Deep hole sealing suite for high-position drilling

Abstract

The utility model belongs to the technical field of gas extraction, and provides a high-position drilling deep hole sealing suite which comprises a screen pipe unit, a screen plug and a hole packer, the screen pipe unit is composed of a plurality of screen hole pipes which are sequentially connected in series, and screen holes are spirally distributed in the axial direction of the pipe wall. The two ends of the sieve mesh pipe are connected through rectangular threads, the connection strength and stability are ensured through the thread design, and the material strength meets the deep hole construction requirement. The hole packer is used in cooperation with a high-expansion-stress gelatinizing agent, and it is ensured that the sieve hole pipe is fixed into a drill hole and seals a hole opening. By means of the integrally-formed sieve hole pipe structure and the spirally-distributed sieve hole design, the deep hole protection capacity and the gas extraction smoothness are effectively improved, the spiral sieve hole pipe is particularly suitable for the deep hole gas extraction scene with the depth larger than 300 m, the extraction efficiency can be remarkably improved, and the gas treatment cost can be reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of gas extraction and relates to a high-position drilling deep hole sealing kit. Background Art

[0002] Coal mine gas extraction is an important means to prevent gas from exceeding the limit, and the construction of coal seam gas extraction drilling is the main measure for coal mine gas control. Due to different geological conditions, most coal mines in my country have the characteristics of high gas pressure, high ground stress, and soft coal seams. In particular, for the construction of deep holes with a height of more than 300m in the roof, as the coal mining working face advances, the stress of the roof surrounding rock changes and the rock mass is damaged, forming three zones in the roof, which eventually leads to serious deformation of the deep holes, and frequent hole collapse and hole breakage. In the actual construction and gas extraction process, in order to improve gas extraction efficiency, increase the drilling coverage area, and reduce gas control costs, a combination of short holes and multiple holes is usually adopted. The implementation of this method often results in hole collapse and multiple hole filling, which easily leads to waste of drilling construction project resources.

[0003] Deep hole extraction from high-position drilling holes over 300m in the coal seam roof faces special problems, mainly manifested in the poor integrity of the entire high-position hole in the roof caused by coal seam mining. Extraction from the borehole in the open hole state is prone to blockage of the gas flow channel by the hole wall, which in turn affects the extraction effect. Therefore, the deep hole protection device is an effective way to ensure the smooth flow of coal seam drilling and extraction channels.

[0004] Currently, gas extraction involves inserting screens through high-level boreholes. However, due to the high gas pressure, high ground stress, and soft coal seams in deep holes, the screens themselves are structurally unsuitable for effective hole protection. This leads to frequent hole collapse and blockage, making it difficult to create a clear gas overflow channel throughout the deep hole, thus affecting extraction efficiency. Therefore, a kit for effectively protecting and sealing deep holes over 300 meters deep is urgently needed to address the limitations of current hole protection methods and provide a solution for efficient gas extraction. Utility Model Content

[0005] In view of this, the purpose of the present invention is to solve the above problems and provide a high-position drilling deep hole sealing kit.

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

[0007] A high-position drilling deep hole sealing kit includes a screen tube unit, a screen plug, and a hole sealer; the two ends of the screen tube unit are respectively connected to the screen plug and the hole sealer; the screen tube unit includes a plurality of screen tubes connected in series, the screen tubes are an integrally formed structure, and the two ends of the screen tubes are provided with rectangular threads and connected by the rectangular threads, and the screen holes on the screen tubes are spirally distributed on the screen tube wall along the axial direction of the screen tube;

[0008] The plugging device is arranged at the hole mouth end of the borehole and closes the hole mouth together with the high-expansion stress gelling agent, sealing the screen pipe unit and the screen plug in the borehole; a gas pipe adapter is provided at the borehole mouth, with one end of the gas pipe adapter connected to the plugging device and the other end connected to the gas drainage pipe.

[0009] Furthermore, the screen plug is connected to the screen hole pipe through a rectangular thread, and screen holes communicating with the inside of the screen hole pipe are provided on the screen plug.

[0010] Furthermore, for the rectangular threads at both ends of the screen hole pipe, one end is an external thread and the other end is an internal thread.

[0011] Furthermore, the inner diameter of the screen hole pipe is 108 - 127 mm, each pipe is 2 m long, and the wall thickness is 7 mm; the material strength grade of the screen hole pipe is not lower than the requirement of DZ65 in GB / T9808 - 2008, and its performance indicators comply with the relevant regulations of GB / T16950 - 2014 and GB / T9253.2 - 2017, with the tensile strength: ≥1180 Mpa and the yield strength: ≥1190 Mpa.

