CN115522890A - Drilling and hole sealing process - Google Patents

Abstract

The invention discloses a drilling and hole sealing process, and belongs to the technical field of coal mine gas extraction. The drilling and sealing process comprises the following steps: s010, after the drilling construction is carried out to the coal seam, withdrawing the drill rod, replacing the drill bit with a punching drill bit, and enabling the drill bit to be matched with the drill rod to be lowered to the coal seam again; step S020, a hydraulic pump is started to punch a hole, the drilling depth penetrates through a coal seam and enters a coal seam roof, a coal body is partially crushed through cutting of a drill bit and impact of water jet, stress in the coal rock is damaged, instability of gas is caused, and the crushed coal body and gas are induced to protrude out of a jet hole; and S030, sealing holes after hydraulic punching, drilling and pore forming so as to discharge coal slime and water flow in the drilled holes naturally. The drilling and sealing process adopts a hydraulic punching technology and a hydraulic fracturing technology, achieves better application effects in different coal seams, causes the stress of coal and rock mass around the drill hole to be reduced, relieves pressure and increases the permeability, adopts a permeability increasing method, enlarges the effective influence range of the drill hole, and improves the gas extraction effect.

Description

A drilling and sealing process

technical field

The invention relates to the technical field of coal mine gas drainage, in particular to a drilling sealing process.

Background technique

With the increase of mining depth and mining intensity, mines are increasingly threatened by gas disasters, the mining technical conditions of coal seams will be worse, and coal mine gas disasters will further threaten the sustainable mining of coal mines.

As my country's coal output continues to increase rapidly, coal mining is experiencing a process from shallow to deep, from simple to complex mining environments, and with a significant increase in mining intensity. With the increase of mining depth, the ground stress increases, and the gas pressure and content of coal seams increase. The original low-gas and high-gas mines are partially upgraded to outburst mines, and the outburst danger of the original outburst mines is becoming more and more serious. Disasters and catastrophic accidents still occur from time to time, and their prominence has become one of the main problems threatening the safety of production in mining areas.

At the same time, drilling gas drainage is one of the most important measures for gas control in single and low-permeability coal seams. Since many high-gas coal seams in my country are low-permeability coal seams, conventional gas drainage methods cannot achieve ideal results. The scope is small, the drilling construction volume of the working face is large, and the extraction efficiency is low. In order to meet the standard of drainage and eliminate coal seam gas disasters, conventional gas drainage methods are difficult to achieve.

Contents of the invention

The object of the present invention is to provide a drilling and sealing process in order to overcome the problems in the prior art.

The present invention provides a drilling and sealing process, including: Step S010, after drilling to the coal seam, withdraw the drill pipe, replace the drill bit with a punching drill bit, cooperate with the drill pipe, and go down to the coal seam again; Step S020, the hydraulic pump Open the pump for punching, the drilling depth goes through the coal seam and enters the coal seam roof, through the cutting of the drill bit and the impact of the water jet, the coal body is partially broken, the internal stress of the coal rock is destroyed, the gas is unstable, and the broken coal is induced. Protruding coal and gas injection holes; step S030, sealing the holes after hydraulic punching, drilling, and forming holes, so that the coal slime and water flow in the drill holes can be discharged naturally; the protruding coal, gas and water flow along the drill pipe and the drill hole The gap between the coal seams flows out to the outside of the coal seam and is introduced into the three-way pipe, and the coal, gas and water flow are introduced into the separator through the branch of the three-way pipe, and the gas gas is pumped away in the separator, and the water and coal block enter the sedimentation tank; steps S040, the sealing pipe is sent to the middle of the coal seam with double-resistance pipe, and the part entering the coal seam is a flower pipe. The joint sealing method of ordinary cement and expanded cement is used for multiple grouting, and the hole is sealed to the junction of coal and rock.

