Gas guide type gas lift reverse circulation large-diameter binding down-the-hole hammer comprehensive crushing drilling tool and method

Abstract

The invention provides a gas guide type gas lift reverse circulation large-diameter binding down-the-hole hammer comprehensive crushing drilling tool and method, and particularly, a gas lift reverse circulation large-diameter binding down-the-hole hammer drilling tool system comprises a drill bit, a three-channel drill rod, a gas lift mixer, a double-channel drill rod and a double-channel steam water faucet. According to the invention, the conventional thinking that a drill bit is sealed with a hole wall is broken through, a reverse circulation large-diameter bundled down-the-hole hammer tail gas is utilized to pass through a gas guide channel, and tail gas pressure is fully utilized to provide a reverse circulation power source for gas lift reverse circulation, so that continuous reverse circulation of the large-diameter bundled down-the-hole hammer is realized; meanwhile, tail gas of the down-hole sub-hammer on the binding body is collected and guided into a central channel of the drill string to be discharged in a reverse circulation mode, and the technical problem that the down-hole hammer cannot do work due to large back pressure is solved.

Description

Technical Field

[0001] This invention relates to the field of bedrock large-diameter drilling engineering technology, and in particular to a gas-guided air-lift reverse circulation large-diameter bound down-the-hole hammer full-scale crushing drill bit and method. Background Technology

[0002] The demand for large-diameter boreholes is increasing in fields such as infrastructure construction, mining, geothermal development, and efficient drilling and rescue in large-diameter mines. Reverse circulation drill bits, which use large-diameter bundled down-the-hole hammer exhaust gas as a gas lift power source, are integrated drilling systems that combine the gas lift principle, reverse circulation technology, and multi-hammer coordinated operation to achieve efficient rock breaking and slag removal.

[0003] The existing technology has the following main problems: 1. Low slag removal efficiency: Existing drill bits refer to the slag removal principle of small-diameter hollow reverse circulation down-the-hole hammer, and set one or more slag suction ports on the bottom surface of the drill bit. They rely on the pressure of the exhaust gas of the down-the-hole hammer for passive reverse circulation, which is not effective in practical applications. 2. Sealing difficulties: In weathered or fractured strata, the bottom lip of the drill bit cannot effectively seal with the borehole wall. A large amount of exhaust gas and rock powder will circulate in a positive manner, preventing rock cuttings from returning to the surface and posing a risk of drill bit burial. 3. Back pressure effect: In water-bearing formations, the pressure of the fluid column in the borehole increases with the depth of the borehole. The back pressure of the fluid column in the borehole seriously affects the working efficiency of the down-the-hole hammer, resulting in high drilling costs. Summary of the Invention

[0004] In view of this, the present invention proposes a gas-guided air-lift reverse circulation large-diameter bound down-the-hole hammer full-scale crushing drill bit and method.

[0005] Specifically, the aforementioned air-lift reverse circulation large-diameter bundled down-the-hole hammer drill system includes: drill; A three-channel drill rod for media transmission is provided at the upper part of the drill bit; An air lift mixer is provided at the upper part of the three-channel drill pipe to form bubbles and achieve air lift; A dual-channel drill rod is provided at the top of the air-lift mixer for inputting high-pressure air and outputting reverse circulation fluid; A dual-channel steam-water tap for inputting high-pressure air and outputting reverse circulation fluid is provided on the upper part of the dual-channel drill rod.

[0006] Based on the above scheme, it also includes: the upper part of the dual-channel drill rod is also provided with a dual-channel air box for inputting high-pressure air and outputting reverse circulation fluid; The upper part of the dual-channel air box is connected to the central channel of the drilling rig power head to output reverse circulation fluid.

[0007] Based on the above solution, the dual-channel soft drink faucet includes: The faucet body; A slag discharge channel is provided on the upper part of the faucet body to change the flow direction in the medium flow path and realize the slag discharge function. The first submerged hammer inlet channel is used to introduce gas into the subsequent gas supply channel. And a dual-channel steam and water tap connecting flange for connecting a dual-channel drill rod is provided at the lower part of the tap body.

