Gas drilling hose liquid injection internal support high-pressure drilling curtain integrated hole sealing process

Abstract

The invention relates to a gas drilling hose liquid injection internal support high-pressure drilling curtain integrated hole sealing process, and belongs to the technical field of gas extraction hole sealing. The liquid injection expansion capsule is inserted into the hole sealing pipe from the outer opening of the hole sealing pipe, the hole sealing pipe is internally supported after expansion of the liquid injection expansion capsule, then the grouting pressure of the grouting section is increased, grout is fully diffused under the high pressure effect to fill a hole wall coal gas leakage channel and cracks, and therefore a closed curtain barrier isolated from the outside is formed; the device has the advantages of safety, reliability, good sealing effect, high gas extraction concentration, long extraction time and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of gas extraction and hole sealing, and in particular relates to a gas drilling hose liquid injection internal support high-pressure drilling curtain integrated hole sealing process. Background Art

[0002] Gas extraction is one of the most effective methods for mine gas control. However, due to various factors, 65% of the gas extraction concentrations in my country's mining faces are lower than 30%, especially the concentration of gas extraction in the layered boreholes is generally low. At present, the "two plugging and two injection" sealing process is mostly used for the sealing of gas extraction boreholes in coal mines. The sealing pipe is mostly made of PE or PVC pipe. Due to the material, the maximum nominal pressure of the sealing pipe is 2.0Mpa. Therefore, the traditional grouting pressure of extraction drilling is mostly around 1.5Mpa. Otherwise, the sealing pipe will be squeezed and deformed or broken by the slurry, affecting the extraction effect. In addition, when constructing extraction drilling holes in areas with high ground stress, soft coal seams, and highly developed surrounding rock fissures, the 1.5Mpa grouting pressure cannot effectively block the fine cracks around the hole wall, resulting in problems such as gas leakage during the drilling and extraction process, low extraction concentration, and fast attenuation. If steel sealing pipes are used, the grouting pressure and effect can be guaranteed, but a large number of steel pipes pre-buried in the coal seam will bring safety hazards to the later mining. Therefore, it is imperative to study a gas extraction drilling high-pressure grouting and hole wall surrounding rock (coal) curtain integrated sealing process. Summary of the invention

[0003] The purpose of the present invention is to provide a gas drilling hose liquid injection internal support high-pressure drilling curtain integrated sealing process, through the "two blocking and two injection" sealing method to solve the problems existing in the prior art, the present invention through the liquid injection expansion capsule after the expansion of the sealing tube for internal support, and then increase the grouting pressure of the grouting section, so that the slurry under high pressure to fully diffuse filling hole wall coal body (rock) gas leakage channel and cracks, thereby forming a closed curtain barrier isolated from the outside, with the advantages of safety and reliability, good sealing effect, high gas extraction concentration, long extraction time, etc.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] A gas drilling hose liquid injection internal support high pressure drilling curtain integrated sealing process, characterized in that it includes the following steps:

[0006] Step 1: Drilling construction, using a drill bit to form a gas release channel under the action of mechanical force

[0007] According to the designed hole depth and diameter of the borehole on the tunnel wall, the borehole is constructed to the designed position, and the hole is fully washed to completely remove the residual coal powder in the borehole before the drill can be pulled out;

[0008] Step 2: Assemble the liquid-filled expansion capsule

[0009] Insert the liquid-injection expansion capsule into the sealing tube from the outer opening of the sealing tube. The front end of the liquid-injection expansion capsule passes through the outer opening of the sealing tube and the outer plugging bag and is inserted into the inner plugging bag to a position not less than 0.5m. The exposed rear end is not less than 0.1m away from the outer opening of the sealing tube. At the same time, ensure that the outer plugging bag is not less than 3m away from the drilling hole.

