Portable two-wall one-annulus full-length screen pipe complete hole sealing system and application thereof

Abstract

The application discloses a portable two-walls-one-annulus full-process screen pipe complete hole sealing system in the field of exploration equipment and application thereof, and relates to the technical field of drilling equipment. The system comprises a drill bit, the outer side wall of the drill bit is provided with external threads, the drill bit is threadedly connected with a gas sampling pipe and a drill rod, the drill rod is sleeved outside the gas sampling pipe, a plurality of sampling holes are formed in the side wall of the gas sampling pipe, hole sealing bags are arranged at both ends of the gas sampling pipe, a grouting area is formed between the two hole sealing bags, and the hole sealing bag away from the drill bit is provided with a grouting pipe and a back grouting pipe and extends into the grouting area. A plurality of support pipes are fixedly connected to the side wall of the gas sampling pipe, the support pipes are in a hollow structure, the support pipes are filled with water-absorbing expansion materials, pressure relief assemblies are slidably connected to the inner walls of the support pipes, a plurality of release holes are formed in the side walls of the support pipes, and rupture marks are arranged on the release holes. In the initial state, the pressure relief assemblies abut against the water-absorbing expansion materials. The water-absorbing expansion materials in the cement slurry are expanded to fill the gaps generated by the hardening shrinkage of the cement slurry, so that the entry of external air or the leakage of gas is avoided.

Description

Technical Field

[0001] This invention belongs to the field of exploration equipment, specifically a portable two-plug-one-injection full-process screen pipe sealing system and its application. Background Technology

[0002] Mine gas is a general term for various harmful gases, primarily methane, that emerge from coal and rock during coal mining operations. It is a major natural factor that seriously threatens the safe production of coal mines. Gas disasters cause enormous casualties and property losses; therefore, preventing gas disasters is of great significance to the healthy and sustainable development of the coal industry. Currently, gas drainage is an important means of controlling gas in mine operations. During gas drainage, it is necessary to ensure that the boreholes are tightly sealed and have a long sealing length to ensure the effectiveness of gas drainage. However, at present, my country's coal mines mainly focus on gas drainage from goaf areas and within the coal seam itself. The difficulties in the gas drainage process, namely the sealing length of the gas drainage boreholes and the sealing problem itself, have not been well resolved.

[0003] Currently, the commonly used borehole sealing device for underground gas drainage mainly adopts the "two-plug-one-injection" method for sealing. This involves binding resin expansion material, such as polyurethane, to both ends of the gas drainage pipe, and then injecting cement slurry between the resin expansion materials at both ends. The existing "two-plug-one-injection" sealing technology involves drilling the hole, removing the drill rod, then placing polyurethane or sealing bags over both ends of the gas drainage pipe and inserting it into the borehole before injecting slurry to seal the hole.

[0004] Because cement shrinks after hardening, conventional sealing techniques leave gaps between the gas extraction pipe and the borehole after the cement slurry hardens. Outside air enters the vicinity of the gas extraction pipe through these gaps, reducing the gas concentration and affecting the accuracy and efficiency of extraction. Therefore, we propose a portable two-plug-one-injection full-process screen pipe sealing system and its application. Summary of the Invention

[0005] The purpose of this invention is to provide a portable two-plug-one-injection full-process screen pipe sealing system and its application, in order to solve the problem that conventional sealing technology leaves gaps between the gas extraction pipe and the borehole after the cement slurry hardens. Outside air enters the vicinity of the gas extraction pipe through the gaps, reducing the gas concentration and affecting the accuracy and efficiency of extraction.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: a portable two-plug-one-injection full-process screen pipe sealing system, including a drill bit, the outer wall of the drill bit is provided with external threads, the side of the drill bit away from the tip is provided with a first threaded hole and a second threaded hole in sequence along the axis, the first threaded hole is threaded to a gas sampling pipe, the second threaded hole is threaded to a drill rod, the drill rod is sleeved on the outside of the gas sampling pipe, the side wall of the gas sampling pipe near the drill bit is provided with several sampling holes, both ends of the gas sampling pipe are provided with sealing bags, a grouting zone is formed between the two sealing bags, the sealing bag away from the drill bit is inserted with a grouting pipe and a return grouting pipe and extends into the grouting zone;

