A viscoelastic reparable emulsion hole-sealing material and its intelligent dynamic hole-sealing process

Abstract

The present invention discloses a viscoelastic reparable emulsion hole-sealing material and its intelligent dynamic hole-sealing process. It consists of a flexible first network polymer with a relatively high crosslinking degree and a second network polymer with a low crosslinking degree. The two are mixed and superimposed to form a double-network gel structure, and nanoparticles are added to enhance the strength and toughness of the double-network gel structure. The viscosity of the hole-sealing material is adjusted by a thickener. The intelligent dynamic hole-sealing process first seals the hole preliminarily through a plugging pocket, and then uses the characteristics of the viscoelastic reparable emulsion to perform secondary hole-sealing, forming a circular curtain for drilling plugging in the disc-shaped slot to ensure the hole-sealing effect. During the subsequent gas drainage process, according to the gas drainage situation, using the characteristics of the viscoelastic reparable emulsion hole-sealing material, the dynamic hole-sealing process continues, which can restore the hole-sealing effect and ultimately ensure the efficiency of gas drainage.

Description

Technical Field

[0001] The present invention relates to a viscoelastic reparable emulsion hole - sealing material and an intelligent dynamic hole - sealing process thereof, belonging to the technical field of gas drainage hole - sealing. Background Art

[0002] Downhole borehole gas drainage is the most effective and fundamental way to prevent coal mine gas disasters, and the quality of borehole sealing is the key to improving the gas drainage concentration. In recent years, the construction of intelligent gas drainage is the general trend of mine development. Therefore, according to the changes in gas drainage parameters, establishing an intelligent decision - making system on the ground and a dynamic hole - sealing system underground is of great significance for improving the gas drainage concentration and underground safety.

[0003] Existing hole - sealing materials and methods mainly include polyurethane hole - sealing, bag - type grouting hole - sealing, modified cement - based hole - sealing, etc. The polyurethane hole - sealing method is simple and fast, but it can only fill short - distance cracks around the borehole, and its compressive capacity is limited, and it is prone to deformation under high in - situ stress or mining interference. The bag - type grouting hole - sealing method is often combined with cement - based hole - sealing materials for "two - plug - one - injection" pressure - maintaining hole - sealing, which can well fill the fissures around the borehole and provide reliable support for the borehole to ensure the stability of the borehole. However, the strength of the "two plugs" is low, resulting in low grouting pressure and unable to achieve strict sealing of the fissures around the borehole. The cement - based hole - sealing material has a fast setting speed, strong fluidity, high compressive and anti - deformation capabilities, and at the same time has the characteristics of slight expansion, which can closely fit the surface of the coal and rock mass. However, it is difficult to avoid shrinkage and cracking during the solidification process, resulting in a decrease in borehole sealing performance, and it is impossible to realize secondary grouting to alleviate the problem of decreasing gas drainage concentration. At present, hole - sealing materials and processes generally cannot penetrate into the primary and new fissures of the borehole surrounding rock, resulting in poor sealing of the expanded fissures around the borehole although the borehole is effectively sealed, so that gas is discharged from the fissures during subsequent gas drainage, ultimately resulting in poor gas drainage effect. In addition, the existing hole - sealing process determines the hole - sealing effect only based on manual experience, which not only has low accuracy but also has problems such as high labor intensity.

[0004] Based on the above - mentioned status of gas drainage borehole plugging and the defects of hole - sealing materials and processes, how to provide a new hole - sealing material and hole - sealing process that can well adapt to the deformation of coal and rock strata during hole - sealing, effectively seal the coal and rock fissures around the borehole, and in the subsequent gas drainage process, monitor the gas drainage situation in real - time, automatically perform multiple dynamic pluggings according to the drainage situation, reduce manual labor, realize intelligent decision - making on the ground and dynamic grouting underground, ensure high - quality plugging of the borehole, improve the gas drainage concentration, is the research direction of this industry. Summary of the Invention

[0005] In view of the problems existing in the above-mentioned prior art, the present invention provides a viscoelastic reparable emulsion hole-sealing material and its intelligent dynamic hole-sealing process, which can well adapt to the deformation of coal and rock strata during hole-sealing, effectively block the coal and rock fissures around the borehole, and in the subsequent gas drainage process, monitor the gas drainage situation in real time, automatically perform multiple dynamic blockages according to the drainage situation, reduce manual labor, realize intelligent decision-making on the ground and dynamic grouting underground, ensure high-quality hole-sealing of the borehole, and improve the gas drainage concentration.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a viscoelastic reparable emulsion hole-sealing material is prepared by mixing a first network polymer and water in a mass ratio of (7 - 9):(1 - 3) as the base material, and adding a second network polymer with a mass fraction of 0.05% - 0.2%, 0.5% nanoparticles, and 2% - 4% tackifier.

