Pneumatic directional long hole drilling and completion drilling tool system and method for crushed soft coal seams in underground coal mines

Abstract

The present invention provides a pneumatic directional long-hole drilling tool system and method for completing a hole in a crushed soft coal seam in a coal mine. The system comprises an air supply mechanism, a conventional double-wall drill pipe, a weighted double-wall drill pipe, a completion drill bit, a screen pipe, a transition short section, and an anchor head, which are connected in sequence. The conventional double-wall drill pipe is clamped in the drilling rig power head and passes through the orifice device. The method comprises six steps: lowering the completion drill tool, performing cyclic punching, lowering the screen pipe, anchoring the anchor head, performing a jet completion operation, and performing a continuous pipe extraction operation. The present invention realizes the integrated completion operation of "lowering the hole protection screen pipe in the center hole of the double-wall drill pipe" and "directing the modification of the hole wall coal body by lifting the drill and increasing extraction" to solve the problem of completing a pneumatic directional hole in a crushed soft coal seam. It achieves the goals of ensuring the smooth flow of the directional drilling extraction channel, expanding the drilling extraction range, improving the drilling extraction efficiency, and shortening the extraction cycle, thereby realizing efficient gas extraction by pneumatic directional drilling in a crushed soft coal seam.

Description

Technical Field

[0001] The present invention belongs to the technical field of directional drilling in coal mines, and relates to a directional long hole drilling and completion drilling tool, and in particular to a pneumatic directional long hole drilling and completion drilling tool system and method for crushed soft coal seams in coal mines. Background Art

[0002] The underground pneumatic directional drilling technology in coal mines has broken through the technical bottleneck of long drilling construction along the broken and soft coal seams. The drilling rate of long boreholes with a depth of more than 300m in typical mining areas has reached more than 75%. Using long boreholes along the seams as extraction channels has laid the foundation for the progressive and efficient extraction and control of gas in the broken and soft coal seams.

[0003] However, there are some particularities in gas control through drilling extraction in broken and soft coal seams: on the one hand, the coal body of broken and soft coal seams has poor integrity and low mechanical strength. After drilling and forming a hole, extraction in the open hole state is prone to hole wall collapse and blockage of gas flow channels, thereby affecting the extraction effect and drilling utilization rate; on the other hand, the coal body of broken and soft coal seams generally has poor permeability and is mostly difficult to extract. The impact radius of drilling extraction is small, the extraction volume decays quickly, and it takes a long time to meet the extraction standards.

[0004] To address the problem of gas drainage in crushed and soft coal seams, which is prone to collapse and blockage during drilling, conventional drilling often uses screens to ensure unobstructed drainage channels. To address the poor permeability and long extraction cycles of crushed and soft coal seams, conventional drilling often employs artificial measures to modify the extraction seams, such as hydraulic flushing, hydraulic grooving, carbon dioxide fracturing, and deep-hole blasting. However, these methods can only ensure smooth gas extraction in soft coal seams. Improving the efficiency of directional long drilling and improving extraction results in crushed and soft coal seams remains a major challenge. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a pneumatic directional long drilling and completion drilling system and method for crushed soft coal seams in coal mines, so as to solve the technical problem that the utilization efficiency and extraction effect of directional long drilling in crushed soft coal seams need to be improved.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A pneumatic directional long drilling and completion drilling tool system for broken soft coal seams in coal mines, including a drilling rig power head, the drilling rig power head clamps the axial rear part of an ordinary double-wall drill rod, and the axial front part of the ordinary double-wall drill rod passes through an orifice device; the axial rear end of the ordinary double-wall drill rod extends out of the drilling rig power head and is installed with an air supply mechanism, the axial front end of the ordinary double-wall drill rod passes through the orifice device and is connected to the axial rear end of the weighted double-wall drill rod, the axial front end of the weighted double-wall drill rod is connected to a completion drill bit, the axial rear end of the screen pipe passes through the completion drill bit, the weighted double-wall drill rod and the ordinary double-wall drill rod in sequence, the axial front end of the screen pipe extends out of the completion drill bit and is fixedly connected to the axial rear end of a transition short section, and the axial front end of the transition short section is fixedly connected to the anchor head.

[0008] The hole-finishing drill bit includes a drill body and a drill inner tube fixedly connected to the weighted double-wall drill rod. The axial ends of the drill body and the drill inner tube are open, and the drill inner tube is coaxially inserted into the drill body; the space inside the drill inner tube is the drill center channel, and the space between the drill inner tube and the drill body is the drill annular channel.

[0009] The axial front part of the drill body is provided with a plurality of air flow channels and air control chambers from back to front, the air flow channels and the air control chamber are connected with the annular channel of the drill bit, and a movable roller is movably arranged in the air control chamber; the axial front part of the drill body is provided with a plurality of jet holes along the radial direction, the jet holes are connected with the air control chamber, and the movable roller can cover the jet holes.

[0010] The present invention also has the following technical features:

[0011] The axial front end surface of the drill body is uniformly and integrally provided with a plurality of bosses, the bosses are provided with cutting teeth, and the bosses next to the cutting teeth are provided with a cover plate, which covers the opening at the axial front end of the air control chamber.

[0012] One end of multiple elastic parts is installed in the axial front part of the drill body, and the other ends of the multiple elastic parts are respectively installed in multiple special-shaped blocks. The special-shaped blocks are located between adjacent bosses. The special-shaped blocks are hinged to the drill body. The special-shaped blocks can partially cover the opening at the axial front end of the drill center channel.

[0013] The drill body includes a drill body main body, and the space inside the drill body main body is, from back to front, the first inner cavity of the drill body, the second inner cavity of the drill body, the third inner cavity of the drill body and the fourth inner cavity of the drill body. The inner diameters of the first inner cavity of the drill body, the second inner cavity of the drill body, the third inner cavity of the drill body and the fourth inner cavity of the drill body decrease in sequence.

