Gas-liquid directional drilling system and method for drilling through geological anomalies in soft coal seams with casing protection

Abstract

The invention discloses a gas-liquid dual-medium directional drilling system for a broken soft coal seam through a geological anomaly, comprising a central drilling tool, a power source system and a hole protection device, wherein the central drilling tool comprises a directional drill bit, a gas-liquid dual-purpose screw motor, a lower non-magnetic drill rod, an upper non-magnetic drill rod and a spiral drill rod connected in sequence; a wireless electromagnetic wave measurement while drilling short section is arranged in the side wall of the lower non-magnetic drill rod, and the rear end of the spiral drill rod is connected to a gas-liquid dual-purpose device; the power source system comprises a nitrogen generator, a mud pump truck, a high-pressure pipeline and a gas-liquid conversion device, and the nitrogen generator and the mud pump truck are both connected to the gas-liquid dual-purpose device through a high-pressure pipeline; the hole protection device comprises a sleeve milling impact sealing drill bit and a hole protection pipe. The invention utilizes two power sources to drive the screw motor and then drive the directional drill bit to efficiently break rocks. When drilling into the geological anomaly, clean water is used as the power source. The construction of directional long holes in the broken soft coal seam through the geological anomaly is realized, safe and efficient drilling is achieved, the amount of drilling construction is reduced, and the effect of gas extraction from the drilling is improved.

Description

Technical Field

[0001] The invention relates to the technical field of underground coal mine drilling, and is used for directional drilling construction of broken soft coal seams penetrating geological anomalies in underground coal mines, and specifically relates to a casing protection hole gas-liquid directional drilling method for penetrating geological anomalies in broken soft coal seams. Background Art

[0002] Directional drilling technology in underground coal mines has been widely promoted and applied in the field of coal mine safety. It has been widely used in the exploration of rock strata, relatively stable and hard coal seams and precise geological structures, as well as water and gas disaster prevention and control in coal mines. With the continuous increase in mining depth and mining intensity, the occurrence conditions of coal seams are becoming more and more complex, especially the porosity of long-distance directional drilling through geological anomalies in broken and soft coal seams has become one of the current problems.

[0003] At present, the construction of drilling holes in broken and soft coal seams uses wind-driven screw motors, with compressed gas or gas-liquid two-phase as the slag removal medium. The impact on the hole wall is relatively small, which is conducive to the stability of the drilling hole. However, for slightly harder coal rock formations, the drilling efficiency is extremely low and the drilling tool is easily damaged due to the performance constraints of the screw motor. When encountering geological anomalies, hydraulic screw motors are used, and water is used as the flushing medium. During the drilling process, the hole wall is flushed, soaked and penetrated, which can easily cause damage to the formation structure, resulting in hole collapse, drill stuck and drill lost, resulting in shallow depth of directional drilling, low porosity and low drilling efficiency.

[0004] To this end, the present invention can realize the rapid conversion function of a screw motor among three power sources: pneumatic, hydraulic, and gas-liquid two-phase by controlling the valve of the gas-liquid conversion device: the screw motor in the broken soft coal seam uses gas as the power source; the screw motor in the geological anomaly body uses liquid as the power source. When encountering a geological anomaly during construction, the expansion sealing glue A and B of the casing milling impact sealing drill bit are mixed to seal the annular space between the hole protection tube and the hole wall. The hole protection tube protects the hole wall of the entire coal seam, reduces the scouring of the coal wall by clean water, improves the stability of the hole wall, and improves the porosity of long-distance drilling, which is beneficial to the extraction of gas from the borehole. Therefore, a gas-liquid dual-medium directional drilling method for casing protection holes in broken soft coal seams through geological anomalies is proposed. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides a gas-liquid dual-medium directional drilling method for penetrating geological anomalies in broken and soft coal seams in underground coal mines with casing protection holes. The method can achieve safe and efficient drilling of broken and soft coal seams through geological anomalies. The gas-liquid dual-purpose screw motor can quickly switch between different power sources to increase the applicability of the screw motor. The hole protection pipe protects the broken and soft coal seams from being flushed by clean water, thereby improving the long-distance drilling rate and improving the drilling gas extraction effect.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] A gas-liquid dual-medium directional drilling system for penetrating geological anomalies in broken soft coal seams comprises a central drilling tool, a power source system and a hole protection device, wherein the central drilling tool comprises a directional drill bit, a gas-liquid dual-purpose screw motor, a lower non-magnetic drill rod, an upper non-magnetic drill rod and a spiral drill rod which are connected in sequence from front to back, and their internal cavities are connected; a wireless electromagnetic wave measurement while drilling short section is arranged in the side wall of the lower non-magnetic drill rod, and the rear end of the spiral drill rod is connected to a gas-liquid dual-purpose device; the power source system comprises a nitrogen generator, a mud pump truck, a high-pressure pipeline and a gas-liquid conversion device, and the nitrogen generator and the mud pump truck are both connected to the gas-liquid dual-purpose device through a high-pressure pipeline; the gas-liquid conversion device is arranged on the high-pressure pipeline; the hole protection device comprises a sleeve milling impact sealing drill bit and a hole protection pipe which are connected front and back; the sleeve milling impact sealing drill bit and the hole protection pipe are integrally sleeved on the outside of the central drilling tool.

