disc to rotate is arranged in the shell; the first telescopic device is vertically arranged in the shell and is configured to drive the power assembly to ascend and descend. The natural gas hydrate rock core is cut under the condition close to the original underground environment.

Description

Technical Field

[0001] The invention relates to the technical field of natural gas hydrate core cutting, and in particular to a cutting device and a cutting method for natural gas hydrate cores. Background Art

[0002] Natural gas hydrate is a kind of cage-type hydrate, which is formed by gas molecules and water molecules under certain temperature and pressure conditions. Natural gas hydrate is mainly distributed in marine continental slopes and permafrost areas on land. Its formation, aggregation, saturation and other characteristics are closely related to the properties of the sediments in which it is stored, such as the composition of the sediments and the size of their pores. In nature, the stability of natural gas hydrate is closely related to its storage conditions. Slight changes in temperature and pressure may cause hydrate decomposition and release methane gas.

[0003] In actual exploration work, gas hydrate cores are drilled from underground gas hydrate reservoirs. Gas hydrate cores contain physical and chemical information of gas hydrates. Due to the difficulty of obtaining gas hydrate cores and the low core acquisition rate, in order to conduct a variety of subsequent experimental tests and studies, a single core sample is often cut into multiple pieces for storage, transportation, and subsequent analysis and testing. In order to maintain the original physical and chemical properties of the gas hydrate core, the gas hydrate core must be cut and processed immediately under a specific temperature and pressure environment after it is obtained.

[0004] A Chinese patent with publication number CN115162988A discloses a natural gas hydrate core pressure-maintaining cutting device, which can be used for core segmentation in a natural gas hydrate core pressure-maintaining transfer system. The cutting device comprises a cutting assembly, a driving assembly, a feeding assembly and a pressure-maintaining shell assembly; the cutting assembly and the feeding assembly are arranged side by side in the pressure-maintaining shell assembly, the driving assembly is arranged on the outside of the pressure-maintaining shell assembly, and its driving shaft passes through the pressure-maintaining shell assembly and is connected to the cutting assembly and the feeding assembly; during cutting, the driving assembly drives the core conduit of the cutting assembly and the core conduit of the feeding assembly to rotate, thereby respectively driving the cutting turntable to perform rotational motion and the feeding turntable to perform axial feeding or retracting motion, that is, the cutting turntable performs feeding or retracting motion in cooperation with the feed turntable to achieve cutting of the core sample. However, during the cutting process, the three blades on the cutting turntable only revolve with the blade fixing seat, and the blades do not rotate on their own. This makes it easy for the blades to collapse when encountering local points with abnormally high strength on the core sample, resulting in blade damage. Due to the complex structure of this cutting device, replacing the blades is time-consuming and labor-intensive, which will affect subsequent cutting work and increase costs. Moreover, since the core guide tube of the cutting component and the core guide tube of the feed component have basically the same structure and are coaxially arranged relative to each other, the lateral length of the pressure-maintaining shell must be at least greater than the length of the two core guide tubes. Sometimes the core samples obtained from the well are longer, which requires a longer pressure-maintaining shell. Therefore, the lateral footprint of the cutting device is larger, and the site area requirement is high. Summary of the invention

[0005] In view of the above analysis, the embodiments of the present invention aim to provide a cutting device and a cutting method for a natural gas hydrate core, so as to solve one or more of the above problems existing in the prior art.

[0006] In one aspect, a cutting device for a natural gas hydrate core is provided, comprising:

[0007] Base;

[0008] The shell is arranged on the base, and is connected with a pressure-maintaining device and a temperature-adjusting device. The pressure in the shell is controlled by the pressure-maintaining device, and the temperature in the shell is controlled by the temperature-adjusting device, so that the cutting and sampling environment of the core sample in the shell is the same as or similar to the actual underground environment; a feed pipe for the core sample to enter is arranged on the shell, and the feed pipe is connected with the pressure-maintaining transfer device;

[0009] A pushing mechanism is disposed in the housing and is configured to push the core sample to move rightward so that the core sample moves the same distance each time;

[0010] A rotating mechanism, disposed at the right end of the feed tube, configured to drive the core sample to rotate;

[0011] The cutting disc is located just above the right side of the feed pipe and is configured to cut the core sample. A power assembly for driving the cutting disc to rotate is disposed in the housing;

[0012] The telescopic device 1 is vertically arranged in the shell and is configured to drive the power component to rise and fall.

