A borehole reaming device for gas drainage holes in soft coal seams

Abstract

The present invention relates to the technical field of hole reaming for gas drainage holes, and particularly relates to a hole reaming device for gas drainage holes in soft coal seams. It includes a main pipe for connecting the drill bit, which is used to be installed on a directional drilling rig. It also includes an extrusion and expansion cylinder, a wall stabilizing mechanism that can be adjusted by water pressure, and a backhaul cylinder. The extrusion and expansion cylinder is fixedly installed on the main pipe for connecting the drill bit. One end of the extrusion and expansion cylinder is detachably and hermetically installed with a drilling cylinder cover. The wall stabilizing mechanism is installed on the extrusion and expansion cylinder, which is used to inject slurry filler into the inner wall of the drill hole, and at the same time is used to increase the density of the inner wall of the drill hole and improve the hole formation rate of the drill hole. The backhaul cylinder is fixedly installed on the main pipe for connecting the drill bit, and the backhaul cylinder is fixedly installed on the side of the extrusion and expansion cylinder away from the drilling cylinder cover. In the present invention, when opening holes required for gas drainage holes in relatively soft coal seams, it not only has a high hole reaming efficiency and a long service life, but also can greatly ensure the formation of the holes after hole reaming, and has strong applicability.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling hole reaming for gas drainage holes, and particularly relates to a drilling hole reaming device for gas drainage holes in soft coal seams. Background Technique

[0002] Coal mine gas drainage is to drill holes into coal seams and gas accumulation areas, connect the drill holes to special pipelines, and use drainage equipment to pump the gas in the coal seams and goafs to the ground for utilization. Gas drainage is not only an important measure to reduce the gas emission during mining, prevent gas overrun and accumulation, and prevent gas explosion and coal and gas outburst accidents, but also can turn harm into benefit and be developed and utilized as an associated resource of coal.

[0003] For stable and long-term gas drainage, the stability of the drill hole well is required. In the prior art, when drilling gas drainage holes, most of them use a directional drill and a down-the-hole drill for cooperative construction. First, a drainage vertical well is drilled through the down-the-hole drill, and then a horizontal docking well that is docked with the drainage vertical well and close to the coal seam is drilled through the directional drill to achieve gas extraction. During the process of drilling with the directional drill, in order to ensure that the diameter of the drainage drill hole meets the standard, it is necessary to continuously perform drilling hole reaming operations on the drill hole well.

[0004] In the prior art, the bit equipment used for drilling hole reaming of the directional drill is generally divided into three types: extrusion expansion type, flow channel type, and cutting type. Among them, the flow channel type and cutting type bit equipment have a fast drilling speed. During the reaming process, a large amount of soil inside the drill hole is broken by rotation, and then the broken soil is discharged out of the hole in large quantities with the mud, which is suitable for areas with soft soil layers but high hole formation quality. The extrusion expansion type bit equipment has a relatively slow drilling speed. During the reaming process, a small amount of soil inside the drill hole is broken by rotation, and a large amount of soil is squeezed to the hole wall to improve the density of the hole wall and increase the hole formation quality. However, when using a directional drill in cooperation with an extrusion expansion type bit equipment to drill and ream holes for gas drainage in coal seams, although the forming rate inside the hole can be improved to a certain extent by extrusion, when the inside of the coal seam is relatively soft, there is still a high probability of collapse inside the hole. Moreover, the existing bit equipment cannot well inject mud filler for supporting the inner wall during the reaming process. When constructing a drill hole in a soft coal seam, during the reaming process, the hole is extremely prone to collapse. When a large-diameter collapse occurs inside the drill hole, the reaming progress of the extrusion expansion type reaming bit equipment will be extremely slow, which will greatly affect the construction progress. Therefore, for opening holes required for gas drainage holes in soft coal seams, we propose a drilling hole reaming device for gas drainage holes in soft coal seams. Summary of the Invention

[0005] (1) Technical Problems to be Solved

[0006] In view of the deficiencies of the prior art, the present invention provides a drilling and reaming device for gas drainage holes in soft coal seams, which is used to solve the problems proposed in the background art, that is, in the prior art, when opening holes for gas drainage holes in soft coal seams, it is not only difficult to form the holes, but also the construction progress is relatively slow.