Preferably, in the step S010, a plurality of boreholes are drilled and punched, and the boreholes are pressurized and injected with high-pressure water by adopting a step-by-step pressurization method. Block the drill holes for coal or water discharge or inject high-pressure water together until multiple drill holes discharge coal or water, so that multiple grid-arranged drill holes are pressed through each other to form a large-area penetrating fracture zone, so that the coal The fissures in the coal body should be unblocked to increase the air permeability of the coal body and increase the gas discharge, so as to achieve the purpose of preventing outbursts. After the fracturing is completed, the high-pressure pipe is removed and connected to the drainage pipe for drainage.

Preferably, in the step S010, an orifice blowout prevention hole device capable of preventing accidents of gas spraying out of limit is adopted during drilling and punching.

Preferably, the drilling sealing process further includes step S011, inserting a drainage pipe and a grouting pipe in the borehole, and installing a spherical valve at the outer end of the grouting pipe; mixing the resin material evenly and quickly Wrap it around the extraction pipe and grouting pipe, tie the towel properly with iron wire, and send it into the drilling hole; wait for the resin material to foam and expand, gradually harden, and the drilling hole is sealed.

Preferably, in the step S040, the outer end of the grouting pipe is connected to the grouting pump; water, ordinary cement and additives are mixed and stirred in proportion and screened; the grouting pump is turned on for grouting, and the pressure does not exceed 0.2MPa, after about 2 minutes, the pressure can be increased appropriately; when the grout flows out of the extraction pipe, stop the grouting immediately; first close the valve of the grouting pipe, remove the connecting pipe for grouting, and then open the valve The cement slurry in the slurry pipe is reflowed; after one round shift; perform secondary grouting to the drilled hole; after the grouting is completed, the pipeline is removed, the pump is cleaned, and the valve of the orifice grouting pipe can be recovered after 12 hours.

Preferably, the additive is expansive cement, and the ratio of water: common cement: expansive cement is 2:2:1.

Preferably, in the step S030, the hydraulic punching, drilling, and hole forming are performed for at least 8 hours, and then the holes are sealed.

Compared with the prior art, the beneficial effects of the present invention are: the drilling and sealing process of the present invention adopts hydraulic punching technology and hydraulic fracturing technology, and achieves better application effects in different coal seams. Hydraulic fracturing measures reduce the stress of the coal and rock mass around the borehole, relieve the pressure and increase the permeability, and enhance the drainage effect. The method of increasing the permeability is adopted to expand the effective impact range of the borehole and improve the gas drainage effect.

Hydraulic punching is to use the characteristics of coal and gas outburst coal seams in the outburst coal seam. When drilling and punching, as the hole is drilled, the injection holes will continue to occur, and the coal, water, and gas will flow out of the hole through the hole. When discharged, the medium around the channel moves violently to the direction of the channel. At the same time, the expansion deformation of the coal body and the relative displacement of the roof and the floor will cause the ground stress to decrease, the pressure of the coal seam to be relieved, and the cracks to increase in the area affected by drilling punching, which will increase the air permeability of the coal seam, promote the desorption and discharge of gas, and increase the strength and humidity of the coal. Increase, combined with gas drainage, greatly improve the drainage efficiency, effectively reduce the coal seam gas content near the punching hole. It not only eliminates the power of outburst, but also changes the nature of outburst coal seams, so as to achieve the effect of outburst elimination;

Compared with the conventional drilling and sealing process, the hydraulic punching anti-reflection process has significantly increased the extraction concentration. After punching anti-reflection measures, the concentration decay rate of drilling gas drainage is significantly lower than that of hydraulic punching anti-reflection technology. The concentration attenuation rate also decreased significantly; after adopting hydraulic permeability enhancement measures, the air permeability of the coal seam increased significantly; The air permeability of the coal seam is increased compared with the adoption of hydraulic punching measures.

Description of drawings

Fig. 1 is the hydraulic punching technological process schematic diagram of the present invention;

Fig. 2 is a schematic diagram of the upward drainage drilling sealing method of the present invention.