[0010] Step 3: Lower the tube

[0011] According to the drilling construction depth and the sealing design requirements, the screen pipe and the sealing pipe assembled in the second step are sequentially lowered into the borehole, and the sealing pipe is fixedly connected to the screen pipe through the sealing device;

[0012] Step 4: Grouting

[0013] First, the liquid-injection expansion capsule in the sealing tube is injected with liquid to expand, and the inner wall of the sealing tube is effectively supported by the liquid-injection expansion capsule to ensure that the sealing tube will not be squeezed and deformed under the action of external high pressure;

[0014] Then, high-stress expansion cement slurry is injected into the outer plugging bag and the inner plugging bag through the outer bag and the inner bag grouting pipe. First, the outer plugging bag and the inner plugging bag are expanded by filling with the slurry. Under the action of the bag filtering water, the water in the slurry is filtered out to remove the remaining expansion cement. Through the continuous increase of the rated pressure, the outer plugging bag and the inner plugging bag are completely coupled with the hole wall to create a ring-shaped closed space for the high-pressure curtain.

[0015] Step 5: Grouting of high pressure curtain section

[0016] After the solidification time of the outer and inner plugging bags after grouting is not less than 2 hours, the grouting pump is connected to the grouting pipe of the high-pressure curtain section. Under the action of high pressure, the slurry is effectively diffused in the space blocked by the high-pressure curtain section, filling the borehole and the surrounding coal and rock wall cracks to form a curtain barrier, achieving the purpose of high-pressure grouting and curtain integration;

[0017] Step 6: Connect the pipes

[0018] After the high-pressure curtain grouting of the fifth step is completed and the slurry solidifies, the injection expansion capsule is depressurized, taken out from the sealing tube, and the borehole is connected to the extraction pipeline, and the construction is completed.

[0019] Furthermore, in the second step, the liquid injection expansion capsule is composed of a liquid inlet joint, an expansion steel wire hose and a blind plug, and the expansion steel wire hose is composed of an inner rubber layer, a steel wire reinforcement layer, a middle rubber layer and an outer rubber layer; when in use, the high-pressure pump is connected to the liquid inlet joint of the liquid injection expansion capsule, and the liquid injection expansion capsule is expanded by injecting clean water, so that the inner wall of the sealing tube expands to support the outer wall, so that the sealing tube is not squeezed and deformed by the slurry during high-pressure grouting.

[0020] Furthermore, in the second step, the sealing tube is made of PE or PVC.

[0021] Furthermore, in the second step, the outer sealing bag and the inner sealing bag are made of elastic water filter cloth, which can filter the water in the slurry, gradually expand under the filling of the slurry and adhere to the hole wall to block the channel, forming a high-pressure curtain section.

[0022] Furthermore, in the third step, holes are evenly distributed on the screen pipe, which are the borehole gas extraction channels to prevent the borehole from collapsing and clogging.

[0023] Furthermore, in the third step, the hole sealer used is a bag-type through-tube direct-connected hole sealer.

[0024] Furthermore, in the process, the injection pressure of the liquid-injected expansion capsule is 4-6 MPa, the grouting pressure of the outer plugging bag and the inner plugging bag of the sealing tube is 1.0-1.5 MPa, and the grouting pressure of the high-pressure curtain section is 4-6 MPa.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention inserts a liquid-injection expansion capsule into the sealing tube to provide effective support and protection for the sealing tube, thereby avoiding the problem of being unable to implement high-pressure grouting due to material problems of the sealing tube.

[0027] 2. The present invention simplifies the construction process, combines the pre-drilling high-pressure curtain and the drilling grouting and sealing into one, reduces the labor intensity and improves the construction efficiency.

[0028] 3. The integrated sealing process of the present invention ensures the sealing quality, improves the extraction effect, and has the advantages of good sealing effect, high gas extraction concentration, and long extraction time. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a view of the integrated sealing process of the gas drilling hose liquid injection inner support high pressure drilling curtain of the present invention;

[0030] Figure 2 This is a real picture of the liquid injection expansion capsule;

[0031] Figure 3 This is the effect diagram of high-pressure drilling curtain integrated sealing;

[0032] Figure 4 The relationship between the pure amount of drilling extraction and the extraction time;

[0033] Figure 5 is the relationship between the borehole extraction concentration and the extraction time;

