CN105041264A - Method for repeated hole sealing on gas extraction drilling hole by rotary jet grouting and solidifying - Google Patents

Abstract

A gas drainage drilling hole rotary spray solidification method that can be sealed multiple times. The high-pressure rotary spray equipment is used to evenly spray the rotary spray solidified material on the wall of the borehole. The material can penetrate well into the coal cracks and solidify. After that, it is closely combined with the coal body and has high strength, which can seal the cracks around the large borehole and fix the pass pattern. Then insert the gas extraction pipe covered with the bag into the borehole, and inject the same material into the bag with a liquid injector. After the material is solidified, the gas drainage pipe is connected for drainage, and the first sealing of the drilling is completed. If the concentration of gas drainage is reduced to 30%, the large borehole can be sealed and solidified again through high-pressure rotary spraying equipment, and the number of sealing holes is not limited to achieve continuous drainage of high-concentration gas. The invention can carry out rotary spraying solidification and sealing to the borehole for many times, which hinders the deformation of the borehole, improves the concentration of gas extraction and prolongs the service life of the borehole.

Description

A method for multiple sealing of gas drainage boreholes by rotary spraying and solidification

technical field

The invention relates to a hole sealing method, in particular to a hole sealing method which is suitable for multiple times of hole sealing by rotary spraying and solidification in underground gas drainage boreholes of coal mines.

Background technique

At present, the hole sealing method mainly adopts cement mortar sealing, polyurethane sealing, hole sealing device sealing, high water material sealing, secondary sealing and so on. However, the mud pump equipment for cement mortar sealing is heavy, and the grouting flow is difficult to control; the cost of polyurethane sealing is high; the sealing device is only suitable for temporary sealing; the setting time of high-water materials is affected by the water-cement ratio. It is difficult to grasp the accurate water-cement ratio in downhole field operations; the concentration of gas drainage during the first sealing of the second hole sealing technology is low. In addition, when the concentration of gas drainage drops below 30%, the conditions for gas utilization cannot be met. The existing technology often can only seal the hole once or twice, and cannot seal the hole multiple times, thus affecting the service life of the drilled hole.

Contents of the invention

Technical problem: to invent a method that is easy to operate, high in sealing efficiency, and capable of multiple sealing in view of the problems of low concentration of mine gas drainage and short service life of drilling holes.

Technical solution: The gas drainage drill hole rotary spray solidification method of the present invention can be sealed multiple times, including the following steps:

a. Use a Φ113mm drill bit to construct a certain length of drill hole on the coal body, and after the drill is withdrawn, use a high-pressure rotary spray equipment to evenly spray the rotary spray solidified material on the wall of the drill hole to form a dense sealing layer;

b. Insert the gas drainage pipe covered with the bladder into the borehole, inject the same material into the bladder through the liquid injection hose with a liquid injector, and close the b valve after the bladder expands;

c. After the solidified material is solidified, open the valve a, connect the gas extraction pipe for extraction, and complete the first sealing of the drilling hole;

d. If the concentration of gas drainage drops to 30% after a period of time, the drill hole can be sealed and solidified again through high-pressure rotary spraying equipment. The number of times of sealing is not limited to achieve continuous drainage of high-concentration gas.

The pressure of the high-pressure rotary spraying equipment is 10-15Mpa.

The material of the pouch is linen.

The thickness of the sealing layer formed by each rotary spraying of the rotary spraying cured material is 0.1-0.5mm, and the sealing length is 12m.

The rotary spray curing material is formed by mixing epoxy resin, talcum powder, aluminum oxide powder, toughening agent, diluent and curing agent. The mass ratio is epoxy resin: talcum powder: alumina powder: toughening agent: diluent: curing agent = 100:50:5:2:30:18.

Beneficial effects: due to the adoption of the above technical solution, the present invention is suitable for gas drainage in near-horizontal boreholes, downholes and upholes. By sealing the drill hole rotary spray solidified material layer many times, the strength of the sealing material layer can well maintain the shape of the drill hole without changing, hinder the deformation of the drill hole, effectively prevent the drill hole from collapsing, and prevent The outside air easily enters the bottom of the hole through the crack channel, which affects the obvious reduction of the gas drainage concentration, greatly increases the gas drainage concentration, and prolongs the service life of the borehole. Compared with the prior art, the present invention has the advantages of simple operation, time saving and labor saving, low cost, good use effect, wide application range and wide practicability in the phase technical field.

Description of drawings

Fig. 1 is a schematic diagram of the layout of the gas drainage borehole rotary spray solidification method for multiple sealing of the present invention.

In Figure 1: 1-coal body, 2-crack, 3-bag, 4-a valve, 5-gas drainage pipe, 6-b valve, 7-liquid injection hose, 8-sealing layer, 9-drill hole.