[0013] Furthermore, the pushing mechanism includes a pushing component and a limiting component. The pushing component is configured to push the core sample to move rightward in the feed pipe, and the limiting component is configured to limit the right end of the core sample.

[0014] Furthermore, the pushing assembly includes a rodless cylinder, which is slidably arranged on the inner wall of the outer shell in a vertical direction. A vertical plate is provided at the bottom of the sliding part of the rodless cylinder, and a triangular guide plate and a turntable 2 are provided on the left and right side surfaces of the vertical plate. A strip groove for the vertical plate to pass through is provided on the top of the feed pipe, and the control system is connected to the rodless cylinder control.

[0015] Furthermore, the left side of the triangular guide plate is an inclined surface.

[0016] Furthermore, the limiting assembly includes a support frame, a baffle and a turntable; wherein the support frame is arranged on the inner wall of the shell, the baffle is arranged on the support frame, the turntable is rotatably arranged on the baffle, and the turntable is against the right end surface of the core sample.

[0017] Furthermore, the cutting device for natural gas hydrate cores also includes a coaxial component, which is configured to adjust the position of the core sample so that the core sample in the cutting state is always coaxial with the feed pipe.

[0018] Furthermore, the rotating mechanism includes a swivel, gear one, gear two, rotating shaft one and motor one; wherein, the swivel is rotatably arranged at the right end of the feed pipe, a plurality of protrusions are arranged on the inner wall of the swivel, gear one is arranged on the outer peripheral wall of the swivel, motor one is arranged on the outer wall of the outer shell, rotating shaft one is connected to the output shaft of motor one and extends into the outer shell, gear two is arranged on rotating shaft one and meshes with gear one.

[0019] Furthermore, the power assembly includes a support frame 2 and a motor 2; wherein, the support frame 2 is slidably arranged on the inner wall of the outer shell in the vertical direction, and the bottom of the support frame 2 is connected to the top telescopic end of the telescopic device 1; the motor 2 is arranged on the support frame 2 and is connected to the control system; the output shaft of the motor 2 is connected to the rotating shaft 2, the cutting disc is arranged on the rotating shaft 2, and a vertical avoidance groove for the rotating shaft 2 to pass through is arranged on the vertically arranged partition in the outer shell.

[0020] Furthermore, a discharge port is arranged at the bottom of the shell, and the discharge port is located directly below the cut core sample. A receiving box is arranged on the base, and the receiving box is connected to the discharge port.

[0021] On the other hand, a cutting method of a cutting device for a natural gas hydrate core is also provided, wherein the natural gas hydrate core sample is cut using the cutting device for a natural gas hydrate core;

[0022] The cutting method comprises the following steps:

[0023] S1, the pressure-maintaining transfer device pushes the core sample into the feed pipe;

[0024] S2, start the power assembly to drive the cutting disc to rotate, and start the rotating mechanism to drive the core sample to rotate;

[0025] S3, driving the power assembly downward through the telescopic device, so that the high-speed rotating cutting disc performs circumferential cutting on the rotating core sample until the core sample is cut off;

[0026] S4. The cut core samples fall into the receiving box at the bottom of the shell, completing the collection of the core samples.

[0027] Compared with the prior art, the cutting device and cutting method for natural gas hydrate core provided by the present invention have at least one of the following beneficial technical effects:

[0028] 1. The entire cutting process is carried out under a certain temperature and pressure environment in the shell, which helps to maintain the original state of the natural gas hydrate core, thereby causing minimal impact on subsequent testing and its results; the circumferential cutting of the core sample is completed by the high-speed rotating cutting disc and the self-rotating core sample, with good cutting effect, and the high-speed rotating cutting disc is not easy to break, has a long service life, and is not easy to affect the normal progress of the cutting work;

[0029] 2. By setting up a coaxial component, it is ensured that the core sample can always remain coaxial with the feed pipe during the cutting process, thereby improving the cutting stability and ensuring the cutting quality of the core sample;

[0030] 3. The cutting disc is arranged above the feed pipe, so that the overall structure of the cutting device is more compact, and the horizontal length of the cutting device can be designed to be smaller, thereby making the horizontal footprint of the cutting device smaller and enabling it to be flexibly installed in a small site.

