Gas extraction three-plugging two-injection water-swellable hole sealing device

Abstract

The utility model discloses a gas extraction three-blocking two-injection water-absorbing expansion hole sealing device which comprises a first hole packer, a second hole packer, a third hole packer, a gas extraction pipe, a first water injection pipe and a second water injection pipe. The first hole packer, the second hole packer and the third hole packer plug a drill hole through the second water injection pipe, so that two sealed spaces are formed, then the first water injection pipe injects water into the two sealed spaces, and finally the drill hole is sealed through the water absorption expansion effect of the water absorption expansion material. A three-plugging two-injection combined water absorption expansion material mode is adopted, extra hole sealing materials such as cement are not needed in the whole process, and therefore the required hole sealing effect can be achieved by directly conducting hole sealing operation under a well. And in addition, even if part of the sealing holes lose efficacy when the subsequent drill holes are pressed and deformed, the water pressure change is observed through the pressure gauge, the water can be supplemented and strengthened in a water supplementing mode, and finally the continuity of the hole sealing effect can be kept.

Description

Technical Field

[0001] The utility model relates to a gas extraction three-blocking and two-injection water-absorbing expansion hole sealing device, belonging to the technical field of gas extraction hole sealing. Background Art

[0002] At present, mine gas extraction systems have been set up in coal mines with high gas content to extract gas from the mined coal seams. Bottom extraction tunnels, also known as floor tunnels, refer to tunnels arranged in the rock layer below the coal seam. Extracting gas from bottom extraction tunnels to protect the excavation of upper coal tunnels is a key technology for controlling gas outbursts.

[0003] Coal seam gas extraction requires drilling holes in the coal seam and sending the extraction pipeline into the holes. In the extraction system, the sealing quality of the extraction holes plays a decisive role. It is directly related to the effect of gas extraction. Therefore, it is necessary to ensure that the holes are tightly sealed.

[0004] At present, the coal mining industry generally adopts the "two blocking and one injection" sealing process. This sealing method requires injecting cement or similar sealing materials into the borehole to complete the sealing. Therefore, cement materials need to be transported underground for sealing, which leads to high labor intensity for workers. After the cement materials solidify, new cracks will be generated because the surrounding rocks of the tunnels are still deforming. Once the borehole leaks, the gas extraction effect will be reduced, and reinforcement cannot be carried out, so the hole can only be completely re-sealed, which also reduces the gas extraction efficiency. Summary of the invention

[0005] In view of the problems existing in the above-mentioned prior art, the utility model provides a gas extraction three-blocking and two-injection water-swellable sealing device, which adopts the method of three-blocking and two-injection combined with water-swellable materials. The whole process does not require additional sealing materials such as cement, so that the sealing operation can be directly carried out underground to achieve the desired sealing effect. In addition, secondary reinforcement can be carried out by water replenishment, so as to ultimately maintain the sustainability of the sealing effect.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a gas extraction three-blocking and two-injection water-absorbing expansion sealing device, comprising a first hole sealer, a second hole sealer, a third hole sealer, a gas extraction pipe, a first water injection pipe and a second water injection pipe;

[0007] The first hole sealer, the second hole sealer and the third hole sealer are all installed on the gas extraction pipe, and the first hole sealer, the second hole sealer and the third hole sealer are all made of water-absorbing and expanding rubber;

[0008] One end of the first water injection pipe passes through the first hole sealer and the second hole sealer in sequence, and is located between the second hole sealer and the third hole sealer. An opening is provided on the water injection pipe between the first hole sealer and the second hole sealer. The opening and one end of the first water injection pipe are both equipped with bursting valves. The two bursting valves are respectively wrapped by two material bags, and the material bags contain water-absorbing and expanding materials. The first water injection pipe is used to inject water into the two material bags, so that the water-absorbing and expanding materials absorb water and expand and burst the material bags, thereby sealing the borehole.

