CN104863542A - Approximately horizontal gas drainage hole drilling cutting and pocket combined hole sealing method - Google Patents

Abstract

The invention relates to a method for sealing holes by combining drilling cuttings and pocket bags for near-horizontal gas drainage, which is suitable for near-horizontal drilling. Construct a large borehole on the coal body, insert a PVC casing with a flower tube at the front end, and insert the PVC casing with a bladder fixed into the large borehole after the drill is withdrawn. Inject the high-water material into the bladder bag through the grouting pipe bound with the bladder bag, and the inner end of the grouting tube is bound together with the PVC casing with iron wire. After the high-water material is solidified, use the small drill bit to continue construction along the large borehole for a certain distance. During the drilling process, the drill chips discharged by the pneumatic drill will fall into the gap between the PVC casing and the wall of the large borehole due to the action of the wind, and will be automatically filled. The gap between the PVC casing and the large drill hole is solidified, and the integration of drilling and sealing is realized. The pouch plays the role of a hole sealer and can well prevent the seepage of high-water materials. The pouch and the drill cuttings discharged during the drilling process can be used to complete the sealing, which reduces the cost of sealing the hole and improves the sealing efficiency. efficiency. The operation is simple and the sealing effect is good.

Description

A combined sealing method of drilling cuttings and pockets for near-horizontal gas drainage

technical field

The invention relates to a hole sealing method, in particular to a hole sealing method which is suitable for a near-horizontal gas drainage underground drilling cuttings and a bag in a coal mine.

Background technique

The key to gas drainage is to adopt suitable sealing technology and material, and the quality of sealing holes directly affects the efficiency of gas drainage. At present, the sealing technologies used at home and abroad mainly include mechanical cement mortar sealing, two-stage grouting sealing, foaming polymer material sealing, and hole sealing device sealing. Among them, mechanical cementing mortar sealing is suitable for inclined drilling; double-stage grouting sealing is suitable for near-horizontal or gently inclined coal seams, but the operation is extremely complicated; foaming polymer material sealing has high foaming ratio, light weight, and easy sealing. The advantages of rapidity, but its high cost, low strength after molding, easy to catch fire, difficult to foam when exposed to water, and high operating requirements. The fast sealing speed and repeated use of the hole sealer can reduce the cost, but the effect is poor, and it is only suitable for temporary extraction and sealing.

Contents of the invention

Technical problem: The object of the present invention is to solve the existing problems in the prior art, and provide a simple, low-cost, and effective near-horizontal gas drainage drilling cuttings and bag sealing method.

Technical solution: The combined sealing method of drilling cuttings and pockets for near-horizontal gas drainage of the present invention includes the following steps:

a. Use a large drill bit to construct a large borehole in a near-horizontal coal body;

b. After the drill is withdrawn, install a PVC casing with a floral tube at the front end into the large drill hole, and at the same time install a grouting pipe fixed at the lower part of the PVC casing, and set a blast valve at the front of the grouting pipe. A pouch for sealing holes is wound on the PVC sleeve and the grouting pipe at the orifice section, and a one-way valve is arranged in the pouch at the rear of the grouting pipe;

c. Inject high-water material through the grouting pipe to block the gap between the outer end of the PVC casing and the large drill hole. At the same time, the one-way valve is automatically opened under the action of the grouting pressure to inject grout into the bladder. When the pressure indication reaches 2MP, the blasting valve at the front end of the grouting pipe bursts to prevent the bladder from being burst due to excessive pressure, and the grouting is completed at this time;

d. After the high-water material is solidified, use a small drill bit to construct a small drill hole inward along the bottom of the large drill hole to ensure that the small drill hole is concentric with the large drill hole, and the drill cuttings discharged during the drilling process fall to the PVC sleeve In the gap between the pipe and the wall of the large borehole, the gap between the PVC casing and the large borehole is automatically filled and compacted;

e. After the small drill bit is drilled to the predetermined position, the drill bit and the drill pipe are withdrawn, and the PVC casing nozzle is connected to the gas drainage pipe network to complete the entire hole sealing process.

The outermost end of the grouting pipe is provided with a pressure gauge for real-time monitoring of the pressure inside the grouting pipe.

The total length of the PVC casing is 12m.

The length of the pouch is 0.8m, and the position of the pouch is adjusted according to the actual situation.