[0031] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this specification. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0033] Figure 1 A schematic diagram of the structure of a pressure-maintaining cutting device for a natural gas hydrate core provided by the present invention;

[0034] Figure 2 A schematic cross-sectional view of a portion of the structure of a pressure-maintaining cutting device for a natural gas hydrate core provided by the present invention;

[0035] Figure 3 A schematic diagram of a portion of the structure of a pressure-maintaining cutting device for a natural gas hydrate core provided by the present invention;

[0036] Figure 4 for Figure 3 The schematic diagram of the structure after removing the arc gear ring and rack;

[0037] Figure 5 for Figure 4 Partial structure diagram Figure 1 ;

[0038] Figure 6 for Figure 4 Partial structure diagram Figure 2 .

[0039] Reference numerals:

[0040] 1. Shell; 2. Feed pipe; 3. Pressure-maintaining pipe; 4. Mounting seat; 5. Strip groove; 6. Core sample; 7. Support frame 1; 8. Baffle; 9. Turntable 1; 10. Rotating ring; 11. Protrusion; 12. Gear 1; 13. Gear 2; 14. Rotating shaft 1; 15. Motor 1; 16. Vertical plate; 17. Triangular guide plate; 18. Turntable 2; 19. Rodless cylinder; 20. Spring; 21. Partition plate; 22. Avoidance groove; 23. Rotating shaft 2; 24. Sealing plate; 25. Support frame 2; 26. Motor 2; 27. Telescopic device 1; 28. Cutting disc; 29. ​​Cylinder; 30. Discharge port; 31. Receiving box; 32. Sealing plate; 33. Connecting rod; 34. Telescopic device 2; 35. Base; 36. Connecting rod; 37. Adjusting disc; 38. Adjusting guide rail; 39. Arc groove; 40. Adjusting rod; 41. Sliding column; 42. Cylinder; 43. Coaxial chuck; 44. Arc gear ring; 45. Rack frame; 46. Rack. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0042] To facilitate the understanding of the embodiments of the present application, the following will be further explained with reference to the accompanying drawings, and the embodiments do not constitute a limitation on the embodiments of the present application. In the accompanying drawings, the sizes and relative sizes of the components may be exaggerated for clarity and / or descriptive purposes. When the exemplary embodiments can be implemented differently, the specific process sequence may be performed in a different order than described. For example, two continuously described processes may be performed substantially simultaneously or in an order opposite to the described order. In addition, the same reference numerals represent the same components.

[0043] The terms used here are for the purpose of describing specific embodiments, and are not intended to be restrictive. As used here, unless the context clearly indicates otherwise, the singular forms "one (kind, person)" and "said (the)" are also intended to include plural forms. In addition, when the terms "comprise" and / or "include" and their variations are used in this specification, it is explained that there are stated features, integral bodies, steps, operations, parts, assemblies and / or their groups, but it is not excluded that there are or add one or more other features, integral bodies, steps, operations, parts, assemblies and / or their groups. It should also be noted that, as used here, the terms "substantially", "approximately" and other similar terms are used as approximate terms and not as degree terms, so that they are used to explain the inherent deviations of the measured values, calculated values ​​and / or the values ​​provided that will be recognized by those of ordinary skill in the art.

[0044] Example 1

[0045] like Figure 1-Figure 3As shown, a cutting device for natural gas hydrate cores proposed by the present invention comprises a base 35, on which a shell 1 is arranged through a mounting seat 4, the shell 1 is a cylinder with sealed ends on both sides, a feed pipe 2 is arranged on the shell 1, a core sample 6 to be cut can be inserted into the feed pipe 2, one end of the feed pipe 2 located outside the shell 1 is connected to a pressure-maintaining transfer device, and the pressure-maintaining transfer device can transfer and push the core sample 6 taken out from underground into the feed pipe 2 under a pressure-maintaining environment; the shell 1 is connected to a pressure-maintaining device and a temperature regulating device, a pressure-maintaining tube 3 arranged on the shell 1 is connected to the pressure-maintaining device, the pressure-maintaining device is used to regulate the pressure in the shell 1, and the temperature regulating device is used to control the temperature of the shell 1; the pressure in the shell 1 is controlled by the pressure-maintaining device and the temperature of the shell 1 is controlled by the temperature regulating device, so that the cutting sampling environment of the core sample 6 in the shell 1 is the same as or similar to the actual underground pressure and temperature environment.