[0007] An intelligent dynamic hole-sealing system includes an intelligent control device, a hole-sealing device, a slurry storage device, and a grouting device;

[0008] The hole-sealing device includes a gas drainage pipe, a first grouting pipe, a second grouting pipe, two plugging bags, a flow stabilizer, and a filter. One end of the gas drainage pipe extends into the gas drainage borehole. The two plugging bags are installed outside the gas drainage pipe in the gas drainage borehole, and there is a certain distance between them. The flow stabilizer and the filter are both installed on the gas drainage pipe outside the gas drainage borehole. The flow stabilizer is used to stabilize the drainage flow in the gas drainage pipe, and the filter is used to filter the extracted gas. One end of the first grouting pipe extends between the two plugging bags, and a grouting port is provided at this end. One end of the second grouting pipe passes through the plugging bag near the borehole orifice and extends into the other plugging bag. Liquid injection ports are provided on the second grouting pipe inside the two plugging bags;

[0009] The grouting device is a double-fluid grouting pump. There are two slurry storage devices. The two slurry storage devices contain a viscoelastic reparable emulsion hole-sealing material and a cement-based hole-sealing material respectively, and are respectively connected to the two inlets of the double-fluid grouting pump. The two outlets of the double-fluid grouting pump are respectively connected to the other ends of the first grouting pipe and the second grouting pipe, and are used to transport the viscoelastic reparable emulsion hole-sealing material through the first grouting pipe into the gas drainage borehole between the two plugging bags, and at the same time transport the cement-based hole-sealing material through the second grouting pipe into the two plugging bags, so as to make the plugging bags expand to block the gas drainage borehole;

[0010] The intelligent control device includes a PLC controller, a mobile terminal, an intelligent flowmeter, a gas concentration sensor, an oxygen concentration sensor, a first pressure sensor, a second pressure sensor, a first intelligent control valve and a second intelligent control valve. The intelligent flowmeter is installed on the gas drainage pipe and is used to monitor the drainage flow in the gas drainage pipe and feedback it to the PLC controller. The first pressure sensor and the first intelligent control valve are both installed on the first grouting pipe, and the second pressure sensor and the second intelligent control valve are both installed on the second grouting pipe. The first pressure sensor and the second pressure sensor are respectively used to monitor the pressures in the first grouting pipe and the second grouting pipe and feedback them to the PLC controller; the first intelligent control valve and the second intelligent control valve are respectively used to control the on-off of the first grouting pipe and the second grouting pipe; the gas concentration sensor and the oxygen concentration sensor are both installed on the flow stabilizer and are respectively used to monitor the gas concentration and the oxygen concentration in the flow stabilizer and feedback them to the PLC controller; the PLC controller is used to receive the monitoring data fed back by the intelligent flowmeter, the gas concentration sensor, the oxygen concentration sensor, the first pressure sensor and the second pressure sensor, analyze and process them, control the working state of the double-fluid grouting pump and the opening and closing of the first intelligent control valve and the second intelligent control valve, and at the same time transmit the fed-back monitoring data and the states of the double-fluid grouting pump, the first intelligent control valve and the second intelligent control valve to the mobile terminal for display.

[0011] Furthermore, the plugging bladder is a double-layer riveted bladder, which includes an inner bladder layer and an outer bladder layer. The inner bladder layer is inside the outer bladder layer, and a plurality of rivets are evenly arranged on the outer surface of the inner bladder layer. A sandwich layer formed between the inner bladder layer and the outer bladder layer is filled with a viscoelastic reparable emulsion hole-sealing material. The liquid injection port on the second grouting pipe is located in the inner bladder layer. When the cement-based material is injected into the inner bladder layer, after the inner bladder layer expands, the rivets on its surface pierce the outer bladder layer so that the viscoelastic reparable emulsion hole-sealing material penetrates into the space between the outer bladder layer and the borehole wall. Adopting this structure can make the viscoelastic reparable emulsion hole-sealing material bond the bladder and the borehole wall when the plugging bladder plugs the borehole, improving the plugging effect of the plugging bladder on the borehole.

[0012] Furthermore, the inner bladder layer is made of rubber, the outer bladder layer is a mining woven bag, the height of the rivets is 5 mm, and the thickness of the sandwich layer filled with the viscoelastic reparable emulsion hole-sealing material is 20 mm. The rubber has good elasticity so that the inner bladder layer will not rupture when it expands; at the same time, the outer bladder layer is a mining woven bag, which is convenient for the subsequent piercing of the outer bladder layer by the rivets to enable the viscoelastic reparable emulsion hole-sealing material to flow out of the sandwich layer smoothly.

[0013] Furthermore, a first one-way valve is installed at the grouting port, and second one-way valves are installed at both liquid injection ports to prevent backflow during grouting.

[0014] Furthermore, level sensors are installed on both of the two slurry storage devices to monitor the amount of slurry in the slurry storage devices and feed back to the PLC controller. By setting the level sensors, the remaining amount of the hole-sealing material in the slurry storage devices can be monitored, facilitating the timely replenishment of the hole-sealing material.

