Coal hole protecting device based on bottom plate comb-shaped directional drilling system

Abstract

The utility model discloses a coal hole protection device which comprises a protection pipe, a fly pipe hanging assembly and a screen pipe, the protection pipe is installed at the front end of the fly pipe hanging assembly, and the screen pipe is installed at the rear end of the fly pipe hanging assembly. The fly pipe hanging assembly comprises a solid pipe and a hanger arranged on the solid pipe, the hanger is rotationally connected to the solid pipe through an elastic supporting rod, and the hanger can support the coal hole inner sleeve when unfolded. The protection pipe is arranged at the front end of the flying pipe hanging assembly, the screen pipe is arranged at the rear end of the flying pipe hanging assembly, and by additionally arranging the protection pipe, once the speed of the hanging assembly in a coal hole is too high, the hanging assembly and the rear screen pipe can be protected by sacrificing the front protection pipe through buffering of the protection pipe when the hanging assembly collides with the bottom of the hole. And the system compressed air pressure is generally below 0.5 MPa, so that the running speed of the sleeve can be effectively controlled.

Description

Technical Field

[0001] The utility model relates to the technical field of underground drilling in coal mines, in particular to a coal hole protection device and a bottom plate comb-shaped directional drilling system. Background Art

[0002] For outburst coal seams in outburst mines, mining the protective layer and pre-extraction of gas areas are the two most commonly used gas control measures, of which the latter is more widely used. For pre-extraction of gas in coal lanes, the most common method is to use the gas control lanes (bottom plate lanes or roof plate lanes) to construct through-layer pre-extraction drilling holes. This method has the advantages of low technical content and mature technology. With the development of directional drilling technology, especially the development of air directional drilling technology, the use of directional long drilling holes to pre-extract coal lane strips is a new regional outburst prevention measure, that is, to construct extraction drilling holes along the coal seam in the coal lane along the excavation direction. Its main advantages are: reduced engineering workload, low construction and maintenance costs, and short construction period.

[0003] However, both the pre-drilling holes through the layers of the top (bottom) lanes and the long directional drilling holes along the layers have certain disadvantages; the pre-drilling holes through the layers of the top (bottom) lanes have disadvantages such as large engineering workload, large manpower input, and high management costs, which make it difficult to meet the current needs of high-quality development; the long directional drilling holes along the layers conflict with the head-on drilling site construction and affect the continuous excavation of the lanes. In addition, under the complex geological conditions of the coal seams, it is difficult to drill holes in one go, resulting in a large number of scrapped holes.

[0004] In view of the shortcomings of the current regional pre-extraction drilling, it is urgent to change the design concept, integrate the technical advantages of through-layer drilling and in-layer directional drilling, and make up for the shortcomings of gas control technology. For this reason, comb drilling is one of the ways to use long in-layer directional drilling to pre-extract gas and eliminate sudden outbursts.

[0005] When comb-shaped drilling is being performed to protect the hole, the casing often cannot be fixed smoothly at the bottom of the hole, that is, the suspension fails, causing the casing to withdraw with the drill pipe. The reason is that the casing runs too fast and hits the bottom of the hole, causing suspension or casing breakage. Therefore, this application proposes a coal hole protection device and a bottom plate comb-shaped directional drilling system to solve the above-mentioned shortcomings. Utility Model Content

[0006] The technical problem to be solved by the utility model is how to solve the problem of suspension failure caused by excessive speed during hole protection in the current comb-shaped drilling.

[0007] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0008] A coal hole protection device comprises a protection pipe, a flying pipe hanging assembly and a screen pipe, wherein the protection pipe is installed at the front end of the flying pipe hanging assembly, and the screen pipe is installed at the rear end of the flying pipe hanging assembly;

[0009] The flying pipe suspension assembly comprises a real pipe and a suspension arranged on the real pipe. The suspension is rotatably connected to the real pipe through an elastic support rod. When the suspension is unfolded, it can support the casing in the coal hole.

[0010] The present application arranges a protective tube at the front end of the flying tube suspension assembly and a screen tube at the rear end. By adding the protective tube, once the suspension assembly hits the bottom of the coal hole at too fast a speed, the front protective tube can be "sacrificed" to buffer and protect the suspension assembly and the rear screen tube. The present application utilizes system compressed air to drive the flying tube suspension assembly to move, and the system compressed air pressure is generally below 0.5MPa, which can effectively control the casing running speed.

[0011] As a further solution of the utility model: it also includes a drill rod, the interior of the drill rod is hollow, and the protection tube, the flying tube hanging assembly and the screen tube can slide inside the drill rod.

[0012] As a further solution of the utility model: the protection tube and the flying tube suspension assembly are plug-connected.

[0013] As a further solution of the utility model: the screen tube and the flying tube suspension assembly are plug-connected.

[0014] As a further solution of the utility model: the suspension is in an inverted triangle structure, with one end rotatably connected to the solid tube and the other end being a pointed end.

[0015] As a further solution of the utility model: one end of the elastic support rod is rotatably connected to the suspension, and the other end is slidably connected to a support rod groove opened on the solid tube.

