A kind of local water-containing soft coal seam gas dynamic directional drilling system and drilling method

Abstract

The application discloses a kind of pneumatic directional drilling system and drilling method suitable for local water-containing soft coal seam, including directional drill bit, screw drill, conversion nipple, non-magnetic drill tool, multiple special directional drill pipes and air feeder connected in order from back to front;The screw drill includes output shaft end head connected with the directional drill bit and stator end head sleeved on one side of output shaft end head, and output shaft end head can rotate relative to the stator end head, by setting screw drill and conversion nipple, both directional drilling in water-containing soft coal seam can be guaranteed, and strong blowing process can be implemented to discharge drill cuttings and formation water in hole to outside of hole in time, keep drilling operation continuous and smooth, greatly reduce the amount of operation of pulling down drill during construction, and the comprehensive drilling efficiency can be improved by more than 20%, solve the technical problems of poor formation adaptability of prior art, and cannot realize strong blowing and cuttings discharge and rapid switching of directional drilling during directional hole construction process in local water-containing soft coal seam, resulting in low drilling efficiency.

Description

Technical Field

[0001] This invention belongs to the field of underground directional drilling technology in coal mines, and relates to a pneumatic directional drilling system, specifically a pneumatic directional drilling system and drilling method for locally water-bearing, fractured, and soft coal seams. Background Technology

[0002] Fragmented and soft coal seams are widely distributed in major coal mining areas in my country. For a long time, efficient treatment of gas extraction through boreholes in fragmented and soft coal seams has been a major problem restricting the safe and efficient mining of coal resources in my country. The treatment projects involve large drilling volume, high cost, long cycle and low efficiency.

[0003] The pneumatic directional drilling technology in coal mines has broken through the technical bottleneck of long borehole construction in fractured and soft coal seams. The borehole formation rate of long boreholes with a depth of more than 300m in typical mining areas has reached more than 75%. Using long boreholes in the same direction as extraction channels has laid the foundation for the progressive and efficient extraction and treatment of gas in fractured and soft coal seams.

[0004] However, with the expanding application of pneumatic directional drilling technology, construction conditions have become increasingly complex and diverse. Local water content in soft, fractured coal seams is a major bottleneck in its implementation. When water emerges in localized sections, the formation water mixes with drill cuttings and easily adheres to the outer wall of the drill string and the borehole wall, making it difficult to move. The inability to promptly remove the water leads to localized blockage of the annular return channel between the drill string and the borehole wall, resulting in high resistance to compressed gas flow, high pressure in the circulation system, and malfunction of the bottom screw motor, often necessitating the cessation of directional drilling operations. As mine depths and areas expand, water content in the roof and floor becomes more frequent, making localized water emergence during directional drilling in soft, fractured coal seams more likely. Furthermore, under coal seam group mining conditions, the impact of water accumulation in the upper goaf on the lower coal seams is increasingly significant. If the problem of slag removal caused by localized water content is not resolved, soft, fractured coal seams with localized water content will become a no-go zone for the application of pneumatic directional drilling technology.

[0005] Currently, when encountering localized water-bearing formations that hinder cuttings removal during pneumatic directional drilling, the common practice is to lift the drill string and replace it with conventional drilling tools for intensive borehole cleaning to remove drill cuttings and formation water. While this method has some effect, it fails to address the fundamental problem and is characterized by complex procedures, low efficiency, and poor results. There is currently a lack of pneumatic directional drilling systems and methods adapted to locally water-bearing, fractured, and soft coal seams. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a pneumatic directional drilling system and method suitable for locally water-bearing, fractured, and soft coal seams, thereby solving the technical problems of poor formation adaptability and low drilling efficiency caused by the inability to quickly switch between strong blowing and slag removal and directional drilling during the construction of directional holes in locally water-bearing, fractured, and soft coal seams.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A pneumatic directional drilling system adapted to locally water-bearing, fractured, and soft coal seams includes, from back to front, a directional drill bit, a screw drill bit, a conversion sub, a non-magnetic drill bit, multiple irregularly shaped directional drill rods, and an air supply unit;

[0009] The screw drill bit includes an output shaft end connected to a directional drill bit and a stator end sleeved on one side of the output shaft end. The output shaft end and the stator end are rotatable relative to each other. A central airflow channel is provided in the middle of the end face of the output shaft end. Multiple cross-shaped grooves are equally spaced along the circumference and distributed along the axial direction on the outer wall of the output shaft end. Each cross-shaped groove has a first airflow channel. A T-shaped stop key is provided at the axial front of the cross-shaped groove. A T-shaped airflow groove is provided on the inner wall of the T-shaped stop key. The first airflow channel connects the central airflow channel and the T-shaped airflow groove.