[0046] The cutting device for gas hydrate core also includes:

[0047] The pushing mechanism is disposed in the housing 1 and is configured to push the core sample 6 to move rightward, and the core sample 6 moves the same distance each time;

[0048] The rotating mechanism is arranged at the right end of the feed pipe 2 and is configured to drive the core sample 6 to rotate;

[0049] The cutting disc 28 is located just above the right side of the feed pipe 2 and is configured to cut the core sample 6. A power assembly for driving the cutting disc 28 to rotate is provided in the housing 1;

[0050] A telescopic device 27 is vertically disposed in the housing 1 and is configured to drive the power assembly to rise and fall;

[0051] And a control system, the control system is controlled and connected with the pushing mechanism, the rotating mechanism, the power component and the telescopic device 27.

[0052] In this embodiment, Figure 5-Figure 6 As shown, the pushing mechanism includes a pushing component for pushing the core sample 6 to move and a limiting component for blocking the right end of the core sample 6. The pushing component pushes the core sample 6 to against the limiting component to complete the precise positioning of the cutting length. After being cut, the core sample 6 falls directly into the outer shell 1.

[0053] Furthermore, the pushing component includes a rodless cylinder 19 which is slidably arranged on the inner wall of the shell 1 in the vertical direction, a vertical plate 16 which is vertically arranged at the bottom of the sliding part of the rodless cylinder 19, the sliding part of the rodless cylinder 19 can drive the vertical plate 16 to move horizontally, thereby realizing the axial pushing force on the core sample 6 and the clamping force on the core sample during cutting, as well as a triangular guide plate 17 and a turntable 18 which are arranged on the left and right side surfaces of the vertical plate 16, a strip groove 5 for the vertical plate 16 to pass through is arranged on the top of the feed pipe 2, the control system is connected to the control of the rodless cylinder 19, the left side of the triangular guide plate 17 is an inclined surface, and the inclined surface is inclined from the upper left to the lower right, the turntable 18 is against the left end of the core sample 6, and the core sample 6 is pushed into the feed pipe 2 to squeeze the inclined surface, so that the vertical plate 16 moves to the top of the core sample 6, and after the core sample 6 moves to the right side of the vertical plate 16, Under the action of gravity, the rodless cylinder 19, the vertical plate 16, the triangular guide plate 17 and the turntable 18 drop to the lowest point. In order to ensure that the rodless cylinder 19 is smoothly in place, multiple groups of springs 20 are vertically arranged on the rodless cylinder 19, and the top of the spring 20 is connected to the inner wall of the outer shell 1. In order to ensure the stability of movement, multiple connecting rods 36 are horizontally arranged on the rodless cylinder 19. Multiple groups of vertically parallel guide plates are arranged on the inner wall of the outer shell 1, and slide rail grooves are formed between two adjacent guide plates. Multiple slide rail grooves are arranged vertically in parallel, and the slide rail grooves cooperate with the ends of the connecting rods 36. The ends of the connecting rods 36 can be movably clamped in the slide rail grooves, thereby ensuring that the rodless cylinder 19 can only move up and down in the vertical direction. During cutting, the rodless cylinder 19 pushes the core sample 6 to move a set distance each time, and the set distance is the single cutting length of the core sample 6.

[0054] Furthermore, the limiting assembly includes a support frame 7 arranged on the inner wall of the shell 1, a baffle 8 arranged on the support frame 7, and a turntable 9 rotatably arranged on the baffle 8, and the turntable 9 is against the right end surface of the core sample 6.