[0016] As a further solution of the utility model: a plurality of eyelet holes are provided on the screen tube.

[0017] The utility model also discloses a bottom plate comb-shaped directional drilling system, including the above-mentioned coal hole protection device, and also includes a rock hole section and a coal hole section connected thereto, wherein the coal hole protection device is located in the coal hole section and protects the coal hole section.

[0018] As a further solution of the utility model: a branch rock hole section is opened on one side of the rock hole section close to the coal hole section, and one end of the branch rock hole section is connected to the branch coal hole section.

[0019] Compared with the prior art, the beneficial effects of the utility model are:

[0020] First, the present application sets a protection tube at the front end of the flying tube suspension assembly and a screen tube at the rear end. By adding the protection tube, once the suspension assembly hits the bottom of the coal hole at too fast a speed, the front protection tube can be "sacrificed" to buffer and protect the suspension assembly and the rear screen tube with the help of the protection tube. The present application uses system compressed air to drive the flying tube suspension assembly to move, and the system compressed air pressure is generally below 0.5MPa, which can effectively control the casing running speed;

[0021] Secondly, the flying pipe technology is the key technology for comb drilling. Different from conventional drilling, comb drilling needs to ensure that the branch hole coal section is protected while not affecting the continued construction of the main hole. Therefore, the hole protection device needs to be placed in the section from the branch point to the bottom of the hole, that is, the coal hole section or the branch coal hole section, which will not affect the branch drilling. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of a comb-shaped directional drilling system based on a bottom plate according to an embodiment of the utility model;

[0023] Figure 2 This is a schematic structural diagram of a coal hole protection device according to an embodiment of the utility model;

[0024] Figure 3 This is a schematic diagram of the structure of the embodiment of the utility model when the drill rod is suspended and extended;

[0025] Figure 4 This is a schematic diagram of a casing composed of a protection tube, a flying tube suspension assembly and a screen tube according to an embodiment of the utility model;

[0026] Description of reference numerals:

[0027] 1A, rock hole section; 1B, coal hole section;

[0028] 2A, branch rock hole section; 2B, branch coal hole section;

[0029] 1. Protective tube;

[0030] 2. Flying tube suspension assembly; 21. Suspension; 22. Elastic support rod; 23. Support rod slot; 24. Solid tube;

[0031] 3. Screen tube;

[0032] 4. Drill rod. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution in the embodiments of the utility model will be clearly and completely described below in combination with the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0034] Example 1

[0035] Reference Figure 2 , Figure 3 and Figure 4 A coal hole protection device includes a protection tube 1, a flying tube hanging assembly 2, a screen tube 3 and a drill pipe 4, wherein the protection tube 1 is installed at the front end of the flying tube hanging assembly 2, and the screen tube 3 is installed at the rear end. It should be noted that the connection between the flying tube hanging assembly 2 and the protection tube 1 is plug-in, which can be done by a pin shaft or a bolt; and the connection between the flying tube hanging assembly 2 and the screen tube 3 is also plug-in, which can also be done by a pin shaft or a bolt.

[0036] For ease of understanding and description, Figure 2 The left side in the middle is the front end, and the right side is the rear end. It should be understood that this orientation setting is only for the convenience of description and understanding, and cannot be understood as a limitation of the present utility model.

[0037] Reference Figure 2 , Figure 3 The protection tube 1 may also be a screen tube, which may or may not have eyelets thereon and is arranged at the front end of the flying tube suspension assembly 2. When the flying tube suspension assembly 2 enters the coal hole section for hole protection by wind pressure, the protection tube 1 contacts the bottom of the hole first. If the speed of the suspension assembly 2 is too fast at this time, the protection tube 1 located in the front will play a buffering role, so as not to cause the suspension assembly 2 to directly and quickly contact the bottom of the hole and cause damage to the suspension assembly 2.

[0038] It should be noted that 2 to 3 screen tubes are added to the front end of the flying tube suspension assembly 2 as protection tubes. Once the flying tube hits the bottom of the hole due to excessive speed, the front protection tube can be "sacrificed" to buffer the protection suspension and the rear screen tube.

[0039] Reference Figure 2 , Figure 3 and Figure 4The flying tube suspension assembly 2 includes a suspension 21, an elastic support rod 22, a support rod groove 23 and a solid tube 24, wherein the solid tube 24 is provided with a suspension 21 near the front end, and the suspension 21 is rotatably connected to the solid tube 24 through the elastic support rod 22. One end of the elastic support rod 22 is rotatably connected to the suspension 21, and the other end is slidably connected to the support rod groove 23 opened on the solid tube 24. The suspension 21 is an inverted triangle structure, and one end is rotatably connected to the solid tube 24, and the other end is a pointed end. When the suspension 21 is unfolded, it can support the casing in the coal hole.

[0040] When the suspension assembly 2 extends from the inner side of the drill rod 4 , the suspension 21 will automatically spread out under the action of the elastic support rod 22 , and then the coal hole section will be supported and fixed by the tip of the suspension 21 .

