A core cylinder with anti-falling material, a core sampler with anti-falling material, and their working method

Abstract

This invention relates to an anti-falling core cylinder, an anti-falling core sampler, and their working method. The core cylinder includes a cylinder body, a core catcher, and a sealing cap. The inner wall of the lower end of the cylinder body has a conical surface for engaging with the sealing cap, with the lower diameter of the conical surface being smaller than the upper diameter. The core catcher and the sealing cap are both installed inside the lower end of the cylinder body, with the core catcher positioned above the sealing cap. One end of the sealing cap is rotatably connected to the cylinder body via a shaft, and the edge of the sealing cap is an inclined surface adapted to the conical surface of the core cylinder. A spring is provided between the sealing cap and the cylinder body. Under the action of the spring, the sealing cap flips downwards around the shaft until it closes with the conical surface of the core cylinder on the cylinder body. The core cylinder of this application has an automatically closing sealing cap at its lower end. When the core enters the core cylinder, the sealing cap automatically closes, preventing rock debris from falling onto the valve seat sealing surface of the pressure-holding sealing mechanism. This ensures smooth closure of the valve disc and valve seat, improving the pressure-holding performance of the pressure-holding core sampler and increasing the success rate of pressure-holding core sampling.

Description

Technical Field

[0001] This invention relates to the field of core sampling technology, and in particular to an anti-falling core cylinder, an anti-falling core sampler, and their working method. Background Technology

[0002] Currently, all types of pressure-holding coring machines available both domestically and internationally use mechanical valves (ball valves or flap valves) as the pressure-holding and sealing mechanism. Due to the erosive effect of a large number of solid particles in the drilling fluid on the valve, and the problem of rock cuttings and rocks falling off during the core barrel extraction process, the valve body and valve seat cannot fit tightly or even close properly, leading to valve seal failure.

[0003] Statistics show that the average success rate of pressure-holding coring operations using existing pressure-holding coring tools for hydrate drilling is less than 60%, far from meeting scientists' needs for pressure-holding hydrate cores and disproportionate to the high cost of natural gas hydrate drilling and coring. Therefore, improving the success rate of pressure-holding coring tools for natural gas hydrates has attracted the attention of scholars worldwide. The key lies in solving the problem of valve disc malfunction caused by rock cuttings falling during the coring process. Summary of the Invention

[0004] This application provides an anti-falling core cylinder, an anti-falling core sampler, and a method for operating the above-mentioned technical problems.

[0005] This application is achieved through the following technical solution:

[0006] This application provides a core cylinder with anti-falling debris, comprising a cylinder body, a core catcher, and a sealing cap. The inner wall of the lower end of the cylinder body has a conical surface for cooperating with the sealing cap, and the diameter of the lower end of the conical surface is smaller than the diameter of the upper end. The core catcher and the sealing cap are both installed inside the lower end of the cylinder body, with the core catcher located above the sealing cap. One end of the sealing cap is rotatably connected to the cylinder body via a shaft, and the edge of the sealing cap is an inclined surface adapted to the conical surface of the core cylinder. A spring is provided between the sealing cap and the cylinder body. Under the action of the spring, the sealing cap flips downward around the shaft until it closes with the conical surface of the core cylinder of the cylinder body.

[0007] Specifically, a sealing ring is installed in a groove on the beveled surface of the sealing cap.

[0008] Specifically, the spring is a torsion spring.

[0009] Optionally, the inner wall of the cylinder includes a first cylindrical surface, a second cylindrical surface, and a core cylinder conical surface. The upper end of the first cylindrical surface is connected to the lower end of the core cylinder conical surface, and the lower end of the second cylindrical surface is connected to the upper end of the core cylinder conical surface. The diameter of the first cylindrical surface is equal to the diameter of the lower end of the core cylinder conical surface, and the diameter of the second cylindrical surface is equal to the diameter of the upper end of the core cylinder conical surface. The cylinder is manufactured integrally.

[0010] Specifically, both the inner and outer surfaces of the sealing cap are cylindrical.