[0055] In this embodiment, the cutting device for natural gas hydrate cores further comprises a coaxial assembly, which is configured to adjust the position of the core sample 6 so that the core sample 6 in the cutting state is always coaxial with the feed pipe 2. In one optional embodiment, Figure 3-Figure 6As shown, the coaxial assembly includes an adjustment disk 37, an adjustment guide rail 38, an adjustment rod 40, a sliding column 41, a cylinder 42, a coaxial chuck 43, an arc gear ring 44, a rack frame 45 and a rack 46; the adjustment disk 37 is rotatably arranged on the left inner wall of the housing 1, the adjustment disk 37 is sleeved on the outside of the feed pipe 2, and a plurality of arc grooves 39 are arranged on the adjustment disk 37; the adjustment guide rail 38 is arranged on the left inner wall of the housing 1, and the adjustment guide rail 38 is arranged along the radial direction of the feed pipe 2, and the number of the adjustment guide rail 38 is the same as the number of the arc grooves 39; the cylinder 42 is radially arranged around the right side of the feed pipe 2 The cylinder 42 is formed with an opening on the inner wall of the feed pipe 2; the sliding column 41 is slidably arranged on the inner wall of the cylinder 42, and the end of the sliding column 41 is rotatably arranged with a coaxial chuck 43, and multiple coaxial chucks 43 are pressed against the outer wall of the core sample 6, so that the core sample 6 and the feed pipe 2 are coaxial, and the coaxial chuck 43 is an elastic member, which can adapt to the small diameter difference of different core samples 6, and a through hole is arranged at the other end of the sliding column 41; the adjusting rod 40 passes through the through hole and the arc groove 39 and is slidably connected to the adjusting guide rail 38; the rack frame 45 is arranged on the vertical plate 16, and the rack 46 is vertically arranged on the rack frame 45 The arc gear ring 44 is arranged on the adjusting disk 37, the arc gear ring 44 is coaxial with the adjusting disk 37, and the rack 46 is meshed with the arc gear ring 44; when the core sample 6 is pushed to the feeding pipe 2, it first contacts with the triangular guide plate 17, and the inclined surface of the triangular guide plate 17 causes the vertical plate 16 to rise and move above the core sample 6. When the vertical plate 16 rises, it drives the rack 46 to move, and the rack 46 drives the adjusting disk 37 to rotate through the arc gear ring 44. Under the restriction of the arc groove 39 and the adjusting guide rail 38, the adjusting rod 40 moves radially outward along the feeding pipe 2, and the adjusting rod 40 moves radially outwardly. The node rod 40 pulls the sliding column 41 to move outward, so that the core sample 6 can pass through smoothly; when the core sample 6 is pushed to the right side of the vertical plate 16, under the action of the spring 20, the vertical plate 16 drops again, and the sliding column 41 moves in the opposite direction, clamping the core sample 6 through multiple coaxial chucks 43 and making it coaxial with the feed pipe 2, thereby improving the stability of the circumferential cutting process of the core sample 6 and improving the cutting quality; during the cutting process, the rack 46 and the arc-shaped gear ring 44 only slide relative to each other and do not rotate, thereby ensuring the effective positioning of the core sample 6 by the coaxial chuck 43.

[0056] In this embodiment, Figure 1 and Figure 5As shown, the rotating mechanism includes a rotating ring 10 rotatably arranged at the right end of the feed pipe 2, a plurality of protrusions 11 arranged on the inner wall of the rotating ring 10, a gear 12 arranged on the outer peripheral wall of the rotating ring 10, a motor 15 arranged on the outer wall of the outer shell 1, a rotating shaft 14 connected to the output shaft of the motor 15 and extending into the outer shell 1, and a gear 2 13 arranged on the rotating shaft 14; wherein, the gear 2 13 is meshed with the gear 12; the control system is controlled and connected to the motor 15; the friction force is provided by squeezing the core sample 6 by the protrusion 11, so that the core sample 6 can be smoothly driven to rotate when the rotating ring 10 rotates, and the protrusion 11 is hemispherical.

[0057] In this embodiment, Figure 2-Figure 3 As shown, the power assembly includes a support frame 25 slidably arranged on the inner wall of the shell 1 in the vertical direction, a motor 26 arranged on the support frame 25, and a rotating shaft 23 connected to the output shaft of the motor 26, a cutting disc 28 is arranged on the rotating shaft 23, a partition 21 is vertically arranged in the shell 1, and a vertical avoidance groove 22 for the rotating shaft 23 to pass through is arranged on the partition 21; the top telescopic end of the telescopic device 27 is connected to the bottom of the support frame 25; the control system is control-connected to the motor 26.