[0014] The inner wall of the drill body is provided with a first step of the drill body, a second step of the drill body and a third step of the drill body. The first step of the drill body is located at the junction of the first inner cavity of the drill body and the second inner cavity of the drill body, the second step of the drill body is located at the junction of the second inner cavity of the drill body and the third inner cavity of the drill body, and the third step of the drill body is located at the junction of the third inner cavity of the drill body and the fourth inner cavity of the drill body.

[0015] The drill bit inner tube includes a drill bit inner tube main body, the axial rear end of the drill bit inner tube main body is flush with the axial rear end of the drill bit body, and the axial front end of the drill bit inner tube main body is tightly against the third step of the drill bit body; a plurality of drill bit inner tube support blocks are provided on the outer wall of the drill bit inner tube main body, and the drill bit inner tube support blocks are located in the second inner cavity of the drill bit body.

[0016] The transition short section includes a short section shell installed on the screen pipe. The short section shell is divided into a screen pipe connecting shell, a flexible rope fixing installation part and an anchor head setting shell from back to front. The screen pipe connecting shell is fixedly connected to the screen pipe; a flexible rope fixing part is detachably installed on the flexible rope fixing installation part, and a flexible rope is arranged in the anchor head setting shell. One end of the flexible rope is installed on the flexible rope fixing installation part through the flexible rope fixing part, and the other end of the flexible rope is connected to the anchor head.

[0017] The anchor head includes an anchor head body fixedly connected to the transition short section, an anchor head piston is provided on the outer fixed sleeve of the axial rear part of the anchor head body, and multiple pairs of anchor claws are movably connected to the inner axial front part of the anchor head body, and the anchor claws can be extended from the anchor claw extension openings opened on the anchor head body.

[0018] The ordinary double-wall drill pipe includes an outer drill pipe tube, an inner drill pipe tube is coaxially arranged inside the outer drill pipe tube, the space inside the inner drill pipe tube is the drill pipe center channel, and the space between the outer drill pipe tube and the inner drill pipe tube is the drill pipe annular channel.

[0019] The weighted double-wall drill pipe includes a weighted drill pipe outer tube, a weighted drill pipe inner tube is coaxially arranged inside the weighted drill pipe outer tube, the space inside the weighted drill pipe inner tube is the weighted drill pipe central channel, and the space between the weighted drill pipe outer tube and the weighted drill pipe inner tube is the weighted drill pipe annular channel.

[0020] The central channel of the drill rod, the central channel of the weighted drill rod, and the central channel of the drill bit are all connected and together constitute the central channel of the completion drill tool, and the central channel of the completion drill tool is connected to the air supply mechanism; the annular channel of the drill rod, the annular channel of the weighted drill rod, and the annular channel of the drill bit together constitute the annular channel of the completion drill tool, and the annular channel of the completion drill tool is also connected to the air supply mechanism.

[0021] The present invention also protects a method for completing a pneumatic directional long hole drilling in a crushed soft coal seam in an underground coal mine. The method uses the above-mentioned pneumatic directional long hole drilling and completion drilling tool system in a crushed soft coal seam in an underground coal mine. The method specifically comprises the following steps:

[0022] Step 1: Assemble ordinary double-wall drill pipe, heavy double-wall drill pipe and completion drill bit, and then use the drilling rig power head to lower the assembled completion drill tool.

[0023] Step 2: Use the air supply mechanism and the hole-finishing drill inserted in step 1 to perform cyclic punching.

[0024] Step 3: Assemble and install the transition nipple and anchor head, and then lower the screen.

[0025] Step 4: Use the air supply mechanism to drive the anchor head to achieve anchoring, so that the anchor head tensions and fixes the screen tube.

[0026] Step 5: Perform jet hole finishing operation:

[0027] Step 5.1: Use the air supply mechanism to send compressed gas into the hole completion drill.

[0028] Step 5.2, perform a hole completion operation:

[0029] The completion drill tool is pulled back. During the process of pulling back the completion drill tool, the compressed gas reaches the completion drill bit at the bottom of the hole through the annular channel of the drill pipe, enters the corresponding air control chamber through multiple air flow channels, and under the control of the movable roller, the jet holes not covered by the movable roller form high-speed gas jets and impact and disturb the upper hole wall. As the completion drill tool rotates, the multiple air control chambers continuously change positions, alternately forming gas jets.

[0030] Step 5.3: Remove the ordinary double-wall drill pipes one by one and continue the hole completion operation.

[0031] Step six: After the hole operation is completed, carry out continuous pipe extraction.

[0032] The present invention also protects a hole completion drill bit as described above.

[0033] Compared with the prior art, the present invention has the following technical effects:

[0034] (I) The pneumatic directional long hole completion drilling tool system for crushed soft coal seams in coal mines of the present invention adopts a completion drill bit to control the directional impact of a gas jet to transform the upper hole wall, thereby inducing local coal body instability and collapse to form accumulation areas and disturbance areas, thereby increasing the effective extraction hole wall area of ​​the directional drilling hole by 2 to 4 times, and improving the comprehensive extraction efficiency of directional drilling holes in crushed soft coal seams by more than 50%.

[0035] (II) The pneumatic directional long hole drilling and completion drilling tool system for crushed soft coal seams in coal mines of the present invention uses a transition short section to connect the hole protection screen pipe with the anchor head. The anchor head is "rushed out" of the central channel at the bottom of the hole with the help of the driving force of high-pressure gas and anchored on the coal body of the hole wall. Then, the screen pipe column is pulled by a flexible rope to be retained in the hole. In the case of deep holes, it is more efficient than the method of "pushing out" the screen pipe column from the hole mouth, and the one-time success rate can reach more than 95%.

[0036] (III) The pneumatic directional long hole completion drilling tool system for crushed soft coal seams in coal mines of the present invention has a weighted double-wall drill rod connected to the rear end of the completion drill bit, which can ensure that the completion drill tool extends into the main hole along the lower hole wall at the branch point. The insertion depth of the completion drill tool assembly can be increased by 200m to 300m compared with conventional methods.