[0010] The T-shaped stop key has a spring mounting hole on its axial rear end face, and a compression spring is installed in the spring mounting hole. The other end of the compression spring contacts the inner wall of the axial rear end in the cross-shaped groove. Multiple corrugated grooves are continuously provided on the outer edge of the rear end face of the stator end, and the grooves match the axial front end of the T-shaped stop key.

[0011] The conversion section includes a splined shaft with one end threadedly connected to the other end of the stator end in the screw drill bit. A central hole is provided in the middle of the splined shaft, connecting the central airflow channel and the inner hole of the non-magnetic drill bit. The splined shaft includes a threaded section, a body section, and a mating section. A second airflow channel and a third airflow channel, both connected to the central hole, are provided on the splined edge of the mating section. The second and third airflow channels are alternately arranged circumferentially and offset axially. A suspension ring mounting groove is provided at the axial front end of the splined edge, and a suspension ring is provided in the suspension ring mounting groove. A first sealing surface is formed between the splined edge and the body section. A splined sleeve is fitted onto the mating section, and a shaft cavity sleeve is threadedly connected to the outer wall of the splined sleeve. The inner wall of the splined sleeve includes a splined mating section and a sealing section. The splined mating section mates with the splined edge, and the sealing section mates with the first sealing surface. An airflow groove is provided at the inner edge of the end face of the sealing section.

[0012] The non-magnetic drill bit is equipped with a measurement while drilling instrument coaxially inside.

[0013] This invention also includes the following technical features:

[0014] The shaft sleeve has a first cavity and a second cavity inside, and the first cavity and the second cavity are connected by a shrinkage cavity.

[0015] The outer side of the output shaft end is fitted with a housing.

[0016] The outer casing is fixed to the end of the output shaft by a pin.

[0017] The aforementioned measurement-while-drilling instrument employs a directional measurement probe.

[0018] A pneumatic directional drilling method for locally water-bearing, fractured, and soft coal seams, employing the aforementioned pneumatic directional drilling system adapted to locally water-bearing, fractured, and soft coal seams, specifically includes the following steps:

[0019] Step 1: Insert the pneumatic directional drilling system adapted to locally water-bearing, fractured, and soft coal seams into the borehole;

[0020] The directional drill bit, screw drill bit, conversion sub, non-magnetic drill bit, irregular directional drill rod and air supply are connected in sequence and lowered into the borehole. A measurement while drilling instrument is installed in the non-magnetic drill bit.

[0021] Step 2: Perform pneumatic directional drilling. Compressed gas flows through the central hole of the air blower, the irregularly shaped directional drill rod, the non-magnetic drill bit, and the conversion sub; and drives the screw drill bit to perform work and output rotational mechanical energy, which drives the directional drill bit to cut and break the rock. The compressed gas after performing work enters the slag return channel through the central airflow channel and the directional drill bit; record the pressure and flow rate at the air blower inlet in real time.

[0022] Step 3: In real time, determine whether there is a significant increase in pressure at the inlet of the air supply unit. If there is, proceed to step 4. If not, continue pneumatic directional drilling until the predetermined design hole depth is reached.

[0023] Step 4: Pull the irregularly shaped directional drill pipe out of the hole to separate the sealing section of the conversion short section from the first sealing surface axially. The second and third airflow channels open, and the compressed gas no longer drives the screw drill bit to do work. It enters the annular flow channel between the drill pipe and the borehole wall through the second and third airflow channels to strongly blow away the cuttings until the drill cuttings and formation water in the hole are discharged to the outside of the hole; proceed to step 5.