Explanation of reference signs:

1. Coal seam, 3. Borehole, 4. Drainage pipe, 5. Cement slurry, 6. Grouting pipe, 7. Resin material, 8. Drill pipe, 9. Tee pipe, 10. Grouting pump, 11. Splitter.

detailed description

The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings 1-2, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Schematic diagram of the hydraulic punching process of the first embodiment, hydraulic punching anti-reflection

A kind of drilling and sealing process provided by the present invention, as shown in Figure 1, includes:

Step S010, after the drill hole 3 is constructed to the coal seam 1, withdraw the drill pipe 8, replace the drill bit with a punching drill bit, cooperate with the drill pipe 8, and go down to the coal seam 1 again;

Step S011, insert the extraction pipe 4 (diameter Φ50mm PVC double resistance pipe) and grouting pipe 6 (Φ20mm aluminum-plastic pipe, the grouting pipe 6 is stretched straight to the flower pipe 21m away from the front end of the extraction pipe 4) into the borehole 3 , the grouting pipe 6 is installed with a spherical valve at the outer end of the orifice; the resin material 7 (Ma Lisan) is evenly mixed and then quickly wound on the extraction pipe 4 and the grouting pipe 6 (the winding length is 0.5m. Generally, it takes 3 to 4 group, keeping the outer end of the grouting pipe 6 exposed by 0.2m), after properly binding the towel with iron wire, send it into the hole 3; wait for the resin material 7 to foam and expand, and gradually harden, and the hole 3 is sealed;

Step S020, the hydraulic pump is turned on for punching, the water supply pressure is 3-4MPa (suitable for coal seams with soft coal quality, too high water pressure will cause excessive coal discharge in the layer-crossing drilling 3, which will affect the coal roadway excavation), and the drilling 3 Depth through the coal seam 1 and into the roof of the coal seam 1, through the cutting of the drill bit and the impact of the water jet, the coal body is partially broken, the stress inside the coal rock is destroyed, the gas is unstable, and the broken coal body and gas outburst are induced orifice;

Step S030, hydraulic punching, drilling 3, sealing the hole after forming the hole for at least 8 hours, so that the coal slime and water flow in the drill hole 3 can be discharged naturally; the protruding coal, gas and water flow along the drill pipe 8 and the drill hole 3 The gaps in the coal seam 1 flow out to the outside of the coal seam 1 and lead into the three-way pipe 9. Through the branches of the three-way pipe 9, the coal block, gas and water flow are introduced into the separator 11. The gas gas is pumped away in the separator 11, and the water and coal block enter Sedimentation tank;

Step S040, the sealing pipe is sent to the middle of the coal seam 1 using a double-resistance pipe, and the part entering the coal seam 1 is the flower pipe 2. The joint sealing method of ordinary cement and expanded cement is used to perform multiple grouting, and the hole is sealed to the junction of coal and rock. ; Connect the outer end of the grouting pipe 6 to the grouting pump 10; mix water, ordinary cement and additives in proportion and sieve; turn on the grouting pump 10 for grouting, the pressure does not exceed 0.2MPa at the beginning, and after about 2 minutes The pressure can be increased appropriately; when there is slurry flowing out in the extraction pipe 4, stop the grouting immediately; first close the valve of the grouting pipe 6, remove the grouting connecting pipe, and then open the grouting valve to make the grouting pipe 6 Medium cement slurry 5 reflows; after one round shift; carries out secondary grouting to borehole 3; removes pipeline after grouting is finished, cleans pump equipment, can reclaim after 12h of orifice grouting pipe 6 valves; described additive is Expansion cement, water: ordinary cement: the ratio of expansion cement is 2:2:1; when using water: ordinary cement: expansion cement = 2:2:1 as the grouting fluid, the quality of drilling and sealing is better. The expected sealing depth can be achieved.

The second embodiment is shown in Figure 2 as a schematic diagram of the drilling sealing method for upward drainage, hydraulic pressure penetration and anti-permeability

Step S010, after the drilling 3 reaches the coal seam 1, withdraw the drill pipe 8, replace the drill bit with a punching drill bit, cooperate with the drill pipe 8, and go down to the coal seam 1 again. Accident orifice blowout prevention device; multiple boreholes 3 are drilled, and multiple boreholes 3 are punched, and high-pressure water is injected into the boreholes 3 by gradually increasing the pressure, and the adjacent boreholes 3 are discharged coal or After the water comes out, the coal or water outlet holes 3 are blocked or high-pressure water is injected together until multiple holes 3 come out of coal or water, so that the holes 3 arranged in grids are pressed through each other to form a large area. Through the fissure zone, make the coal fissure unimpeded, so as to increase the air permeability of the coal body and increase the gas discharge, so as to achieve the purpose of preventing outburst.