[0008] Furthermore, the gas-liquid dual-purpose screw motor is driven by hydraulic power or wind power, or uses a gas-liquid two-phase body as a power source.

[0009] Furthermore, the gas-liquid dual-purpose device adopts a water feeder.

[0010] Furthermore, the gas-liquid conversion device adopts a pneumatic three-way ball valve.

[0011] Furthermore, the sleeve milling impact sealing drill bit includes a drill bit, and two cavities are symmetrically provided at the upper and lower parts of the drill bit, and a slide rail is provided on the side wall of the cavity, and a sliding piece that can move along the slide rail is installed on the slide rail. An outlet connecting the cavity is provided on the side wall at the front end of the slide rail, and the sliding piece covers the outlet and is fixed with a pin, and expansion sealing glue A glue and B glue are respectively encapsulated in the two cavities.

[0012] Furthermore, the auger rod adopts a large through-hole auger rod, the inner diameter of which is greater than 40 mm.

[0013] Furthermore, the wireless electromagnetic wave measurement while drilling short section includes a wireless electromagnetic wave measurement probe, a battery tube and a non-magnetic outer tube. The non-magnetic outer tube is installed in the side wall of the lower non-magnetic drill pipe. The wireless electromagnetic wave measurement probe is connected to the battery tube and then installed in the non-magnetic outer tube.

[0014] On the other hand, the present invention also provides a method for directional drilling of gas-liquid dual-medium holes in a broken soft coal seam through a geological anomaly body, which adopts the above-mentioned gas-liquid dual-medium directional drilling system for drilling of gas-liquid dual-medium holes in a broken soft coal seam through a geological anomaly body of the present invention to perform directional drilling, comprising the following steps:

[0015] Step 1: Drill a hole according to the designed height, inclination and azimuth, and lift the drill after drilling 11 to 13 meters; use the reaming drill to expand the hole and drill 1.5 to 2.5 meters, lift the reaming drill, put the orifice pipe into the hole and fix it to seal it, and install the orifice device;

[0016] Step 2, install the wireless electromagnetic wave measurement while drilling short section in the lower non-magnetic drill rod, connect the central drilling tool in turn, which is the directional drill bit, the gas-liquid dual-purpose screw motor, the lower non-magnetic drill rod, the upper non-magnetic drill rod, the spiral drill rod and the gas-liquid dual-purpose device, then connect the high-pressure pipeline, the gas-liquid conversion device and the power source system, and then send the central drilling tool into the hole for drilling construction;

[0017] Step 3, construction in the broken soft coal seam; during the drilling process, the radio electromagnetic wave drilling measurement short section in the hole transmits the measured borehole inclination and azimuth to the hole mouth receiving device, and the receiving device displays the measurement results and the drilling trajectory; at the same time, during the drilling process, when the return slag is rock powder and the feed pressure increases abruptly, it is judged that the drilling has reached a geological anomaly, and the steps are executed.

[0018] Step 4, drilling the geological anomaly body. During the drilling process, if there is no rock powder in the returned slag and the feed pressure decreases, then execute step 5;

[0019] Step 5: After passing through the geological anomaly, switch to the nitrogen generator through the gas-liquid conversion device, continue to introduce nitrogen to dry the inner wall of the hole protection pipe, and then use the nitrogen generator as the power source to continue drilling using the sliding drilling process;

[0020] Step 6, drill to the designed depth, and complete the drilling construction. First, withdraw the components of the center drill one by one, and then use a rotary method to withdraw the hole protection tube and the sleeve milling impact sealing drill bit.