[0037] (IV) The pneumatic directional long hole completion method for crushed soft coal seams in coal mines of the present invention adopts a drilling rig power head to push down the hole completion drill tools one by one into the main hole of the pneumatic directional hole, and after the hole completion drill tools are lowered to the bottom of the hole, the hole protection screen pipe is lowered through the central channel of the hole completion drill tool; during the drilling process, an air supply mechanism is used to input compressed gas into the hole completion drill tool through the central channel and the annular channel of the hole completion drill tool, wherein the gas input from the annular channel of the hole completion drill tool can form a radial gas jet to impact the coal body near the upper hole wall when flowing through the hole completion drill bit, thereby forming a certain range of collapse, while the gas input from the central channel of the hole completion drill tool carries some fine coal slag chips and flows back to the hole mouth through the channel between the hole completion drill tool and the hole wall.

[0038] Through the above process, the present invention realizes the integrated completion operation of "lowering the protective screen pipe in the center hole of the double-wall drill pipe" and "directionally transforming the coal body in the hole wall by lifting the drill with gas jet to increase extraction", solves the problem of completing pneumatic directional holes in broken and soft coal seams, and achieves the purposes of ensuring the smooth flow of directional drilling extraction channels, expanding the scope of drilling extraction influence, improving the extraction efficiency of drilling, shortening the extraction cycle, and thus realizing efficient gas extraction by pneumatic directional drilling in broken and soft coal seams.

[0039] (IV) The present invention provides a method for completing a pneumatic directional long hole in a crushed soft coal seam in a coal mine. This method can be implemented using the pneumatic directional drilling power equipment—a drilling rig and a compressed air source—that are used in conjunction with the drilling operation. This method eliminates the need for an additional auxiliary power source, resulting in a simple equipment system, minimal auxiliary work, and low overall operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a schematic diagram of the structure of a completion drill bit without a screen pipe installed.

[0041] Figure 2 This is a schematic diagram of the structure of the axial front end of the completion drill bit without a screen pipe installed.

[0042] Figure 3 Schematic diagram of the structure of a completion drill bit equipped with a screen pipe.

[0043] Figure 4 It is a schematic diagram of the structure of the axial front end of the completion drill bit with a screen pipe installed.

[0044] Figure 5 Schematic diagram of the structure of the drill body.

[0045] Figure 6 Schematic diagram of the structure of the inner tube of the drill bit.

[0046] Figure 7 This is a schematic diagram of the overall structure of the pneumatic directional long hole drilling and completion drilling tool system for broken soft coal seams in underground coal mines.

[0047] Figure 8 Schematic diagram of the installation structure of the transition pup joint and anchor head.

[0048] Figure 9 Schematic diagram of the working status of the transition short section and anchor head at the bottom of the hole.

[0049] Figure 10 Schematic diagram of the structure of the anchor head.

[0050] Figure 11 Schematic diagram of the structure of ordinary double-wall drill pipe and heavy-weight double-wall drill pipe.

[0051] Figure 12 Schematic diagram of the working principle of weighted double-wall drill pipe.

[0052] Figure 13 This is a schematic diagram of the working status of the pneumatic directional long hole drilling and completion drilling tool system in the broken soft coal seam in the coal mine; Figure 13 Middle: The red arrows represent compressed gas, and the green arrows represent gas carrying some fine coal slag.

[0053] Figure 14 for Figure 13 AA surface cross-section.

[0054] The meanings of the numbers in the figure are: 1-drilling rig power head, 2-conventional double-wall drill pipe, 3-orifice device, 4-air supply mechanism, 5-weighted double-wall drill pipe, 6-completion drill bit, 7-screen pipe, 8-transition short section, 9-anchor head, 10-sealing pipe, 11-branch cross hole section, 12-main hole, 13-collapse body, 14-disturbed fracture zone;

[0055] 201-drill pipe outer tube, 202-drill pipe inner tube, 203-drill pipe central channel, 204-drill pipe annular channel;

[0056] 301-gas and fine coal dust outlet, 302-large particle coal slag outlet;

[0057] 401-dual-channel blower, 402-compressed gas source, 403-gas delivery pipeline, 404-gas control valve;

[0058] 501-weighted drill pipe outer tube, 502-weighted drill pipe inner tube, 503-weighted drill pipe central channel, 504-weighted drill pipe annular channel;

[0059] 601- drill bit body, 602- drill bit inner tube, 603- drill bit center channel, 604- drill bit annular channel, 605- air flow channel, 606- air control chamber, 607- movable roller, 608- jet hole, 609- boss, 610- cutting tooth, 611- cover plate, 612- elastic member, 613- special-shaped stopper, 614- pin shaft;

[0060] 801- short section housing, 802- flexible cable fixing piece, 803- flexible cable;

[0061] 901-anchor head body, 902-anchor head piston, 903-anchor claw, 904-anchor claw extension port, 905-long hole, 906-tension spring adjustment shaft, 907-tension spring connecting shaft;

[0062] 40101-air blower body, 40102-center channel air inlet, 40103-annular channel air inlet;

[0063] 60101 - drill bit body, 60102 - first inner cavity of drill bit body, 60103 - second inner cavity of drill bit body, 60104 - third inner cavity of drill bit body, 60105 - fourth inner cavity of drill bit body, 60106 - first step of drill bit body, 60107 - second step of drill bit body, 60108 - third step of drill bit body;

[0064] 60201-drill bit inner tube body, 60202-drill bit inner tube support block;

[0065] 80101-screen tube connection shell, 80102-flexible rope fixing installation part, 80103-anchor head setting shell.

[0066] The specific contents of the present invention are further explained in detail below with reference to the embodiments. DETAILED DESCRIPTION

[0067] It should be noted that, unless otherwise specified, all components in the present invention are components known in the art.

[0068] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0069] Example 1:

[0070] This embodiment provides a hole-finishing drill bit, such as Figures 1 to 4 As shown, it includes a drill bit body 601 and a drill bit inner tube 602. The axial ends of the drill bit body 601 and the drill bit inner tube 602 are open, and the drill bit inner tube 602 is coaxially inserted into the drill bit body 601; the space inside the drill bit inner tube 602 is the drill bit center channel 603, and the space between the drill bit inner tube 602 and the drill bit body 601 is the drill bit annular channel 604.