[0008] Based on the above scheme, the dual-channel drill pipe includes: A connecting flange on the dual-channel drill rod is connected to the connecting flange of the dual-channel steam water tap; The dual-channel drill pipe body is provided at the lower part of the flange on the dual-channel drill pipe for transmitting torque and resisting tensile stress and returning the medium through the central channel; A dual-channel drill pipe lower connecting flange for connecting the gas lift mixer is provided at the lower part of the dual-channel drill pipe body; A second downhole hammer gas supply channel is provided between the upper flange of the dual-channel drill pipe and the lower flange of the dual-channel drill pipe for introducing gas into the subsequent gas supply channel.

[0009] Based on the above scheme, the three-channel drill pipe includes: The three-channel drill pipe upper connecting flange is used to connect the air lift mixer, and the three-channel drill pipe lower connecting flange is used to connect the drill bit. A three-channel drill pipe body is axially arranged between the upper connecting flange and the lower connecting flange of the three-channel drill pipe for transmitting torque, meeting tensile stress resistance, and central slag discharge; A fourth down-the-hole hammer air inlet channel for introducing gas into the subsequent air supply channel and a second down-the-hole hammer exhaust channel for exhausting gas are provided on the outside of the three-channel drill pipe body.

[0010] Based on the above scheme, the drill bit is a reverse circulation large-diameter bundled down-the-hole hammer full-break drill bit.

[0011] Based on the above scheme, the drill bit includes: A connecting flange on the drill bit used to connect a three-channel drill pipe; A drill bit center tube is axially arranged at the lower part of the connecting flange of the drill bit for transmitting torque, rotational speed, tensile and compressive stress, and slag removal; A fifth down-the-hole hammer air inlet channel for introducing gas into the subsequent down-the-hole hammer air supply and a third down-the-hole hammer exhaust channel for discharging exhaust gas are provided on the outside of the drill bit center tube. An air intake chamber for accommodating compressed air is provided at the lower part of the air intake channel of the fifth submersible hammer; Several submerged hammer impactors are installed at the lower part of the air intake chamber to generate impact force by using the energy of compressed air to drive the reciprocating motion of the internal piston. And an exhaust chamber for accommodating the exhaust gas discharged from the downhole hammer impactor, located at the lower part of the exhaust channel of the third downhole hammer.

[0012] Based on the above scheme, the drill bit also includes: An outer guide groove is provided on the outer cylinder of the air intake chamber, and the outer guide groove is semi-circular concave.

[0013] Based on the above scheme, the drill bit also includes: A slag discharge channel is provided between several down-the-hole hammers, the slag discharge channel extends out of the air inlet chamber and converges into the drill bit center tube.

[0014] In addition, the drilling method of the air-lift reverse circulation large-diameter bundled down-the-hole hammer drill bit, using the aforementioned air-lift reverse circulation large-diameter bundled down-the-hole hammer drill bit system, includes the following steps: S1: High-pressure air source start-up and primary air supply: High-pressure air enters the intake chamber and concentrates energy through the first downhole hammer air intake channel of the dual-channel steam-water tap, the second downhole hammer air supply channel of the dual-channel drill rod, the third downhole hammer air intake channel of the air lift mixer, and the fourth downhole hammer air intake channel of the three-channel drill rod. S2: Down-the-hole hammer breaking rock: After the high-pressure air is charged in the intake chamber, it opens the check valve on the rear connector of the downhole hammer, driving the piston of the downhole hammer impactor to impact the hammer head at high frequency to break the rock. The exhaust gas after doing work enters the exhaust chamber through the side outlet on the downhole hammer impactor. S3: Cuttings Collection and Reverse Circulation Slag Removal: The exhaust gas in the exhaust chamber reaches the first down-the-hole hammer exhaust channel of the gas lift mixer through the third down-the-hole hammer exhaust channel on the drill bit and the second down-the-hole hammer exhaust channel on the three-channel drill rod. It pushes open the check valve and enters the mixing chamber. Through the exhaust gas inlet on the central tube of the gas lift mixer, the bubbles mix with the liquid in the central tube of the mixer to form a bubble state. The gas lift reverse circulation continuous slag removal drilling is achieved by relying on the negative pressure of the central channel of the drill bit. The circulating medium carrying rock cuttings returns to the surface and undergoes three-phase separation of gas, liquid, and solid in a sedimentation tank. The liquid then enters the borehole through a circulation tank for continuous reverse circulation cuttings removal drilling.