[0015] The working method of the above intelligent dynamic hole-sealing system is specifically as follows:

[0016] A. Construct a disk-shaped slot: In the gas drainage borehole to be sealed, use the high-pressure hydraulic slotting technology to perform slotting operations in the preset plugging area in advance to form a disk-shaped slot with a certain thickness. The radius of the disk-shaped slot is 5 - 10 times the radius of the gas drainage borehole;

[0017] B. Install the intelligent dynamic hole-sealing system: Prepare the viscoelastic reparable emulsion hole-sealing material and the cement-based hole-sealing material respectively, and inject them into the two slurry storage devices for storage. Then connect the two slurry storage devices to the double-fluid grouting pump respectively; Next, send the hole-sealing device into the preset plugging area in the borehole, and make the disk-shaped slot located between the two plugging bags. Then connect the first grouting pipe and the second grouting pipe to the double-fluid grouting pump respectively to complete the installation process of the intelligent dynamic hole-sealing system; At the same time, set the minimum gas drainage concentration C L , safety oxygen concentration C B , minimum grouting pressure P L parameters through the mobile terminal and send them to the PLC controller for storage;

[0018] C. Preliminary hole-sealing with the plugging bags: First, start the double-fluid grouting pump to inject the cement-based hole-sealing material into the inner layer of the two double-layer rivet bags through the second grouting pipe. At this time, the inner layer of the bag continuously expands. After reaching a certain degree, the rivets on its surface pierce the outer layer of the bag and embed into the coal wall, causing the viscoelastic reparable emulsion hole-sealing material in the interlayer to flow out. Part of it seeps into the surrounding rock fissures, and the other part adheres the double-layer rivet bag to the borehole wall, fully supporting the borehole wall and forming a closed space in the gas drainage borehole between the two double-layer rivet bags; The second pressure sensor on the second grouting pipe transmits data to the PLC controller in real time. When the value of the second pressure sensor gradually stabilizes at 3 MPa, the PLC controller sends adjustment instructions to the second intelligent control valve and the double-fluid grouting pump, reduces the valve opening, and gradually stops injecting the cement-based hole-sealing material to complete the preliminary hole-sealing process with the plugging bags;

[0019] D. Hole-sealing with the viscoelastic reparable emulsion: After the closed space is formed, start the double-fluid grouting pump to inject the viscoelastic reparable emulsion hole-sealing material into the closed space through the first grouting pipe, and the grouting pressure is not lower than the set minimum grouting pressure P L, so that the viscoelastic repairable emulsion hole-sealing material enters the surrounding rock fissures and disc-shaped slots around the gas drainage borehole, and then the viscoelastic repairable emulsion hole-sealing material forms a circular curtain for borehole plugging in the disc-shaped slot; the first pressure sensor on the first grouting pipe transmits data to the PLC controller in real time. When the value of the first pressure sensor reaches 2 MPa, the PLC controller sends an adjustment instruction to the first intelligent control valve and the double-fluid grouting pump to reduce the valve opening, so that the grouting mode of the double-fluid grouting pump becomes a pulsating cycle mode, with a pulsation period of grouting for 2 minutes and pausing for 0.5 minutes. Continue to inject until the value of the first pressure sensor remains stable for 10 minutes, and then stop injecting the viscoelastic repairable emulsion hole-sealing material to complete the gas drainage borehole plugging process;

[0020] E. Gas drainage and intelligent dynamic hole sealing: Connect the underground gas pipeline with the gas drainage pipe to start gas drainage. During the gas drainage process, the liquid level sensor, gas concentration sensor, oxygen concentration sensor, and intelligent flowmeter transmit data to the PLC controller in real time. At the same time, the PLC controller uploads the data to the mobile terminal, and the staff can obtain the gas drainage data and grouting situation from the mobile terminal; when the liquid level sensor sends a signal, it means that the hole-sealing material in the corresponding slurry storage device is insufficient, and the hole-sealing material needs to be replenished to the corresponding slurry storage device in time; when the gas concentration sensor measures the concentration C M is lower than the set minimum gas drainage concentration C L , and the oxygen concentration sensor measures the oxygen concentration C O is higher than the set safe oxygen concentration C B , first stop the gas drainage work. At this time, the PLC controller controls the first intelligent control valve to open and starts the double-fluid grouting pump to inject the viscoelastic repairable emulsion hole-sealing material into the closed space again in a pulsating cycle mode, with a pulsation period of grouting for 2 minutes and pausing for 0.5 minutes. Continue to inject until the value of the first pressure sensor remains stable for 10 minutes, and then stop injecting the viscoelastic repairable emulsion hole-sealing material; then continue the gas drainage work, and repeat this cycle to achieve intelligent dynamic hole sealing during the gas drainage process and ensure the efficiency of gas drainage.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. The viscoelastic reparable emulsion sealing material prepared by the present invention is composed of a first network polymer (FNP) with flexibility and relatively high crosslinking degree and a second network polymer (SNP) with low crosslinking degree. The two are mixed and superimposed to form a double-network gel structure, and nanoparticles are added to enhance the strength and toughness of the double-network gel structure; and the viscosity of the sealing material is adjusted by a thickener. The specific performance of the sealing material during actual use: First, when injecting into the borehole and surrounding fissures, it will be subjected to shear forces and produce sliding and deformation distortion. It has good viscoelasticity, which can effectively ensure the stability of the material structure, adapt to the dynamic deformation of the borehole fissures at the same time, and it can closely combine with the fissure surface and firmly adhere to the coal wall, eliminating the air leakage channel between the sealing material and the borehole wall; this sealing material belongs to a non-Newtonian fluid, and its viscosity will decrease under the action of shear during injection. Its low viscosity and high fluidity enable it to smoothly fill and penetrate into all parts of the fissure under a relatively low injection pressure and fill the disc-shaped slot. Secondly, after the sealing material comes into contact with air, its surface layer will condense to form a condensation layer, which wraps the material, and its interior remains liquid; when the sealing material deforms with the borehole fissure, the surface condensation layer cracks, and the internal emulsion sealing material can automatically flow and fill into the cracked area to fill the gap and restore the integrity of the material, thereby achieving the sealing effect. Finally, the nanoparticles and the second network polymer in the sealing material can form small particles after absorbing water. These small particles can effectively block the air flow channel after entering the fissure, increase the air flow resistance, limit the free passage of gas through the fissure. At the same time, the presence of the particles can also disperse the pressure, resist the excessive compressive deformation of the fissure, and maintain the stability of the sealing effect.