[0071] A plurality of air flow channels 605 and an air control chamber 606 are provided in the axial front portion of the drill bit body 601 from back to front. The air flow channels 605 and the air control chamber 606 are connected to the drill bit annular channel 604. A movable roller 607 is movably provided in the air control chamber 606. A plurality of jet holes 608 are provided in the axial front portion of the drill bit body 601 along the radial direction. The jet holes 608 are connected to the air control chamber 606. The movable roller 607 can cover the jet holes 608.

[0072] In this embodiment, the movable roller 607 is made of a high-density alloy known in the prior art. As the drill bit body 601 rotates, the position of the movable roller 607 in the air control chamber 606 changes, thereby opening and closing the jet hole 608.

[0073] As a specific solution of this embodiment, Figures 1 to 4 As shown, a plurality of bosses 609 are evenly distributed on the axial front end surface of the drill body 601, and cutting teeth 610 are provided on the bosses 609. A cover plate 611 is provided on the bosses 609 next to the cutting teeth 610, and the cover plate 611 covers the opening at the axial front end of the control air chamber 606.

[0074] In this embodiment, the cover plate 611 can limit the movable roller 607 and serve as a component of the air control chamber 606 .

[0075] As a specific solution of this embodiment, Figures 1 to 4 As shown, one end of multiple elastic members 612 is installed in the axial front part of the drill body 601, and the other ends of the multiple elastic members 612 are respectively installed in multiple special-shaped blocks 613. The special-shaped blocks 613 are located between adjacent bosses 609. The special-shaped blocks 613 are hinged on the drill body 601. The special-shaped blocks 613 can partially cover the opening of the axial front end of the drill center channel 603.

[0076] In this embodiment, the special-shaped stopper 613 is movably mounted on the axial front end of the drill body 601 via a pin shaft 614. The special-shaped stopper 613 can rotate around the pin shaft 614, so that the central channel of the hole-finishing drill tool forms two states: "closed" and "open".

[0077] In this embodiment, the elastic member 612 adopts a conventional elastic steel needle known in the prior art. The elastic member 612 can maintain the special-shaped stopper 613 in a normally closed state to prevent a large amount of coal slag from entering the drill bit center channel 603 and causing blockage; the elastic member 612 can bend after being subjected to force, so that the special-shaped stopper 613 opens outward, allowing the screen tube 7 to be smoothly lowered through the drill bit center channel 603; in the process of using gas jet to transform the hole wall, multiple special-shaped stops 613 rotate with the drill bit body and slide circumferentially relative to the screen tube 7, ensuring that the sieve holes on the screen tube 7 are unobstructed.

[0078] In this embodiment, the number of the air control chamber 606 , the movable roller 607 , the boss 609 , the cutting teeth 610 , the cover plate 611 and the special-shaped stopper 613 is three.

[0079] As a specific solution of this embodiment, Figure 5 As shown, the drill bit body 601 includes a drill bit body main body 60101, and the space inside the drill bit body main body 60101 is, from back to front, a first inner cavity 60102 of the drill bit body, a second inner cavity 60103 of the drill bit body, a third inner cavity 60104 of the drill bit body and a fourth inner cavity 60105 of the drill bit body, and the inner diameters of the first inner cavity 60102 of the drill bit body, the second inner cavity 60103 of the drill bit body, the third inner cavity 60104 of the drill bit body and the fourth inner cavity 60105 of the drill bit body decrease in sequence.

[0080] The inner wall of the drill body 60101 is provided with a first step 60106, a second step 60107 and a third step 60108 of the drill body. The first step 60106 of the drill body is located at the junction of the first inner cavity 60102 and the second inner cavity 60103 of the drill body. The second step 60107 of the drill body is located at the junction of the second inner cavity 60103 and the third inner cavity 60104 of the drill body. The third step 60108 of the drill body is located at the junction of the third inner cavity 60104 and the fourth inner cavity 60105 of the drill body.

[0081] As a specific solution of this embodiment, Figure 6 As shown, the drill bit inner tube 602 includes a drill bit inner tube main body 60201, the axial rear end of the drill bit inner tube main body 60201 is flush with the axial rear end of the drill bit body 601, and the axial front end of the drill bit inner tube main body 60201 is tightly against the third step 60108 of the drill bit body; a plurality of drill bit inner tube support blocks 60202 are provided on the outer wall of the drill bit inner tube main body 60201, and the drill bit inner tube support blocks 60202 are located in the second inner cavity 60103 of the drill bit body.

[0082] In this embodiment, the drill bit inner tube support block 60202 plays a role in supporting the drill bit inner tube 602 and can ensure that the drill bit inner tube 602 and the drill bit body 601 remain coaxial.

[0083] Example 2:

[0084] This embodiment provides a pneumatic directional long hole completion drilling system for crushed soft coal seams in underground coal mines. The system uses the hole completion drill bit in Example 1.

[0085] like Figure 7 As shown, the system includes a drilling rig power head 1, in which the axial rear part of an ordinary double-wall drill pipe 2 is clamped, the axial front part of the ordinary double-wall drill pipe 2 passes through the orifice device 3, the axial rear end of the ordinary double-wall drill pipe 2 extends out of the drilling rig power head 1 and is installed with an air supply mechanism 4, the axial front end of the ordinary double-wall drill pipe 2 extends out of the orifice device 3 and is fixedly connected to the axial rear end of a weighted double-wall drill pipe 5, and the axial front end of the weighted double-wall drill pipe 5 is fixedly connected to a completion drill bit 6; the axial rear end of the screen tube 7 passes through the completion drill bit 6, the weighted double-wall drill pipe 5 and the ordinary double-wall drill pipe 2 in sequence, the axial front end of the screen tube 7 extends out of the completion drill bit 6 and is fixedly connected to the axial rear end of a transition short section 8, and the axial front end of the transition short section 8 is fixedly connected to an anchor head 9.