[0015] Compared with existing devices, this invention proposes a gas-guided air-lift reverse circulation large-diameter bundled down-the-hole hammer full-break drilling tool and method, which breaks the conventional thinking of sealing the drill bit and the hole wall. It collects the exhaust gas of the down-the-hole hammer on the bundled body and introduces it into the central channel of the drill string, making full use of the exhaust gas pressure to provide a reverse circulation power source for the "air-lift" reverse circulation, realizing continuous reverse circulation of the large-diameter bundled down-the-hole hammer, while overcoming the technical problem that the down-the-hole hammer cannot do work due to high back pressure. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a large-diameter bundled down-the-hole hammer fully fractured drill bit with air-lift reverse circulation according to an exemplary embodiment. Figure 2 This is a schematic diagram of a large-diameter bundled down-the-hole hammer fully fractured drill bit with air lift reverse circulation according to an exemplary embodiment (specific component names are shown). Figure 3 This is a schematic diagram of a dual-channel soft drink tap according to an exemplary embodiment; Figure 4 This is a schematic diagram of the structure of an air-lift mixer according to an exemplary embodiment; Figure 5 for Figure 4 Sectional view along axis AA; Figure 6 This is a schematic diagram of a three-channel drill pipe according to an exemplary embodiment; Figure 7 This is a schematic diagram of a drill bit structure according to an exemplary embodiment (showing that the drill bit is a reverse circulation large-diameter bundled down-the-hole hammer full-break drill bit). Figure 8 for Figure 7 A cross-sectional view along direction AA (showing the number and arrangement of down-the-hole hammers, the number and location of slag discharge channels, and the layout of the outer guide channel on the outer casing of the gas chamber). Figure 9 for Figure 7 A BB-direction sectional view (showing the square shape of the front connector of the downhole hammer and the layout structure of the outer guide groove on the outer cylinder of the drill bit). Figure 10 This is a schematic diagram of a drill bit assembly with its air inlet chamber connected to an air inlet pipe and its exhaust chamber connected to an exhaust pipe, according to an exemplary embodiment. Figure 11 This is a schematic diagram of the drill bit slag suction port and slag suction channel according to an exemplary embodiment; Figure 12 This is a schematic diagram of a down-the-hole hammer according to an exemplary embodiment (showing the vent hole near the hammerhead of the impactor). Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that the embodiments described below are intended to facilitate the understanding of the present invention and do not constitute any limitation thereof.

[0018] Example 1 This application provides a specific implementation of a gas-guided air-lift reverse circulation large-diameter bundled down-the-hole hammer drill system, such as... Figure 1 As shown, the air-guided air-lift reverse circulation large-diameter bundled down-the-hole hammer drill bit system includes: Drill bit 6; A three-channel drill rod 5 for media transmission is provided on the upper part of the drill bit 6; An air lift mixer 4 is installed on the upper part of the three-channel drill pipe 5 to form bubbles and achieve air lift; A dual-channel drill rod 3 is installed at the top of the air-lift mixer 4 for inputting high-pressure air and outputting reverse circulation fluid; A dual-channel steam-water tap 1 is installed on the upper part of the dual-channel drill pipe 3 for inputting high-pressure air and outputting reverse circulation fluid.

[0019] In particular, as a power head drilling rig, the upper part of the dual-channel drill rod is also equipped with a dual-channel air box 2 for inputting high-pressure air and outputting reverse circulation fluid; the upper part of the dual-channel air box 2 is connected to the power head of the drilling rig, and the air-guided reverse circulation drilling technology is realized by replacing the dual-channel steam and water tap 1 with the power head and the dual-channel air box 2.

[0020] As a specific implementation plan, such as Figures 2-3 As shown, the dual-channel steam-water tap 1 includes a tap body 101, a slag discharge channel 102 provided on the upper part of the tap body 101 for changing the flow direction in the medium flow path and realizing the slag discharge function, a first downhole hammer air inlet channel 103 for introducing gas into the subsequent air supply channel, and a dual-channel steam-water tap connecting flange 104 provided on the lower part of the tap body 101 for connecting the dual-channel drill rod 3.