[0009] One end of the second water injection pipe passes through the first hole sealer and the second hole sealer in sequence, and extends into the third hole sealer. The second water injection pipe is provided with water injection ports on the pipelines inside the first hole sealer and the second hole sealer respectively. The second water injection pipe is used to inject water into the first hole sealer, the second hole sealer and the third hole sealer respectively, so that the first hole sealer, the second hole sealer and the third hole sealer absorb water and expand, thereby sealing the borehole.

[0010] Furthermore, a first control valve is installed on the pipeline close to the other end of the first water injection pipe, which is used to control the injection of water into the first water injection pipe.

[0011] Furthermore, a second control valve is installed on the pipeline near the other end of the second water injection pipe, wherein the second control valve is used to control the injection of water into the second water injection pipe; and the pressure gauge is used to monitor the real-time pressure in the second water injection pipe.

[0012] Furthermore, the water injection port inside each of the first and second hole sealers and the other end of the second water injection pipe are equipped with a one-way valve, which is used to allow water to flow from the second water injection pipe to each hole sealer in one direction during water injection to prevent water backflow; this ensures the sealing effect of each hole sealer after water injection.

[0013] Furthermore, the first hole sealer, the second hole sealer and the third hole sealer are all cylindrical bodies with cavities inside, which is more convenient to put into the drilled hole and can have a more stable sealing effect after absorbing water and swelling.

[0014] Furthermore, the water-swelling material is a granular water-swelling rubber or a water-swelling resin. These water-swelling materials are not only easy to purchase, but also can achieve the desired water-swelling effect.

[0015] Compared with the prior art, the utility model adopts a combination of a first hole sealer, a second hole sealer, a third hole sealer, a gas extraction pipe, a first water injection pipe and a second water injection pipe, which has the following advantages:

[0016] 1. The utility model adopts a three-blocking and two-injection method to seal the borehole. First, the first, second and third hole sealers are used to seal the borehole through the second water injection pipe, thereby forming two sealed spaces. Then, the first water injection pipe is used to inject water into the two sealed spaces, and the water-absorbing and swelling effect of the water-swelling material is utilized to finally seal the borehole. The whole process does not require additional sealing materials such as cement, but only requires water injection, which facilitates direct sealing operations underground and can achieve the desired sealing effect.

[0017] 2. Since the utility model adopts three-blocking and two-injection method combined with water-absorbing and expanding materials to seal the hole, the sealed part also has a certain deformation performance when the subsequent drilling hole is compressed and deformed. Even if part of the sealing fails, the water pressure change can be observed through the pressure gauge, and it can be supplemented and strengthened by replenishing water, so as to finally maintain the continuity of the sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0019] In the figure: 1. first hole sealer; 2. second hole sealer; 3. third hole sealer; 4. first material bag; 5. second material bag; 6. first water injection pipe; 7. second water injection pipe; 8. gas extraction pipe; 9. first control valve; 10. second control valve; 11. pressure gauge; 12. one-way valve; 13. bursting valve; 14. drilling hole. DETAILED DESCRIPTION

[0020] The utility model will be further described below.

[0021] like Figure 1 As shown, the utility model comprises a first hole sealer 1, a second hole sealer 2, a third hole sealer 3, a gas extraction pipe 8, a first water injection pipe 6 and a second water injection pipe 7;

[0022] The first hole sealer 1, the second hole sealer 2 and the third hole sealer 3 are all installed on the gas extraction pipe 8, and the first hole sealer 1, the second hole sealer 2 and the third hole sealer 3 are all made of water-absorbing and swelling rubber;