[0007] Several support tubes are fixedly connected to the side wall of the gas sampling tube. The support tubes are hollow and filled with water-absorbing and expanding material. A pressure relief component is slidably connected to the inner wall of the support tube away from the gas sampling tube. Several release holes are opened on the side wall of the support tube. The release holes have fracture marks. In the initial state, the pressure relief component and the water-absorbing and expanding material are in contact.

[0008] The principles and beneficial effects of this solution:

[0009] This solution uses a drill bit with double threaded holes. A gas sampling tube with sealing bags at both ends and the drill rod are threaded together with the drill bit. During drilling, they are inserted into the borehole together. The drill rod is withdrawn by rotating in the opposite direction. Simultaneously, cement slurry is injected into the grouting area through the grouting pipe, improving sealing efficiency. Furthermore, because the gas sampling tube has several support pipes on its sidewall, when the drill rod is withdrawn, the borehole rock strata apply pressure to the pressure relief component. The water-absorbing and expanding material is compressed and broken by the pressure. The water-absorbing and expanding material is then pumped into the cement slurry through the release hole. On one hand, it absorbs water from the cement slurry and expands to fill the gaps created by the hardening and shrinkage of the cement slurry, preventing the entry of outside air or gas leakage. On the other hand, absorbing water from the cement slurry accelerates cement hardening, improving the system's load-bearing capacity. This solves the problem of gaps remaining between the gas extraction pipe and the borehole after the cement slurry hardens, allowing outside air to enter the vicinity of the gas extraction pipe, reducing gas concentration and affecting extraction accuracy and efficiency, which is a common problem in conventional sealing techniques.

[0010] Furthermore, the pressure relief assembly includes a first pressure block and a second pressure block that are slidably connected to the inner wall of the support tube, and a spring is connected between the first pressure block and the second pressure block.

[0011] Beneficial effects: The spring installed between the first and second pressure blocks can act as a buffer when the rock strata apply pressure to the pressure relief component, preventing the support pipe from breaking due to excessive rock pressure. It can also allow the water-absorbing and expanding material to be released slowly, so that the water-absorbing and expanding material can fully contact the cement slurry.

[0012] Furthermore, the side wall of the first pressure block is provided with a number of first comb teeth along the axis of the support tube, and the inner wall of the support tube is provided with a number of second comb teeth along its axis. The first comb teeth can mesh with the second comb teeth.

[0013] Beneficial effects: The meshing of the first and second comb teeth can improve the airtightness of the support tube and prevent the water-absorbing and expanding material from leaking from the side wall of the first pressure block under pressure, thus avoiding waste of the water-absorbing and expanding material.

[0014] Furthermore, the outer wall of the support tube away from the gas sampling tube is provided with several auxiliary support components. The auxiliary support components include a U-shaped groove with the support tube sidewall, the U-shaped groove is filled with hydraulic oil, and the two ends of the U-shaped groove are slidably connected to an auxiliary support rod and a limiting rod, respectively. The auxiliary support rod is provided with a bayonet, the limiting rod is sharp on the side near the auxiliary support rod, and the end of the auxiliary support rod away from the support tube is inclined at an angle A, which is in the range of 30-60°.

[0015] Beneficial effects: The auxiliary support rod is tilted, which increases the support range. When the auxiliary support rod is displaced by the rock pressure, it squeezes the hydraulic oil in the U-shaped groove. Since the U-shaped groove is a closed space, the hydraulic oil squeezes the limiting rod, causing the limiting rod to extend and its tip to insert into the bayonet of the auxiliary support rod, thus limiting the auxiliary support rod and preventing it from continuing to displace, thereby further improving the stability of the system.

[0016] Furthermore, an absorbent grass mesh is fitted onto the outer wall of the gas sampling tube, and the absorbent grass mesh is fixedly connected to the end of the support tube away from the gas sampling tube.