[0021] Furthermore, in step 3, the construction in the broken soft coal seam includes the following steps:

[0022] A radio electromagnetic wave measurement while drilling short section is used to measure the drilling position information, which is transmitted to the borehole receiving device to determine the drilling trajectory, and then the gas-liquid dual-purpose screw motor elbow is adjusted to extend the drilling trajectory in the coal seam in a predetermined direction; the gas-liquid conversion device is switched to the nitrogen-making locomotive as the power source, and the high-pressure gas drives the gas-liquid dual-purpose screw motor rotor to rotate and transmit it to the directional drill bit to rotate and cut the coal body, and then the coal dust is transported to the borehole for discharge through the rotating spiral drill rod; or, the gas-liquid conversion device is controlled to be in the middle position, and the mud pump truck and the nitrogen-making locomotive are started at the same time, and the gas-liquid two-phase body drives the gas-liquid dual-purpose screw motor rotor to rotate and transmit it to the directional drill bit to rotate and cut the coal body, and is ejected through the directional drill bit hole nozzle to form a gas-liquid two-phase jet, and the gas-liquid two-phase body jet acts on the coal body at the bottom of the hole; at the same time, the spiral drill rod rotates.

[0023] Furthermore, in step 4, the implementation of drilling the geological anomaly specifically includes the following steps:

[0024] Step 41, lift the center drill tool a certain distance away from the bottom of the hole to stop drilling;

[0025] Step 42, connect the sleeve milling impact sealing drill bit to the hole protection tube through threads, adopt wind-driven rotary drilling, stop drilling after drilling to a certain distance from the geological anomaly, and use the impact force of the drilling rig rotator to move the sliding piece to shear the pin, and the pressurized expansion sealing glue A glue and expansion sealing glue B glue flow out from the outlet of the sleeve milling impact sealing drill bit, mix and expand to form a mixture of expansion sealing glue A glue and B glue, which is densely filled into the annular space between the hole protection tube and the hole wall.

[0026] Step 43, through the gas-liquid conversion device switching, using the mud pump truck as the power source, using the composite drilling process, controlling the spiral drill rod and the gas-liquid dual-purpose screw motor to rotate simultaneously, high-pressure water drives the directional drill bit to cut the coal rock mass, and the rotation of the spiral drill rod drives the directional drill bit to rotate at the same time.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. Through the cooperation of the gas-liquid dual-purpose screw motor, the gas-liquid dual-purpose device, and the gas-liquid conversion device, the two power sources of the nitrogen generator and the mud pump truck can be used to realize the efficient and safe rotation of the gas-liquid dual-purpose screw motor rotor with different power sources (high-pressure water, high-pressure wind, gas-liquid two-phase), thereby driving the directional drill to efficiently break the rock. When drilling in the broken soft coal seam, the wind is used to drive the gas-liquid dual-purpose screw motor, and the compressed gas or gas-liquid two-phase body is used as the slag removal medium. Its impact on the hole wall is relatively small, which is conducive to maintaining the stability of the drilling hole and improving the drilling efficiency. When drilling into the geological anomaly, clean water is used as the power source, and high-pressure water drives the gas-liquid dual-purpose screw motor to operate. At the same time, the clean water is prevented from soaking and scouring the hole wall, and the stability of the hole wall is protected. The directional long drilling construction of the broken soft coal seam through the geological anomaly in the coal mine is realized, and safe and efficient drilling is achieved, the drilling construction volume is reduced, and the drilling gas extraction effect is improved.

[0029] 2. To prevent clean water from soaking and scouring the coal seam hole wall, a hole protection device is formed by connecting a milling impact sealing drill bit and a hole protection tube in front and back. The core component, the milling impact sealing drill bit, can realize the milling effect in the broken soft coal seam. When encountering a geological anomaly, the drill bit moves forward, and the sliding piece is rubbed by the rock mass and moves backward relative to the drill bit, exposing the through hole at the front end of the slide rail on the upper and lower cavity side walls of the drill bit. The expanded sealing glue A glue and B glue flow out and mix to fill the annular space between the sealing hole protection tube and the hole wall and solidify, preventing clean water from soaking and scouring the hole wall and protecting the stability of the hole wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the three parts of the central drilling tool, the power source system and the hole protection device of the equipment of the present invention.