[0034] In the figure, 1. liquid injection expansion capsule, 2. outer bag and inner bag grouting pipe, 3. high-pressure curtain section grouting pipe, 4. tunnel wall, 5. sealing pipe, 6. outer sealing bag, 7. inner sealing bag, 8. screen pipe, 9. high-pressure curtain section, 10. drill hole. DETAILED DESCRIPTION

[0035] The technical solution and effects of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0036] Example 1

[0037] A gas drilling hose liquid injection internal support high pressure drilling curtain integrated sealing process, such as Figure 1 and 3 As shown, the following steps are included:

[0038] Step 1: Drilling construction, using a drill bit to form a gas release channel under the action of mechanical force

[0039] According to the designed hole depth and diameter of the borehole 10 on the roadway wall 4, the borehole 10 is constructed to the designed position, and the drill can be pulled out only after the hole is fully washed to completely remove the residual coal powder in the borehole 10.

[0040] Step 2: Assemble the liquid-filled expansion capsule

[0041] Insert the liquid-injection expansion capsule 1 into the sealing tube 5 from the outer opening of the sealing tube, and the front end of the liquid-injection expansion capsule 1 passes through the outer opening of the sealing tube and the outer sealing bag 6 and is inserted into the inner sealing bag 7 at a position not less than 0.5m, and the rear end is exposed at a distance not less than 0.1m from the outer opening of the sealing tube. At the same time, ensure that the outer sealing bag 6 is not less than 3m away from the drilled hole.

[0042] In this embodiment, the actual picture of the liquid injection expansion capsule 1 is as follows Figure 2 As shown, a single set of the liquid injection expansion capsule 1 is composed of a liquid inlet joint (i.e., the water injection port position), an expansion wire hose (the expansion wire hose is composed of an inner rubber layer, a steel wire (nylon wire) reinforcement layer, a middle rubber layer, and an outer rubber layer. The reinforcement layer of this embodiment is preferably a 4-layer steel wire winding reinforcement layer) and a blind plug. When in use, the liquid injection device (high-pressure pump) is connected to the liquid inlet joint of the liquid injection expansion capsule 1, and the liquid injection expansion capsule 1 is expanded by injecting clean water, and the inner wall of the sealing tube 5 expands to support the outer wall, so that the sealing tube 5 is not squeezed and deformed by the slurry during high-pressure grouting.

[0043] Step 3: Lower the tube

[0044] According to the construction depth of the borehole 10 and the sealing design requirements, the screen pipe 8 and the sealing pipe 5 assembled in the second step are sequentially lowered into the hole, and the sealing pipe 5 is fixedly connected to the screen pipe 8 by a sealing device; wherein, the screen pipe 8 is evenly distributed with holes, which are the borehole gas continuous extraction channels to prevent the borehole from collapsing and clogging.

[0045] In this embodiment, the outer sealing bag 6 and the inner sealing bag 7 block the channel and act as a plug. They are made of elastic water filter cloth, which can filter water in the slurry. When filled with slurry, they gradually expand and fit the hole wall to block the channel, forming a high-pressure curtain section 9.

[0046] In this embodiment, the sealing tube 5 is made of PE or PVC, the sealing device is a φ50mm*20m bag-type through-tube directly connected sealing device, and the size of the liquid injection expansion capsule 1 is φ30mm*19m (can be customized as needed).

[0047] Step 4: Grouting

[0048] First, the liquid-injected expansion capsule 1 in the sealing tube 5 is expanded by injecting liquid, and the inner wall of the sealing tube 5 is effectively supported by the liquid-injected expansion capsule 1 to ensure that the sealing tube 5 will not be squeezed and deformed under the action of external high pressure; then, high-stress expansion cement slurry is injected into the outer sealing bag 6 and the inner sealing bag 7 through the outer bag and the inner bag grouting pipe 2. First, the outer sealing bag 6 and the inner sealing bag 7 are expanded by filling with the slurry, and the remaining expansion cement is filtered out of the water in the slurry under the action of bag filtration. The outer sealing bag 6 and the inner sealing bag 7 are completely coupled with the hole wall through the continuous increase of the rated pressure to create a ring-shaped closed space for the high-pressure curtain.