[0017] Beneficial effects: On the one hand, the absorbent grass mat can prevent rock fragments from falling, and on the other hand, it can absorb moisture around the borehole to reduce the gaps near the borehole and prevent outside air from flowing in and affecting gas sampling.

[0018] Furthermore, the outer diameter of both ends of the gas sampling tube is a, the inner diameter of the borehole is b, and the outer diameter of the middle part of the gas sampling tube is c, and a < c ≤ 0.5b.

[0019] Beneficial effects: The outer diameter of the middle part of the gas sampling tube is larger than the outer diameters at both ends of the gas sampling tube, which can reduce the amount of cement used. The outer diameter of the middle part of the gas sampling tube is less than half of the inner diameter of the borehole, which makes it easier for the grouting pipe and the return grouting pipe to have enough space to be inserted into the grouting area for grouting.

[0020] Furthermore, a pressure pipe is inserted into the sealing bag on the side away from the drill bit and extends into the grouting area. The end of the pressure pipe away from the grouting area is connected to a pressure pump.

[0021] Beneficial effects: The pressure pipe extends into the grouting area to apply pressure to the sealing bag and cement grout, which on the one hand allows the sealing bag to fit closely to the inner wall of the borehole, and on the other hand allows the cement grout to be evenly dispersed.

[0022] Furthermore, the portable two-plug-one-injection full-process screen pipe sealing system is used for borehole sealing during gas extraction. Attached Figure Description

[0023] Figure 1 This is a cross-sectional view of a portable two-plug-one-injection full-process screen pipe sealing system according to an embodiment of the present invention.

[0024] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0025] Figure 3 for Figure 2 Enlarged view of point B in the middle. Detailed Implementation

[0026] The following detailed description illustrates the specific implementation method:

[0027] The reference numerals in the accompanying drawings include: drill bit 1, gas sampling pipe 2, sampling hole 201, support pipe 202, water-absorbing and expanding material 203, release hole 204, first pressure block 205, second pressure block 206, spring 207, U-shaped groove 208, auxiliary support rod 209, limiting rod 210, bayonet 211, drill rod 3, sealing bag 4, grouting pipe 5, grout return pipe 6, grouting area 7, water-absorbing straw mat 8, pressure pipe 9, pressure pump 10.

[0028] The basic implementation examples are as follows: Figures 1-3 As shown: A portable two-stop-one-injection full-process screen pipe sealing system includes a drill bit 1. The outer wall of the drill bit 1 is provided with external threads. On the side of the drill bit 1 away from the tip, a first threaded hole and a second threaded hole are opened sequentially along the axis. The first threaded hole is threaded to a gas sampling tube 2, and the second threaded hole is threaded to a drill rod 3. The outer diameter of both ends of the gas sampling tube 2 is a, the inner diameter of the drill hole is b, and the outer diameter of the middle part of the gas sampling tube 2 is c, where a < c ≤ 0.5b. The drill rod 3 is sleeved on the outside of the gas sampling tube 2. Several sampling holes 201 are opened on the side wall of the gas sampling tube 2 near the drill bit 1. Both ends of the gas sampling tube 2 are fitted with sealing bags 4. A grouting zone 7 is formed between the two sealing bags 4. The sealing bag 4 away from the drill bit 1 is inserted with a pressure pipe 9, a grouting pipe 5, and a return grouting pipe 6 and extends into the grouting zone 7. The end of the pressure pipe 9 away from the grouting zone 7 is connected to a pressure pump 10.

[0029] Several support tubes 202 are fixedly connected to the side wall of the gas sampling tube 2. The support tubes 202 have a hollow structure and are filled with water-absorbing and expanding material 203. A pressure relief component is slidably connected to the inner wall of the support tube 202 away from the gas sampling tube 2. The pressure relief component includes a first pressure block 205 and a second pressure block 206 that are slidably connected to the inner wall of the support tube 202. A spring 207 is connected between the first pressure block 205 and the second pressure block 206. Several release holes 204 are opened on the side wall of the support tube 202. The release holes 204 are marked with fracture marks. In the initial state, the first pressure block 205 abuts against the water-absorbing and expanding material 203.