[0024] Step 5: Determine if step 4 has been executed 3 to 4 times. If yes, proceed to step 6; otherwise, return to step 2.

[0025] Step 6: Perform the drilling through-hole operation and return to step 2;

[0026] The aforementioned drill-through operation involves pulling out several irregularly shaped directional drill rods, injecting compressed gas into the hole through an air supply device, and simultaneously driving the drill rig to rotate the irregularly shaped directional drill rod string in the forward direction. The screw drill bit rotates synchronously with the irregularly shaped directional drill rods. The compressed gas enters the annular flow channel between the drill rod and the borehole wall through the second and third airflow channels for strong blowing and slag removal. The irregularly shaped directional drill rods assist in slag removal and hole opening.

[0027] Compared with the prior art, the beneficial technical effects of this invention are:

[0028] (I) By setting up a screw drill bit and a conversion sub, this invention can ensure directional drilling in water-bearing, fractured, and soft coal seams, and also implement a strong blowing process to promptly discharge drill cuttings and formation water from the hole to the outside, maintaining continuous and smooth drilling operations, significantly reducing the amount of drilling operations during construction, and improving the overall drilling efficiency by more than 20%. This solves the technical problems of poor formation adaptability and low drilling efficiency caused by the inability to quickly switch between strong blowing and directional drilling during the construction of directional holes in local water-bearing, fractured, and soft coal seams.

[0029] (II) The pneumatic directional drilling process implemented by the system of the present invention can improve the hole formation rate by 30% to 60%. The intermittent "strong blowing" of high-energy gas to assist in slag removal and hole flushing can promptly discharge the drill cuttings and formation water in the hole to the outside, avoiding water and slag accumulation. This results in good hole cleaning effect and high drill cuttings discharge efficiency during drilling. The flow resistance of the annular channel between the drill string and the hole wall is small and the pressure of the compressed gas circulation system is low, which is conducive to improving the hole formation depth of directional drilling in local water-bearing fractured soft coal seams.

[0030] (III) The drilling method of the present invention can perform "strong blowing" to assist in slag removal in a timely manner according to the pressure change of the compressed gas circulation system during the drilling process, so as to ensure the stable pressure of the circulation system. At the same time, under the protection of the stator and rotor relative reverse braking function, the failure rate of the pneumatic screw motor can be significantly reduced, and the continuous fault-free working time can be increased by 2 to 3 times.

[0031] (IV) The drilling system of the present invention adds a "split" spline connection structure between the screw drill and the measurement while drilling instrument. Compared with the all-thread "integrated" structure, it has a certain vibration isolation effect, which can weaken and absorb part of the lateral vibration of the bottom hole pneumatic screw motor and reduce the adverse effects on the measurement while drilling instrument. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the drilling system composition and the circulation path under drilling conditions of the present invention;

[0033] Figure 2 This is a schematic diagram of the screw drill bit structure;

[0034] Figure 3This is a schematic diagram of the output shaft end in a screw drill bit;

[0035] Figure 4 This is a schematic diagram of the transition section;

[0036] Figure 5 This is a schematic diagram of the spline shaft in the conversion short section;

[0037] Figure 6 This is a schematic diagram of the spline sleeve in the conversion short section;

[0038] Figure 7 This is a schematic diagram of the T-type stop key in a screw drill bit;

[0039] Figure 8 This is a schematic diagram of the circulation path of the drilling system of the present invention under the strong blowing and slag removal state.

[0040] The meanings of the labels in the diagram are as follows: 1-directional drill bit, 2-screw drill string, 3-converter sub, 4-non-magnetic drill string, 5-irregular directional drill pipe, 6-air supply device, 7-drilling measurement instrument;

[0041] 201-Output shaft end, 202-Stator end, 203-Gear groove, 204-Housing shell, 205-Pin;

[0042] 20101-Central airflow channel, 20102-Cross-shaped groove, 20103-First airflow channel, 20104-T-shaped stop key, 20105-T-shaped airflow groove, 20106-Spring mounting hole, 20107-Compression spring;

[0043] 301-Splined shaft, 302-Center hole, 303-Spline ridge, 304-Second airflow channel, 305-Third airflow channel, 306-Suspension ring mounting groove, 307-Suspension ring, 308-First sealing surface, 309-Splined sleeve, 3010-Shaft cavity sleeve;

[0044] 30101 - Threaded section, 30102 - Body section, 30103 - Mating section;

[0045] 301001 - First cavity, 301002 - Second cavity, 301003 - Reduction cavity

[0046] 30901 - Spline mating section, 30902 - Sealing section, 30903 - Airflow groove.