[0086] As a specific solution of this embodiment, Figure 8 As shown, the transition short section 8 includes a short section shell 801 installed on the screen tube 7. The short section shell 801 is divided into a screen tube connecting shell 80101, a flexible rope fixing installation part 80102 and an anchor head setting shell 80103 from back to front. The screen tube connecting shell 80101 is fixedly connected to the screen tube 7; a flexible rope fixing part 802 is detachably installed on the flexible rope fixing installation part 80102, and a flexible rope 803 is arranged in the anchor head setting shell 80103. One end of the flexible rope 803 is installed on the flexible rope fixing installation part 80102 through the flexible rope fixing part 802, and the other end of the flexible rope 803 is connected to the anchor head 9.

[0087] In this embodiment, the flexible cable 803 enables the transition section 8 and the anchor head 9 to be relatively separated and can transmit tension to achieve reliable anchoring.

[0088] In this embodiment, the flexible cable fixing member 802 adopts a conventional fixing screw known in the prior art.

[0089] As a specific solution of this embodiment, Figures 8 to 10 As shown, the anchor head 9 includes an anchor head body 901 fixedly connected to the transition short section 8. An anchor head piston 902 is fixedly sleeved on the axial rear portion of the anchor head body 901. A plurality of pairs of flukes 903 are movably connected to the axial front portion of the anchor head body 901. The flukes 903 can be extended from fluke extension openings 904 provided on the anchor head body 901.

[0090] As a specific solution of this embodiment, Figures 8 to 10As shown, an elongated hole 905 is formed in the axial front portion of the anchor head body 901. A tension spring adjustment shaft 906 is movably disposed in the elongated hole 905. The tension spring adjustment shaft 906 is movably connected to the inner ends of a pair of tension spring connecting shafts 907. The outer ends of the tension spring connecting shafts 907 are movably connected to the fluke 903. The structure composed of the tension spring adjustment shaft 906 and the tension spring connecting shaft 907 is the tension spring.

[0091] As a specific solution of this embodiment, Figure 7 As shown, the air supply mechanism 4 includes a dual-channel air supply 401 installed on an ordinary double-wall drill pipe 2, and the dual-channel air supply 401 includes an air supply body 40101. The interior of the air supply body 40101 is provided with a central channel air inlet 40102 along the axial direction, and the outer cylindrical surface of the air supply body 40101 is provided with an annular channel air inlet 40103; the air supply mechanism 4 also includes a compressed gas source 402, and the compressed gas source 402 is connected to the central channel air inlet 40102 and the annular channel air inlet 40103 through a gas delivery pipe 403, and a gas control valve 404 is provided on the gas delivery pipe 403.

[0092] As a specific solution of this embodiment, Figure 11 As shown, the ordinary double-wall drill pipe 2 includes a drill pipe outer tube 201, a drill pipe inner tube 202 is coaxially arranged inside the drill pipe outer tube 201, the space inside the drill pipe inner tube 202 is the drill pipe central channel 203, and the space between the drill pipe outer tube 201 and the drill pipe inner tube 202 is the drill pipe annular channel 204.

[0093] As a specific solution of this embodiment, Figure 11 As shown, the weighted double-wall drill pipe 5 includes a weighted drill pipe outer tube 501, a weighted drill pipe inner tube 502 is coaxially arranged inside the weighted drill pipe outer tube 501, the space inside the weighted drill pipe inner tube 502 is the weighted drill pipe central channel 503, and the space between the weighted drill pipe outer tube 501 and the weighted drill pipe inner tube 502 is the weighted drill pipe annular channel 504.

[0094] In this embodiment, the weight of the weighted double-wall drill pipe 5 is about twice that of the ordinary double-wall drill pipe 2. The outer tube 501 of the weighted drill pipe is a thick-walled structure, which can control the double-wall drill assembly to adhere to the lower hole wall and extend and lower in the main hole 12.

[0095] As a specific solution of this embodiment, the drill rod center channel 203, the weighted drill rod center channel 503, and the drill bit center channel 603 are all connected and together constitute the hole completion drill tool center channel, and the hole completion drill tool center channel is connected to the center channel air inlet 40102; the drill rod annular channel 204, the weighted drill rod annular channel 504 and the drill bit annular channel 604 together constitute the hole completion drill tool annular channel, and the hole completion drill tool annular channel is connected to the annular channel air inlet 40103.

[0096] In this embodiment, the central channel of the completion drill tool has dual functions: one is to transport gas, and the other is to lower the screen pipe; the annular channel of the completion drill tool is a gas channel, which is used to transport high-pressure gas to the completion drill bit to form a gas jet to modify the hole wall.

[0097] As a specific solution of this embodiment, Figure 7 As shown, the orifice device 3 is a four-way structure, the upper opening of the orifice device 3 is a gas and fine coal dust outlet 301, and the lower opening of the orifice device 3 is a large particle coal slag outlet 302; the axial rear end of the orifice device 3 is fixedly connected to a sealing pipe 10.

[0098] Example 3:

[0099] This embodiment provides a method for completing a pneumatic directional long hole drilling in a broken soft coal seam in a coal mine. The method adopts the pneumatic directional long hole drilling and completion drilling tool system for completing a broken soft coal seam in a coal mine in Example 2; Figures 12 to 14 As shown, the method specifically includes the following steps:

[0100] Step 1: Run the drilling tool into the hole:

[0101] Drill to the designed depth using pneumatic directional drilling. After the pneumatic directional drilling construction of the broken soft coal seam is completed and the original drilling tool in the hole is withdrawn, the weighted double-wall drill pipe 5 and the completion drill bit 6 are first connected. After the weighted double-wall drill pipe 5 and the completion drill bit 6 are lowered into the hole through the center of the orifice device 3 and the sealing pipe 10, ordinary double-wall drill pipes 2 are added one by one, and the assembled completion drill tool is pushed by the drilling rig power head 1; when the completion drill bit 6 passes through the branch intersection hole section 11, the drilling tool in the hole is rotated at a speed of 30 to 40 r / min, and under the guidance of the weighted double-wall drill pipe 5, the completion drill tool is allowed to enter the main hole 12 along the lower hole wall.

