Embedded hollow spray pipe type single-wall coring device and working method thereof

Abstract

The invention belongs to the field of drilling sampling, and relates to an embedded hollow spray pipe type single-wall coring device and a working method thereof.The device comprises a coring pipe, an embedded coring barrel and a connector, the coring pipe and the embedded coring barrel are in clearance fit, a groove in the inner wall of the coring pipe forms the hollow spray pipe, a drill bit nozzle on the front portion of the coring pipe is connected with the hollow spray pipe, and the hollow spray pipe is connected with the embedded coring barrel. The coring pipe is connected with the drill rod through the connector. When the device is adopted for sampling, compressed air enters the hollow spray pipe through the inner cavity of the drill rod and flows out at a high speed through the coring drill bit nozzle, heat generated by cutting friction of the drill bit is rapidly taken away, disturbance to drilling cuttings particles is reduced, a core sample embedded in the coring barrel does not make direct contact with the wall of the coring pipe, and air in a gap forms a heat insulation layer; the taken core sample is complete, keeps the original property, and is suitable for coal seam gas content measurement coring and broken coal measure strata down hole drilling coring.

Description

Technical Field

[0001] The invention belongs to the field of drilling sampling and relates to an embedded hollow nozzle type single-wall coring device and a working method thereof. Background Art

[0002] As one of the most important basic parameters of coal seam gas occurrence, coal seam gas content is a key indicator for mine gas grade identification, gas emission prediction, coal seam gas resource recovery, and mine outburst prevention and control. Its accuracy is very important for coal mine gas disaster prevention and control and coal seam gas resource recovery. The sampling methods for direct determination of coal seam gas content mainly include orifice powder collection method, compressed air sampling, negative pressure injection sampling, reverse circulation sampling, closed coring, core tube sampling and frozen sampling. According to the requirements of "Direct Determination Method of Coal Seam Gas Content Underground" (GB / T 23250-2009), the determination of coal seam gas content must adopt core tube sampling or other proven and effective fixed-point sampling methods, and core tube sampling is recommended.

[0003] Coring tube sampling can achieve fixed-point sampling, solve the problem of mixed samples, and realize deep-hole sampling. However, due to the long coring time, the coal core is exposed for a long time, the heat generated by the coring drill bit cutting the coal body and the heat generated by the friction between the coring tube and the coal seam will cause the temperature of the coal core to rise and accelerate the desorption of coal core gas, resulting in a large amount of gas loss, and even the phenomenon that the taken coal core cannot desorb gas.

[0004] With the construction of transportation network in the mountainous areas of southwest China, a large number of tunnels need to pass through coal-bearing strata. Different from coal mining, tunnel coal mining has the characteristics of large cross-section and complex construction process. The occurrence and gas parameters of the coal seams to be mined are poorly understood. At present, the main method of geophysical prospecting + drilling is used for advanced geological prediction. When drilling and coring in fragmented coal-bearing strata, traditional coring tubes often use compressed air or water to cool the drill bit. The fluid directly flushes the fragmented coal and rock mass through the inner cavity of the coring tube, further reducing its structural stability and causing the loss of core samples. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide an embedded hollow nozzle single-wall coring device and a working method thereof, so as to achieve rapid heat dissipation during coal seam core sampling, reduce gas desorption losses, reduce disturbance of drill cuttings particles, ensure the integrity of the core sample and maintain its original properties, and improve the sampling success rate and the efficiency of coal seam gas content determination.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] An embedded hollow nozzle type single-wall coring device, comprising a coring tube and an embedded coring barrel;

[0008] The core tube comprises a core tube body with openings at both ends, a cutting tooth fixed at the front end of the core tube body, and a nozzle arranged at the rear of the cutting tooth, a limit stopper is arranged at the front end of the inner wall of the core tube body, and a plurality of non-through grooves are arranged on the inner wall of the core tube body, and the grooves are connected to the nozzle;

[0009] The embedded coring barrel comprises a coring barrel body with an open end, a heat insulating rubber pad disposed at the open end of the coring barrel body, and a movable folding handle disposed at one end of the coring barrel body away from the open end;

[0010] The embedded coring barrel is placed inside the coring tube in a clearance fit manner, and the thermal insulation pad is abutted against the limit stopper, so that the outer wall of the embedded coring barrel and a plurality of grooves form a group of hollow nozzles connected to the nozzle.