[0041] Reference Figure 4 A plurality of flower holes are provided on the screen pipe 3. The screen pipe 3 with flower holes is mainly used for extracting gas. The gas can enter the interior of the pipe through the flower holes and then be extracted from the hole opening.

[0042] Reference Figure 2 and Figure 3 The drill pipe 4 is hollow inside, and the protection tube 1, the flying tube suspension assembly 2 and the screen tube 3 can slide inside the drill pipe 4. The sliding power comes from the system compressed air. The compressed air pressure output by the air compressor can reach more than 1MPa. The strong wind pressure is the main reason for the excessive running speed of the casing. The system compressed air pressure is generally below 0.5MPa, which effectively controls the running speed of the collar formed by the protection tube 1, the flying tube suspension assembly 2 and the screen tube 3.

[0043] Example 2

[0044] A bottom plate comb-shaped directional drilling system, comprising the coal hole protection device in Example 1, and a rock hole section 1A and a branch rock hole section 2A opened in the rock section, and also comprising a coal hole section 1B and a branch coal hole section 2B opened in the coal seam section, wherein the rock hole section 1A is connected to the coal hole section 1B, and the branch rock hole section 2A is connected to the branch coal hole section 2B; one end of the rock hole section 1A close to the coal hole section 1B is branched, namely the branch rock hole section 2A;

[0045] The coal hole protection device of Example 1 protects the coal hole section 1B and each branch coal hole section 2B.

[0046] Treatment principle of branch coal hole section:

[0047] like Figure 1As shown, the rock hole section is first drilled into the rock formation, and hydraulic directional drilling is used until it stops at the coal seam, which is the rock hole section 1A. Subsequently, pneumatic directional drilling is performed on the coal hole section to form the coal hole section 1B. Then, the coal hole section 1B is protected by a coal hole protection device. After completion, the drill bit is lowered again to branch from the contact point between the rock hole section 1A and the coal hole section 1B, and hydraulic directional drilling is used in the rock formation to form a branch rock hole section 2A. Similarly, pneumatic directional drilling is performed on the coal hole section to form a branch coal hole section 2B. Subsequently, the branch coal hole section 2B is protected by a coal hole protection device, and similarly, all branch holes are completed.

[0048] The operating principle of the coal hole protection device of the present application is as follows:

[0049] ① Lower the bare drill into the coal hole section 1B or the branch coal hole section 2B to a position 5m to 10m from the bottom of the hole;

[0050] ② Connect the protection pipe-suspension device-screen pipe in sequence; determine the total length of the casing according to the length of the corresponding coal hole section, and the total length of the casing must be such that its end is located between the branch point and the coal point where the coal seam is visible;

[0051] ③After the casing is lowered into the drill pipe, a water braid is installed at the tail of the drill pipe, and the compressed air is turned on to blow the casing to the bottom of the hole. At this time, the casing formed by the protective tube, suspension and screen tube is blown out of the bare drill (drill pipe) into the hole;

[0052] ④ Start drilling and use the bottom hanger to keep the casing in the hole.

[0053] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coal hole protection device, characterized in that: It comprises a protection tube (1), a flying tube hanging assembly (2) and a screen tube (3), wherein the protection tube (1) is installed at the front end of the flying tube hanging assembly (2), and the screen tube (3) is installed at the rear end of the flying tube hanging assembly (2); The flying tube suspension assembly (2) comprises a solid tube (24) and a suspension (21) arranged on the solid tube (24); the suspension (21) is rotatably connected to the solid tube (24) via an elastic support rod (22); and the suspension (21) can support the casing in the coal hole when it is unfolded.

2. A coal hole protection device according to claim 1, characterized in that: It also comprises a drill rod (4), the interior of the drill rod (4) is hollow, and the protection tube (1), the flying tube suspension assembly (2) and the screen tube (3) are capable of sliding inside the drill rod (4).

3. A coal hole protection device according to claim 1, characterized in that: The protection tube (1) and the flying tube suspension assembly (2) are plugged in.

4. A coal hole protection device according to claim 1, characterized in that: The screen tube (3) and the flying tube suspension assembly (2) are plug-connected.

5. A coal hole protection device according to claim 1, characterized in that: The suspension (21) is in an inverted triangle structure, one end of which is rotatably connected to the solid tube (24) and the other end of which is a pointed end.

6. A coal hole protection device according to claim 2, characterized in that: One end of the elastic support rod (22) is rotatably connected to the suspension (21), and the other end is slidably connected to a support rod groove (23) provided on the solid tube (24).

7. A coal hole protection device according to claim 1, characterized in that: The screen tube (3) is provided with a plurality of eyelet holes.

8. A base plate comb-shaped directional drilling system, characterized in that: The coal hole protection device comprises the coal hole protection device as claimed in any one of claims 1 to 7, and further comprises a rock hole section (1A) and a coal hole section (1B) connected thereto, wherein the coal hole protection device is located in the coal hole section and protects the coal hole section.

9. The base plate comb-shaped directional drilling system according to claim 8, characterized in that: A branch rock hole section (2A) is provided on one side of the rock hole section (1A) close to the coal hole section (1B), and one end of the branch rock hole section (2A) is connected to the branch coal hole section (2B).

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