[0102] Step 2: Perform cyclic punching:

[0103] After the completion drill bit 6 reaches the bottom of the main hole 12, the dual-channel air supply 401 is connected to the completion drill tool, the compressed air source 402 is started, and the gas control valve 404 is manipulated to allow the compressed gas to reach the bottom of the hole through the central channel air inlet 40102 of the dual-channel air supply 401. At the same time, the drill tool in the hole is rotated at a speed of 30 to 40 r / min to remove the accumulated slag at the front end of the completion drill bit 6. After the cyclic punching, the completion drill tool is lifted about 5 m away from the bottom of the hole. After stopping the gas injection, the dual-channel air supply 401 is removed.

[0104] Step 3: Lower the screen tube:

[0105] After ensuring that one end of the flexible cable 803 is connected to the anchor head 9, the other end of the flexible cable 803 is connected to the short section shell 801 through the flexible cable fixing part 802 of the transition short section 8, and then the transition short section 8 and the anchor head 9 are plugged together, and then the first screen pipe 7 is connected to the transition short section 8 by means of a threaded connection. After the connection is completed, it is placed in the central channel of the completion drilling tool, and then the screen pipes 7 are added one by one and pushed into the hole until the anchor head 9 reaches the completion drill bit 6 at the bottom of the hole.

[0106] Step 4: Anchor the head:

[0107] The dual-channel air supply device 401 is connected to the completion drill bit, the compressed air source 402 is started, and the gas control valve 404 is manipulated to allow the compressed gas to reach the bottom of the hole through the central channel air inlet 40102. The air pressure increases under the obstruction of the anchor head piston 902 of the anchor head 9, thereby generating axial thrust. When the air pressure reaches about 1.0 MPa, the axial force formed on the anchor head piston 902 is sufficient to push the anchor head 9 toward the bottom of the hole, so that the anchor head 9 is separated from the transition short section 8. When the anchor head 9 passes through the completion drill bit 6, it pushes away the special-shaped block 613 and enters the borehole; at the same time, the anchor claw 903 opens under the action of elastic force and embeds into the coal body 13 of the hole wall, completing the anchoring; after the anchor head 9 enters the borehole, the flexible cable 803 is stretched and unfolded, and then the screen pipe 7 is tensioned and fixed to the bottom of the hole through the transition short section 8.

[0108] Step 5: Perform jet hole finishing operation:

[0109] Step 5.1: Use the air supply mechanism 4 to send compressed gas into the hole completion drilling tool:

[0110] When the wind pressure shows a "peak" and the orifice returns air normally, indicating that the anchoring is completed, the opening of the gas control valve 404 is controlled at this time, and the compressed gas with a volume flow of about 70% enters the drill pipe annular channel 204 through the annular channel air inlet 40103 of the dual-channel air supply unit 401, and the remaining gas enters the drill pipe central channel 203 through the central channel air inlet 40102 of the dual-channel air supply unit 401.

[0111] Step 5.2, perform a hole completion operation:

[0112] The drill string rotates at a speed of 20 to 25 r / min while simultaneously pulling back the completion drill bit 6 at a mechanical speed of approximately 12 m / h. During this process, compressed gas, arriving at the completion drill bit 6 at the bottom of the hole through the drill pipe annular passage 204, enters the corresponding gas control chamber 606 via multiple airflow passages 605. Under the control of the movable rollers 607, the jet holes 608 not covered by the movable rollers 607 form high-speed gas jets that impact and disturb the upper hole wall. As the completion drill string rotates, the multiple gas control chambers 606 continuously change position, alternating the formation of gas jets. In this embodiment, the gas jets directional impact the upper coal wall, generating a collapsed body 13 and a disturbed fracture zone 14, achieving directional transformation and expanding the radial impact range of the drill hole.

[0113] In this embodiment, during the hole completion operation, the compressed gas that reaches the bottom of the hole through the central channel 203 of the drill pipe enters the hole through the gap between the screen tube 7 and the hole completion drill bit 6 and the holes on the screen tube 7 and flows into the hole. The airflow flowing into the hole has a dual function: one is to prevent the jet gas from carrying coal slag dust to flow back to the central channel and block the holes of the screen tube 7; the other is that when the gas flows through the collapsed body 13, it can carry away fine coal dust to improve the air permeability of the collapsed body.

[0114] In this embodiment, during the hole completion operation, the two streams of compressed gas that reach the bottom of the hole through the central channel and the annular channel of the hole completion drill tool merge and carry some coal slag dust back along the gap between the hole completion drill tool and the hole wall, and then return to the hole mouth for primary gas-solid separation: the gas carrying some coal dust is discharged through the gas and fine coal dust outlet 301, and the large-particle coal dust is deposited through the large-particle coal dust outlet 302.

[0115] In this embodiment, the principle of the movable roller 607 controlling the airflow is as follows: when the drill body 601 rotates, the air control chamber 606 will change position with the rotation. When a certain air control chamber 606 rotates below the horizontal plane of the drill body axis, the movable roller 607 slides down under the action of gravity and just covers the jet hole 608. At this time, the movable roller 607 in the air control chamber 606 located at other positions will not cover the jet hole 608, and the airflow will not flow out from the covered jet hole 608, but will flow out from other uncovered jet holes 608.

[0116] Step 5.3, continue with hole finishing operation:

[0117] When a hole completion operation is completed, the gas control valve 404 is manipulated to cut off the air flow channel, the rotation of the hole completion drilling tool is stopped, and then the dual-channel air supply 401 and an ordinary double-wall drill pipe 2 are removed, and the dual-channel air supply 401 is reconnected to repeat the hole completion operation.

[0118] Step 6: Conduct continuous pipe extraction:

[0119] When the drill bit 6 is 10 to 15 meters away from the lower end of the sealing pipe 10, stop supplying gas, pull back the drilling tool, and leave the screen pipe 7 in the hole to keep the extraction channel unobstructed; connect the negative pressure pipeline to the orifice device 3 for extraction.