[0023] 2. The present invention arranges a corresponding intelligent dynamic sealing system based on the characteristics of the viscoelastic reparable emulsion sealing material. The intelligent dynamic sealing system first seals the borehole preliminarily through a sealing bag, and then uses the characteristics of the viscoelastic reparable emulsion for secondary sealing. A circular curtain for borehole sealing is formed in the disc-shaped slot by the viscoelastic reparable emulsion sealing material. This circular curtain can block the connectivity between the fissures generated around the borehole, thereby improving the sealing effect; in addition, when the sealing bag seals the borehole, the viscoelastic reparable emulsion sealing material flowing out of its interlayer, a part of it seeps into the surrounding rock fissures, and the other part bonds the double-layer rivet bag to the borehole wall, fully supporting the borehole wall and forming a closed space in the gas drainage borehole between two double-layer rivet bags, ensuring the sealing quality; in addition, during the subsequent gas drainage process, due to the influence of ground pressure and other conditions, the surrounding rock deforms, which will lead to a decline in the sealing effect. At this time, using the characteristics of the viscoelastic reparable emulsion sealing material to continue the dynamic sealing process can restore the sealing effect and ultimately ensure the efficiency of gas drainage. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of the intelligent dynamic sealing system in the present invention;

[0025] Figure 2 is a schematic structural diagram of the hole sealing device in the present invention;

[0026] Figure 3 is a schematic structural diagram of the double-layer rivet pocket structure in the present invention.

[0027] In the figure: 1. Gas drainage pipe, 2. Second grouting pipe, 3. First grouting pipe, 4. Double-layer rivet pocket, 5. Rivet, 6. Second one-way valve, 7. First one-way valve, 8. Second pressure sensor, 9. First pressure sensor, 10. Filter, 11. Intelligent flowmeter, 12. Flow stabilizer, 13. Gas concentration sensor, 14. Oxygen concentration sensor, 15. Second intelligent control valve, 16. First intelligent control valve, 17. Grout storage device, 18. Liquid level sensor, 19. Double-fluid grouting pump, 20. PLC controller, 21. Mobile terminal, 22. Disk-shaped slot, 23. Viscoelastic reparable emulsion hole-sealing material. Specific embodiments

[0028] The present invention will be further described below.

[0029] As Figure 1 shown, an intelligent dynamic hole sealing system includes an intelligent control device, a hole sealing device, a grout storage device 17, and a grouting device;

[0030] As Figure 2As shown, the hole-sealing device includes a gas drainage pipe 1, a first grouting pipe 3, a second grouting pipe 2, two plugging bags, a flow stabilizer 12 and a filter 10. One end of the gas drainage pipe 1 extends into the gas drainage borehole. The two plugging bags are installed outside the gas drainage pipe 1 in the gas drainage borehole, and there is a certain distance between them. The flow stabilizer 12 and the filter 10 are both installed on the gas drainage pipe 1 outside the gas drainage borehole. The flow stabilizer 12 is used to stabilize the drainage flow in the gas drainage pipe 1, and the filter 10 is used to filter the extracted gas to remove the particulate matter therein. One end of the first grouting pipe 3 extends between the two plugging bags, and a grouting port is provided at this end. One end of the second grouting pipe 2 passes through the plugging bag near the borehole opening and extends into the other plugging bag. Liquid injection ports are provided on the second grouting pipe 2 inside the two plugging bags. The plugging bag is a double-layer riveted bag 4, which includes an inner bag layer and an outer bag layer. The inner bag layer is inside the outer bag layer, and a plurality of rivets 5 are evenly arranged on the outer surface of the inner bag layer. The interlayer formed between the inner bag layer and the outer bag layer is filled with a viscoelastic reparable emulsion hole-sealing material 23. The liquid injection port on the second grouting pipe 2 is located in the inner bag layer. When the cement-based material is injected into the inner bag layer, after the inner bag layer expands, the rivets 5 on its surface pierce the outer bag layer, so that the viscoelastic reparable emulsion hole-sealing material 23 penetrates between the outer bag layer and the borehole wall. Adopting this structure can make the viscoelastic reparable emulsion hole-sealing material 23 bond the bag and the borehole wall when the plugging bag seals the borehole, improving the sealing effect of the plugging bag on the borehole. The grouting port is equipped with a first one-way valve 7, and the two liquid injection ports are both equipped with second one-way valves 6 to prevent backflow during grouting.