[0011] Furthermore, a joint is also included. An inner thread of the core tube is provided on the inner wall of the core tube body behind the groove to connect the joint.

[0012] Furthermore, the joint is a hollow tube, one end of which is provided with an external thread, which is connected to the internal thread of the core tube, and the other end is provided with an internal thread, which is connected to the drill rod, and a group of slots are provided on the outside of the joint to facilitate tightening the joint.

[0013] Furthermore, the angle between the nozzle and the axial direction of the core tube is 10° to 15°.

[0014] Furthermore, the core tube, the embedded core barrel and the joint are made of aluminum alloy, and the cutting teeth are PDC.

[0015] Furthermore, a downhole hard coal anti-lost mechanism or a downhole soft coal anti-lost mechanism is detachably connected to the front of the inner cavity of the coring barrel body to ensure that the core sample is fixed in the embedded coring barrel when the drill is withdrawn.

[0016] Furthermore, the anti-lost mechanism for the downhole hard coal comprises a casing, an umbrella-shaped support rod arranged on the inner wall of the casing, and the umbrella-shaped support rod is connected to the inner wall of the casing by a pressure spring, the outer wall of the casing is detachably connected to the inner wall of the core barrel body, and the umbrella-shaped support rod is arranged obliquely toward a side away from the mouth end of the core barrel body;

[0017] The anti-lost mechanism for soft coal in the downward hole includes an annular base, a rotating shaft is provided in the middle of the annular base, semicircular movable cover plates are provided on both sides of the rotating shaft, the movable cover plates are connected to the rotating shaft through a torsion spring, and the outer wall of the annular base is detachably connected to the inner wall of the core barrel body.

[0018] A working method of an embedded hollow nozzle type single-wall coring device, using the embedded hollow nozzle type single-wall coring device, specifically comprises the following steps:

[0019] S1. After drilling to the specified sampling depth, stop construction, use compressed air to wash the hole, discharge the remaining drill cuttings in the hole, and then withdraw the drill rod and drill bit;

[0020] S2. Analyze the sampling drilling parameters. When the drilling inclination is negative, install the corresponding anti-lost mechanism at the front of the embedded coring barrel according to the collected physical and mechanical property parameters of the target coal seam and the hardness of the coal quality: when the coal quality is hard and the cut coal core is cylindrical, use the anti-lost mechanism for hard coal in the downward hole; when the coal quality is soft and the cut coal core is broken particles or powder, use the anti-lost mechanism for soft coal in the downward hole;

[0021] S3, connecting the embedded hollow nozzle type single-wall coring device to the drill pipe, using the drill rig to advance to a predetermined sampling depth and then start the drill rig to cut the coal body for coring operation, the air in the compressed air pipe flows through the inner cavity of the drill pipe into the hollow nozzle, and flows out at a high speed through the nozzle to cool the cutting teeth;

[0022] The wind flow directly ejected along the hollow nozzle rotates with drilling to form a barrier to ensure that the core sample inside the core tube enters the embedded core barrel, while preventing external drill cuttings from mixing into the embedded core barrel;

[0023] S4. After the coring is completed, the embedded hollow nozzle type single-wall coring device is withdrawn from the borehole through the drilling rig, and the embedded hollow nozzle type single-wall coring device is separated from the drill pipe, and then the embedded coring barrel is pulled out through the movable folding handle, and finally the core sample can be collected in the embedded coring barrel.

[0024] Furthermore, in step S3, when coring with the downhole hard coal anti-lost mechanism, the cylindrical coal core produced by cutting pushes up the umbrella-shaped support rod and the pressure spring as the drilling rig advances, and the pressure spring pushes the tip of the umbrella-shaped support rod against the core sample, ensuring that the core sample is fixed in the embedded coring barrel when the drill is withdrawn;

[0025] When coring with the downward-hole soft coal anti-loss mechanism, the broken particles or powdered coal cores produced by cutting are pushed open with the drilling rig to push open the semicircular movable cover plate and enter the embedded coring barrel. After coring is completed, the semicircular movable cover plate is closed again under the action of the torsion spring to ensure that the core sample is enclosed in the embedded coring barrel when the drill is withdrawn.