[0011] Optionally, the diameter of the inner surface of the sealing cap is equal to the diameter of the first cylindrical surface of the cylinder. When the sealing cap is fully opened, the inner surface of the sealing cap is flush with the top and bottom of the first cylindrical surface of the cylinder.

[0012] Optionally, the spatial curved surface obtained by cutting a semi-circular tube segment with a conical or spherical surface can be used as the sealing cap.

[0013] The outer wall of the cylinder has a core tube protrusion.

[0014] The anti-falling core sampler provided in this application includes an outer cylinder, a central rod, a pressure-holding and sealing mechanism, a drill bit, and the aforementioned anti-falling core cylinder. The pressure-holding and sealing mechanism is installed inside the outer cylinder and includes a valve seat and a valve disc. The drill bit is installed at the lower end of the outer cylinder, and the lower end of the central rod extends into the outer cylinder. The anti-falling core cylinder is installed inside the outer cylinder, and the central rod has a central rod protrusion that matches the protrusion of the core cylinder.

[0015] The working method of the anti-chip-dropping core extractor includes the following steps:

[0016] In the initial state, the anti-slag core cylinder is located inside the valve seat, the valve disc is open, and the sealing cover is closed with the conical surface of the core cylinder;

[0017] During drilling and core extraction, the core pushes open the sealing cap, while the spring stores elastic potential energy.

[0018] The core enters the cylinder and is captured by the core catcher. The core catcher is lifted upwards, and the core is cut off by the core catcher. The sealing cap automatically closes with the conical surface of the core cylinder under the action of the spring.

[0019] Lift the center rod upwards, and the center rod moves the anti-falling rock core cylinder upwards in sync. When the lower end of the anti-falling rock core cylinder is higher than the top of the valve disc, the valve disc automatically flips and closes with the valve seat.

[0020] Compared with the prior art, this application has the following beneficial effects:

[0021] The core cylinder of this application is equipped with an automatically closing sealing cover at the lower end. When the core enters the core cylinder, the sealing valve cover can automatically close, thereby preventing the rock cuttings inside the core cylinder from falling onto the valve seat sealing surface of the pressure-holding sealing mechanism. This ensures that the valve disc and valve seat close smoothly, which helps to improve the pressure-holding performance of the pressure-holding core extractor and increase the success rate of pressure-holding core extraction. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of the embodiments of this application and form part of this application, do not constitute a limitation on the embodiments of the present invention.

[0023] Figure 1This is a first longitudinal sectional view of the anti-slag-falling rock core cylinder in the embodiment;

[0024] Figure 2 This is a cross-sectional view of the second longitudinal direction of the anti-slag-falling rock core cylinder in the embodiment;

[0025] Figure 3 This is a schematic diagram of the cylinder structure in the embodiment;

[0026] Figure 4 This is a three-dimensional view of the sealing cap in the embodiment;

[0027] Figure 5 This is a schematic diagram of the lower part of the anti-chip-dropping core extractor in the initial state of the embodiment;

[0028] Figure 6 This is a schematic diagram of the lower part of the anti-falling core extractor at the end of the core extraction process in the embodiment;

[0029] In the diagram: the first vertical axis is perpendicular to the second vertical axis. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other. It should also be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments; similar or identical parts between embodiments can be referred to interchangeably.

[0033] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0034] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0035] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] like Figure 1 , Figure 2 As shown, the anti-falling rock core cylinder disclosed in this embodiment includes a cylinder body 1, a core catcher 2, and a sealing cover 3. The core catcher 2 and the sealing cover 3 are installed inside the lower end of the cylinder body 1. The core catcher 2 is located below the sealing cover 3. One end of the sealing cover 3 is rotatably connected to the cylinder body 1 through a shaft 4.

[0037] like Figure 3 As shown, the inner wall of the lower end of the cylinder 1 has a core cylinder conical surface 11 for mating with the sealing cap 3. The diameter of the lower end of the core cylinder conical surface 11 is smaller than the diameter of the upper end. The edge of the sealing cap 3 is an inclined surface 31 adapted to the core cylinder conical surface 11. Figure 4 As shown.