[0031] The grouting device is a two-fluid grouting pump 19. There is a set of slurry suction valve and slurry discharge valve at each end of its working cylinder, which can simultaneously suck and discharge the same kind of hole-sealing material, or separately suck and discharge two different hole-sealing materials. There are two slurry storage devices 17. The two slurry storage devices 17 are respectively filled with viscoelastic reparable emulsion hole-sealing material 23 and cement-based hole-sealing material, and are respectively connected to the two inlets of the two-fluid grouting pump 19. The two outlets of the two-fluid grouting pump 19 are respectively connected to the other end of the first grouting pipe 3 and the other end of the second grouting pipe 2, and are used to transport the viscoelastic reparable emulsion hole-sealing material 23 through the first grouting pipe 3 into the gas drainage borehole between the two plugging bags, and at the same time transport the cement-based hole-sealing material through the second grouting pipe 2 into the two plugging bags, so as to make the plugging bags expand to plug the gas drainage borehole; The viscoelastic reparable emulsion hole-sealing material 23 is prepared by mixing a first network polymer and water in a mass ratio of (7-9):(1-3) as the base material, adding a second network polymer with a mass fraction of 0.05%-0.2%, 0.5% nanoparticles, and 2%-4% thickener. This formula can ensure that the viscoelastic reparable emulsion hole-sealing material has good viscoelasticity, reparability, fluidity, strong adhesion to the coal wall, and can well adapt to the deformation of coal and rock strata. The first network polymer is one of polyacrylamide-based-2-methyl-1-propanesulfonic acid, alginic acid, agar, and VAE emulsion. The second network polymer is one of polyacrylamide, poly-6-acrylamide hexanoic acid, polyvinyl alcohol, and sodium polyacrylate. The nanoparticles are one of the nano-powders of nano-silica, iron tetroxide, graphene, and calcium carbonate. The thickener is one of sodium carboxymethyl cellulose, xanthan gum, kaolin, and montmorillonite.

[0032] The intelligent control device includes a PLC controller 20, a mobile terminal 21, an intelligent flowmeter 11, a gas concentration sensor 13, an oxygen concentration sensor 14, a first pressure sensor 9, a second pressure sensor 8, a first intelligent control valve 15 and a second intelligent control valve 14. The intelligent flowmeter 11 is installed on the gas drainage pipe 1 and is used to monitor the drainage flow in the gas drainage pipe 1 and feedback it to the PLC controller 20. The first pressure sensor 9 and the first intelligent control valve 15 are both installed on the first grouting pipe 3, and the second pressure sensor 8 and the second intelligent control valve 14 are both installed on the second grouting pipe 2. The first pressure sensor 9 and the second pressure sensor 8 are respectively used to monitor the pressures in the first grouting pipe 3 and the second grouting pipe 2 and feedback them to the PLC controller 20; the first intelligent control valve 16 and the second intelligent control valve 15 are respectively used to control the on-off of the first grouting pipe 3 and the second grouting pipe 2; the gas concentration sensor 13 and the oxygen concentration sensor 14 are both installed on the flow stabilizer 12 and are respectively used to monitor the gas concentration and oxygen concentration in the flow stabilizer 12 and feedback them to the PLC controller 20; the PLC controller 20 is used to receive the monitoring data fed back by the intelligent flowmeter 11, the gas concentration sensor 13, the oxygen concentration sensor 14, the first pressure sensor 9 and the second pressure sensor 8, analyze and process them, and then control the working state of the double-fluid grouting pump 19 and the opening and closing of the first intelligent control valve 16 and the second intelligent control valve 15. At the same time, the fed-back monitoring data, the states of the double-fluid grouting pump 19, the first intelligent control valve 16 and the second intelligent control valve 15 are transmitted to the mobile terminal 21 for display.

[0033] As an improvement of the present invention, as Figure 3 shown, the inner layer of the bladder is made of rubber, the outer layer of the bladder is made of a mining woven bag, the height of the rivet 5 is 5 mm, and the thickness of the sandwich layer after filling the viscoelastic reparable emulsion sealing material 23 is 20 mm. The rubber has good elasticity so that the inner layer of the bladder will not rupture when it expands; at the same time, the outer layer of the bladder uses a mining woven bag, which is convenient for the subsequent rivet 5 to pierce the outer layer of the bladder and make the viscoelastic reparable emulsion sealing material 23 flow out of the sandwich layer smoothly.

[0034] As another improvement of the present invention, level sensors 18 are installed on both of the two slurry storage devices 17 and are used to monitor the slurry volume in the slurry storage devices 17 and feedback it to the PLC controller 20. By setting the level sensors 18, the remaining amount of the sealing material in the slurry storage devices 17 can be monitored, which is convenient for timely replenishing the sealing material.