[0026] Furthermore, the embedded hollow nozzle type single-wall coring device also includes a joint for connecting a drill pipe, and a core pipe internal thread is provided on the inner wall of the core pipe body behind the groove to connect the end of the joint away from the drill pipe;

[0027] In step S3, the embedded hollow nozzle type single-wall coring device is connected to the drill pipe through a joint;

[0028] In step S4, before the embedded coring barrel is pulled out by the movable folding handle, the joint needs to be separated from the coring barrel.

[0029] The beneficial effects of the present invention are:

[0030] 1. Efficient cooling: By forming a hollow nozzle through the grooves embedded in the outer wall of the core barrel and the inner wall of the core tube, this device can significantly increase the air flow rate, which flows to the cutting teeth at high speed through the nozzle, quickly taking away the heat generated by cutting friction during the coring process.

[0031] 2. Good thermal insulation performance: The core sample in the embedded coring barrel in this device does not directly contact the coring tube wall, and the air in the gap forms an insulation layer. At the same time, a thermal insulation rubber pad is designed at the front end of the embedded coring barrel, which effectively reduces the heat from the cutting of the cutter teeth and the friction between the coring tube wall and the borehole wall and drill cuttings and is transferred to the core sample.

[0032] 3. High sampling success rate: Compared with the traditional core tube, the wind flow ejected from the hollow nozzle along the inner wall of the core tube during coring in this device rotates with drilling to form a barrier, reducing the disturbance of the wind flow on the drill cuttings particles of the soft coal body in front, and preventing external drill cuttings from mixing into the core tube; at the same time, an anti-loss mechanism is designed for down-hole sampling of different coal hardnesses, which effectively improves the sampling success rate.

[0033] 4. Light and fast: This device is a single-wall core tube, the main structure is made of aluminum alloy with a density of 2.7g / cm 3 , compared to steel density 7.8g / cm 3 , only 1 / 3 of it; and its specific strength is 2 to 5 times that of steel, which effectively reduces the intensity of manual handling.

[0034] 5. Wide adaptability: The joint of this device can be connected to drill rods of various specifications and is suitable for various forms of drilling rigs. It has wide adaptability and high market promotion value.

[0035] 6. Improve the accuracy of parameter measurement: The core sample taken out by this device is complete and can maintain its original properties, which can effectively improve the accuracy of coal seam gas content measurement.

[0036] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0038] Figure 1 It is a structural schematic diagram of a single-wall coring device with an embedded hollow nozzle in the present invention;

[0039] Figure 2It is a schematic cross-sectional view of the assembly of the core tube and the embedded core barrel;

[0040] Figure 3 It is a structural schematic diagram of the anti-lost mechanism of the hard coal in the downhole;

[0041] Figure 4 It is a structural schematic diagram of the soft coal anti-loss mechanism in the downward hole;

[0042] Figure 5 is a schematic diagram of the structure of the joint;

[0043] Figure 6 A route diagram of compressed air provided for the drill pipe of the embodiment being ejected at high speed from the nozzle through the hollow nozzle.

[0044] Figure markings: 1-coring tube, 1-1-cutting teeth, 1-2-nozzle; 1-3-limit block, 1-4-groove, 1-5-coring tube internal thread, 1-6-coring tube body, 2-embedded coring barrel, 2-1-thermal insulation pad, 2-2-movable folding handle, 2-3-down-hole hard coal anti-loss mechanism, 2-31-casing, 2-32-support rod, 2-33-pressure spring, 2-4-down-hole soft coal anti-loss mechanism, 2-41-annular base, 2-42-rotating shaft, 2-43-semicircular movable cover plate, 2-44-torsion spring, 2-5-hollow nozzle, 2-6-coring tube body, 3-connector, 3-1-external thread, 3-2-internal thread, 3-3-slot. DETAILED DESCRIPTION

[0045] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0046] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0047] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0048] See also Figure 1 to Figure 6 As introduced in the background technology, there are deficiencies in the prior art. In order to solve the technical problems of the background technology, this embodiment provides an embedded hollow nozzle type single-wall coring device and a working method thereof.