[0047] The specific content of the present invention will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0048] It should be noted that, unless otherwise specified, all components in this invention are those known in the art.

[0049] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0050] This invention provides a pneumatic directional drilling system adapted to locally water-bearing, fractured, and soft coal seams, comprising, from back to front, a directional drill bit 1, a screw drill bit 2, a conversion sub 3, a non-magnetic drill bit 4, multiple irregularly shaped directional drill rods 5, and an air supply device 6;

[0051] The screw drill bit 2 includes an output shaft end 201 connected to the directional drill bit 1 and a stator end 202 sleeved on one side of the output shaft end 201. The output shaft end 201 and the stator end 202 can rotate relative to each other. A central airflow channel 20101 is provided in the middle of the end face of the output shaft end 201. Multiple cross-shaped grooves 20102 are equally spaced along the circumference and distributed along the axial direction on the outer wall of the output shaft end 201. Each cross-shaped groove 20102 has a first airflow channel 20103. A T-shaped stop key 20104 is provided at the axial front of the cross-shaped groove 20102. A T-shaped airflow groove 20105 is provided on the inner wall of the T-shaped stop key 20104. The first airflow channel 20103 connects the central airflow channel 20101 and the T-shaped airflow groove 20105.

[0052] The T-shaped stop key 20104 has a spring mounting hole 20106 on its axial rear end face. One end of a compression spring 20107 is installed in the spring mounting hole 20106. The other end of the compression spring 20107 contacts the inner wall of the axial rear end in the cross-shaped groove 20102. Multiple corrugated grooves 203 are continuously provided on the outer edge of the rear end face of the stator end 202. The grooves 203 match the axial front end of the T-shaped stop key 20104.

[0053] The conversion section 3 includes a splined shaft 301, one end of which is threadedly connected to the other end of the stator end 202 in the screw drill 2. A central hole 302 is provided in the middle of the splined shaft 301, connecting the central airflow channel 20101 and the inner hole of the non-magnetic drill 4. The splined shaft 301 includes a threaded section 30101, a body section 30102, and a mating section 30103. A second airflow channel 304 and a third airflow channel 305, both communicating with the central hole 302, are provided on the spline ridge 303 of the mating section 30103. The second airflow channel 304 and the third airflow channel 305 are alternately arranged circumferentially and offset axially. A suspension ring mounting groove 306 is provided at the axial front end of the spline rib 303, and a suspension ring 307 is provided in the suspension ring mounting groove 306. The first sealing surface 308 is between the spline rib 303 and the body section 30102. A spline sleeve 309 is fitted on the mating section 30103. A shaft cavity sleeve 3010 is threaded on the outer wall of the spline sleeve 309. The inner wall of the spline sleeve 309 includes a spline mating section 30901 and a sealing section 30902. The spline mating section 30901 mates with the spline rib 303, and the sealing section 30902 mates with the first sealing surface 308. An airflow groove 30903 is provided at the inner edge of the end face of the sealing section 30902.

[0054] The non-magnetic drill bit 4 is coaxially equipped with a drilling measurement instrument 7.

[0055] In the above technical solution, by setting the screw drill bit 2 and the conversion sub 3, it is possible to ensure directional drilling of water-bearing fractured soft coal seams, and also to implement the strong blowing process to promptly discharge drill cuttings and formation water from the hole to the outside, maintaining continuous and smooth drilling operations, significantly reducing the amount of drilling operations during construction, and improving the overall drilling efficiency by more than 20%. This solves the technical problem of low drilling efficiency caused by the inability of existing technologies to achieve random and rapid switching between strong blowing for cuttings removal and directional drilling during the construction of directional holes in local water-bearing fractured soft coal seams.