[0021] The slag discharge channel 102 of the aforementioned faucet body 101 is aligned with the central channel 302 of the double-channel drill rod 3, the air inlet channel 103 of the first downhole hammer air supply faucet is aligned with the second downhole hammer air supply channel 305 of the double-channel drill rod 3, and the double-channel steam and water faucet connecting flange 104 is bolted to the double-channel drill rod connecting flange 301 of the double-channel drill rod 3.

[0022] Specifically, the main purpose of the dual-channel steam-water tap 1 is to control and transport air and return a mixed medium of steam and liquid carrying rock cuttings. It provides the necessary circulating medium for the slag discharge stage and the air supply stage of the down-the-hole hammer in the whole set of equipment. Through its dual-channel design, the output of steam and water can be controlled separately or in concert to meet the requirements of medium flow rate, pressure and other aspects under different working conditions. It is a key component for medium input and distribution. Another auxiliary function of the dual-channel steam-water tap 1 is that when the central pipeline rotates with the lower drill string, the air supply bend and the slag discharge bend of the outer shell do not rotate, which avoids the high-pressure hose and the slag discharge pipe from getting tangled in the drill rod.

[0023] As a specific implementation plan, such as Figure 2 As shown, the dual-channel drill rod 3 (including square drill rod) has a relatively simple structure. The dual-channel drill rod 3 includes a dual-channel upper connecting flange 301 connected to the dual-channel steam and water tap connecting flange 104, a dual-channel drill rod tube body 302 provided at the lower part of the dual-channel upper connecting flange 301 for transmitting torque and resisting tensile stress and returning medium through the central channel, a dual-channel drill rod lower connecting flange 308 provided at the lower part of the dual-channel drill rod tube body 302 for connecting the gas lift mixer 4, and a second downhole hammer gas supply channel 305 provided between the dual-channel upper connecting flange 301 and the dual-channel lower connecting flange 308 for introducing gas into the subsequent gas supply channel.

[0024] In particular, the aforementioned dual-channel drill pipe 3 is not limited to the parallel double-pipe flange connection, but can also be a dual-channel drill pipe with concentric double-wall drill pipe thread connection or other structures.

[0025] As a specific implementation plan, such as Figures 4-5 As shown, the gas lift mixer 4 includes an upper mixer connecting flange 401 connected to the lower connecting flange 308 of the dual-channel drill pipe, a central mixer tube 402 disposed below the upper mixer connecting flange 401 for mixing gas and liquid that transmits torque, meets tensile stress, and returns gas and liquid from the center, a lower mixer connecting flange 408 disposed below the central mixer tube 402 for connecting to the upper connecting flange 501 of the three-channel drill pipe, a mixing chamber 404 disposed on one side of the central mixer tube 402 for mixing gas and liquid, a third down-the-hole hammer inlet channel 405 disposed between the upper mixer connecting flange 401 and the lower mixer connecting flange 408 for introducing gas into the subsequent gas supply channel, a first down-the-hole hammer exhaust channel 407 disposed at the bottom of the mixing chamber 404 for discharging the exhaust gas of the down-the-hole hammer into the mixing chamber 404, and a check valve 406 disposed inside the first down-the-hole hammer exhaust channel 407 for blocking the liquid flow back into the inlet of the first down-the-hole hammer exhaust channel 407.

[0026] Specifically, the mixer center tube 402 of the air-lift mixer 4 has the drilling tool capability of transmitting torque and resisting tensile stress. The upper connecting flange 401 and the lower connecting flange 408 of the mixer are welded to both ends of the mixer center tube 402, connecting the upper double-channel drill rod 3 and the lower three-channel drill rod 5. When connecting, the mixer center tube 402 is aligned with the upper double-channel drill rod tube 302 and the lower three-channel drill rod tube 502. The third down-the-hole hammer air inlet channel 405 is aligned with the second down-the-hole hammer air supply channel 305 of the upper double-channel drill rod 3 and the fourth down-the-hole hammer air inlet channel 505 of the lower three-channel drill rod 5. The first down-the-hole hammer exhaust channel 407 is aligned with the second down-the-hole hammer exhaust channel 507 of the lower three-channel drill rod 5.