[0031] Figure 2 The present invention is a schematic diagram of the structure of the sleeve milling impact sealing drill bit. (a) is before the pin is shortened; (b) is after the pin is shortened.

[0032] Figure 3 It is a schematic diagram of the construction principle of drilling holes in a crushed soft coal seam according to the present invention.

[0033] Figure 4 It is a schematic diagram of the construction principle of drilling holes through a geological anomaly in a broken soft coal seam according to the present invention.

[0034] Figure 5 It is a schematic diagram of the construction principle of drilling through a geological anomaly according to the present invention.

[0035] The meaning of each number in the figure is: 1-directional drill bit; 2-gas-liquid dual-purpose screw motor; 3-lower non-magnetic drill rod; 4-radio electromagnetic wave measurement while drilling short section; 5-upper non-magnetic drill rod; 6-auger drill rod; 7-gas-liquid dual-purpose device; 8-high-pressure pipeline; 9-gas-liquid conversion device; 10-nitrogen generator; 11-mud pump truck; 12-gas-liquid dual-purpose screw motor power source system; 13-expansion sealing glue A glue; 14-pin; 15-expansion sealing glue B glue; 16-hole protection pipe; 17-old top; 18-direct top; 19-broken soft coal seam; 20-direct bottom; 21-old bottom; 22-center drilling tool; 23-coal dust; 24-geological anomaly; 25-milling impact sealing drill bit; 26-sliding piece; 27-outlet; 28-expansion sealing glue A and B mixture. DETAILED DESCRIPTION

[0036] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the following will be combined with the present invention Figure 1-4 , the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0037] See also Figure 1 The gas-liquid dual-medium directional drilling system for penetrating geological anomalies in broken soft coal seams of the present invention comprises a central drilling tool 22, a power source system 12 and a hole protection device, wherein: the central drilling tool 22 comprises a directional drill bit 1, a gas-liquid dual-purpose screw motor 2, a lower non-magnetic drill rod 3, an upper non-magnetic drill rod 5 and a spiral drill rod 6 which are connected in sequence from front to back, and their internal cavities are connected; a wireless electromagnetic wave measurement while drilling short section 4 is arranged in the side wall of the lower non-magnetic drill rod 3, and the rear end of the spiral drill rod 6 is connected to a gas-liquid dual-purpose device; the power source system 12 comprises a nitrogen generator 10, a mud pump truck 11, a high-pressure pipeline 8 and a gas-liquid conversion device 9, and the nitrogen generator 10 and the mud pump truck 11 are both connected to the gas-liquid dual-purpose device 7 through the high-pressure pipeline 8; the gas-liquid conversion device 9 is arranged on the high-pressure pipeline 8; the hole protection device comprises a sleeve milling impact sealing drill bit 25 and a hole protection pipe 16 which are connected front and back; the sleeve milling impact sealing drill bit 25 and the hole protection pipe 16 are integrally sleeved on the outside of the central drilling tool 22.

[0038] In the above technical scheme, different power sources (i.e., nitrogen generator 10 and mud pump truck 11) can be quickly switched through the gas-liquid conversion device 9, which can realize efficient drilling of broken soft coal seams and safe drilling of geological anomalies. When drilling in broken soft coal seams, the pneumatic method of the nitrogen generator 10 can be used as the power for drilling. When encountering geological anomalies, the hole wall of the broken soft coal seam can be protected by the hole protection pipe 16. Hydraulic or gas-liquid two-phase force can be used to drive the gas-liquid dual-purpose screw motor to increase the output torque and increase the output speed, which is beneficial to the discharge of fragments from the hole and improves the drilling efficiency.

[0039] The selection of components in the system is as follows:

[0040] The gas-liquid dual-purpose screw motor 2 can be driven by hydraulic power or wind power, or use a gas-liquid two-phase body as a power source.

[0041] The gas-liquid dual-purpose device 7 serves to connect the auger rod 6 with the power source system 12, so that high-pressure water, high-pressure wind or gas-liquid two-phase enters the auger rod 6 as required, and then enters the gas-liquid dual-purpose screw motor 2 to drive it to work. Specifically, the gas-liquid dual-purpose device 7 adopts a water feeder, which is generally referred to as a water feeder in the art.