[0056] The aforementioned drilling system employs pneumatic directional drilling technology, which can increase the hole formation rate by 30% to 60%. By using high-energy gas intermittent "strong blowing" to assist in slag removal and hole flushing, drilling slag and formation water can be discharged from the hole in a timely manner, avoiding water and slag accumulation. This results in good hole cleaning effect and high drilling slag removal efficiency during drilling. The flow resistance of the annular channel between the drill string and the hole wall is small, and the pressure of the compressed gas circulation system is low, which is conducive to increasing the hole formation depth of directional drilling in local water-bearing fractured and soft coal seams.

[0057] A "split" spline connection structure was added between the screw drill bit and the measurement while drilling instrument. Compared with the all-thread "integrated" structure, it has a certain vibration isolation effect, which can weaken and absorb some of the lateral vibration of the bottom hole pneumatic screw motor and reduce the adverse effects on the measurement while drilling instrument.

[0058] Specifically, the shaft sleeve 3010 has a first cavity 301001 and a second cavity 301002 inside, and the first cavity 301001 and the second cavity 301002 are connected through a shrinkage cavity 301003.

[0059] Specifically, a housing 204 is fitted onto the outer side of the output shaft end 201.

[0060] Specifically, the outer casing 204 is fixed to the output shaft end 201 by a pin 205.

[0061] Specifically, the measurement while drilling instrument 7 uses a directional measurement probe.

[0062] This invention also provides a pneumatic directional drilling method for locally water-bearing, fractured, and soft coal seams, such as... Figures 1 to 8 As shown, the pneumatic directional drilling system adapted to locally water-bearing, fractured, and soft coal seams is adopted, specifically including the following steps:

[0063] Step 1: Insert a pneumatic directional drilling system adapted to the local water-bearing, fractured, and soft coal seam into the borehole;

[0064] The directional drill bit 1, screw drill bit 2, conversion short section 3, non-magnetic drill bit 4, irregular directional drill rod 5 and air supply device 6 are connected in sequence and lowered into the borehole. A measurement while drilling instrument 7 is installed in the non-magnetic drill bit 4.

[0065] Step 2: Perform pneumatic directional drilling. Compressed gas flows through the central hole 302 of the air supply unit 6, the irregularly shaped directional drill rod 5, the non-magnetic drill bit 4, and the conversion sub 3; and drives the screw drill bit 2 to perform work and output rotational mechanical energy, which drives the directional drill bit 1 to cut and break rocks. The compressed gas after performing work enters the slag return channel through the central airflow channel 20101 and the directional drill bit 1; and the pressure and flow rate at the inlet of the air supply unit 6 are recorded in real time.

[0066] Step 3: In real time, determine whether there is a significant increase in pressure at the inlet of the air supply unit 6. If there is, proceed to step 4. If not, continue pneumatic directional drilling until the predetermined design hole depth is reached.

[0067] Step 4: Pull the irregularly shaped directional drill rod 5 out of the hole so that the sealing section 30902 of the conversion short section 3 is separated from the first sealing surface 308 axially. The second airflow channel 304 and the third airflow channel 305 are opened. The compressed gas no longer drives the screw drill bit 2 to do work. It enters the annular flow channel between the drill rod and the borehole wall through the second airflow channel 304 and the third airflow channel 305 to strongly blow away the slag until the drill slag and formation water in the hole are discharged to the outside of the hole. Proceed to step 5.

[0068] Step 5: Determine if step 4 has been executed 3 to 4 times. If yes, proceed to step 6; otherwise, return to step 2.

[0069] Step 6: Perform the drilling through-hole operation and return to step 2;

[0070] The drilling and hole-opening operation involves pulling out several irregularly shaped directional drill rods 5, injecting compressed gas into the hole through the air supply device 6, and simultaneously driving the irregularly shaped directional drill rod string 5 to rotate in the forward direction through the air supply device 6. The screw drill bit 2 rotates synchronously with the irregularly shaped directional drill rods 5. The compressed gas enters the annular flow channel between the drill rod and the borehole wall through the second airflow channel 304 and the third airflow channel 305 for strong blowing and slag removal. The irregularly shaped directional drill rods 5 assist in slag removal and hole opening.