[0007] (II) Technical solution

[0008] To achieve the above object, the present invention provides the following technical solution: A drilling and reaming device for gas drainage holes in soft coal seams includes a drill bit connection main pipe for installation on a directional drilling rig, and also includes an expansion cylinder, a wall stabilizing mechanism that can be adjusted by water pressure, and a backhaul cylinder;

[0009] The expansion cylinder is fixedly installed on the drill bit connection main pipe, and a drilling cylinder cover is detachably and sealingly installed at one end of the expansion cylinder;

[0010] The wall stabilizing mechanism is installed on the expansion cylinder, and is used to inject mud filler into the inner wall of the drill hole, and at the same time is used to increase the density of the inner wall of the drill hole and improve the hole formation rate of the drill hole;

[0011] The backhaul cylinder is fixedly installed on the drill bit connection main pipe, and the backhaul cylinder is fixedly installed on the side of the expansion cylinder away from the drilling cylinder cover;

[0012] A plurality of crushing heads are fixedly installed on both the side of the backhaul cylinder away from the expansion cylinder and the side of the drilling cylinder cover away from the expansion cylinder, and are used to quickly crush the soil at the caving position inside the drill hole.

[0013] As a preferred technical solution of the present application, the wall stabilizing mechanism includes:

[0014] Wall stabilizing components. There are multiple groups of the wall stabilizing components. A plurality of wall protection installation holes are arranged in a wave shape on the expansion cylinder, and multiple groups of the wall stabilizing components are respectively installed in the multiple wall protection installation holes;

[0015] Each group of the wall stabilizing components includes:

[0016] A spraying block is fixedly installed in the wall protection installation hole. An expansion hole limiting groove is formed on the spraying block, and at least two spraying through holes are formed between the expansion hole limiting groove and the expansion cylinder;

[0017] An expansion block is rotatably installed in the expansion hole limiting groove at a 90° angle.

[0018] On the basis of the above-mentioned solution, both the backhaul cylinder and the expansion cylinder are fixedly installed with the drill bit connection main pipe through a plurality of strengthening support rods.

[0019] On the basis of the foregoing solution, a plurality of wear-resistant protection plates are fixedly installed on both the side of the backhaul cylinder away from the extrusion cylinder and the extrusion cylinder.

[0020] On the basis of the foregoing solution, a plurality of slurry inlet through holes communicating with the backhaul cylinder and the extrusion cylinder are provided on the main drill bit connecting pipe.

[0021] On the basis of the foregoing solution, an octagonal quick connector is fixedly installed at one end of the main drill bit connecting pipe close to the backhaul cylinder, and a backhaul pull head is fixedly installed at one end of the main drill bit connecting pipe close to the drill-in cylinder cover.

[0022] On the basis of the foregoing solution, a plurality of sludge crushing diversion grooves are equiangularly provided on the backhaul cylinder.

[0023] On the basis of the foregoing solution, a slurry spraying pipe is communicated between every two adjacent crushing heads on the backhaul cylinder.

[0024] (III) Beneficial effects

[0025] Compared with the known public technology, the present invention provides a borehole reaming device for gas drainage holes in soft coal seams, which has the following

[0026] beneficial effects:

[0027] 1. In the present invention, when the borehole reaming device is driven by a directional drilling rig to open a hole required for a gas drainage hole in a relatively soft coal seam, through the extrusion cylinder and the hole stabilizing mechanism on the extrusion cylinder, in an extrusion manner, a large amount of soil in the hole is extruded into the inside of the hole wall to improve the strength of the hole wall. At the same time, a large amount of hole wall protection slurry filler can be extruded into the inside of the hole wall along the main drill bit connecting pipe and the extrusion cylinder through the directional drilling rig and the hole stabilizing mechanism, further increasing the strength of the hole wall and greatly reducing the occurrence of hole collapse after reaming;

[0028] 2. In the present invention, during the backhaul reaming process, through the crushing heads installed on the backhaul cylinder and the sludge crushing diversion grooves provided, the collapsed soil in the hole can be quickly broken up, which can greatly improve the reaming efficiency, and part of the broken soil is diverted to the extrusion cylinder through the sludge crushing diversion grooves. Through the hole stabilizing mechanism on the extrusion cylinder, part of the soil can be extruded to the hole wall again to strengthen the hole wall;

[0029] 3. In the present invention, by fixedly installing a plurality of wear-resistant protection plates on both the backhaul cylinder and the extrusion cylinder, during the reaming process, the direct contact between the backhaul cylinder and the extrusion cylinder and the media such as soil, sand grains, and coal seam debris inside the hole can be greatly reduced, which can greatly improve the service life of the borehole reaming device;

[0030] Therefore, when the borehole reaming device for gas drainage in soft coal seams is used to create holes for gas drainage in relatively soft coal seams, it not only has a high reaming efficiency and a long service life, but also can greatly ensure the formation of the holes after reaming, with strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0032] Figure 1 It is a three-dimensional structural schematic diagram of a partial cross-section of the present invention;

[0033] Figure 2 It is a three-dimensional structural schematic diagram of the whole of the present invention;

[0034] Figure 3 It is a three-dimensional structural schematic diagram of another angle of the whole of the present invention;

[0035] Figure 4 For the present invention Figure 1 It is a partial enlarged structural schematic diagram at position A in the present invention;

[0036] Figure 5 For the present invention Figure 1 It is a partial enlarged structural schematic diagram at position B in the present invention.