[0023] One end of the first water injection pipe 6 passes through the first hole sealer 1 and the second hole sealer 2 in sequence, and is located between the second hole sealer 2 and the third hole sealer 3. An opening is provided on the water injection pipe between the first hole sealer 1 and the second hole sealer 2. The opening and one end of the first water injection pipe are both equipped with a bursting valve 13. The two bursting valves 13 are respectively wrapped by two material bags, which are plastic bags containing water-absorbing and expanding materials. The water-absorbing and expanding materials are granular water-absorbing and expanding rubber or water-absorbing and expanding resin. The use of these existing water-swellable materials is not only easy to purchase and obtain, but also can achieve the required water-swelling effect; the first material bag 4 is located between the first hole sealer 1 and the second hole sealer 2, and the second material bag 5 is located between the second hole sealer 2 and the third hole sealer 3. The first water injection pipe 6 is used to inject water into the two material bags, so that the water-swellable material absorbs water and expands to burst the material bags, thereby sealing the borehole 14; a first control valve 9 is installed on the pipeline near the other end of the first water injection pipe 6, which is used to control the injection of water into the first water injection pipe 6.

[0024] One end of the second water injection pipe 7 passes through the first hole sealer 1 and the second hole sealer 2 in sequence, and extends into the third hole sealer 3. The second water injection pipe 7 is provided with water injection ports on the pipelines inside the first hole sealer 1 and the second hole sealer 2 respectively. The second water injection pipe 7 is used to inject water into the first hole sealer 1, the second hole sealer 2 and the third hole sealer 3 respectively, so that the first hole sealer 1, the second hole sealer 2 and the third hole sealer 3 absorb water and expand, thereby sealing the borehole 14; a second control valve 10 is installed on the pipeline near the other end of the second water injection pipe 7, wherein the second control valve 10 is used to control the injection of water into the second water injection pipe 7; the pressure gauge 11 is used to monitor the real-time pressure in the second water injection pipe 7.

[0025] As an improvement of the present invention, the water injection ports inside the first hole sealer 1 and the second hole sealer 2 and the other end of the second water injection pipe 7 are equipped with a one-way valve 12, which is used to allow water to flow from the second water injection pipe 7 to each hole sealer in one direction during water injection to prevent water backflow; this ensures the sealing effect of each hole sealer after water injection.

[0026] As another improvement of the present invention, the first hole sealer 1, the second hole sealer 2 and the third hole sealer 3 are all cylindrical bodies with cavities inside. This structure is more convenient to put into the borehole 14, and can have a more stable sealing effect after absorbing water and swelling.

[0027] The first control valve 9, the second control valve 10, the burst valve 13, the one-way valve 12 and the pressure gauge 11 are all existing components and can be directly purchased in the market.

[0028] Before using the utility model to seal the borehole, the utility model is first assembled, and then the gas extraction pipe 8 is passed through the first hole sealer 1, the second hole sealer 2 and the third hole sealer 3 in sequence, and the first hole sealer 1, the second hole sealer 2 and the third hole sealer 3 are all fixed to the gas extraction pipe 8; finally, the whole is placed in the borehole 14 to be sealed, so that the first hole sealer 1 is closest to the hole opening in the borehole 14, and the third hole sealer 3 is farthest from the hole opening; then the first water injection pipe 6 and the second water injection pipe 7 are connected to the underground water supply pipeline, and the first control valve 9 and the second control valve 10 are both in the closed state, and the layout work is completed;

[0029] When the sealing work begins, first open the second control valve 10, and inject water into the first hole sealer 1, the second hole sealer 2 and the third hole sealer 3 through the second water injection pipe 7, so that the water-absorbing and swelling rubber absorbs water and expands. At this time, the first hole sealer 1, the second hole sealer 2 and the third hole sealer 3 squeeze the gas extraction pipe 8 inward and squeeze the borehole wall outward. During the water injection process, observe the reading of the pressure gauge 11 to understand the water pressure inside the first hole sealer 1, the second hole sealer 2 and the third hole sealer 3. When the required pressure value is reached, close the second control valve 10 to stop the water injection. Due to the effect of the one-way valve 12, the one-way valve 12 will be closed after the water injection is stopped to prevent water backflow; this ensures the sealing effect of each hole sealer after water injection; at this time, a first sealed space is formed between the first hole sealer 1 and the second hole sealer 2, and a second sealed space is formed between the second hole sealer 2 and the third hole sealer 3;