[0030] The side wall of the first pressure block 205 is provided with a number of first comb teeth along the axis of the support tube 202, and the inner wall of the support tube 202 is provided with a number of second comb teeth along its axis. The first comb teeth can mesh with the second comb teeth.

[0031] The outer wall of the support tube 202 away from the gas sampling tube 2 is provided with several auxiliary support components. The auxiliary support components include a U-shaped groove 208 with the side wall of the support tube 202. The U-shaped groove 208 is filled with hydraulic oil. The two ends of the U-shaped groove 208 are slidably connected to an auxiliary support rod 209 and a limiting rod 210, respectively. The auxiliary support rod 209 is provided with a bayonet 211. The limiting rod 210 is sharp on the side near the auxiliary support rod 209. The end of the auxiliary support rod 209 away from the support tube 202 is inclined at an angle of A, which is 45°.

[0032] The outer wall of the gas sampling tube 2 is fitted with an absorbent grass mat 8, which is fixedly connected to the end of the support tube 202 away from the gas sampling tube 2.

[0033] The specific implementation process is as follows:

[0034] Before use, place the sealing bag 4 on both ends of the gas sampling tube 2, insert the pressurizing pipe 9, the grouting pipe 5 and the return grout pipe 6 into the sealing bag 4 on the side away from the drill bit 1 and extend them into the grouting area 7. The pressurizing pipe 9 is connected to the pressurizing pump 10, and the grouting pipe 5 is connected to the cement slurry supply device. Then, connect the gas sampling tube 2 and the drill rod 3 to the drill bit 1 through the first threaded hole and the second threaded hole, respectively.

[0035] In use, drill rod 3 is connected to the power unit, and drill bit 1 is aligned with the target drilling area for drilling. This scheme uses a drill bit 1 with a double threaded hole. During drilling, gas sampling tube 2 is inserted into the borehole along with drill rod 3, reducing operation steps and avoiding the low sealing efficiency and unsupported danger of the existing technology that requires removing drill rod 3 and re-inserting gas sampling tube 2. After drill bit 1 reaches the target depth, drill rod 3 is rotated in the opposite direction to exit the borehole. At the same time as drill rod 3 exits the borehole, pressure pump 10 and cement slurry supply device start working. Pressure pipe 9 applies pressure to grouting area 7 and sealing bag 4, and grouting pipe 5 injects cement slurry into grouting area 7, which allows sealing bag 4 to adhere to the inner wall of the borehole. On the one hand, it allows the cement slurry to be evenly dispersed. On the other hand, since the side wall of the gas sampling pipe 2 is provided with several support pipes 202, when the drill rod 3 is withdrawn, the drilled rock layer applies pressure to the second pressure block 206. After being buffered by the spring 207, the pressure reaches the first pressure block 205. The water-absorbing and expanding material 203 is subjected to pressure and the fracture mark is squeezed and broken. The water-absorbing and expanding material 203 raises the release hole 204 and pumps it into the cement slurry. On the one hand, it can absorb the water in the cement slurry and expand to fill the gaps generated by the hardening and shrinkage of the cement slurry, avoiding the entry of outside air or gas leakage. On the other hand, absorbing the water in the cement slurry can accelerate the hardening of cement and improve the bearing capacity of this system.

[0036] Because several auxiliary support rods 209 are slidably connected to the outer wall of the end of the support pipe 202 away from the gas sampling pipe 2, and the auxiliary support rods 209 are in an inclined state, the support range can be increased. When the auxiliary support rods 209 are displaced by the rock pressure, they squeeze the hydraulic oil in the U-shaped groove 208. Since the U-shaped groove 208 is a closed space, the hydraulic oil squeezes the limiting rod 210, causing the limiting rod 210 to extend and its tip to insert into the bayonet 211 of the auxiliary support rod 209, thus limiting the auxiliary support rod 209 and preventing it from continuing to displace, thereby further improving the stability of the system.