[0071] In the above technical solution, the number of irregular directional drill pipes can be determined according to the specific situation, with at least one; a significant jump refers to a pressure that is significantly greater than the empirical pressure value at the inlet of the air supply device 6 when the drill bit is working stably.

[0072] When performing pneumatic directional drilling in step 2, at the output shaft end 201 of the screw drill 2, the compressed gas in the central airflow channel 20101 enters the cross-shaped groove 20102 through the first airflow channel 20103 and the T-shaped airflow groove 20105, pushing the T-shaped stop key 20104 to compress the stop spring 20107. The T-shaped stop key 20104 disengages from the corrugated toothed groove 203 on the stator output end 202, and they rotate relative to each other without contact.

[0073] During steps 4 and 5, no compressed gas flows through the screw drill 2, and no airflow enters the cross-shaped groove 20102 in the central airflow channel 20101 of the output shaft end 201. The T-shaped stop key 20104 extends axially under the action of the compression spring 20107 and engages with the corrugated toothed groove 203 on the end face of the stator end 202 to achieve stop. That is, when the screw drill 2 is not working, the drill bit in the rotating hole will not rotate relative to the output shaft end 201 and the stator end 202 under the action of the T-shaped stop key 20104, which can prevent the screw drill from malfunctioning due to slag return and slag suction under strong blowing and slag discharge conditions.

[0074] The above drilling method can perform "forced blowing" to assist in slag removal in a timely manner according to the pressure changes of the compressed gas circulation system during the drilling process, so as to ensure stable pressure in the circulation system. At the same time, under the protection of the stator and rotor relative reverse braking function, it can significantly reduce the failure rate of the pneumatic screw motor and increase the continuous fault-free working time by 2 to 3 times.

Claims

1. A pneumatic directional drilling system for soft coal seams with local water content, characterized in that, It includes, from back to front, a directional drill bit (1), a screw drill bit (2), a conversion sub (3), a non-magnetic drill bit (4), multiple irregularly shaped directional drill rods (5), and an air supply device (6). The screw drill bit (2) includes an output shaft end (201) connected to the directional drill bit (1) and a stator end (202) sleeved on one side of the output shaft end (201). The output shaft end (201) and the stator end (202) rotate relative to each other. A central airflow channel (20101) is provided in the middle of the end face of the output shaft end (201). Multiple cross-shaped grooves distributed axially are provided at equal intervals along the circumferential direction on the outer wall of the output shaft end (201). (20102), each of the cross-shaped grooves (20102) is provided with a first airflow channel (20103); a T-shaped stop key (20104) is provided at the axial front of the cross-shaped groove (20102), and a T-shaped airflow groove (20105) is provided on the inner wall of the T-shaped stop key (20104); the first airflow channel (20103) connects the central airflow channel (20101) and the T-shaped airflow groove (20105); The T-shaped stop key (20104) has a spring mounting hole (20106) on its axial rear end face. One end of a compression spring (20107) is provided in the spring mounting hole (20106), and the other end of the compression spring (20107) contacts the inner wall of the axial rear end of the cross-shaped groove (20102). The stator end (202) has a plurality of corrugated toothed grooves (203) continuously formed on the outer edge of its rear end face. The toothed grooves (203) match the axial front end of the T-shaped stop key (20104). The conversion section (3) includes a splined shaft (301) with one end threadedly connected to the other end of the stator end (202) in the screw drill (2). The splined shaft (301) has a central hole (302) in the middle, which connects the central airflow channel (20101) and the inner hole of the non-magnetic drill (4). The splined shaft (301) includes a threaded section (30101), a body section (30102), and a mating section (30103). The splined edge (303) of the mating section (30103) has a second airflow channel (304) and a third airflow channel (305) that both communicate with the central hole (302). The second airflow channel (304) and the third airflow channel (305) are alternately arranged in the circumferential direction and staggered in the axial direction. The axial front end of the spline ridge (303) is provided with a suspension ring mounting groove (306), and a suspension ring (307) is provided in the suspension ring mounting groove (306). The spline ridge (303) and the body section (30102) are connected to a first sealing surface (308). A spline sleeve (309) is fitted on the mating section (30103). A shaft cavity sleeve (3010) is threaded on the outer wall of the spline sleeve (309). The inner wall of the spline sleeve (309) includes a spline mating section (30901) and a sealing section (30902). The spline mating section (30901) mates with the spline ridge (303), and the sealing section (30902) mates with the first sealing surface (308). An airflow groove (30903) is provided at the inner edge of the end face of the sealing section (30902). The non-magnetic drill bit (4) is equipped with a drilling measurement instrument (7) coaxially.