Claims

1. A pneumatic directional long hole drilling and completion drilling system for crushed soft coal seams in underground coal mines, comprising a drilling rig power head (1), wherein the axial rear portion of a conventional double-wall drill rod (2) is clamped in the drilling rig power head (1), and the axial front portion of the conventional double-wall drill rod (2) passes through an orifice device (3), characterized in that ； The axial rear end of the ordinary double-wall drill pipe (2) extends out of the drilling rig power head (1) and is installed with an air supply mechanism (4); the axial front end of the ordinary double-wall drill pipe (2) passes through the orifice device (3) and is connected to the axial rear end of the weighted double-wall drill pipe (5); the axial front end of the weighted double-wall drill pipe (5) is connected to the hole completion drill bit (6); the axial rear end of the screen pipe (7) passes through the hole completion drill bit (6), the weighted double-wall drill pipe (5) and the ordinary double-wall drill pipe (2) in sequence; the axial front end of the screen pipe (7) extends out of the hole completion drill bit (6) and is fixedly connected to the axial rear end of the transition short section (8); the axial front end of the transition short section (8) is fixedly connected to the anchor head (9); The hole-finishing drill bit (6) comprises a drill bit body (601) and a drill bit inner tube (602) fixedly connected to a weighted double-wall drill rod (5); the drill bit body (601) and the drill bit inner tube (602) are open at both axial ends, and the drill bit inner tube (602) is coaxially plugged into the drill bit body (601); the space inside the drill bit inner tube (602) is a drill bit central channel (603), and the space between the drill bit inner tube (602) and the drill bit body (601) is a drill bit annular channel (604); The axial front portion of the drill bit body (601) is provided with a plurality of air flow channels (605) and air control chambers (606) from back to front, the air flow channels (605) and the air control chamber (606) are connected to the drill bit annular channel (604), and a movable roller (607) is movably provided in the air control chamber (606); the axial front portion of the drill bit body (601) is provided with a plurality of jet holes (608) along the radial direction, the jet holes (608) are connected to the air control chamber (606), and the movable roller (607) can cover the jet holes (608).

2. The pneumatic directional long hole drilling and completion drilling system for crushed soft coal seams in underground coal mines according to claim 1, characterized in that: A plurality of bosses (609) are evenly distributed on the axial front end surface of the drill bit body (601), and cutting teeth (610) are provided on the bosses (609). A cover plate (611) is provided on the bosses (609) next to the cutting teeth (610), and the cover plate (611) covers the opening at the axial front end of the control air chamber (606).

3. The pneumatic directional long hole drilling and completion drilling tool system for crushed soft coal seams in underground coal mines according to claim 1, characterized in that: One end of a plurality of elastic members (612) is installed in the axial front portion of the drill bit body (601), and the other ends of the plurality of elastic members (612) are respectively installed in a plurality of special-shaped stoppers (613). The special-shaped stoppers (613) are located between adjacent bosses (609). The special-shaped stoppers (613) are hinged to the drill bit body (601), and the special-shaped stoppers (613) can partially cover the opening at the axial front end of the drill bit center channel (603).

4. The pneumatic directional long hole drilling and completion drilling system for crushed soft coal seams in underground coal mines according to claim 1, characterized in that: The drill bit body (601) includes a drill bit body main body (60101), and the spaces within the drill bit body main body (60101) are, from back to front, a first inner cavity (60102) of the drill bit body, a second inner cavity (60103) of the drill bit body, a third inner cavity (60104) of the drill bit body, and a fourth inner cavity (60105) of the drill bit body. The inner diameters of the first inner cavity (60102), the second inner cavity (60103), the third inner cavity (60104), and the fourth inner cavity (60105) of the drill bit body decrease in sequence. The inner wall of the drill body (60101) is provided with a first step (60106), a second step (60107) and a third step (60108) of the drill body. The first step (60106) of the drill body is located at the junction of the first inner cavity (60102) and the second inner cavity (60103) of the drill body, the second step (60107) of the drill body is located at the junction of the second inner cavity (60103) and the third inner cavity (60104) of the drill body, and the third step (60108) of the drill body is located at the junction of the third inner cavity (60104) and the fourth inner cavity (60105) of the drill body.

5. The pneumatic directional long hole drilling and completion drilling tool system for crushed soft coal seams in underground coal mines according to claim 4, characterized in that: The drill bit inner tube (602) includes a drill bit inner tube main body (60201), the axial rear end of the drill bit inner tube main body (60201) is flush with the axial rear end of the drill bit body (601), and the axial front end of the drill bit inner tube main body (60201) is tightly against the third step (60108) of the drill bit body; a plurality of drill bit inner tube support blocks (60202) are provided on the outer wall of the drill bit inner tube main body (60201), and the drill bit inner tube support blocks (60202) are located in the second inner cavity (60103) of the drill bit body.

6. The pneumatic directional long hole drilling and completion drilling tool system for crushed soft coal seams in underground coal mines according to claim 1, characterized in that: The transition short section (8) includes a short section housing (801) installed on the screen tube (7). The short section housing (801) is divided into a screen tube connection housing (80101), a flexible rope fixing installation portion (80102) and an anchor head setting housing (80103) from back to front. The screen tube connection housing (80101) is fixedly connected to the screen tube (7); a flexible rope fixing part (802) is detachably installed on the flexible rope fixing installation portion (80102), and a flexible rope (803) is arranged in the anchor head setting housing (80103). One end of the flexible rope (803) is installed on the flexible rope fixing installation portion (80102) through the flexible rope fixing part (802), and the other end of the flexible rope (803) is connected to the anchor head (9).

7. The pneumatic directional long hole drilling and completion drilling tool system for crushed soft coal seams in underground coal mines according to claim 1, characterized in that: The anchor head (9) comprises an anchor head body (901) fixedly connected to the transition short section (8); an anchor head piston (902) is fixedly sleeved on the axial rear portion of the anchor head body (901); and a plurality of pairs of flukes (903) are movably connected to the axial front portion of the anchor head body (901). The flukes (903) can be extended from fluke extension openings (904) provided on the anchor head body (901).