[0049] Step 5: Grouting of high pressure curtain section

[0050] After the solidification time of the outer plugging bag 6 and the inner plugging bag 7 after grouting is not less than 2 hours, the grouting pump is connected to the φ16mm high-pressure curtain section grouting pipe 3. Under the action of high pressure, the slurry is effectively diffused in the space blocked by the high-pressure curtain section 9, filling the borehole and surrounding coal and rock wall cracks to form a curtain barrier, thereby achieving the purpose of high-pressure grouting and curtain integration.

[0051] Step 6: Connect the pipes

[0052] After the high-pressure curtain grouting of the fifth step is completed and the slurry solidifies, the injection expansion capsule 1 is depressurized, taken out from the sealing tube 5, and the borehole is connected to the extraction pipeline, and the construction is completed.

[0053] In this embodiment, the first step of drilling construction has a hole diameter of 113mm; the sealing process is: "two blocking and two injection" high-pressure grouting and curtain integrated sealing process; the diameter of the drilling and sealing pipe 5 is φ50mm; the diameter of the screen pipe 8 is: φ40mm; the length of the sealing section is 15m.

[0054] In this embodiment, the injection pressure of the liquid-injection expansion capsule 1 is 4-6Mpa, the grouting pressure of the outer plugging bag 6 and the inner plugging bag 7 of the sealing tube is 1.0-1.5Mpa, and the grouting pressure of the high-pressure curtain section is 4-6Mpa. Compared with the prior art, the grouting pressures of each embodiment belong to high-pressure grouting, so that the slurry can fully diffuse and fill the gas leakage channels and cracks of the coal body (rock body) of the hole wall under high pressure, thereby forming a closed curtain barrier isolated from the outside, which has the advantages of safety and reliability, good sealing effect, high gas extraction concentration, and long extraction time.

[0055] Example: Gas drilling hose injection internal support high pressure drilling curtain integrated sealing process, 4 boreholes (regional gas content 3.86m³ / t) were tested in the 21102 working face of a coal mine of our company, and the extraction time was 30 days. The grouting and sealing effects are as follows:

[0056] 1. Comparison of grouting effects

[0057] According to statistics, the average grouting volume of the comparative drilling and test drilling was increased from 137.5Kg / hole in the original process (using "two blocking and two injection" low-pressure sealing) to 318.75Kg / hole, an increase of 128.5%. The improvement effect was obvious, and the slurry was effectively diffused through high pressure to form a curtain space, thereby improving the quality of drilling and sealing and achieving the integrated drilling and curtain sealing effect.

[0058]

[0059] 2. Extraction Effect

[0060] like Figure 4-5 As shown, test boreholes 1#, 2#, 3# and 4# adopted the integrated sealing process of high-pressure drilling curtain supported by hose injection, and comparison boreholes 1-1#, 2-1#, 3-1# and 4-1# adopted the "two blocking and two injection" low-pressure sealing. The test time was 30 days. By comparing the gas concentrations and extraction quantities of the test boreholes and the comparison boreholes, there was no obvious difference in the initial gas concentrations and initial extraction quantities of the test boreholes and the comparison boreholes, but the extraction concentration and extraction quantity of the comparison boreholes decayed after 6 days of extraction, and the extraction concentration decayed faster after 9 days of extraction, while the re-extraction concentration and extraction quantity of the test boreholes were relatively stable. Through comparison, it can be found that the use of the integrated sealing process of high-pressure drilling curtain supported by hose injection for gas drilling can achieve high-concentration and long-lasting extraction of the boreholes.