[0042] The gas-liquid conversion device 9 is used to control the rapid switching of the two power sources of the mud pump truck 11 and the nitrogen generator 10, and can also realize the mixing of high-pressure water and high-pressure wind in proportion to form a gas-liquid two-phase power source to drive the gas-liquid dual-purpose screw motor 2. Preferably, the gas-liquid conversion device 9 adopts a pneumatic three-way ball valve to adjust the ratio of air supply and water supply.

[0043] The structure of the sleeve milling impact sealing drill bit 25 is as follows Figure 2 As shown, it includes a drill bit, two cavities are symmetrically arranged at the upper and lower parts of the drill bit, a slide rail is arranged on the side wall of the cavity, a sliding piece 26 that can move along the slide rail is installed on the slide rail, an outlet 27 connected to the cavity is arranged on the side wall at the front end of the slide rail, the sliding piece 26 covers the outlet 27 and is fixed by a pin 14, and expansion sealing glue A glue 13 and B glue 15 are respectively encapsulated in the two cavities. The casing milling impact sealing drill bit 25 can realize casing milling in the broken soft coal seam. When encountering a geological anomaly, the drill bit moves forward, and the sliding piece is rubbed by the rock mass and moves backward relative to the drill bit, exposing the through hole at the front end of the slide rail on the side wall of the upper and lower cavities of the drill bit. After the expansion sealing glue A glue 13 and B glue 15 flow out, they are mixed and fill the annular space between the sealing hole protection pipe and the hole wall and solidify, preventing the hole wall from being soaked and scoured by clean water, and protecting the stability of the hole wall.

[0044] The auger drill rod 6 adopts a large through-hole auger drill rod. The large through-hole structure can reduce the power source loss and ensure that the pressure and flow meet the drilling requirements. The spiral structure of the large through-hole auger drill rod plays the role of stirring and assisting slag discharge when the drill rod rotates, thereby improving the efficiency of discharging large pieces of drill cuttings. Among them, the large through-hole drill rod is a drill rod with an inner diameter greater than 40 mm.

[0045] The wireless electromagnetic wave measurement while drilling sub 4 comprises a wireless electromagnetic wave measurement probe, a battery tube and a non-magnetic outer tube. The non-magnetic outer tube is installed in the side wall of the lower non-magnetic drill pipe 3. The wireless electromagnetic wave measurement probe is connected to the battery tube and then installed in the non-magnetic outer tube. The battery tube provides power for the wireless electromagnetic wave measurement probe, and the wireless measurement probe transmits the measured drilling data to the hole receiving device in the form of electromagnetic waves through the transmitting device.

[0046] The method for directional drilling using the gas-liquid dual-medium directional drilling system for drilling through geological anomalies in a broken soft coal seam of the present invention is achieved by the following steps:

[0047] Step 1: Drill a hole according to the designed height, inclination and azimuth, use small-volume hydraulic deslagging, and lift the drill after drilling about 12 meters; use the reaming drill bit to expand the hole and drill about 2 meters, lift the reaming drill bit, send the orifice pipe into the hole and fix it to seal, and install the orifice device;

[0048] Step 2, install the wireless electromagnetic wave measurement while drilling short section 4 in the lower non-magnetic drill rod 3, connect the central drilling tool in sequence, namely, the directional drill bit 1, the gas-liquid dual-purpose screw motor 2, the lower non-magnetic drill rod 3, the upper non-magnetic drill rod 5, the spiral drill rod 6 and the gas-liquid dual-purpose device 7, then connect the high-pressure pipeline 8, the gas-liquid conversion device 9 and the power source system 12, and then send the central drilling tool 22 into the hole for drilling construction;

[0049] Step 3, see Figure 3 In order to facilitate the detailed description of the specific construction conditions of the present invention, taking coal seam drilling as an example, the normal stratum refers to the direct roof 18 and old roof 17 above the broken soft coal seam 19 and the direct bottom 20 and old bottom 21 below which are not affected by the geological anomaly.