[0038] A spring 5 is installed between the sealing cover 3 and the cylinder 1. Under the action of the spring 5, the sealing cover 3 flips downward around the shaft 4 until it closes with the conical surface 11 of the core cylinder of the cylinder 1.

[0039] The core catcher 2 includes core clamps for cutting off the core, which is a conventional technique in the field and will not be described in detail here.

[0040] In one possible design, a sealing ring 32 is installed in the groove on the inclined surface 31 of the sealing cover 3. When the sealing cover 3 is closed with the conical surface 11 of the core cylinder, the sealing ring 32 can provide a soft seal between the sealing cover 3 and the cylinder 1.

[0041] In one possible design, spring 5 is a torsion spring, which is connected to the back of the sealing cover 3.

[0042] To facilitate cooperation with the center rod, a core tube protrusion 14 is provided on the outer wall of the cylinder 1.

[0043] In one possible design, such as Figure 3 As shown, the inner wall of the cylinder 1 includes a first cylindrical surface 12, a second cylindrical surface 13, and a core cylinder conical surface 11. The upper end of the first cylindrical surface 12 is connected to the lower end of the core cylinder conical surface 11, and the lower end of the second cylindrical surface 13 is connected to the upper end of the core cylinder conical surface 11. The diameter of the first cylindrical surface 12 is equal to the diameter of the lower end of the core cylinder conical surface 11, and the diameter of the second cylindrical surface 13 is equal to the diameter of the upper end of the core cylinder conical surface 11. The cylinder 1 is manufactured integrally.

[0044] Optionally, both the inner and outer surfaces of the sealing cap 3 are cylindrical.

[0045] In one possible design, the diameter of the inner surface of the sealing cover 3 is equal to the diameter of the first cylindrical surface 12 of the cylinder 1. When the sealing cover 3 is fully opened, the inner surface of the sealing cover 3 is flush with the first cylindrical surface 12 of the cylinder 1.

[0046] In one possible design, the spatial curved body obtained by cutting a semi-circular tube segment with a conical or spherical surface is the sealing cover 3, and the outer diameter of the semi-circular tube segment matches the inner diameter of the cylinder 1.

[0047] like Figure 5 , Figure 6 As shown, the anti-falling core sampler disclosed in this embodiment includes an outer cylinder 6, a central rod 7, a pressure-holding and sealing mechanism, a drill bit 9, and the aforementioned anti-falling core cylinder. The anti-falling core cylinder and the pressure-holding and sealing mechanism are installed inside the outer cylinder 6. The drill bit 9 is installed at the lower end of the outer cylinder 6. The lower end of the central rod 7 extends into the outer cylinder 6. The central rod 7 has a central rod protrusion that matches the core cylinder protrusion 14.

[0048] The pressure-holding and sealing mechanism includes a valve seat 81 and a valve disc 82. One end of the valve disc 82 is movably connected to the upper end of the valve seat 81. The top of the valve seat 81 has a sealing surface that matches the valve disc 82. This is conventional technology in the field and will not be described in detail here.

[0049] As shown in the figure, in the initial state, the anti-slag core cylinder is located inside the valve seat 81, the valve disc 82 is open, and the sealing cover 3 is closed with the conical surface 11 of the core cylinder.

[0050] As drilling progresses, the core will push open the sealing cap 3, while the spring 5 stores elastic potential energy.

[0051] The core enters the cylinder 1, and the core extractor is lifted upwards to form a large drill. The core is cut off by the chuck of the core extractor 2, and the sealing cover 3 closes automatically under the action of the spring 5 to prevent rock cuttings from falling out of the cylinder 1.

[0052] The center rod 7 is lifted upwards, and the center rod 7 moves upwards synchronously with the anti-falling rock core cylinder. When the lower end of the anti-falling rock core cylinder is higher than the top of the valve disc 82, the valve disc 82 automatically flips and closes with the valve seat 81.

[0053] The core cylinder of this application is provided with an automatically closing sealing cover 3 at the lower end. When the core enters the core cylinder, the sealing valve cover can automatically close, thereby preventing the rock debris in the core cylinder from falling onto the valve seat sealing surface of the pressure-holding sealing mechanism, thus ensuring that the valve disc and valve seat close smoothly, which is conducive to improving the pressure-holding performance of the pressure-holding core extractor and increasing the success rate of pressure-holding core extraction.