The pouch is made of waterproof, flame-retardant and anti-static three-proof cloth material that is impermeable to high-water material slurry.

The diameter of the large borehole is 113mm, and the hole depth is 13m.

The diameter of the small borehole is 75mm.

The inner end of the flower tube is 0.5m away from the bottom of the hole, and the outer end of the PVC sleeve is 0.5m away from the orifice.

Beneficial effects: Due to the adoption of the above technical scheme, compared with the prior art, the present invention uses the bladder and the drill cuttings discharged during the drilling process to automatically complete the hole sealing process, and the drill cuttings fill and compact the PVC casing and the wall surface of the large borehole The gap between them realizes the integration of drilling and sealing. The combination of special bladder and PVC sleeve simplifies the grouting process and reduces the use of high water materials. The pouch acts as a hole sealer and does a good job of preventing seepage of high water materials. The invention has simple operation and good hole sealing effect, and is suitable for near-horizontal drilling. The hole sealing can be completed by using the pouch and the drill cuttings discharged during the drilling process, which reduces the sealing cost and improves the sealing efficiency. The utility model has the advantages of simple operation, good sealing effect and wide practicability.

Description of drawings

Fig. 1 is a schematic diagram of a method for sealing holes in combination of drilling cuttings and pocket bags for near-horizontal gas drainage of the present invention;

Fig. 2 is a schematic diagram of the structure of A-A in Fig. 1 .

In the figure: 1-PVC casing, 2-grouting pipe, 3-pressure gauge, 4-bag, 5-big hole, 6-small hole, 7-one-way valve, 8-burst valve, 9- Cuttings, 10-flower tubes.

Detailed ways

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

As shown in Fig. 1, the method for sealing the hole by combining drilling cuttings and pockets for near-horizontal gas drainage of the present invention includes using a large drill bit of Φ113mm, a small drill bit of Φ75mm, a drill pipe of Φ42mm, a PVC casing, a floral tube, Blank, grouting pipe, pressure gauge, the plugging material used is high water material and drilling cuttings. In order to ensure the smooth construction of near-horizontal gas drainage drilling and the accurate fall of cuttings into the predetermined position, the preliminary preparations are made:

(1) Use a geological compass to determine the azimuth and inclination of the drilling rig;

(2) Directly use the downhole air pipe for air supply and powder discharge;

(3) Connect the drill pipe and the drill bit, and start the drilling rig for drilling operations.

Specific steps are as follows:

a. Use a large drill bit of Φ113mm to construct a large borehole 5 in the near-horizontal coal body, and when the depth of the hole reaches 13m, withdraw the drill pipe and the large drill bit;

b. After withdrawing the drill, install the PVC sleeve 1 with the flower tube 10 at the front end into the large drill hole 5, and at the same time install the grouting pipe 2 fixed at the lower part of the PVC sleeve 1, and place it on the front of the grouting pipe 2. A blasting valve 8 is provided, and a sealing bag 4 is wound on the PVC casing 1 and the grouting pipe 2 at the orifice section, and a one-way valve 7 is arranged in the bag 4 at the back of the grouting pipe 2; The length of the floral tube 10 at the front end of the PVC casing 1 is 1m, the total length of the PVC casing 1 is 12m, the PVC casing 1 fixed with the pouch 4 is inserted into the large borehole 5, and the length of the pouch 4 is 0.8m , the position of the pouch 4 is adjusted according to the actual situation, so that the 10 li ends of the flower tube are 0.5m away from the bottom of the hole, and the outer end of the PVC casing 1 is 0.5m away from the orifice.

c. Inject high-water material into the bladder 4 through the grouting pipe 2 bound to the bladder 4 to block the gap between the outer end of the PVC sleeve 1 and the large drill hole 5, and at the same time the one-way valve 7 is in the Under the action of the grouting pressure, it will be opened automatically, and grouting will be injected into the bladder 4. With the injection of high-water materials, the reading of the pressure gauge 3 will gradually increase from 0. When the reading of the pressure gauge 3 reaches 2MP, the grouting pipe 2 will The blasting valve 8 at the front end is blasted to prevent the bladder 4 from being burst due to excessive pressure, and the reading on the pressure gauge 3 quickly drops to 0, and the grouting is completed at this time;

d. After the high-water material is solidified, use a small drill bit of Φ75mm to continue to construct a small drill hole 6 along the bottom of the big drill hole 5 to ensure that the small drill hole 6 is concentric with the big drill hole 5 and discharge during the drilling process. The drill cuttings 9 fall into the gap between the PVC casing 1 and the wall of the large borehole, automatically filling and compacting the gap between the PVC casing 1 and the large borehole 5

e. After the small drill bit is drilled to the predetermined position, the drill bit and the drill pipe are withdrawn, and the PVC casing 1 is connected to the gas drainage pipe network to complete the entire sealing process.