[0037] The reference numerals in the drawings respectively represent: 001, wall stabilizing mechanism;

[0038] 1, drill bit connection main pipe; 2, expansion cylinder; 3, drilling cylinder cover; 4, backhaul cylinder; 5, crushing head; 6, spraying block; 7, spraying through hole; 8, expansion block; 9, strengthening support rod; 10, wear-resistant protection plate; 11, slurry inlet through hole; 12, octagonal quick connector; 13, backhaul pull head; 14, crushed mud diversion groove; 15, spraying pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0040] Please refer to Figures 1 to 5, a borehole reaming device for gas drainage in soft coal seams, includes a drill bit connecting main pipe 1 for installation on a directional drill. It also includes an extrusion expansion cylinder 2, a wall stabilizing mechanism 001 adjustable by water pressure, and a backhaul cylinder 4. The diameter of the extrusion expansion cylinder 2 is larger than that of the backhaul cylinder 4. A plurality of slurry inlet through holes 11 communicating with the backhaul cylinder 4 and the extrusion expansion cylinder 2 are provided on the drill bit connecting main pipe. A plurality of broken mud diversion grooves 14 are equiangularly provided on the backhaul cylinder 4. One end of the drill bit connecting main pipe 1 close to the backhaul cylinder 4 is fixedly installed with an octagonal quick connector 12, and one end of the drill bit connecting main pipe 1 close to the drilling cylinder cover 3 is fixedly installed with a backhaul pull head 13. Through the octagonal quick connector 12, the borehole reaming device can be quickly connected to the drill pipe used by the directional drill. By setting the backhaul pull head 13, after the reaming is completed, equipment such as pipes required for backhauling gas extraction in the hole can be pulled back into the hole.

[0041] In the above, the extrusion expansion cylinder 2 is fixedly installed on the drill bit connecting main pipe 1. One end of the extrusion expansion cylinder 2 is detachably and hermetically installed with a drilling cylinder cover 3. The drilling cylinder cover 3 is designed in a conical shape. When the directional drill drives the borehole reaming device to open the hole required for gas drainage, and when the directional drill pushes the borehole reaming device to clean the hole after the reaming is completed, the conically arranged drilling cylinder cover 3 can play a good guiding function and can effectively prevent the borehole reaming device from deviating from the hole during the pushing process.

[0042] In the above, the wall stabilizing mechanism 001 is installed on the extrusion expansion cylinder 2, which is used to inject slurry filler into the inner wall of the borehole, and at the same time is used to increase the density of the inner wall of the borehole and improve the hole formation rate of the borehole;

[0043] Among them, the wall stabilizing mechanism 001 includes wall stabilizing components. There are multiple groups of wall stabilizing components. The expanding cylinder 2 is provided with a plurality of wave-shaped wall protection mounting holes. The multiple groups of wall stabilizing components are respectively installed in the plurality of wall protection mounting holes. Each group of wall stabilizing components includes a grouting block 6 and an expanding block 8. The grouting block 6 is fixedly installed in the wall protection mounting hole. The grouting block 6 is provided with an expanding hole limiting groove. At least two grouting through holes 7 are provided between the expanding hole limiting groove and the expanding cylinder 2. The expanding blocks 8 are all rotatably installed in the expanding hole limiting groove at a 90° angle. Specifically, when the directional drill drives the drilling and hole expanding device to rotate and pull back for hole expansion, mud filler is pumped into the interior of the expanding cylinder 2 through the directional drill. The mud filler is ejected through the grouting through holes 7. When ejected, it drives the expanding blocks 8 to move, and part of the expanding blocks 8 is moved to the outside of the expanding cylinder 2. As the drilling and hole expanding device rotates, the expanding blocks 8 come into contact with the inner wall of the hole. The expanding blocks 8 are arc-shaped and are mainly used to squeeze most of the excess soil, sand and other particulate media inside the hole into the soil layer inside the hole wall during the hole expansion process. And because the expanding blocks 8 are arranged in a wave shape, compared with the case where the traditional expanding drill bit moves and squeezes the hole in a threaded manner inside the hole, the same position of the hole wall is squeezed and leveled multiple times by the squeezing blocks, and the hole expansion effect is better. Moreover, in this application, during the hole expansion process of the expanding blocks 8, the mud filler ejected through the grouting holes directly contacts the inner wall of the drill hole, greatly reducing the contact between the mud filler and the original mud inside the drill hole and reducing the risk of excessive dilution of the mud filler. Through the pressure inside the hole, the mud filler is directly pressed into the inner wall of the drill hole, further improving the strength of the inner wall of the hole.