[0050] When constructing in the broken soft coal seam 19, specifically: use a radio electromagnetic wave drilling measurement short section to measure the drilling position information, transmit it to the borehole receiving device to determine the drilling trajectory, and then adjust the gas-liquid dual-purpose screw motor elbow to extend the drilling trajectory in the coal seam in a predetermined direction. Switch to the nitrogen-making locomotive 10 as the power source through the gas-liquid conversion device 9, and the high-pressure gas drives the gas-liquid dual-purpose screw motor 2 to rotate and transmit it to the directional drill bit 1 to rotate and cut the coal body. The high-pressure gas plays the role of carrying the coal dust 23, and then transports the coal dust to the orifice for discharge through the rotating spiral drill rod 6; or, control the gas-liquid conversion device 9 to be in the middle position, that is, water and wind are mixed, and the mud pump truck 11 and the nitrogen-making locomotive 10 are turned on at the same time, and the high-pressure water and high-pressure gas can be mixed in proportion, and the gas-liquid two-phase body drives the gas-liquid dual-purpose screw motor 10 to drive ... The rotation of the rotor of the screw motor 2 is transmitted to the directional drill bit 1 to rotate and cut the coal body, and is ejected through the nozzle of the hole of the directional drill bit 1 to form a gas-liquid two-phase jet. The gas-liquid two-phase jet acts on the coal body at the bottom of the hole, which is beneficial to the extension and expansion of cracks in the coal body at the bottom of the hole. Cooperating with the cutting action of the directional drill bit 1, the coal breaking efficiency is improved. At the same time, the gas-liquid two-phase body carries the coal dust 23 and is discharged from the hole along the annular space; at the same time, the rotation of the spiral drill rod 6 increases the power of coal dust transportation, greatly reduces the retention of coal dust at the bottom of the hole, avoids repeated crushing, and improves the drilling speed and efficiency.

[0051] During drilling, the radio electromagnetic wave drilling measurement sub 4 in the hole transmits the measured borehole inclination and azimuth to the receiving device at the hole mouth, and the receiving device displays the measurement results and drilling trajectory. The operator can adjust the tool face angle according to the measurement results to drill to the designed trajectory.

[0052] Meanwhile, during the drilling process, when the returned slag is rock powder and the feed pressure increases in a jump-like manner, it is determined that the drilling has reached the geological anomaly body 24, and step 4 is executed.

[0053] See also Figure 4 In order to facilitate the detailed description of the specific construction conditions of the present invention, taking coal seam drilling as an example, the geological anomaly 24 refers to the direct top 18, old top 17, direct bottom 20 and old bottom 21 of the broken soft coal seam 19 being affected by the geological structure.

[0054] Step 4, implement drilling of the geological anomaly body. During the drilling process, if there is no rock powder in the returned slag and the feed pressure is reduced, then execute step 5, which includes the following sub-steps:

[0055] Step 41, lift the center drill 22 away from the bottom of the hole by a distance L (L is the distance from the directional drill bit 1 to the turning point of the gas-liquid dual-purpose screw motor 2) to stop drilling.

[0056] Step 42, connect the sleeve milling impact sealing drill bit 25 to the hole protection tube 16 through threads, adopt wind-driven rotary drilling, and stop drilling after drilling to the geological anomaly 24 at a distance M (M is the length of the sliding piece 26 of the sleeve milling impact sealing drill bit 25, which is 30 cm in this embodiment). The sliding piece 26 is moved to cut off the pin 14 by the impact force of the drilling rig rotary device, and the pressurized expansion sealing glue A glue 13 and the expansion sealing glue B glue 15 flow out from the outlet 27 of the sleeve milling impact sealing drill bit 25 and expand to form a mixture 28 of expansion sealing glue A glue and B glue, which is densely filled into the annular space between the hole protection tube 16 and the hole wall to prevent clean water from contacting the coal seam hole wall. The hole protection tube 16 protects the entire coal seam hole wall to prevent clean water from soaking and scouring the hole wall, thereby protecting the stability of the hole wall.

[0057] Step 43, through the switching of the gas-liquid conversion device 9, the mud pump truck 11 is used as the power source, and the composite drilling process is adopted to control the spiral drill rod 6 and the gas-liquid dual-purpose screw motor 2 to rotate simultaneously. The high-pressure water forms a pressure difference at both ends of the gas-liquid dual-purpose screw motor to drive the directional drill bit 1 to cut the coal rock mass. The rotation of the spiral drill rod 6 also drives the directional drill bit 1 to rotate, thereby enhancing the cutting ability. The high-pressure water plays a role in cooling the directional drill bit 1 and carrying the coal dust 23. At the same time, the high-pressure water carries the coal dust 23 and flows out of the hole through the wall of the hole protection tube 16.