[0049] See also Figure 1 , this embodiment provides an embedded hollow nozzle type single-wall coring device, comprising a coring tube 1, an embedded coring barrel 2 and a joint 3;

[0050] See also Figure 2 The core tube 1 comprises a core tube body 1-6 with openings at both ends, a cutting tooth 1-1 fixed at the front end of the core tube body 1-6, and a nozzle 1-2 arranged at the rear of the cutting tooth 1-1. A limit stopper 1-3 is provided at the front end of the inner wall of the core tube body 1-6, and a plurality of non-through grooves 1-4 are provided on the inner wall of the core tube, and an inner thread of the core tube is provided behind the groove 1-4 (at the end away from the cutting tooth 1-1). The angle between the nozzle 1-2 and the axial direction of the core tube is 10° to 15°, and the tail of the nozzle is connected and penetrated with the groove 1-4.

[0051] The embedded coring barrel 2 comprises a coring barrel body 2-6 with an open end, a heat insulating rubber pad 2-1 disposed at the open end of the coring barrel body 2-6, and a movable folding handle 2-2 disposed at the rear end (the end away from the open end) of the coring barrel body 2-6;

[0052] The core tube 1, the embedded core barrel 2 and the joint 3 are made of aluminum alloy, and the cutting teeth 1-1 are PDC (polycrystalline diamond composite drill bit).

[0053] See also Figure 3 A detachable down-hole hard coal anti-lost mechanism 2-3 is provided in the part near the opening end of the core barrel body 2-6. The down-hole hard coal anti-lost mechanism 2-3 includes a casing 2-31 and an umbrella-shaped support rod 2-32 arranged on the inner wall of the casing. The support rod 2-32 is connected to the inner wall of the casing by a pressure spring 2-33.

[0054] Specifically, the umbrella-shaped support rod 2-32 is arranged obliquely toward the side away from the open end of the core barrel body 2-6, so that the cylindrical coal core produced by cutting can push open the support rod and compression spring of the inner wall of the casing as the drilling rig advances, and the compression spring pushes the tip of the support rod against the core sample, ensuring that the core sample is fixed in the embedded core barrel when the drill is withdrawn.

[0055] See also Figure 4 A detachable anti-lost mechanism 2-4 for soft coal in the downward hole is provided in the part near the opening end of the coring barrel body 2-6. The anti-lost mechanism 2-4 for soft coal in the downward hole comprises an annular base 2-41. A rotating shaft 2-42 is provided in the middle of the annular base. Semicircular movable cover plates 2-43 are provided on both sides of the rotating shaft. The semicircular movable cover plates 2-43 are connected to the rotating shaft 2-42 through a torsion spring 2-44, so that the broken particles or powdered coal cores produced by cutting can be pushed open by the drilling rig to push open the semicircular movable cover plates and enter the embedded coring barrel. After coring is completed, the movable cover plates are closed again under the action of the torsion spring to ensure that the core sample is enclosed in the embedded coring barrel when the drill is withdrawn.

[0056] Specifically, the downward-hole hard coal anti-loss mechanism 2-3 and the downward-hole soft coal anti-loss mechanism 2-4 are both detachably connected to the inner wall of the coring barrel body 2-6, and the specific connection method can be threaded connection or snap connection.

[0057] See also Figure 5 The joint 3 is a hollow tube, one end of which is provided with an external thread 3-1, which is connected to the core tube 1 (core tube internal thread); the other end is provided with an internal thread 3-2, which is connected to the drill pipe; and a group of slots 3-3 are provided on the outside of the joint to facilitate tightening the joint.

[0058] See also Figure 2 and Figure 6 The embedded coring barrel 2 is placed inside the coring tube 1 in a clearance fit manner, and the heat-insulating rubber pad 2-1 of the embedded coring barrel 2 is pressed against the limit block 1-3 to limit the axial movement of the embedded coring barrel 2 and reduce the heat generated by the drill bit cutting friction and conduct it to the embedded coring barrel 2; and a group of hollow nozzles 2-5 are formed by the outer wall of the embedded coring barrel and the plurality of grooves 1-4 on the inner wall of the coring tube.