[0044] Another usage mode of the hole stabilizing mechanism 001 is that during the actual construction process, after the reaming of the inside of the drill hole is completed, it is usually necessary to push the drill hole reaming equipment for the last reaming back along the original path, observe the thrust of the directional drill when pushing the drill hole equipment, so as to judge the forming effect of the drill hole, and the effect of cleaning the inside of the drill hole can be achieved. However, as is well known, after the drill hole is reamed by the drill hole reaming equipment, the pressure inside the drill hole will decrease, and the phenomenon of hole shrinkage will occur. During the process of pushing the drill hole equipment back along the original path, the diameter of the drill hole equipment in the prior art will exceed the diameter inside the drill hole, and the friction with the inner wall of the drill hole will increase during the pushing process, which is likely to cause damage to the inner wall of the just-formed drill hole. The prior art usually adopts replacing the drill bit equipment smaller than the drill hole diameter for the hole cleaning detection operation. However, when the drill bit equipment is much smaller than the drill hole diameter, a large amount of mud will flow through the gap between the drill hole and the drill bit equipment during the hole cleaning process, which will greatly affect the hole cleaning effect. And when the gap between the drill hole and the drill bit equipment is large, the detection pressure fluctuation is relatively small, and there will also be a large error in the detection effect. When the hole cleaning operation is carried out by the drill hole reaming device of the present application, all the expanding blocks 8 are rotated into the reaming limiting grooves, reducing the diameter of the drill hole reaming device when it rotates. After the drill hole shrinks, the matching degree between the inner diameter of the hole and the diameter of the drill hole reaming device is high. Since a large amount of mud filler does not need to be pumped into the drill hole during the hole cleaning process, it can be ensured during the hole cleaning process that the expanding blocks 8 are always located in the reaming limiting grooves. During the actual use process, magnets can be installed inside the reaming limiting grooves. When the mud filler pressure inside the expanding cylinder 2 increases to a certain value, the expanding blocks 8 are pushed open and rotated into the inside of the reaming limiting grooves. When the mud pressure decreases, under the suction of the magnets, the expanding blocks 8 are rotated back into the inside of the reaming limiting grooves. By pushing the drill hole reaming device by the directional drill, the gap between the drill hole reaming device and the drill hole can be better controlled without damaging the inner wall of the drill hole, and the hole cleaning detection quality is relatively high.

[0045] As described above, the backhaul cylinder 4 is fixedly installed on the drill bit connecting main pipe 1, and the backhaul cylinder 4 is fixedly installed on the side of the expanding cylinder 2 away from the drilling cylinder cover 3. A plurality of crushing heads 5 are fixedly installed on both the backhaul cylinder 4 and the side of the drilling cylinder cover 3 away from the expanding cylinder 2, which are used to quickly crush the soil at the caved-in position inside the drill hole. Specifically, the present application sets the backhaul cylinder 4 on the side where the expanding cylinder 2 is backhauled, mainly to prevent the phenomenon of cave-in inside the drill hole during the process of backhauling and reaming the drill hole by the drill hole reaming device. Even when a cave-in occurs inside the drill hole, when the directional drill drives the drill hole reaming device to rotate, the crushing heads 5 on the backhaul cylinder 4 can also quickly crush the soil at the caved-in position. After the soil is crushed, it will flow along the mud diversion groove to the expanding cylinder 2. Through the movement of the expanding blocks 8 on the expanding cylinder 2, part of the granular medium can be extruded into the inner wall of the drill hole to reinforce the inner wall of the drill hole. By setting the backhaul cylinder 4, the drilling efficiency can be greatly increased.

[0046] The present application also has the following effects:

[0047] By arranging a plurality of reinforcing struts 9 between both the backhaul cylinder 4 and the extrusion and expansion cylinder 2 and the drill bit connecting main pipe 1, the stability between the backhaul cylinder 4 and the extrusion and expansion cylinder 2 and the drill bit connecting main pipe 1 can be greatly increased.