[0027] Specifically, the mixing chamber 404 is a closed space formed by an annular surrounding cylinder 403 and the outer wall of the semi-enclosed mixer central tube 402. Multiple venting openings are provided on the mixer central tube 402 to facilitate the formation of air-lifted bubbles. To prevent liquid in the central tube from flowing back into the down-the-hole hammer exhaust channel through the openings, a check valve 406 is installed in the mixing chamber 404 at the outlet of the first down-the-hole hammer exhaust channel 407. The check valve 406 is fixed to the lower connecting flange 408 of the mixer. The check valve 406 prevents liquid in the drill bit's central channel from flowing back into the down-the-hole hammer exhaust chamber 620, which would increase the back pressure of the down-the-hole hammer.

[0028] The aforementioned air-lift mixer 4 is a key component in the air-lift reverse circulation system drill bit. The exhaust gas after the down-the-hole hammer has finished working is in the drill bit exhaust chamber 620 and reaches the outlet of the first down-the-hole hammer exhaust channel 407 of the air-lift mixer 4 through the exhaust channel. It pushes open the check valve 406 and enters the mixing chamber 404. It forms numerous bubbles through the ventilation holes of the mixer's central tube 402 and mixes with the liquid in the mixer's central tube 402 to achieve the air-lift power source.

[0029] As a specific implementation plan, such as Figure 6 As shown, the three-channel drill pipe 5 includes a three-channel upper connecting flange 501 for connecting the gas lift mixer 4 and a three-channel lower connecting flange 508 for connecting the drill bit 6; a three-channel drill pipe body 502 axially arranged between the three-channel upper connecting flange 501 and the three-channel lower connecting flange 508 for transmitting torque, meeting tensile stress and central slag discharge; a fourth down-the-hole hammer air inlet channel 505 for introducing gas into the subsequent air supply channel and a second down-the-hole hammer exhaust channel 507 for exhausting gas, both arranged on the outside of the three-channel drill pipe body 502.

[0030] The aforementioned three-channel drill pipe 5 serves as the connection and transmission component of the entire system. The upper connecting flange 501 of the three-channel drill pipe connects to the lower connecting flange 408 of the air-lift mixer 4, and the lower connecting flange 508 is aligned with the upper connecting flange 601 of the lower drill bit 6. During flange connection, the upper part of the central three-channel drill pipe body 502 of the three-channel drill pipe 5 is aligned with the central mixing pipe body 402 of the air-lift mixer 4, and the lower part is aligned with the central drilling pipe body 602 of the drill bit. The fourth down-the-hole hammer air inlet channel 505 is aligned vertically with the third down-the-hole hammer air inlet channel 405 of the air-lift mixer 4 and the fifth down-the-hole hammer air inlet channel 605 of the drill bit 6, respectively. The second down-the-hole hammer exhaust channel 507 is aligned vertically with the first down-the-hole hammer exhaust channel 407 of the air-lift mixer 4 and the third down-the-hole hammer exhaust channel 607 of the drill bit 6, respectively.

[0031] In particular, the aforementioned three-channel drill pipe 5 is not limited to the parallel three-pipe flange connection, but can also be a concentric double-wall drill pipe connected in parallel with a duct flange or other forms of three-channel drill pipe.

[0032] like Figures 7-9 As shown, in a specific embodiment of drill bit 6, drill bit 6 is a reverse circulation large-diameter bundled down-the-hole hammer full-break drill bit. Drill bit 6 includes a drill bit connecting flange 601 at the top for connecting the three-channel drill rod 5, a drill bit center tube 602 axially arranged at the lower part of the drill bit connecting flange 601 for transmitting torque, rotational speed, tensile and compressive stress and slag discharge, a fifth down-the-hole hammer air intake channel 605 arranged outside the drill bit center tube 602 for air intake and communicating with the fourth down-the-hole hammer air intake channel 505, and a discharge channel. The exhaust gas is discharged through a third downhole hammer exhaust channel 607 connected to the second downhole hammer exhaust channel 507; an intake chamber 612 located below and connected to the fifth downhole hammer intake channel 605 for receiving compressed air; several downhole hammer impactors 613 located below the intake chamber 612 for using the energy of compressed air to drive the reciprocating motion of the internal piston to generate impact force; and an exhaust chamber 620 located below and connected to the third downhole hammer exhaust channel 607 for receiving the exhaust gas discharged by the downhole hammer impactors 613.