[0059] A working method of an embedded hollow nozzle type single-wall coring device comprises the following steps:

[0060] S1. After drilling to the specified sampling depth, stop construction, use compressed air to wash the hole, discharge the remaining drill cuttings in the hole, and then withdraw the drill rod and drill bit.

[0061] S2. Analyze the sampling drilling parameters. When the drilling inclination is a negative value, that is, when drilling downward, install the corresponding anti-loss mechanism at the front end of the embedded coring tube 2 according to the physical and mechanical property parameters of the target coal seam collected and the hardness of the coal quality: when the coal quality is hard and the cutting coal core is cylindrical, the downward-hole hard coal anti-loss mechanism 2-3 is used; when the coal quality is soft and the cutting coal core is broken particles or powder, the downward-hole soft coal anti-loss mechanism 2-4 is used.

[0062] S3, connect the coring tube 1, the embedded coring barrel 2, the joint 3 and the drill pipe, use the drill rig to advance to the predetermined sampling depth and then start the drill rig to cut the coal body for coring operation; the air flow in the compressed air pipe enters the hollow nozzle 2-5 through the inner cavity of the drill pipe, flows out at high speed through the nozzle 1-2, and cools the cutting teeth 1-1; the air flow ejected from the hollow nozzle 2-5 along the inner wall of the coring tube rotates with the drilling to form a barrier, ensuring that the core sample cut inside the coring tube directly enters the embedded coring barrel, while preventing external drill cuttings from mixing into the embedded coring barrel 2.

[0063] S4. After coring is completed, the embedded hollow nozzle type single-wall coring device is withdrawn through the drilling rig, the coring tube and the joint are separated by a tool, and the embedded coring tube 2 is pulled out through the movable folding handle at the bottom, and the core sample can be collected in the embedded coring tube 2.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. An embedded hollow nozzle type single-wall coring device, characterized in that: It comprises a core tube (1) and an embedded core barrel (2); The core tube (1) comprises a core tube body (1-6) with openings at both ends, a cutting tooth (1-1) fixed at the front end of the core tube body (1-6), and a nozzle (1-2) arranged at the rear of the cutting tooth (1-1); a limit stopper (1-3) is provided at the front end of the inner wall of the core tube body (1-6); and a plurality of non-through grooves (1-4) are provided on the inner wall of the core tube body (1-6), and the grooves (1-4) are connected to the nozzle (1-2); The embedded coring barrel (2) comprises a coring barrel body (2-6) with an opening at one end, a heat insulating rubber pad (2-1) disposed at the open end of the coring barrel body (2-6), and a movable folding handle (2-2) disposed at the end of the coring barrel body (2-6) away from the open end; The embedded coring barrel (2) is placed inside the coring tube (1) in a clearance fit manner, and the heat insulating rubber pad (2-1) is abutted against and connected to the limit stopper (1-3), so that the outer wall of the embedded coring barrel (2) and a plurality of grooves (1-4) form a group of hollow nozzles (2-5) connected to the nozzle (1-2).

2. The device according to claim 1, characterized in that: It also comprises a joint (3), and a core tube internal thread (1-5) is provided on the inner wall of the core tube body (1-6) behind the groove (1-4) to connect the joint (3).

3. The device according to claim 2, characterized in that: The joint (3) is a hollow tube, one end of which is provided with an external thread (3-1) for matching and connecting with the internal thread (1-5) of the core tube, and the other end of which is provided with an internal thread (3-2) for matching and connecting with the drill rod. A group of slots (3-3) are provided on the outside of the joint (3) to facilitate tightening the joint.

4. The device according to claim 1, characterized in that: The angle between the nozzle (1-2) and the axial direction of the core tube is 10° to 15°.

5. The device according to claim 1, characterized in that: The core tube (1), the embedded core barrel (2) and the joint (3) are made of aluminum alloy, and the cutting teeth (1-1) are PDC.

6. The device according to any one of claims 1 to 5, characterized in that: A downhole hard coal anti-lost mechanism (2-3) or a downhole soft coal anti-lost mechanism (2-4) is detachably connected to the front of the inner cavity of the coring barrel body (2-6) to ensure that the core sample is fixed in the embedded coring barrel when the drill is withdrawn.