[0035] The working method of the above intelligent dynamic sealing system specifically includes the following steps:

[0036] A. Construction of a disc-shaped slot: In the gas drainage borehole to be sealed, the high-pressure hydraulic slotting technology is used to perform slotting operations in the set plugging area in advance, forming a disc-shaped slot 22 with a certain thickness. The radius of the disc-shaped slot 22 is 5-10 times the radius of the gas drainage borehole;

[0037] B. Layout of the intelligent dynamic sealing system: Prepare the viscoelastic reparable emulsion sealing material 23 and the cement-based sealing material respectively. The cement-based sealing material is prepared by using the existing formula and preparation method. The specific preparation process of the viscoelastic reparable emulsion sealing material 23 in this embodiment is as follows: Mix the first network polymer and water according to a mass ratio of 8:2, stir in a magnetic stirrer at 400 r / min for 3 min. After stirring evenly, increase the rotation speed of the magnetic stirrer to 1000 r / min, and add the weighed 0.05 wt.% of the second network polymer, 4 wt.% of the tackifier, and 0.5 wt.% of the nanoparticles into the mixture of the first network polymer and water in small amounts and multiple times to ensure that each component is fully and evenly dispersed in the mixture. Then, reduce the rotation speed to 400 r / min to avoid generating bubbles, and stir for another 3 min to further ensure the homogeneity and stability of the emulsion sealing material. Finally, obtain the viscoelastic reparable emulsion sealing material 23. Inject the two materials into two slurry storage devices 17 for storage respectively, and then connect the two slurry storage devices 17 to the double-fluid grouting pump 19 respectively; then send the sealing device into the set plugging area in the borehole, and make the disc-shaped slot 22 located between the two plugging bags, and then connect the first grouting pipe 3 and the second grouting pipe 2 to the double-fluid grouting pump 19 respectively to complete the layout process of the intelligent dynamic sealing system; at the same time, set the minimum gas drainage concentration C L , safety oxygen concentration C B , minimum grouting pressure P L parameters and send them to the PLC controller 20 for storage;

[0038] C. Preliminary sealing of the plugging bag: First, start the double-fluid grouting pump 19 to inject the cement-based sealing material into the inner layer of the two double-layer rivet bags 4 through the second grouting pipe 2. At this time, the inner layer of the bag continues to expand. After reaching a certain degree, the rivets 5 on its surface pierce the outer layer of the bag and embed into the coal wall, so that the viscoelastic reparable emulsion sealing material 23 in the interlayer flows out. Part of it seeps into the surrounding rock fissures, and the other part bonds the double-layer rivet bag 4 to the borehole wall to fully support the borehole wall, forming a closed space in the gas drainage borehole between the two double-layer rivet bags 4; the second pressure sensor 8 on the second grouting pipe 2 transmits data to the PLC controller 20 in real time. When the value of the second pressure sensor 8 gradually stabilizes to 3 MPa, the PLC controller 20 sends adjustment instructions to the second intelligent control valve 15 and the double-fluid grouting pump 19, reduces the valve opening, and gradually stops injecting the cement-based sealing material to complete the preliminary sealing process of the plugging bag;

[0039] D. Viscous-elasticity reparable emulsion hole sealing: After the closed space is formed, start the double-fluid grouting pump 19 to inject the viscous-elasticity reparable emulsion hole-sealing material 23 into the closed space through the first grouting pipe 9, and the grouting pressure shall not be lower than the set minimum grouting pressure P L , so that the viscous-elasticity reparable emulsion hole-sealing material 23 enters the surrounding rock fissures and the disc-shaped slot 22 around the gas drainage borehole, and then the viscous-elasticity reparable emulsion hole-sealing material 23 forms a circular curtain for borehole plugging in the disc-shaped slot 22; the first pressure sensor 9 on the first grouting pipe 3 transmits data to the PLC controller 20 in real time. When the value of the first pressure sensor 9 reaches 2 MPa, the PLC controller 20 sends an adjustment instruction to the first intelligent control valve 16 and the double-fluid grouting pump 19 to reduce the valve opening, so that the grouting mode of the double-fluid grouting pump 19 becomes a pulsating cycle mode, with a pulsation period of grouting for 2 min and pausing for 0.5 min. Continuously inject until the value of the first pressure sensor 9 remains stable for 10 min, then stop injecting the viscous-elasticity reparable emulsion hole-sealing material 23 to complete the gas drainage borehole plugging process;

[0040] E. Gas drainage and intelligent dynamic hole sealing: Connect the underground gas pipeline with the gas drainage pipe 1 to start gas drainage. During the gas drainage process, the liquid level sensor 18, the gas concentration sensor 13, the oxygen concentration sensor 14 and the intelligent flowmeter 11 transmit data to the PLC controller 20 in real time. At the same time, the PLC controller 20 uploads the data to the mobile terminal 21, and the staff can obtain the gas drainage data and grouting situation from the mobile terminal 21; when the liquid level sensor 18 sends a signal, it means that the hole-sealing material in the corresponding slurry storage device 17 where it is located is insufficient, and the hole-sealing material needs to be replenished to the corresponding slurry storage device 17 in time; when the gas concentration sensor 13 measures the concentration C M is lower than the set minimum gas drainage concentration C L , and the oxygen concentration sensor 14 measures the oxygen concentration C O is higher than the set safe oxygen concentration C B , first stop the gas drainage work. At this time, the PLC controller 20 controls the first intelligent control valve 16 to open and starts the double-fluid grouting pump 19 to inject the viscous-elasticity reparable emulsion hole-sealing material 23 into the closed space again in a pulsating cycle mode, with a pulsation period of grouting for 2 min and pausing for 0.5 min. Continuously inject until the value of the first pressure sensor 9 remains stable for 10 min, then stop injecting the viscous-elasticity reparable emulsion hole-sealing material 23; then continue the gas drainage work, and repeat the cycle like this, so as to realize the intelligent dynamic hole sealing during the gas drainage process and ensure the efficiency of gas drainage.