[0058] Step 5, see Figure 5 After passing through the geological anomaly, the nitrogen generator 10 is switched to through the gas-liquid conversion device 9, and nitrogen is continuously introduced to dry the inner wall of the hole protection pipe 16 to prevent the drill cuttings from sticking to the hole protection pipe 16, and then the nitrogen generator 10 is used as the power source to continue drilling by adopting the sliding drilling process;

[0059] Step 6, drilling to the designed depth, the drilling construction is completed, firstly, the components of the central drilling tool 22 are withdrawn one by one, and then the hole protection tube 16 and the sleeve milling impact sealing drill bit 25 are withdrawn in a rotary manner.

Claims

1. A gas-liquid dual-medium directional drilling method for penetrating geological anomalies in a broken soft coal seam, characterized in that: The method adopts a gas-liquid dual-medium directional drilling system for penetrating a geological anomaly in a broken soft coal seam to perform directional drilling. The gas-liquid dual-medium directional drilling system for penetrating a geological anomaly in a broken soft coal seam comprises a central drilling tool (22), a power source system (12) and a hole protection device, wherein the central drilling tool (22) comprises a directional drill bit (1), a gas-liquid dual-purpose screw motor (2), a lower non-magnetic drill rod (3), an upper non-magnetic drill rod (5) and a spiral drill rod (6) which are connected in sequence from front to back, and their internal cavities are connected; a wireless electromagnetic wave measurement while drilling short section (4) is arranged in the side wall of the lower non-magnetic drill rod (3), and the spiral drill rod (6) is provided with a directional drilling tool (12). 6) is connected to a gas-liquid dual-purpose device at the rear end; the power source system (12) comprises a nitrogen generator (10), a mud pump truck (11), a high-pressure pipeline (8) and a gas-liquid conversion device (9); the nitrogen generator (10) and the mud pump truck (11) are both connected to the gas-liquid dual-purpose device (7) through the high-pressure pipeline (8); the gas-liquid conversion device (9) is arranged on the high-pressure pipeline (8); the hole protection device comprises a sleeve milling impact sealing drill bit (25) and a hole protection pipe (16) connected front and rear; the sleeve milling impact sealing drill bit (25) and the hole protection pipe (16) are integrally mounted on the outside of the center drilling tool (22); and the following steps are included: Step 1: Drill a hole according to the designed height, inclination and azimuth, and lift the drill after drilling 11 to 13 meters; use the reaming drill to expand the hole and drill 1.5 to 2.5 meters, lift the reaming drill, put the orifice pipe into the hole and fix it to seal it, and install the orifice device; Step 2, install the wireless electromagnetic wave measurement while drilling short section (4) in the lower non-magnetic drill rod (3), connect the central drilling tool in sequence, namely, the directional drill bit (1), the gas-liquid dual-purpose screw motor (2), the lower non-magnetic drill rod (3), the upper non-magnetic drill rod (5), the spiral drill rod (6) and the gas-liquid dual-purpose device (7), then connect the high-pressure pipeline (8), the gas-liquid conversion device (9) and the power source system (12), and then send the central drilling tool (22) into the hole for drilling construction; Step 3, construction in the broken soft coal seam (19); during the drilling process, the radio electromagnetic wave drilling measurement short section (4) in the hole transmits the measured borehole inclination and azimuth to the hole mouth receiving device, and the receiving device displays the measurement results and the drilling trajectory; at the same time, during the drilling process, when the return slag is rock powder and the feed pressure increases in a jump-like manner, it is determined that the drilling has reached a geological anomaly (24), and step 4 is executed; Step 4, drilling the geological anomaly body. During the drilling process, if there is no rock powder in the returned slag and the feed pressure decreases, then execute step 5; Step 5, after passing through the geological anomaly, switch to the nitrogen generator (10) through the gas-liquid conversion device (9), continue to introduce nitrogen to dry the inner wall of the hole protection pipe (16), and then continue drilling using the nitrogen generator (10) as a power source and a sliding drilling process; Step 6, drilling to the designed depth, the drilling construction is completed, firstly, the components of the central drilling tool (22) are withdrawn one by one, and then the hole protection tube (16) and the sleeve milling impact sealing drill bit (25) are withdrawn in a rotary manner.