[0012] Furthermore, for the inner and external threads at both ends of the screen hole pipe, the deviation of the half - angle of the thread tooth profile is ≤±0.5′, the cumulative deviation of the thread pitch within a 25 - mm length is ≤±0.3 mm, and within the full length range, it is not greater than ±0.06 mm; the thread taper deviation is ≤±(0.5)′, and the tightness tolerance deviation during thread fitting is ≤±0.2 mm.

[0013] Furthermore, the coaxiality between the inner and external threads at both ends of the screen hole pipe and the outer circle of the screen hole pipe is ≤0.15 mm.

[0014] Furthermore, the threaded parts of the inner and external threads at both ends of the screen hole pipe are smooth and flat, with the surface roughness <Ra1.6. There are no cracks, no damages and other influences, and no thread continuity or strength defects; it is not allowed to correct, remove or repair the defects.

[0015] Furthermore, the diameter of the screen holes on the screen hole pipe is 20 mm.

[0016] Furthermore, the connection diameter of the plugging device is 160 - 198 mm.

[0017] The beneficial effects of the present utility model are as follows:

[0018] The sieve hole pipe of the utility model adopts an integrally formed structure, the wall thickness of the device is 7mm, the tensile strength is ≥1180Mpa and the yield strength is ≥1190Mpa. In the process of gas extraction, facing the characteristics of high gas pressure, high ground stress and soft coal seam in deep holes, it can effectively protect the hole and form an overall unobstructed gas overflow channel in the high-position deep hole, solving the problems of hole collapse and screen pipe breakage caused by existing hole protection methods; the spiral distribution sieve hole design of the sieve hole pipe effectively improves the patency of the gas extraction channel; the rectangular thread design ensures the strength and stability of the sieve hole pipe connection, solving the problem of insufficient strength of the current high-position drilling self-connecting threads and joints; it is especially suitable for deep holes above 300m.

[0019] Other advantages, objectives, and features of the present invention will be described in detail in the following description and, to some extent, will be apparent to those skilled in the art upon examination and study of the following or may be learned from practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] 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 with reference to the accompanying drawings, in which:

[0021] Figure 1 This is a schematic diagram of the installation of the high-level drilling and deep hole sealing kit of the utility model.

[0022] Figure 2 It is a schematic diagram of the rectangular threads at both ends of the sieve tube in the present invention.

[0023] Figure numerals: 1-internal thread; 2-external thread; 3-sieve tube; 4-sieve plug; 5-hole sealer; 6-gas tube adapter; 7-gas extraction tube; 8-high expansion stress gelling agent. DETAILED DESCRIPTION

[0024] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. The details in this specification can also be modified or changed 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 are only schematic illustrations of the basic concept of the present invention. The following embodiments and the features in the embodiments can be combined with each other without conflict.

[0025] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.

[0026] 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 there are terms such as "upper", "lower", "left", "right", "front", "back", etc. indicating directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional 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.

[0027] See also Figures 1-2 , is a high-position drilling deep hole sealing kit, including a screen tube unit, a screen plug 4, and a sealer 5; the two ends of the screen tube unit are respectively connected to the screen plug 4 and the sealer 5, the screen tube unit includes a plurality of sieve tubes 3 connected in series, the sieve tubes 3 are formed in one piece by a full-body forging process, and rectangular threads are provided at both ends of the sieve tube 3 and connected by rectangular threads. The sieve holes on the sieve tube 3 are spirally distributed on the wall of the sieve tube 3 along the axial direction of the sieve tube 3; the diameter of the sieve holes on the sieve tube 3 is 20 mm.

[0028] A sealer 5 is installed at the borehole end, 30 meters from the borehole mouth. A high-expansion stress gelling agent 8 is injected to seal the borehole, sealing the screen unit and screen plug 4 within the borehole. A gas pipe adapter 6 is installed at the borehole mouth. One end of the gas pipe adapter 6 is connected to the sealer 5, and the other end is connected to the gas extraction pipe 7. The connection diameter of the sealer 5 is 160 to 198 mm.

[0029] The mesh plug 4 is connected to the mesh tube 3 via rectangular threads and is provided with mesh holes that communicate with the interior of the mesh tube 3. The mesh tube 3 has an inner diameter of 108-127 mm, a length of 2 m, and a wall thickness of 7 mm. The material strength grade of the mesh tube 3 is no less than that specified in DZ65 of GB / T9808-2008, and its performance indicators comply with the relevant provisions of GB / T16950-2014 and GB / T9253.2-2017, with a tensile strength of ≥1180 MPa and a yield strength of ≥1190 MPa.