After borehole 3 is formed, hydraulic punching is used to form a certain pressure relief space, and then borehole 3 is selected for hydraulic fracturing to increase coal fractures. During the fracturing process, the pressure is slowly increased at intervals, and the pressure is stabilized for 1 to 5 minutes under each pressure value, so that the pressure is fully transmitted, and the surroundings of the borehole 3 are evenly compressed and destroyed. After reaching the set pressure value, stabilize the pressure for about 30 minutes. After the fracturing is completed, remove the high-pressure pipe and connect the extraction pipe 4 for extraction;

Step S011, insert the extraction pipe 4 (diameter Φ50mm PVC double resistance pipe) and grouting pipe 6 (Φ20mm aluminum-plastic pipe, the grouting pipe 6 is stretched straight to the flower pipe 21m away from the front end of the extraction pipe 4) into the borehole 3 , the grouting pipe 6 is installed with a spherical valve at the outer end of the orifice; the resin material 7 (Ma Lisan) is evenly mixed and then quickly wound on the extraction pipe 4 and the grouting pipe 6 (the winding length is 0.5m. Generally, it takes 3 to 4 group, keep the outer end of the grouting pipe 6 exposed 0.2m), tie the towel properly with iron wire, and send it into the hole 3; wait for the resin material 7 to foam and expand, and gradually harden, and the hole 3 is sealed.

Step S020, the hydraulic pump is turned on for punching, the water supply pressure is 3-4MPa (suitable for coal seams with soft coal quality, too high water pressure will cause excessive coal discharge in the layer-crossing drilling 3, which will affect the coal roadway excavation), and the drilling 3 Depth through the coal seam 1 and into the roof of the coal seam 1, through the cutting of the drill bit and the impact of the water jet, the coal body is partially broken, the stress inside the coal rock is destroyed, the gas is unstable, and the broken coal body and gas outburst are induced orifice;

Step S030, hydraulic punching, drilling 3, sealing the hole after forming the hole for at least 8 hours, so that the coal slime and water flow in the drill hole 3 can be discharged naturally; the protruding coal, gas and water flow along the drill pipe 8 and the drill hole 3 The gaps in the coal seam 1 flow out to the outside of the coal seam 1 and lead into the three-way pipe 9. Through the branches of the three-way pipe 9, the coal block, gas and water flow are introduced into the separator 11. The gas gas is pumped away in the separator 11, and the water and coal block enter Sedimentation tank;

Step S040, the sealing pipe is sent to the middle of the coal seam 1 using a double-resistance pipe, and the part entering the coal seam 1 is the flower pipe 2. The joint sealing method of ordinary cement and expanded cement is used to perform multiple grouting, and the hole is sealed to the junction of coal and rock. ; Connect the outer end of the grouting pipe 6 to the grouting pump 10; mix water, ordinary cement and additives in proportion and sieve; turn on the grouting pump 10 for grouting, the pressure does not exceed 0.2MPa at the beginning, and after about 2 minutes The pressure can be increased appropriately; when there is slurry flowing out in the extraction pipe 4, stop the grouting immediately; first close the valve of the grouting pipe 6, remove the grouting connecting pipe, and then open the grouting valve to make the grouting pipe 6 Medium cement slurry 5 reflows; after one round shift; carries out secondary grouting to borehole 3; removes pipeline after grouting is finished, cleans pump equipment, can reclaim after 12h of orifice grouting pipe 6 valves; described additive is Expansion cement, water: ordinary cement: the ratio of expansion cement is 2:2:1; when using water: ordinary cement: expansion cement = 2:2:1 as the grouting fluid, the quality of drilling and sealing is better. The expected sealing depth can be achieved.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications and substitutions can be made to these embodiments without departing from the principle and spirit of the present invention. and modifications, the scope of the invention is defined by the appended claims and their equivalents.