2. The method for directional drilling with gas and liquid dual media through geological anomalies in a broken soft coal seam according to claim 1, characterized in that: In step 3, the construction in the crushed soft coal seam (19) comprises the following steps: The drilling position information is measured by a radio electromagnetic wave measurement while drilling short section, and transmitted to a borehole receiving device to determine the drilling trajectory, and then the gas-liquid dual-purpose screw motor elbow is adjusted to extend the drilling trajectory in the coal seam in a predetermined direction; the gas-liquid conversion device (9) is switched to a nitrogen generator (10) as a power source, and the high-pressure gas drives the gas-liquid dual-purpose screw motor (2) to rotate and transmit the rotor to the directional drill bit (1) to rotate and cut the coal body, and then the coal dust is transported to the borehole for discharge through the rotating spiral drill rod (6); or, the gas-liquid conversion device (9) is controlled to be in the middle position, and the mud pump vehicle (11) and the nitrogen generator (10) are turned on at the same time, and the gas-liquid two-phase body drives the gas-liquid dual-purpose screw motor (2) to rotate and transmit the rotor to the directional drill bit (1) to rotate and cut the coal body, and is ejected through the directional drill bit (1) hole nozzle to form a gas-liquid two-phase jet, and the gas-liquid two-phase body jet acts on the coal body at the bottom of the hole; at the same time, the spiral drill rod (6) rotates.

3. The method for directional drilling with gas and liquid dual media through geological anomalies in a broken soft coal seam according to claim 1, characterized in that: In step 4, the implementation of drilling into the geological anomaly specifically includes the following steps: Step 41, lift the center drilling tool (22) a certain distance away from the bottom of the hole to stop drilling; Step 42, the sleeve milling impact sealing drill bit (25) is connected to the hole protection tube (16) through a thread, and wind-driven rotary drilling is adopted. After drilling to a certain distance from the geological anomaly (24), the drilling is stopped, and the sliding piece (26) is moved to cut the pin (14) by the impact force of the drilling rig rotary device, and the pressurized expansion hole sealing glue A glue (13) and the expansion hole sealing glue B glue (15) flow out from the outlet (27) of the sleeve milling impact sealing drill bit (25) and expand to form a mixture (28) of the expansion hole sealing glue A glue and B glue, which is densely filled into the annular gap between the hole protection tube (16) and the hole wall; Step 43, through the gas-liquid conversion device (9), the mud pump truck (11) is used as the power source, and a composite drilling process is adopted to control the spiral drill rod (6) and the gas-liquid dual-purpose screw motor (2) to rotate simultaneously, and high-pressure water drives the directional drill bit (1) to cut the coal rock mass. The rotation of the spiral drill rod (6) also drives the directional drill bit (1) to rotate.

4. The method for directional drilling of gas-liquid dual-medium holes through geological anomalies in broken soft coal seams according to claim 1, characterized in that: The gas-liquid dual-purpose screw motor (2) is driven by hydraulic power or wind power, or uses a gas-liquid two-phase body as a power source.

5. The method for directional drilling with gas and liquid dual media through geological anomalies in a broken soft coal seam according to claim 1, characterized in that: The gas-liquid dual-purpose device (7) adopts a water feeder.

6. The method for directional drilling with gas and liquid dual media in a broken soft coal seam through a geological anomaly according to claim 1, characterized in that: The gas-liquid conversion device (9) adopts a pneumatic three-way ball valve.

7. The method for directional drilling with gas and liquid dual media through geological anomalies in a broken soft coal seam according to claim 1, characterized in that: The sleeve milling impact sealing drill bit (25) comprises a drill bit, two cavities are symmetrically arranged at the upper and lower parts of the drill bit, a slide rail is arranged on the side wall of the cavity, a sliding sheet (26) is installed on the slide rail and can move along the slide rail, an outlet (27) connected to the cavity is arranged on the side wall at the front end of the slide rail, the sliding sheet (26) covers the outlet (27) and is fixed by a pin (14), and expansion sealing glue A glue (13) and B glue (15) are respectively encapsulated in the two cavities.

8. The method for gas-liquid dual-medium directional drilling in a broken soft coal seam through a geological anomaly according to claim 1, characterized in that: The auger rod (6) is a large through-hole auger rod, the inner diameter of which is greater than 40 mm.

9. The method for directional drilling with gas and liquid dual media through geological anomalies in a broken soft coal seam according to claim 1, characterized in that: The wireless electromagnetic wave measurement while drilling short section (4) comprises a wireless electromagnetic wave measurement probe, a battery tube and a non-magnetic outer tube. The non-magnetic outer tube is installed in the side wall of the lower non-magnetic drill rod (3). The wireless electromagnetic wave measurement probe is connected to the battery tube and installed in the non-magnetic outer tube.

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