7. The device according to claim 6, characterized in that: The anti-lost mechanism for the hard coal in the downward hole comprises a casing (2-31), an umbrella-shaped support rod (2-32) arranged on the inner wall of the casing, and the umbrella-shaped support rod (2-32) is connected to the inner wall of the casing via a pressure spring (2-33), the outer wall of the casing (2-31) is detachably connected to the inner wall of the coring barrel body (2-6), and the umbrella-shaped support rod (2-32) is arranged obliquely toward a side away from the opening end of the coring barrel body (2-6); The hole-diving soft coal anti-loss mechanism comprises an annular base (2-41), a rotating shaft (2-42) is provided in the middle of the annular base, semicircular movable cover plates (2-43) are provided on both sides of the rotating shaft, the movable cover plates are connected to the rotating shaft via a torsion spring (2-44), and the outer wall of the annular base (2-41) is detachably connected to the inner wall of the coring barrel body (2-6).

8. A working method of an embedded hollow nozzle type single-wall coring device, characterized in that: The embedded hollow nozzle type single-wall coring device described in claim 7 specifically comprises the following steps: S1. After drilling to the specified sampling depth, stop construction, use compressed air to wash the hole, discharge the remaining drill cuttings in the hole, and then withdraw the drill rod and drill bit; S2. Analyze the sampling drilling parameters. When the drilling inclination is negative, install the corresponding anti-lost mechanism at the front of the embedded coring barrel according to the collected physical and mechanical property parameters of the target coal seam and the hardness of the coal: when the coal is hard and the cut coal core is cylindrical, use the anti-lost mechanism for hard coal in the hole (2-3); when the coal is soft and the cut coal core is broken particles or powder, use the anti-lost mechanism for soft coal in the hole (2-4); S3, connecting the embedded hollow nozzle type single-wall coring device to the drill pipe, and starting the drill to cut the coal body for coring after advancing the drill to a predetermined sampling depth, and the air in the compressed air pipe flows through the inner cavity of the drill pipe into the hollow nozzle (2-5), and flows out at a high speed through the nozzle (1-2), thereby cooling the cutting teeth (1-1); The wind flow directly ejected along the hollow nozzle (2-5) forms a barrier as it rotates during drilling to ensure that the core sample inside the core tube (1) enters the embedded core barrel (2) and prevents external drill cuttings from mixing into the embedded core barrel (2); S4. After coring is completed, the embedded hollow nozzle type single-wall coring device is withdrawn from the borehole through the drilling rig, and the embedded hollow nozzle type single-wall coring device is separated from the drill pipe, and then the embedded coring barrel (2) is pulled out through the movable folding handle (2-2), and finally the core sample can be collected in the embedded coring barrel.

9. The working method of the embedded hollow nozzle type single-wall coring device according to claim 8, characterized in that: In step S3, when coring is performed using the downward-hole hard coal anti-loss mechanism (2-3), the cylindrical coal core produced by cutting pushes open the umbrella-shaped support rod (2-32) and the pressure spring (2-33) as the drilling rig advances, and the pressure spring pushes the tip of the umbrella-shaped support rod (2-32) against the core sample, ensuring that the core sample is fixed in the embedded coring barrel when the drill is withdrawn; When coring is performed using the hole-down soft coal anti-loss mechanism (2-4), the broken particles or powdered coal cores produced by cutting are pushed open by the drilling rig to push open the semicircular movable cover plate (2-43) and enter the embedded coring barrel. After coring is completed, the semicircular movable cover plate (2-43) is closed again under the action of the torsion spring (2-44), ensuring that the core sample is enclosed in the embedded coring barrel when the drill is withdrawn.

10. The working method of the embedded hollow nozzle type single-wall coring device according to claim 8, characterized in that: The embedded hollow nozzle type single-wall coring device also includes a joint (3) for connecting a drill pipe, and a core pipe internal thread (1-5) is provided on the inner wall of the core pipe body (1-6) behind the groove (1-4) to connect the end of the joint (3) away from the drill pipe; In step S3, the embedded hollow nozzle type single-wall coring device is connected to the drill pipe via a joint (3); In step S4, before the embedded coring tube (2) is pulled out by the movable folding handle (2-2), the joint (3) must be separated from the coring tube (1).

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