[0037] After the grouting zone 7 is filled with cement grout, the pressurized pipe 9, the grouting pipe 5 and the return grout pipe 6 are sealed. The water-absorbing and expanding material 203 and the straw mat absorb the cement grout and the water around the grouting zone 7, so that the cement grout hardens quickly to support the drilled rock strata.

[0038] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0039] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A portable two-plug-one-injection complete screen pipe sealing system, characterized in that: The system includes a drill bit with external threads on its outer side wall. On the side of the drill bit away from the tip, a first threaded hole and a second threaded hole are sequentially opened along the axis. A gas sampling tube is threadedly connected to the first threaded hole, and a drill rod is threadedly connected to the second threaded hole. The drill rod is sleeved over the gas sampling tube. Several sampling holes are opened on the side wall of the gas sampling tube near the drill bit. Both ends of the gas sampling tube are fitted with sealing bags, and a grouting zone is formed between the two sealing bags. A grouting pipe and a return grouting pipe are inserted through the sealing bag on the side away from the drill bit and extend into the grouting zone. Several support tubes are fixedly connected to the side wall of the gas sampling tube. The support tubes are hollow and filled with water-absorbing and expanding material. A pressure relief component is slidably connected to the inner wall of the support tube away from the gas sampling tube. Several release holes are opened on the side wall of the support tube. The release holes are marked with fracture marks. In the initial state, the pressure relief component is in contact with the water-absorbing and expanding material. The pressure relief assembly includes a first pressure block and a second pressure block that are slidably connected to the inner wall of the support pipe, and a spring is connected between the first pressure block and the second pressure block. When the drill rod is withdrawn, the drilled rock strata apply pressure to the second pressure block. After being buffered by the spring, the pressure reaches the first pressure block. The water-absorbing and expanding material is subjected to pressure and the fracture mark is squeezed off. The water-absorbing and expanding material is pumped into the release hole to the cement slurry.

2. The portable two-plug-one-injection full-process screen pipe sealing system according to claim 1, characterized in that: The first pressure block sidewall is provided with a number of first comb teeth along the axis of the support tube, and the inner wall of the support tube is provided with a number of second comb teeth along its axis. The first comb teeth can mesh with the second comb teeth.

3. The portable two-plug-one-injection full-process screen pipe sealing system according to claim 2, characterized in that: The outer wall of the support tube away from the gas sampling tube is provided with several auxiliary support components. The auxiliary support components include a U-shaped groove with the side wall of the support tube. The U-shaped groove is filled with hydraulic oil. The two ends of the U-shaped groove are slidably connected to an auxiliary support rod and a limiting rod, respectively. The auxiliary support rod is provided with a bayonet. The limiting rod is sharp on the side near the auxiliary support rod. The end of the auxiliary support rod away from the support tube is inclined at an angle A, which is 30-60°.

4. The portable two-plug-one-injection full-process screen pipe sealing system according to claim 3, characterized in that: The outer wall of the gas sampling tube is fitted with an absorbent grass mesh mat, which is fixedly connected to the end of the support tube away from the gas sampling tube.

5. The portable two-plug-one-injection full-process screen pipe sealing system according to claim 4, characterized in that: The outer diameter of the two ends of the gas sampling tube is a, the inner diameter of the borehole is b, and the outer diameter of the middle part of the gas sampling tube is c, where a < c ≤ 0.5b.

6. The portable two-plug-one-injection full-process screen pipe sealing system according to claim 5, characterized in that: The sealing bag on the side away from the drill bit is inserted with a pressure pipe that extends into the grouting area. The end of the pressure pipe away from the grouting area is connected to a pressure pump.

7. Application of a portable two-plug-one-injection complete screen pipe sealing system, based on the portable two-plug-one-injection complete screen pipe sealing system according to any one of claims 1-6, characterized in that: The portable two-stop-one-injection full-process screen pipe sealing system is used for sealing boreholes during gas extraction.

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