[0058] In order to ensure the non-high-pressure state on the right side of the partition 21, a sealing plate 24 is slidably arranged on the left side surface of the partition 21 in the vertical direction. The second rotating shaft 23 passes through the sealing plate 24 and is rotatably connected with the sealing plate 24. An elastic sealing layer is arranged on the sealing plate 24 to close the avoidance groove 22, so that the space where the motor 2 26 and the telescopic device 1 27 are located is separated from the cutting space. The motor 2 26 and the telescopic device 1 27 do not need to work under high-pressure state, thereby improving the service life of the motor 2 26 and the telescopic device 1 27.

[0059] In an optional embodiment, a cylinder 29 is horizontally arranged on the left side of the sealing plate 24, and the second rotating shaft 23 passes through the cylinder 29. A bearing is arranged between the second rotating shaft 23 and the cylinder 29, and the supporting stability of the second rotating shaft 23 is improved by the cylinder 29 and the bearing.

[0060] In this embodiment, Figure 1-Figure 2As shown, a discharge port 30 is arranged at the bottom of the housing 1, and the discharge port 30 is located directly below the cut core sample 6. A receiving box 31 is arranged on the base 35, and the receiving box 31 is connected to the discharge port 30, that is, the cut core sample 6 passes through the discharge port 30 and falls into the receiving box 31. A sealing door is arranged on the receiving box 31, and the cut core sample 6 can be opened to take out the cut core sample 6. In order not to affect the pressure-maintaining state in the housing 1 when taking out the material, a sealing plate 32 is slidably arranged in the housing 1, and a connecting rod 33 is horizontally connected to the sealing plate 32. The connecting rod 33 passes through the left side of the shell 1, and a telescopic device 2 34 is provided on the base 35 to drive the connecting rod 33 to move to the right. The control system is controlled and connected to the telescopic device 2 34. During the cutting operation, the sealing plate 32 is located on the left side of the discharge port 30. When the cutting is completed and the material needs to be taken out, the telescopic device 2 34 pushes the sealing plate 32 to the right through the connecting rod 33, and the discharge port 30 is closed by the sealing plate 32. At this time, the sample in the receiving box 31 can be taken out, and the pressure maintenance effect in the shell 1 can be minimized as much as possible.

[0061] In this embodiment, the temperature regulating device includes a refrigeration component and a heating component. The refrigeration principle of the refrigeration component can adopt refrigerant refrigeration, such as liquid nitrogen or a mixed solution of liquid nitrogen and alcohol, and the heating component adopts a resistance wire or an electric heating plate. For example, a refrigeration cavity is provided around the outer wall of the shell 1, and the refrigerant is filled in the refrigeration cavity. The temperature inside the shell 1 is reduced by heat transfer. Furthermore, the refrigerant in the refrigeration cavity can circulate, that is, the refrigeration cavity is connected to the refrigerant source through a circulation pipeline, and a good cooling effect is maintained by the circulation of the refrigerant. The resistance wire or the electric heating plate is arranged on the shell 1, which can heat the refrigeration cavity, or directly heat the space inside the shell 1, so as to achieve temperature regulation inside the shell 1.

[0062] This embodiment also provides a method for cutting a natural gas hydrate core. The method uses the cutting device for a natural gas hydrate core in this embodiment to cut a natural gas hydrate core sample 6, comprising the following steps:

[0063] S1. The pressure-maintaining transfer device pushes the core sample 6 into the feed pipe 2. After the core sample 6 is in place, it is clamped by the coaxial assembly to achieve coaxial positioning of the core sample 6 and the feed pipe 2. Specifically, the core sample 6 needs to be pushed to the right side of the turntable 2 18. During the pushing process, the vertical plate 16 first moves upward and then returns to the lowest point, and the coaxial assembly clamps the core sample 6;

[0064] S2, start the power assembly to drive the cutting disc 28 to rotate at high speed, start the rotating mechanism to drive the core sample 6 to rotate at a slow speed, specifically start the motor 2 26 and the motor 1 15;

[0065] S3, the power assembly is driven downward by the telescopic device 27, so that the circumferential cutting of the core sample 6 can be completed by the high-speed rotating cutting disc 28 and the self-rotating core sample 6, until the core sample 6 is cut off;

[0066] S4. The cut core sample 6 falls into the receiving box 31 at the bottom of the outer shell 1, completing the collection of the core sample 6. Specifically, the cut core sample 6 passes through the discharge port 30 and falls into the receiving box 31. When the cutting is completed and the material needs to be taken, the telescopic device 2 34 pushes the sealing plate 32 to the right through the connecting rod 33, and the discharge port 30 is closed by the sealing plate 32. At this time, the core sample in the receiving box 31 can be taken, and the pressure maintenance effect in the outer shell 1 can be minimized as much as possible.