[0048] On one side of the backhaul cylinder 4 away from the extrusion and expansion cylinder 2 and on the extrusion and expansion cylinder 2, a plurality of wear-resistant protection plates 10 are fixedly installed. The wear-resistant protection plates 10 are preferably made of flexible metal steel plates. Since this drilling and reaming device is mainly used for drilling construction inside a soil layer containing a large amount of coal seams, and the coal seams contain a large amount of media with high hardness, it is easy to cause serious wear to the drilling and reaming device. By installing the wear-resistant protection plates 10, the direct contact between the media with high hardness inside the drill hole and the backhaul cylinder 4 and the extrusion and expansion cylinder 2 can be greatly reduced, and the service life of this drilling and reaming device can be greatly improved. During actual use, when the wear-resistant protection plates 10 and the crushing head 5 are severely worn, the wear-resistant protection plates 10 and the crushing head 5 can be replaced. When the extrusion block 8 is severely worn, by opening the drilling cylinder cover 3, the extrusion block 8 can be replaced, greatly reducing the scrapping rate of the drilling and reaming device.

[0049] In the present application, slurry pipes 15 are connected between two adjacent crushing heads 5 on the backhaul cylinder 4. By spraying slurry fillers through the slurry pipes 15, not only can the crushing heads 5 be cooled to increase the service life of the crushing heads 5, but also the efficiency of the backhaul and reaming can be accelerated.

[0050] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A borehole reaming device for gas drainage holes in soft coal seams, including a main drill bit connecting pipe (1) for installation on a directional drilling rig, characterized in that, It further includes: An expansion cylinder (2), which is fixedly installed on the main drill pipe connection (1), and a drilling cylinder cover (3) is detachably and sealed at one end of the expansion cylinder (2); A hole stabilizing mechanism (001) adjustable by water pressure, which is installed on the expansion cylinder (2) and is used to inject mud filler into the inner wall of the drill hole, and at the same time is used to increase the density of the inner wall of the drill hole and improve the hole formation rate of the drill hole; A backhaul cylinder (4), which is fixedly installed on the main drill pipe connection (1), and the backhaul cylinder (4) is fixedly installed on the side of the expansion cylinder (2) away from the drilling cylinder cover (3); A plurality of crushing heads (5) are fixedly installed on both the side of the backhaul cylinder (4) away from the expansion cylinder (2) and the side of the drilling cylinder cover (3) away from the expansion cylinder (2), and are used to quickly crush the soil at the position of the cave-in in the drill hole; The hole stabilizing mechanism (001) includes: A hole stabilizing assembly, and there are multiple groups of the hole stabilizing assemblies. A plurality of hole stabilizing installation holes are arranged in a wave shape on the expansion cylinder (2), and multiple groups of the hole stabilizing assemblies are respectively installed in the multiple hole stabilizing installation holes; Each group of the hole stabilizing assemblies includes: A slurry spraying block (6), which is fixedly installed in the hole stabilizing installation hole. An expansion hole limiting groove is opened on the slurry spraying block (6), and at least two slurry spraying through holes (7) are opened between the expansion hole limiting groove and the expansion cylinder (2); An expansion block (8), and the expansion blocks (8) are all rotatably installed in the expansion hole limiting groove at a 90° angle.

2. The borehole reaming device for gas drainage holes in soft coal seams according to claim 1, characterized in that, Both the backhaul cylinder (4) and the expansion cylinder (2) are fixedly installed with the main drill pipe connection (1) through a plurality of strengthening support rods (9).

3. The reaming device for boreholes of gas drainage in soft coal seams according to claim 2, wherein, A plurality of wear-resistant protection plates (10) are fixedly installed on both the side of the backhaul cylinder (4) away from the expansion cylinder (2) and the expansion cylinder (2).

4. The reaming device for a borehole of a soft coal seam gas drainage hole according to claim 3, characterized in that, A plurality of slurry inlet through holes (11) communicating with the backhaul cylinder (4) and the expansion cylinder (2) are opened on the main drill pipe connection (1).

5. The reaming device for boreholes of gas drainage in soft coal seams according to claim 4, wherein An octagonal quick connector (12) is fixedly installed at one end of the main drill pipe connection (1) close to the backhaul cylinder (4), and a backhaul pull head (13) is fixedly installed at one end of the main drill pipe connection (1) close to the drilling cylinder cover (3).

6. The reaming device for boreholes of gas drainage in soft coal seams according to claim 5, characterized in that, A plurality of mud crushing diversion grooves (14) are arranged at equal angles on the backhaul cylinder (4).

7. The reaming device for drilling gas drainage holes in soft coal seams according to claim 6, characterized in that, A slurry spraying pipe (15) is communicated between two adjacent crushing heads (5) on the backhaul cylinder (4).

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