[0041] In addition, during the drainage process, according to the obtained drainage gas flow rate Q and the gas drainage concentration C M the pure gas drainage volume Q is obtainedP , evaluate the gas drainage efficiency and the service life of the drainage boreholes through the pure gas drainage volume Q P .

[0042] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. An intelligent dynamic hole-sealing system for a viscoelastic reparable emulsion hole-sealing material, characterized in that, It includes an intelligent control device, a hole sealing device, a slurry storage device and a grouting device; The hole sealing device includes a gas drainage pipe, a first grouting pipe, a second grouting pipe, two plugging bags, a flow stabilizer and a filter. One end of the gas drainage pipe extends into the gas drainage borehole. The two plugging bags are installed outside the gas drainage pipe in the gas drainage borehole, and there is a certain distance between them. The flow stabilizer and the filter are both installed on the gas drainage pipe outside the gas drainage borehole. The flow stabilizer is used to stabilize the drainage flow in the gas drainage pipe, and the filter is used to filter the extracted gas. One end of the first grouting pipe extends between the two plugging bags, and a grouting port is provided at this end. One end of the second grouting pipe passes through the plugging bag near the borehole orifice and extends into the other plugging bag. Liquid injection ports are provided on the second grouting pipe inside the two plugging bags. The plugging bag is a double-layer riveted bag, which includes an inner bag layer and an outer bag layer. The inner bag layer is inside the outer bag layer, and a plurality of rivets are evenly arranged on the outer surface of the inner bag layer. A sandwich formed between the inner bag layer and the outer bag layer is filled with a viscoelastic reparable emulsion hole-sealing material. The liquid injection port on the second grouting pipe is in the inner bag layer. When the cement-based material is injected into the inner bag layer, after the inner bag layer expands, the rivets on its surface pierce the outer bag layer, so that the viscoelastic reparable emulsion hole-sealing material penetrates between the outer bag layer and the borehole wall; The grouting device is a double-fluid grouting pump. There are two slurry storage devices. The two slurry storage devices contain a viscoelastic reparable emulsion hole-sealing material and a cement-based hole-sealing material respectively, and are respectively connected to the two inlets of the double-fluid grouting pump. The two outlets of the double-fluid grouting pump are respectively connected to the other ends of the first grouting pipe and the second grouting pipe, and are used to transport the viscoelastic reparable emulsion hole-sealing material through the first grouting pipe into the gas drainage borehole between the two plugging bags, and at the same time transport the cement-based hole-sealing material through the second grouting pipe into the two plugging bags, so as to make the plugging bags expand to seal the gas drainage borehole; The intelligent control device includes a PLC controller, a mobile terminal, an intelligent flowmeter, a gas concentration sensor, an oxygen concentration sensor, a first pressure sensor, a second pressure sensor, a first intelligent control valve, and a second intelligent control valve. The intelligent flowmeter is installed on the gas drainage pipe and is used to monitor the drainage flow in the gas drainage pipe and feed it back to the PLC controller. The first pressure sensor and the first intelligent control valve are both installed on the first grouting pipe, and the second pressure sensor and the second intelligent control valve are both installed on the second grouting pipe. The first pressure sensor and the second pressure sensor are respectively used to monitor the pressures in the first grouting pipe and the second grouting pipe and feed them back to the PLC controller; the first intelligent control valve and the second intelligent control valve are respectively used to control the on-off of the first grouting pipe and the second grouting pipe; the gas concentration sensor and the oxygen concentration sensor are both installed on the flow stabilizer and are respectively used to monitor the gas concentration and oxygen concentration in the flow stabilizer and feed them back to the PLC controller; the PLC controller is used to receive the monitoring data fed back by the intelligent flowmeter, the gas concentration sensor, the oxygen concentration sensor, the first pressure sensor, and the second pressure sensor, analyze and process them, and then control the working state of the double-fluid grouting pump and the opening and closing of the first intelligent control valve and the second intelligent control valve. At the same time, the fed-back monitoring data, the states of the double-fluid grouting pump, the first intelligent control valve, and the second intelligent control valve are transmitted to the mobile terminal for display.

2. The intelligent dynamic hole sealing system according to claim 1, wherein The viscoelastic reparable emulsion sealing material is prepared by mixing a first network polymer and water in a mass ratio of (7-9):(1-3) as the base material, adding 0.05%-0.2% of a second network polymer, 0.5% of nanoparticles, and 2%-4% of a tackifier.