[0030] Then open the first control valve 9 and inject water into the first water injection pipe 6. When the pressure in the first water injection pipe 6 is greater than the opening pressure of the bursting valve 13, the bursting valves 13 in the first material bag 4 and the second material bag 5 are opened. At this time, the water in the first water injection pipe 6 rushes into the first material bag 4 and the second material bag 5 at a relatively high pressure, causing the water-absorbing and swelling materials inside the material bags to absorb water and swell, thereby bursting the two material bags. The water-absorbing and swelling materials in the first material bag 4 continue to absorb water and swell in the first sealed space, and the water-absorbing and swelling materials in the second material bag 5 continue to absorb water and swell in the second sealed space, until the first sealed space and the second sealed space are both filled with water, and then the first control valve 9 is closed to complete the filling and plugging work in the two sealed spaces; subsequently, the gas extraction pipe is connected to the downhole extraction pipeline for gas extraction; during the extraction process, the water pressure changes in the second water injection pipe 7 are observed through the pressure gauge 11. If the water pressure drops to a certain value, the second control valve 10 is opened to replenish water in each sealer, thereby ensuring the continuity of the overall sealing of the borehole 14.

[0031] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A three-blocking and two-injection water-absorbing expansion sealing device for gas extraction, characterized in that: It includes a first hole sealer, a second hole sealer, a third hole sealer, a gas extraction pipe, a first water injection pipe and a second water injection pipe; The first hole sealer, the second hole sealer and the third hole sealer are all installed on the gas extraction pipe, and the first hole sealer, the second hole sealer and the third hole sealer are all made of water-absorbing and expanding rubber; One end of the first water injection pipe passes through the first hole sealer and the second hole sealer in sequence, and is located between the second hole sealer and the third hole sealer. An opening is provided on the water injection pipe between the first hole sealer and the second hole sealer. The opening and one end of the first water injection pipe are both equipped with bursting valves. The two bursting valves are respectively wrapped by two material bags, and the material bags contain water-absorbing and expanding materials. The first water injection pipe is used to inject water into the two material bags, so that the water-absorbing and expanding materials absorb water and expand and burst the material bags, thereby sealing the borehole. One end of the second water injection pipe passes through the first hole sealer and the second hole sealer in sequence, and extends into the third hole sealer. The second water injection pipe is provided with water injection ports on the pipelines inside the first hole sealer and the second hole sealer respectively. The second water injection pipe is used to inject water into the first hole sealer, the second hole sealer and the third hole sealer respectively, so that the first hole sealer, the second hole sealer and the third hole sealer absorb water and expand, thereby sealing the borehole.

2. According to claim 1, the gas extraction three-blocking and two-injection water-absorbent expansion sealing device is characterized in that: A first control valve is installed on the pipeline close to the other end of the first water injection pipe, which is used to control the water injection into the first water injection pipe.

3. According to claim 1, the gas extraction three-blocking and two-injection water-absorbent expansion sealing device is characterized in that: A second control valve is installed on the pipeline near the other end of the second water injection pipe, wherein the second control valve is used to control the water injection into the second water injection pipe; and the pressure gauge is used to monitor the real-time pressure in the second water injection pipe.

4. According to claim 1, the three-blocking and two-injection water-swellable sealing device for gas extraction is characterized in that: The water injection ports inside the first and second hole sealers and the other end of the second water injection pipe are equipped with one-way valves to prevent water backflow from the second water injection pipe to each hole sealer during water injection.

5. According to claim 1, the three-blocking and two-injection water-swellable sealing device for gas extraction is characterized in that: The first hole sealer, the second hole sealer and the third hole sealer are all cylindrical bodies with cavities inside.

6. The three-blocking and two-injection water-swellable sealing device for gas extraction according to claim 1 is characterized in that: The water-swelling material is a granular water-swelling rubber or a water-swelling resin.

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