[0067] When using the cutting device to cut the natural gas hydrate core, the core sample 6 is first pushed into the feed pipe 2 through the pressure-maintaining transfer equipment, so that the core sample 6 moves to the right side of the turntable 18, and then the rodless cylinder 19 pushes the core sample 6 to move against the turntable 9, and the circumferential cutting of the core sample 6 is completed by the high-speed rotating cutting disc 28 and the self-rotating core sample 6. After the cutting is completed, the telescopic device 1 27 pushes the power component to the top to prepare for the next cutting. The cut core sample 6 passes through the discharge port 30 and falls into the receiving box 31. When the cutting is completed and the material needs to be taken, the telescopic device 2 34 pushes the sealing plate 32 to the right through the connecting rod 33, and the discharge port 30 is closed by the sealing plate 32. At this time, the sample in the receiving box 31 can be taken, and the pressure maintenance effect on the outer shell 1 can be minimized.

[0068] Compared with the prior art, the cutting device and cutting method for natural gas hydrate core provided in this embodiment have the following beneficial effects:

[0069] 1. The circumferential cutting of the core sample is completed by the high-speed rotating cutting disc and the rotating core sample, and the cutting effect is good. During the cutting process, the cutting disc and the core sample to be cut rotate in opposite directions, and the contact between the cutting disc and the outer peripheral surface of the core sample is point contact. The cutting contact point is at the same distance from the center of the cutting disc. Since the cutting disc rotates at a constant speed, the core sample is cut according to a circular arc trajectory during the cutting process, and gradually approaches the axis of the core sample on the outer peripheral surface of the core. Compared with the cutting method in which the cutting disc rotates and the core sample is fixed, the cutting effect is good, and the high-speed rotating cutting disc is not easy to break, has a long service life, and is not easy to affect the normal progress of the cutting work.

[0070] 2. The pressure in the shell is controlled by a pressure-maintaining device, and the temperature in the shell is controlled by a temperature regulating device, so that the cutting and sampling environment of the core sample in the shell is the same as or similar to the actual underground pressure and temperature environment, which helps to maintain the original state of the natural gas hydrate core, avoid the impact of the cutting environment change on the state of the natural gas hydrate core, and will not affect the subsequent analysis and detection results.

[0071] 3. By setting up a coaxial component, it is ensured that the core sample can always remain coaxial with the feed tube during the cutting process, thereby improving the cutting stability and ensuring the cutting quality of the core sample.

[0072] 4. The cutting disc is arranged above the feed pipe, so that the overall structure of the cutting device is more compact, and the horizontal length of the cutting device can be designed to be smaller, thereby making the horizontal footprint of the cutting device smaller and enabling it to be flexibly installed in a small site.

[0073] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto, and various changes can be made within the knowledge scope of technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A cutting device for natural gas hydrate core, characterized in that: include: Base (35); The housing (1) is arranged on the base (35), and the housing 1 is connected to a pressure-maintaining device and a temperature-adjusting device. The pressure in the housing (1) is controlled by the pressure-maintaining device, and the temperature in the housing (1) is controlled by the temperature-adjusting device, so that the cutting sampling environment of the core sample (6) in the housing (1) is the same as or similar to the actual underground environment. A feed pipe (2) for the core sample (6) to enter is arranged on the housing (1), and the feed pipe (2) is connected to the pressure-maintaining transfer device. A pushing mechanism is arranged in the housing (1) and is configured to push the core sample (6) to move rightward so that the core sample (6) moves the same distance each time; A rotating mechanism, disposed at the right end of the feed pipe (2), configured to drive the core sample (6) to rotate; A cutting disc (28) is located directly above the right side of the feed pipe (2) and is configured to cut the core sample (6). A power assembly for driving the cutting disc (28) to rotate is disposed in the housing (1); The telescopic device (27) is vertically arranged in the housing (1) and is configured to drive the power component to move up and down.