2. The adaptive, local, aqueous, soft seam gas directional drilling system of claim 1, wherein, The shaft sleeve (3010) has a first cavity (301001) and a second cavity (301002) inside, and the first cavity (301001) and the second cavity (301002) are connected through a shrinkage cavity (301003).

3. The adaptive, locally water-laden soft seam gas directional drilling system of claim 1, wherein, The outer side of the output shaft end (201) is fitted with a housing (204).

4. The adaptive, locally water-laden soft seam gas directional drilling system of claim 3, wherein, The outer casing (204) is fixed to the output shaft end (201) by a pin (205).

5. The adaptive, locally water-laden soft seam gas directional drilling system of claim 1, wherein, The aforementioned measurement while drilling instrument (7) uses a directional measurement probe.

6. A method of locally water-laden soft coal seam gas dynamic directional drilling, characterized in that, The pneumatic directional drilling system adapted to locally water-bearing, fractured, and soft coal seams as described in any one of claims 1 to 5 specifically includes the following steps: Step 1: Insert the pneumatic directional drilling system adapted to locally water-bearing, fractured, and soft coal seams into the borehole; The directional drill bit (1), screw drill bit (2), conversion sub (3), non-magnetic drill bit (4), irregular directional drill rod (5) and air supply device (6) are connected in sequence and lowered into the borehole; a drilling measurement instrument (7) is installed in the non-magnetic drill bit (4). Step 2: Perform pneumatic directional drilling. Compressed gas flows along the central hole (302) of the air blower (6), the irregular directional drill rod (5), the non-magnetic drill bit (4), and the conversion sub (3); and drives the screw drill bit (2) to perform work and output rotational mechanical energy, which drives the directional drill bit (1) to cut and drill through the rock. After the work is done, the compressed gas enters the slag return channel through the central airflow channel (20101) and the directional drill bit (1); record the pressure and flow rate at the inlet of the air blower (6) in real time. Step 3: In real time, determine whether there is a significant increase in pressure at the inlet of the blower (6). If there is, proceed to step 4. If not, continue pneumatic directional drilling until the predetermined design hole depth is reached. Step 4: Pull the irregularly shaped directional drill rod (5) out of the hole so that the sealing section (30902) of the conversion short section (3) is separated from the first sealing surface (308) axially. The second airflow channel (304) and the third airflow channel (305) are opened. The compressed gas no longer drives the screw drill (2) to do work. It enters the annular flow channel between the drill rod and the borehole wall through the second airflow channel (304) and the third airflow channel (305) to strongly blow away the slag until the drill slag and formation water in the hole are discharged to the outside of the hole. Then proceed to step 5. Step 5: Determine if step 4 has been executed 3-4 times. If yes, proceed to step 6; otherwise, return to step 2. Step 6: Perform the drilling through-hole operation and return to step 2; The aforementioned drilling and hole-opening operation involves pulling out several irregularly shaped directional drill rods (5), inputting compressed gas into the hole through the air supply device (6), and simultaneously driving the irregularly shaped directional drill rods (5) to rotate in the forward direction. The screw drill bit (2) rotates synchronously with the irregularly shaped directional drill rods (5). The compressed gas enters the annular flow channel between the drill rod and the borehole wall through the second airflow channel (304) and the third airflow channel (305) for strong blowing and slag removal. The irregularly shaped directional drill rods (5) assist in slag removal and hole opening.

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