3. The intelligent dynamic hole sealing system according to claim 1, wherein The inner layer of the bladder is rubber, the outer layer of the bladder is a mining woven bag, the height of the rivet is 5 mm, and the thickness of the interlayer after filling with the viscoelastic reparable emulsion sealing material is 20 mm.

4. The intelligent dynamic hole sealing system according to claim 1, characterized in that, The grouting port is equipped with a first one-way valve, and both injection ports are equipped with second one-way valves to prevent backflow during grouting.

5. The intelligent dynamic hole sealing system according to claim 1, characterized in that Level sensors are installed on both of the two slurry storage devices to monitor the slurry volume in the slurry storage devices and feed it back to the PLC controller.

6. A working method of the intelligent dynamic hole sealing system according to claim 1, characterized in that, The specific steps are as follows: A. Construct a disc-shaped slot: In the gas drainage borehole to be sealed, use high-pressure hydraulic slotting technology to pre-perform slotting operations in the set plugging area to form a disc-shaped slot with a certain thickness. The radius of the disc-shaped slot is 5-10 times the radius of the gas drainage borehole. B. Installation of intelligent dynamic hole - sealing system: Prepare viscoelastic repairable emulsion hole - sealing material and cement - based hole - sealing material respectively, and inject them into two slurry storage devices for storage. Then connect the two slurry storage devices to a double - liquid grouting pump respectively. Next, send the hole - sealing device to the set plugging area in the borehole, and make the disc - shaped slot between two plugging bags. Then connect the first grouting pipe and the second grouting pipe to the double - liquid grouting pump respectively to complete the installation process of the intelligent dynamic hole - sealing system. At the same time, set the minimum gas drainage concentration C L , safe oxygen concentration C B , minimum grouting pressure P L parameters through a mobile terminal and send them to the PLC controller for storage; C. Initial sealing of the plugging bag: First, start the double-fluid grouting pump to inject the cement-based hole-sealing material into the inner layer of the two double-layer rivet bags through the second grouting pipe. At this time, the inner layer of the bag continues to expand. After reaching a certain degree, the rivets on its surface pierce the outer layer of the bag and embed into the coal wall, causing the viscoelastic reparable emulsion hole-sealing material in the interlayer to flow out. Part of it seeps into the surrounding rock fissures, and the other part bonds the double-layer rivet bag to the borehole wall, fully supporting the borehole wall and forming a closed space in the gas drainage borehole between the two double-layer rivet bags. The second pressure sensor on the second grouting pipe transmits data to the PLC controller in real time. When the value of the second pressure sensor gradually stabilizes at 3 MPa, the PLC controller sends adjustment instructions to the second intelligent control valve and the double-fluid grouting pump, reduces the valve opening, and gradually stops injecting the cement-based hole-sealing material to complete the initial sealing process of the plugging bag. D. Sealing the borehole with viscoelastic repairable emulsion: After the closed space is formed, start the double-fluid grouting pump to inject the viscoelastic repairable emulsion sealing material into the closed space through the first grouting pipe, and the grouting pressure shall not be lower than the set minimum grouting pressure P L , so that the viscoelastic repairable emulsion sealing material enters the surrounding rock fissures and disc-shaped slots around the gas drainage borehole, and then the viscoelastic repairable emulsion sealing material forms a circular curtain for borehole plugging in the disc-shaped slot; the first pressure sensor on the first grouting pipe transmits data to the PLC controller in real time. When the value of the first pressure sensor reaches 2 MPa, the PLC controller sends an adjustment instruction to the first intelligent control valve and the double-fluid grouting pump to reduce the valve opening, so that the grouting method of the double-fluid grouting pump becomes a pulsating cycle type, with a pulsation period of grouting for 2 minutes and pausing for 0.5 minutes. Continue to inject until the value of the first pressure sensor remains stable for 10 minutes, then stop injecting the viscoelastic repairable emulsion sealing material to complete the process of plugging the gas drainage borehole; E. Gas drainage and intelligent dynamic sealing: Connect the underground gas pipeline with the gas drainage pipe to start gas drainage. During the gas drainage process, the liquid level sensor, gas concentration sensor, oxygen concentration sensor, and intelligent flowmeter transmit data to the PLC controller in real-time. At the same time, the PLC controller uploads the data to the mobile terminal, and the staff can obtain the gas drainage data and grouting situation from the mobile terminal. When the liquid level sensor sends a signal, it means that the sealing material in the corresponding slurry storage device is insufficient, and the sealing material needs to be replenished in time. When the gas concentration sensor measures the concentration C M is lower than the set minimum gas drainage concentration C L , and the oxygen concentration sensor measures the oxygen concentration C O is higher than the set safe oxygen concentration C B , first stop the gas drainage work. At this time, the PLC controller controls the first intelligent control valve to open and starts the double-fluid grouting pump to inject the viscoelastic reparable emulsion sealing material into the closed space again in a pulsating cycle. The pulsating cycle is 2 minutes of grouting and 0.5 minutes of pause, and continue to inject until the value of the first pressure sensor remains stable for 10 minutes, then stop injecting the viscoelastic reparable emulsion sealing material. Then continue the gas drainage work, and repeat this cycle to achieve intelligent dynamic sealing during the gas drainage process and ensure the efficiency of gas drainage.

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