Claims (7)

1. A drilling and sealing process, characterized in that, comprising Step S010, after drilling (3) to the coal seam (1), withdraw the drill pipe (8), replace the drill bit with a punching drill bit, cooperate with the drill pipe (8), and go down to the coal seam (1); Step S020, the hydraulic pump is turned on to punch holes, the drill hole (3) penetrates the coal seam (1) deeply and enters the roof of the coal seam (1), and through the cutting of the drill bit and the impact of the water jet, the coal body is partially broken and the coal rock is destroyed Internal stress causes gas instability and induces broken coal bodies and gas outburst nozzles; Step S030, hydraulic punching, drilling (3), sealing the hole after forming the hole, so that the coal slime and water flow in the drill hole (3) can be discharged naturally; the protruding coal, gas and water flow along the drill pipe (8) and the drill The gap between the holes (3) flows out to the outside of the coal seam (1) and is introduced into the three-way pipe (9), and the coal block, gas and water flow are introduced into the separator (11) through the branch of the three-way pipe (9), and the gas gas is discharged into the separator (11). The inside of the separator (11) is pumped away, and water and coal lumps enter the settling tank; Step S040, the sealing pipe is sent to the middle of the coal seam (1) using a double-resistance pipe, and the part entering the coal seam (1) is a flower pipe (2). The joint sealing method of ordinary cement and expansive cement is used to perform multiple times of grouting to seal the hole. hole to the coal-rock junction. 2. The drilling and sealing process according to claim 1, characterized in that, in the step S010, a plurality of boreholes (3) are drilled, and a plurality of boreholes (3) are punched, by taking step by step Inject high-pressure water into the borehole (3) by means of pressurization. After coal or water is discharged from the adjacent borehole (3), the borehole (3) that produces coal or water is blocked or injected with high-pressure water together until multiple boreholes (3) are discharged. The holes (3) discharge coal or water, so that the multiple grid-arranged drill holes (3) are pressed through each other to form a large-area penetrating fissure zone, so that the coal fissures are unblocked, so as to increase the air permeability of the coal body and increase the gas consumption. discharge, so as to achieve the purpose of prevention and control, when the fracturing is over, the high-pressure pipe is removed, and the drainage pipe (4) is connected for drainage. 3 . The drilling and sealing process according to claim 1 , characterized in that, in the step S010 , when drilling and punching holes, an orifice blowout prevention device capable of preventing accidents of gas ejection exceeding limits is adopted. 4 . 4. The drilling sealing process according to claim 1, further comprising step S011, inserting a drainage pipe (4) and a grouting pipe (6) in the borehole (3), the grouting pipe ( 6) Install a spherical valve at the outer end of the orifice; mix the resin material (7) evenly and quickly wrap it on the extraction pipe (4) and the grouting pipe (6), tie the towel properly with iron wire, and send it into the borehole ( 3) mouth; wait for the resin material (7) to expand and gradually harden, and the hole (3) is sealed. 5. The drilling and sealing process according to claim 1, characterized in that, in said step S040, the outer end of the grouting pipe (6) is connected to the grouting pump (10); water, common cement and additives are Mix and stir in proportion and sieve; open the grouting pump (10) to carry out grouting, the pressure is not more than 0.2MPa at the beginning, and the pressure can be increased appropriately after about 2min; when there is slurry flowing out in the extraction pipe (4), Stop the grouting immediately; first close the valve of the grouting pipe (6), remove the grouting connecting pipe, and then open the grouting valve to make the grout (5) in the grouting pipe (6) flow back; after one round shift; Drill the hole (3) for secondary grouting; remove the pipeline after the grouting is completed, clean the pump, and the valve of the orifice grouting pipe (6) can be recovered after 12 hours. 6. The drilling and sealing process according to claim 5, wherein the additive is expansive cement, and the ratio of water: common cement: expansive cement is 2:2:1. 7. The drilling and sealing process according to claim 1, characterized in that, in the step S030, the hydraulic punching, drilling (3), and hole forming are carried out for at least 8 hours, and then the holes are sealed.

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