[0030] The rectangular threads at both ends of the perforated pipe 3, one end is external thread 2, and the other end is internal thread 1. The thread profile half-angle deviation of the internal thread 1 and external thread 2 at both ends of the perforated pipe 3 is ≤ ±0.5′. The pitch deviation of the thread is within 25 mm length, the cumulative deviation is ≤ ±0.3 mm, and within the full length range, it is not greater than ±0.06 mm; the thread taper deviation is ≤ ±0.5′, and the tightness distance deviation during thread fitting is ≤ ±0.2 mm.

[0031] The coaxiality between the internal thread 1 and external thread 2 at both ends of the perforated pipe 3 and the outer circle of the perforated pipe 3 is ≤ 0.15 mm. The thread parts of the internal thread 1 and external thread 2 at both ends of the perforated pipe 3 are smooth and flat, and the surface roughness < Ra1.6. There are no cracks, no damages and other impacts, no thread continuity or strength defects; it is not allowed to correct, remove or repair the defects.

[0032] Utilizing the strength of the thread profiles of the internal thread 1 and external thread 2, the front end is connected to the screen plug 4, and the front and rear internal and external threads 2 of each screen pipe are connected in a self-connecting manner and are successively sent into a deep hole more than 300 m deep to avoid twisting and breaking at the joints and thread connections.

[0033] When using the high-position drilling deep-hole sealing kit, the internal thread 1 and external thread 2 before and after each perforated pipe 3 are connected in a self-connecting manner, the front end is connected to the screen plug 4, and they are successively sent into a deep hole more than 300 m deep. The thread profiles and joints of the internal thread 1 and external thread 2 have certain strength, and twisting and breaking are avoided in the deep hole. The sealant 5 is connected within the range of 30 m from the hole mouth and the high-expansion stress gelling agent 8 is injected to complete the hole sealing of the drilling. Finally, the gas pipe adapter 6 and the gas drainage pipe 7 are connected at the hole mouth for subsequent gas drainage.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A high-position drilling and deep hole sealing kit, characterized by: The device comprises a sieve tube unit, a sieve plug, and a hole sealer; the two ends of the sieve tube unit are respectively connected to the sieve plug and the hole sealer; the sieve tube unit comprises a plurality of sieve tubes connected in series, the sieve tubes are an integrally formed structure, the two ends of the sieve tubes are provided with rectangular threads and connected by the rectangular threads, and the sieve holes on the sieve tubes are spirally distributed on the sieve tube wall along the axial direction of the sieve tube; The sealer is arranged at the orifice end of the borehole and seals the orifice together with the high expansion stress gelling agent, sealing the screen tube unit and the screen plug in the borehole; a gas pipe adapter is provided at the orifice end of the borehole, one end of the gas pipe adapter is connected to the sealer, and the other end is connected to the gas extraction pipe.

2. The high-position drilling and deep hole sealing kit according to claim 1, characterized in that: The sieve plug is connected to the sieve tube via a rectangular thread, and the sieve plug is provided with sieve holes communicating with the inside of the sieve tube.

3. The high-position drilling and deep hole sealing kit according to claim 1, characterized in that: The rectangular threads at both ends of the sieve tube are external threads at one end and internal threads at the other end.

4. The high-position drilling and deep hole sealing kit according to claim 1, characterized in that: The inner diameter of the sieve tube is 108-127 mm, each tube is 2 m long, and has a wall thickness of 7 mm.

5. The high-position drilling and deep hole sealing kit according to claim 3, characterized in that: The thread tooth profile half-angle deviation of the internal and external threads at both ends of the sieve tube is ≤±0.5′, the thread pitch deviation is within a length of 25mm, the cumulative deviation is ≤±0.3mm, and is not greater than ±0.06mm in the entire length; the thread taper deviation is ≤±0.5′, and the close distance deviation when the threads are matched is ≤±0.2mm.

6. The high-position drilling and deep hole sealing kit according to claim 3, characterized in that: The coaxiality between the internal threads and external threads at both ends of the sieve tube and the outer circle of the sieve tube is ≤0.15mm.

7. The high-position drilling and deep hole sealing kit according to claim 3, characterized in that: The threaded parts of the internal and external threads at both ends of the sieve tube are smooth and flat, with a surface roughness of <Ra1.6。 8. The high-position drilling and deep hole sealing kit according to claim 1, characterized in that: The diameter of the sieve holes on the sieve tube is 20 mm.

9. The high-position drilling and deep hole sealing kit according to claim 1, characterized in that: The connection diameter of the hole sealer is 160 to 198 mm.

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