[0061] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A gas drilling hose liquid injection internal support high pressure drilling curtain integrated sealing process, characterized in that: The following steps are involved: Step 1: Drilling construction, using a drill bit to form a gas release channel under the action of mechanical force According to the designed hole depth and diameter of the borehole on the tunnel wall, the borehole is constructed to the designed position, and the drill can be pulled out only after the hole is fully washed to completely remove the residual coal powder in the borehole; Step 2: Assemble the liquid-filled expansion capsule Insert the liquid-injection expansion capsule into the sealing tube from the outer opening of the sealing tube. The front end of the liquid-injection expansion capsule passes through the outer opening of the sealing tube and the outer plugging bag and is inserted into the inner plugging bag to a position not less than 0.5m. The exposed rear end is not less than 0.1m away from the outer opening of the sealing tube. At the same time, ensure that the outer plugging bag is not less than 3m away from the drilling hole. Step 3: Lower the tube According to the drilling construction depth and the sealing design requirements, the screen pipe and the sealing pipe assembled in the second step are sequentially lowered into the borehole, and the sealing pipe is fixedly connected to the screen pipe through the sealing device; Step 4: Grouting First, the liquid-injection expansion capsule in the sealing tube is injected with liquid to expand, and the inner wall of the sealing tube is effectively supported by the liquid-injection expansion capsule to ensure that the sealing tube will not be squeezed and deformed under the action of external high pressure; Then, high-stress expansion cement slurry is injected into the outer plugging bag and the inner plugging bag through the outer bag and the inner bag grouting pipe. First, the outer plugging bag and the inner plugging bag are expanded by filling with the slurry. Under the action of the bag filtering water, the water in the slurry is filtered out to remove the remaining expansion cement. Through the continuous increase of the rated pressure, the outer plugging bag and the inner plugging bag are completely coupled with the hole wall to create a ring-shaped closed space for the high-pressure curtain. Step 5: Grouting of high pressure curtain section After the solidification time of the outer and inner plugging bags after grouting is not less than 2 hours, the grouting pump is connected to the grouting pipe of the high-pressure curtain section. Under the action of high pressure, the slurry is effectively diffused in the space blocked by the high-pressure curtain section, filling the borehole and the surrounding coal and rock wall cracks to form a curtain barrier, achieving the purpose of high-pressure grouting and curtain integration; Step 6: Connect the pipes After the high-pressure curtain grouting of the fifth step is completed and the slurry solidifies, the injection expansion capsule is depressurized, taken out from the sealing tube, and the borehole is connected to the extraction pipeline, and the construction is completed.

2. The integrated sealing process for gas drilling hose liquid injection internal support high pressure drilling curtain according to claim 1 is characterized in that: In the second step, the liquid injection expansion capsule is composed of a liquid inlet joint, an expansion steel wire hose and a blind plug. The expansion steel wire hose is composed of an inner rubber layer, a steel wire reinforcement layer, a middle rubber layer and an outer rubber layer. When in use, the high-pressure pump is connected to the liquid inlet joint of the liquid injection expansion capsule, and the liquid injection expansion capsule is expanded by injecting clean water. The inner wall of the sealing tube expands to support the outer wall, so that the sealing tube is not squeezed and deformed by the slurry during high-pressure grouting.

3. The integrated sealing process for gas drilling hose liquid injection internal support high pressure drilling curtain according to claim 1 is characterized in that: In the second step, the sealing tube is made of PE or PVC.

4. The integrated sealing process for gas drilling hose liquid injection internal support high pressure drilling curtain according to claim 1 is characterized in that: In the second step, the outer and inner sealing bags are made of elastic water filter cloth, which can filter the water in the slurry. When filled with slurry, they gradually expand and adhere to the hole wall to block the channel, forming a high-pressure curtain section.

5. The integrated sealing process for gas drilling hose liquid injection internal support high pressure drilling curtain according to claim 1 is characterized in that: In the third step, holes are evenly distributed on the screen pipe, which are the borehole gas extraction channels to prevent the borehole from collapsing and clogging.

6. The integrated sealing process for gas drilling hose liquid injection internal support high pressure drilling curtain according to claim 1 is characterized in that: In the third step, the hole sealer used is a bag-type through-tube direct-connected hole sealer.

7. The integrated sealing process for gas drilling hose liquid injection internal support high pressure drilling curtain according to claim 1 is characterized in that: In the process, the injection pressure of the liquid-injected expansion capsule is 4-6 MPa, the grouting pressure of the outer plugging bag and the inner plugging bag of the sealing tube is 1.0-1.5 MPa, and the grouting pressure of the high-pressure curtain section is 4-6 MPa.

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