[0054] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A drop-debris-proof core barrel, characterized by: include: The inner wall of the cylinder (1) has a core cylinder conical surface (11) for matching with the sealing cap (3), and the diameter of the lower end of the core cylinder conical surface (11) is smaller than the diameter of the upper end; The core catcher (2) is installed inside the lower end of the cylinder (1) and located above the sealing cover (3); The sealing cover (3) is installed inside the lower end of the cylinder (1). One end of the sealing cover (3) is rotatably connected to the cylinder (1) via a shaft (4). The edge of the sealing cover (3) is an inclined surface (31) that is adapted to the conical surface (11) of the core cylinder. Spring (5) is installed between sealing cover (3) and cylinder (1). Under the action of spring (5), sealing cover (3) flips downward with axis (4) as the center until it closes with the core conical surface (11) of cylinder (1). The inner wall of the cylinder (1) includes a first cylindrical surface (12), a second cylindrical surface (13), and a core cylinder conical surface (11). The upper end of the first cylindrical surface (12) is connected to the lower end of the core cylinder conical surface (11), and the lower end of the second cylindrical surface (13) is connected to the upper end of the core cylinder conical surface (11). The diameter of the first cylindrical surface (12) is equal to the diameter of the lower end of the core cylinder conical surface (11), and the diameter of the second cylindrical surface (13) is equal to the diameter of the upper end of the core cylinder conical surface (11). The cylinder (1) is integrally manufactured. The inner and outer surfaces of the sealing cap (3) are both cylindrical surfaces. The diameter of the inner surface of the sealing cap (3) is equal to the diameter of the first cylindrical surface (12) of the cylinder (1). When the sealing cap (3) is fully opened, the inner surface of the sealing cap (3) is flush with the first cylindrical surface (12) of the cylinder (1).

2. A sloughing-resistant core barrel according to claim 1, characterised in that: The sealing cover (3) has a groove on its inclined surface (31) and a sealing ring (32) is installed.

3. A sloughing-resistant core barrel according to claim 1, wherein: Spring (5) is a torsion spring.

4. A sloughing-resistant core barrel according to claim 1, characterized in that: The spatial curved surface obtained by cutting a semi-circular tube segment with a conical or spherical surface is the sealing cap (3).

5. A sloughing-resistant core barrel according to claim 1, wherein: Core tube protrusions (14) are provided on the outer wall of the cylinder (1).

6. A core lifter against sloughing, comprising an outer cylinder (6), a central rod (7), a pressure-maintaining sealing mechanism and a drill bit (9), the pressure-maintaining sealing mechanism being installed in the outer cylinder (6), the pressure-maintaining sealing mechanism comprising a valve seat (81) and a valve flap (82), the drill bit (9) being mounted at the lower end of the outer cylinder (6), the lower end of the central rod (7) extending into the outer cylinder (6), characterized in that: It also includes a core tube for preventing slag shedding as described in any one of claims 1-5, wherein the core tube for preventing slag shedding is installed inside the outer tube (6), and the central rod (7) has a central rod protrusion that is adapted to the core tube protrusion (14).

7. The working method of the anti-falling core extractor as described in claim 6, characterized in that: Includes the following steps: In the initial state, the anti-falling core cylinder is located inside the valve seat (81), the valve disc (82) is open, and the sealing cover (3) is closed with the conical surface (11) of the core cylinder; During drilling and core taking, the core pushes open the sealing cap (3), while the spring (5) stores elastic potential energy. The core enters the cylinder (1), the core is captured by the core catcher (2), the core catcher is lifted upward, the core is cut off by the core catcher (2), and the sealing cap (3) automatically closes with the conical surface (11) of the core cylinder under the action of the spring (5); The center rod (7) is lifted upwards, and the center rod (7) moves upwards synchronously with the anti-falling rock core cylinder. When the lower end of the anti-falling rock core cylinder is higher than the top of the valve disc (82), the valve disc (82) automatically flips and closes with the valve seat (81).

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