Detailed ways

An embodiment of the present invention will be further described below in conjunction with accompanying drawing:

The drilling and sealing method for mine gas drainage of the present invention adopts instruments such as drill bits, drill pipes, drilling rigs, extraction pipes, bladders, high-pressure rotary spraying equipment, liquid injectors, and uses rotary spraying solidified materials as sealing materials ,Specific steps are as follows:

As shown in Figure 1, first use a drill bit of Φ113mm to construct a drill hole 9 of the required depth on the coal body, drill the drill bit to the required set depth and back drill, and use high-pressure rotary spraying equipment to evenly spray the solidified material on the drill hole 9 wall surface to form a dense sealing layer 8, the thickness of the sealing layer 8 is 0.1-0.5mm, and the sealing length is 12m; the pressure of the high-pressure rotary spraying equipment can reach 10-15Mpa. Then insert the gas extraction pipe 5 covered with the bladder 3 into the borehole 9. The length of the gas extraction tube 5 is 1.2-1.5m and the diameter is 90mm. The material of the bladder 3 is flax The cloth is made of linen, and the length of the pouch 3 is 0.6m. The length of the gas drainage pipe 5 exposed at the orifice end is 0.4m, and the length exposed in the hole is 0.2m. Insert the injection hose 7 into the pouch 3, open the b valve 6 on the injection hose 7, inject the same material into the pouch 3 through the injection hose 7 with a liquid injector, after the pouch 3 expands Close b valve 6. After the material is solidified, connect the gas drainage pipe 5 to the gas drainage pipe network, open the a valve 4 to connect the gas drainage pipe 5 for drainage, and complete the first sealing of the drilling 9; after a period of gas drainage , due to the deformation and displacement of the coal seam, the fissures 2 in the coal seam around the borehole 9 expand and develop, and the outside air easily enters the bottom of the hole through the fissure channel, so that the gas drainage concentration drops significantly. When the concentration is reduced to less than 30%, the gas If the drainage cannot meet the utilization conditions, the high-pressure rotary spraying equipment is used to spray the solidified material into the borehole 9 again to form another dense sealing layer 8 to seal and solidify the hole, so as to increase the concentration of the drainage gas; Repeatedly, spray the solidified material into the borehole 9 for many times to seal the hole, and the number of times of sealing is not limited, so that the concentration of gas drainage can be kept above 30%, so as to realize the continuous drainage of high-concentration gas.

The rotary spray curing material is formed by mixing epoxy resin, talcum powder, aluminum oxide powder, toughening agent, diluent and curing agent. The mass ratio is epoxy resin: talcum powder: alumina powder: toughening agent: diluent: curing agent = 100:50:5:2:30:18.

Claims (6)

1. A gas drainage borehole rotary spray solidification can seal the method repeatedly, it is characterized in that comprising the steps: a. Use a drill bit of Φ113mm to construct a drill hole (9) with a required depth on the coal body. After the drill is withdrawn, use a high-pressure rotary spraying equipment to spray the solidified material evenly on the wall of the drill hole (9), so that the drill hole (9) ) the wall surface forms a dense sealing layer (8); b. Insert the gas drainage pipe (5) covered with the bag (3) into the drill hole (9), insert the injection hose (7) into the bag (3), and open the injection hose (7) ) on b valve (6), inject the same material into the pouch (3) with a liquid injector through the liquid injection hose (7), and close the b valve (6) after the pouch (3) expands; c. After the solidified material is solidified, open the a valve (4), connect the gas extraction pipe (5) for extraction, and complete the first sealing of the borehole (9); d. When the concentration of gas drainage was reduced to 30%, the borehole (9) was sealed and solidified by high-pressure rotary spray equipment along the gas extraction pipe (5) again to form another layer of dense sealing layer ( 8) Seal and solidify the holes to prevent outside air from entering the bottom of the hole from the crack channel, so as to increase the concentration of gas drainage and meet the gas drainage conditions; in this way, the number of times of hole sealing is not limited, so as to realize the continuous pumping of high-concentration gas Pick. 2. A method for gas drainage drilling and rotary spraying solidification that can be sealed multiple times according to claim 1, characterized in that: the length of the gas drainage pipe (5) is 1.2-1.5m, and the diameter is 90mm. 3. A method for gas drainage drilling and rotary spraying solidification that can be sealed multiple times according to claim 1, characterized in that: the pouch (3) is made of linen, and the pouch (3) The length is 0.6m. 4. A method for multiple sealing of gas drainage drilling holes by rotary spraying and solidification according to claim 1, characterized in that: the pressure of the rotary spraying of the high-pressure rotary spraying equipment can reach 10-15Mpa. 5. A method for multiple sealing of gas drainage boreholes by rotary spraying and solidification according to claim 1, characterized in that: the thickness of the sealing layer (8) is 0.1-0.5mm, and the sealing length is 12m. 6. A kind of gas drainage drilling method according to claim 1 that can be sealed multiple times by rotary spraying and solidification, characterized in that: the curing material of the rotary spraying is epoxy resin, talcum powder, aluminum oxide powder, Toughener, Thinner and Hardener are mixed together. The mass ratio is epoxy resin: talcum powder: alumina powder: toughening agent: diluent: curing agent = 100:50:5:2:30:18.