[0033] Specifically, the air inlet chamber 612 includes an upper cover plate 609 for sealing the chamber, an outer casing 610 for protection and support, and a lower cover plate 611 for sealing the chamber and resisting impact reaction. The steel plate connected to the rear connector 614 of the downhole hammer is called the lower cover plate 611, also known as the high-frequency rear seat.

[0034] Specifically, the exhaust chamber 620 includes an exhaust chamber upper cover plate 617 for sealing the exhaust chamber, an exhaust chamber outer casing 618 for protection and support, and an exhaust chamber lower cover plate 619 for sealing the exhaust chamber and fixing the front connector 615 of the impactor.

[0035] like Figure 8 As shown, the reverse circulation large-diameter bundled down-the-hole hammer full-break drill bit 6 also includes an outer guide groove 604 on the outer cylinder 610 of the air inlet chamber 612, a slag discharge channel 603 extending from the inside of the air inlet chamber 612 and converging at the drill bit center tube 602, a down-the-hole hammer rear connector 614, a fifth down-the-hole hammer air inlet channel 605, and a third down-the-hole hammer exhaust channel 607 arranged on the air inlet chamber 612. The outer guide groove 604 is a semi-circular concave shape. This design effectively improves slag discharge efficiency, better guiding and accommodating rock cuttings and other waste carried up from the bottom of the hole, allowing the waste to flow more smoothly within the groove, reducing the accumulation and blockage of waste during the slag discharge process, thereby improving slag discharge efficiency.

[0036] like Figure 9 As shown, the reverse circulation large-diameter bundled down-the-hole hammer fully crushing drill bit 6 also includes: The outer cylinder 616 of the drill bit has a semi-circular concave external guide groove 604 machined on the outer side of its cylinder wall to optimize the slag discharge flow field and reduce the risk of rock cuttings adhesion; the outer cylinder 616 of the drill bit integrates a slag discharge channel 603, which works in conjunction with the central slag discharge channel to achieve efficient rock cuttings transportation; the hammer head 615 of the down-the-hole hammer adopts an involute toothed joint and is arranged in a triangular array to ensure full coverage of the crushing working face; at the same time, a third down-the-hole hammer exhaust channel 607 is provided on the exhaust chamber cover plate 617, which is radially distributed to achieve balanced collection and guidance of exhaust gas.

[0037] like Figure 10 As shown, the reverse circulation large-diameter bundled down-the-hole hammer fully crushing drill bit 6 has the following combined structure: drill bit connecting flange 601, drill bit center tube 602, air inlet chamber 612 (air inlet chamber upper cover plate 609, outer cylinder 610, lower cover plate (high frequency back seat) 611 combination), exhaust chamber 620 (upper cover plate 617, outer cylinder 618, lower cover plate (drill bit bottom lip plate) 619 combination), fifth down-the-hole hammer air inlet channel 605, and third down-the-hole hammer exhaust channel 607.

[0038] like Figure 11As shown, the reverse circulation large-diameter bundled down-the-hole hammer fully crushing drill bit 6 has a drill bit connecting flange 601, drill bit center tube 602, and slag discharge channel 603 converging at the drill bit center tube 602, an air inlet chamber 612 (composed of an air inlet chamber upper cover plate 609, an air inlet chamber outer casing 610, and an air inlet chamber lower cover plate 611 (high frequency back seat)), an exhaust chamber 620 (composed of an exhaust chamber upper cover plate 617, an exhaust chamber outer casing 618, and an exhaust chamber lower cover plate 619 (drill bit bottom lip plate), a fifth down-the-hole hammer air inlet channel 605, a third down-the-hole hammer exhaust channel 607, a slag suction device 701, and a slag suction port 702 combined structure.