8. The pneumatic directional long hole drilling and completion drilling tool system for crushed soft coal seams in underground coal mines according to claim 1, characterized in that: The conventional double-wall drill pipe (2) comprises a drill pipe outer tube (201), a drill pipe inner tube (202) is coaxially arranged inside the drill pipe outer tube (201), the space inside the drill pipe inner tube (202) is a drill pipe central channel (203), and the space between the drill pipe outer tube (201) and the drill pipe inner tube (202) is a drill pipe annular channel (204); The weighted double-wall drill pipe (5) comprises a weighted drill pipe outer tube (501), a weighted drill pipe inner tube (502) is coaxially arranged inside the weighted drill pipe outer tube (501), the space inside the weighted drill pipe inner tube (502) is a weighted drill pipe central channel (503), and the space between the weighted drill pipe outer tube (501) and the weighted drill pipe inner tube (502) is a weighted drill pipe annular channel (504); The drill rod central channel (203), the weighted drill rod central channel (503), and the drill bit central channel (603) are all connected and together constitute the hole completion drilling tool central channel, which is connected to the air supply mechanism (4); the drill rod annular channel (204), the weighted drill rod annular channel (504), and the drill bit annular channel (604) together constitute the hole completion drilling tool annular channel, which is also connected to the air supply mechanism (4).

9. A method for completing a pneumatic directional long hole in a broken soft coal seam in a coal mine, characterized in that: The method adopts the pneumatic directional long hole drilling and completion drilling tool system for crushed soft coal seams in underground coal mines according to any one of claims 1 to 8; the method specifically comprises the following steps: Step 1: assemble a common double-wall drill pipe (2), a weighted double-wall drill pipe (5) and a hole-finishing drill bit (6), and then use a drilling rig power head (1) to lower the assembled hole-finishing drill tool; Step 2, using the air supply mechanism (4) and the hole-finishing drill inserted in step 1 to perform cyclic punching; Step 3: Assemble and install the transition nipple (8) and anchor head (9), and then lower the screen tube (7); Step 4: Using the air supply mechanism (4) to drive the anchor head (9) to achieve anchoring, so that the anchor head (9) stretches and fixes the screen tube (7); Step 5: Perform jet hole finishing operation: Step 5.1, using the air supply mechanism (4), to supply compressed gas into the hole completion drilling tool; Step 5.2, perform a hole completion operation: The hole-finishing drill tool is pulled back. During the process of pulling back the hole-finishing drill tool, the compressed gas that reaches the hole-finishing drill bit (6) at the bottom of the hole through the drill rod annular channel (204) enters the corresponding air control chamber (606) through multiple air flow channels (605). Under the control of the movable roller (607), the jet holes (608) not covered by the movable roller (607) form high-speed gas jets and impact and disturb the upper hole wall. As the hole-finishing drill tool rotates, the multiple air control chambers (606) continuously change positions, alternately forming gas jets. Step 5.3, withdraw the ordinary double-wall drill pipes (2) one by one and continue the hole completion operation; Step six: After the hole operation is completed, carry out continuous pipe extraction.

10. A hole-finishing drill bit, characterized in that: The drill bit comprises a drill body (601) and a drill bit inner tube (602), wherein both axial ends of the drill bit body (601) and the drill bit inner tube (602) are open, and the drill bit inner tube (602) is coaxially plugged into the drill bit body (601); the space inside the drill bit inner tube (602) is a drill bit central channel (603), and the space between the drill bit inner tube (602) and the drill bit body (601) is a drill bit annular channel (604); The axial front portion of the drill bit body (601) is provided with a plurality of air flow channels (605) and an air control chamber (606) in sequence from back to front. The air flow channels (605) and the air control chamber (606) are connected to the drill bit annular channel (604). A movable roller (607) is movably provided in the air control chamber (606). The axial front portion of the drill bit body (601) is provided with a plurality of jet holes (608) along the radial direction. The jet holes (608) are connected to the air control chamber (606). The movable roller (607) can cover the jet holes (608). The drill bit body (601) is provided with a plurality of bosses (609) uniformly distributed on the axial front end surface, and the outer surface of the bosses (609) is provided with cutting teeth (610). A cover plate (611) is provided on the bosses (609) next to the cutting teeth (610), and the cover plate (611) covers the opening at the axial front end of the control air chamber (606); One end of a plurality of elastic members (612) is installed in the axial front portion of the drill bit body (601), and the other ends of the plurality of elastic members (612) are respectively installed in a plurality of special-shaped stoppers (613). The special-shaped stoppers (613) are located between adjacent bosses (609). The special-shaped stoppers (613) are hinged to the drill bit body (601), and the special-shaped stoppers (613) can partially cover the opening at the axial front end of the drill bit center channel (603); The drill bit body (601) includes a drill bit body main body (60101), and the spaces within the drill bit body main body (60101) are, from back to front, a first inner cavity (60102) of the drill bit body, a second inner cavity (60103) of the drill bit body, a third inner cavity (60104) of the drill bit body, and a fourth inner cavity (60105) of the drill bit body. The inner diameters of the first inner cavity (60102), the second inner cavity (60103), the third inner cavity (60104), and the fourth inner cavity (60105) of the drill bit body decrease in sequence. The inner wall of the drill body (60101) is provided with a first step (60106), a second step (60107) and a third step (60108). The first step (60106) is located at the junction of the first inner cavity (60102) and the second inner cavity (60103) of the drill body. The second step (60107) is located at the junction of the second inner cavity (60103) and the third inner cavity (60104) of the drill body. The third step (60108) is located at the junction of the third inner cavity (60104) and the fourth inner cavity (60105) of the drill body. The drill bit inner tube (602) includes a drill bit inner tube main body (60201), the axial rear end of the drill bit inner tube main body (60201) is flush with the axial rear end of the drill bit body (601), and the axial front end of the drill bit inner tube main body (60201) is tightly against the third step (60108) of the drill bit body; a plurality of drill bit inner tube support blocks (60202) are provided on the outer wall of the drill bit inner tube main body (60201), and the drill bit inner tube support blocks (60202) are located in the second inner cavity (60103) of the drill bit body.

Images