The above-mentioned embodiment only expresses one embodiment of the present invention, but should not be construed as limiting the scope of the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Claims (8)

1. nearly horizontal firedamp taking-out discharging drilling drilling cuttings and pouch combine a method for sealing of hole, it is characterized in that comprising the steps:

A. construct in the coal body of nearly level one with large drill bit and hole (5) greatly;

B. after moving back brill, the PVC sleeve pipe (1) of front end with floral tube (10) is loaded in large boring (5), load the Grouting Pipe (2) being fixed on PVC sleeve pipe (1) bottom simultaneously, and an explosive valve (8) is set in the front portion of Grouting Pipe (2), be positioned at the PVC sleeve pipe (1) of aperture section and the upper pouch (4) being wound around sealing of hole of Grouting Pipe (2), and be arranged in pouch (4) at Grouting Pipe (2) rear portion an one way valve (7) is set;

C. high-water material is injected by Grouting Pipe (2), realize PVC sleeve pipe (1) outer end portion and the shutoff in the space between (5) of holing greatly, one way valve (7) is automatically opened under the effect of grouting pressure simultaneously, to pouch (4) interior slip casting, explosive valve (8) explosion of Grouting Pipe (2) front end when pressure meter (3) registration reaches 2MP, prevent pouch (4) to be bursting at the collision because pressure is excessive, now complete slip casting;

D. after high-water material solidifies, inwardly to construct at the bottom of the hole of large boring (5) small bore (6) with little drill bit, ensure that small bore (6) is concentric with hole greatly (5), the drilling cuttings (9) of discharging in drilling process drops down onto in PVC sleeve pipe (1) and the space of holing between (5) wall greatly, automatic filling compacting PVC sleeve pipe (1) and the space of holing between (5) greatly;

E. after little drill bit creeps into precalculated position, drill bit and drilling rod are exited, PVC sleeve pipe (1) mouth of pipe is connected with gas drainage under suction pipe network, complete whole sealing of hole process.

2. a kind of nearly horizontal firedamp taking-out discharging drilling drilling cuttings according to claim 1 and pouch combine the method for sealing of hole, it is characterized in that: described Grouting Pipe (2) outermost end is provided with the pressure meter (3) of Real-Time Monitoring Grouting Pipe (2) interior pressure.

3. a kind of nearly horizontal firedamp taking-out discharging drilling drilling cuttings according to claim 1 and pouch combine the method for sealing of hole, it is characterized in that: described PVC sleeve pipe (1) total length is 12m.

4. a kind of nearly horizontal firedamp taking-out discharging drilling drilling cuttings according to claim 1 and pouch combine the method for sealing of hole, it is characterized in that: the length of described pouch (4) is 0.8 m, and the position of pouch (4) is regulated according to actual conditions.

5. a kind of near horizontal firedamp taking-out discharging drilling drilling cuttings according to claim 1 or 4 and pouch combine the method for sealing of hole, it is characterized in that: described pouch (4) adopts the impervious waterproof of high-water material slurries, protective cloth material that is fire-retardant, antistatic is made.

6. a kind of nearly horizontal firedamp taking-out discharging drilling drilling cuttings according to claim 1 and pouch combine the method for sealing of hole, it is characterized in that: the diameter of described large boring (5) is 113mm, and hole depth is 13m.

7. a kind of nearly horizontal firedamp taking-out discharging drilling drilling cuttings according to claim 1 and pouch combine the method for sealing of hole, it is characterized in that: described small bore (6) diameter is 75mm.

8. a kind of nearly horizontal firedamp taking-out discharging drilling drilling cuttings according to claim 1 and pouch combine the method for sealing of hole, it is characterized in that: 0.5m, PVC sleeve pipe (1) outer end distance aperture 0.5m at the bottom of described floral tube (10) inner distance hole.