2. The cutting device for natural gas hydrate core according to claim 1, characterized in that: The pushing mechanism comprises a pushing component and a limiting component. The pushing component is configured to push the core sample (6) to move rightward in the feed pipe (2), and the limiting component is configured to limit the right end of the core sample (6).

3. The cutting device for natural gas hydrate core according to claim 2, characterized in that: The pushing assembly comprises a rodless cylinder (19), which is slidably arranged on the inner wall of the outer shell (1) in the vertical direction, a vertical plate (16) is arranged at the bottom of the sliding part of the rodless cylinder (19), a triangular guide plate (17) and a turntable (18) are arranged on the left and right side surfaces of the vertical plate (16), a strip groove (5) for the vertical plate (16) to pass through is arranged at the top of the feed pipe (2), and a control system is connected to the control of the rodless cylinder (19).

4. The cutting device for natural gas hydrate core according to claim 3, characterized in that: The left side of the triangular guide plate (17) is an inclined plane.

5. The cutting device for natural gas hydrate core according to claim 2, characterized in that: The limiting assembly comprises a support frame (7), a baffle (8) and a turntable (9); wherein the support frame (7) is arranged on the inner wall of the housing (1), the baffle (8) is arranged on the support frame (7), the turntable (9) is rotatably arranged on the baffle (8), and the turntable (9) abuts against the right end surface of the core sample (6).

6. The cutting device for natural gas hydrate core according to claim 2, characterized in that: It also includes a coaxial component, which is configured to adjust the position of the core sample (6) so that the core sample (6) in the cutting state is always coaxial with the feed pipe (2).

7. The cutting device for natural gas hydrate core according to claim 1, characterized in that: The rotating mechanism comprises a rotating ring (10), a gear 1 (12), a gear 2 (13), a rotating shaft 1 (14) and a motor 1 (15); The rotating ring (10) is rotatably arranged at the right end of the feed pipe (2), a plurality of protrusions (11) are arranged on the inner wall of the rotating ring (10), a gear 1 (12) is arranged on the outer peripheral wall of the rotating ring (10), a motor 1 (15) is arranged on the outer wall of the housing (1), a rotating shaft 1 (14) is connected to the output shaft of the motor 1 (15) and extends into the housing (1), and a gear 2 (13) is arranged on the rotating shaft 1 (14) and meshes with the gear 1 (12).

8. The cutting device for natural gas hydrate core according to claim 1, characterized in that: The power assembly includes a second support frame (25) and a second motor (26); The second support frame (25) is slidably arranged on the inner wall of the outer shell (1) in the vertical direction, and the bottom of the second support frame (25) is connected to the top telescopic end of the telescopic device (27); the second motor (26) is arranged on the second support frame (25) and is connected to the control system; the output shaft of the second motor (26) is connected to the second rotating shaft (23), the cutting disc (28) is arranged on the second rotating shaft (23), and a vertical avoidance groove (22) for the second rotating shaft (23) to pass through is arranged on the partition (21) vertically arranged in the outer shell (1).

9. The cutting device for natural gas hydrate core according to claim 1, characterized in that: A discharge port (30) is arranged at the bottom of the housing (1), and the discharge port (30) is located directly below the cut core sample (6). A material receiving box (31) is arranged on the base (35), and the material receiving box (31) is connected to the discharge port (30).

10. A cutting method for a natural gas hydrate core cutting device, characterized in that: Cutting a natural gas hydrate core sample (6) using the natural gas hydrate core cutting device according to any one of claims 1 to 9; The cutting method comprises the following steps: S1, the pressure-maintaining transfer device pushes the core sample (6) into the feed pipe (2); S2, starting the power assembly to drive the cutting disc (28) to rotate, and starting the rotating mechanism to drive the core sample (6) to rotate; S3, driving the power assembly to move downward through the telescopic device 1 (27), so that the high-speed rotating cutting disc (28) performs circumferential cutting on the rotating core sample (6) until the core sample (6) is cut off; S4. The cut core sample (6) falls into the receiving box (31) at the bottom of the housing (1), completing the collection of the core sample (6).

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