[0039] like Figure 12 As shown, the down-the-hole hammer structure includes an impactor 613, a down-the-hole hammer rear connector 614 (connecting to a fixed connector), a front connector connecting to the hammer head, a hammer head 615, and three exhaust holes are provided on the outer circumference of the impactor 613 near the hammer head 615. The exhaust holes allow the exhaust gas after the down-the-hole hammer has done work to enter the exhaust chamber 620, and then enter the mixing chamber 404 of the air lift mixer 4 through the third down-the-hole hammer exhaust channel 607, the second down-the-hole hammer exhaust channel 507, and the first down-the-hole hammer exhaust channel 407. Finally, it passes through the ventilation holes on the central tube 402 of the air lift mixer 4 to achieve air lift reverse circulation with countless bubbles.

[0040] As another specific implementation of drill bit 6, drill bit 6 can also be a reverse circulation large-diameter bundled down-the-hole hammer reamer drill bit.

[0041] Based on the aforementioned drilling system, active reverse circulation drilling is achieved by collecting exhaust gas from the down-the-hole hammer to provide a gas lift power source, specifically including: The drill bit connecting flange 601 of the reverse circulation large-diameter bundled down-the-hole hammer full-break drill bit 6 is bolted to the lower connecting flange 508 of the three-channel drill rod 5. During connection, the drill bit center tube 602, the fifth down-the-hole hammer air inlet channel 605, and the third down-the-hole hammer exhaust channel 607 of the reverse circulation large-diameter bundled down-the-hole hammer full-break drill bit 6 are respectively aligned with the flange bolts of the three-channel drill rod body 502, the fifth down-the-hole hammer air inlet channel 605, and the second down-the-hole hammer exhaust channel 507 of the three-channel drill rod 5.

[0042] Multiple three-channel drill pipes 5 are connected end to end by flanges. During connection, the upper connecting flange 501 of each three-channel drill pipe is connected to the lower connecting flange 508 of the three-channel drill pipe. The three-channel drill pipe body 502, the fifth down-the-hole hammer air inlet channel 605, and the second down-the-hole hammer exhaust channel 507 are aligned and connected by flange bolts.

[0043] The uppermost connecting flange 501 of the three-channel drill rod 5 is connected to the lower connecting flange 408 of the air lift mixer 4. The drill rod middle tube 502, the fifth down-the-hole hammer air inlet channel 605, and the second down-the-hole hammer exhaust channel 507 of the three-channel drill rod 5 are respectively aligned with the mixer center tube 402, the third down-the-hole hammer air inlet channel 405, and the first down-the-hole hammer exhaust channel 407 of the air lift mixer 4 and are bolted to the flange.

[0044] The air lift mixer 4 is flanged to the dual-channel drill rod 3. During connection, the upper connecting flange 401 of the mixer is connected to the lower connecting flange 308 of the dual-channel drill rod 3. The mixer center tube 402, the third down-the-hole hammer air inlet channel 405 of the air lift mixer 4 are aligned with the flange bolts of the dual-channel drill rod tube 302 and the second down-the-hole hammer air supply channel 305 of the air lift mixer 4.

[0045] Multiple dual-channel drill rods 3 are connected end to end in sequence. During connection, the upper connecting flange 301 of the dual-channel drill rod 3 is connected to the lower connecting flange 308 of the dual-channel drill rod. The upper and lower connected dual-channel drill rod tube body 302 and the second downhole hammer air supply channel 305 are aligned with the flange bolts and connected.

[0046] The dual-channel steam and water tap 1 is flanged to the dual-channel drill rod 3. During connection, the upper connecting flange 301 of the dual-channel drill rod 3 is connected to the first lower connecting flange 104 of the dual-channel steam and water tap. The dual-channel drill rod body 302 and the second downhole hammer air supply channel 305 are respectively aligned with the central slag discharge channel 102 and air inlet channel 103 of the dual-channel steam and water tap, and the flange is bolted together.

[0047] In the above scheme, the drill bit center tube 602 of drill bit 6, the center three-channel drill rod body 502 of three-channel drill rod 5, the center tube 402 of air lift mixer 4, the center double-channel drill rod body 302 of double-channel drill rod 3, and the center slag discharge channel 102 of double-channel steam and water tap are connected to form a slag discharge channel; the air inlet channel 605 of drill bit 6, the air inlet channel 505 of three-channel drill rod 5, the air inlet channel 405 of air lift mixer 4, the second downhole hammer air supply channel 305 of double-channel drill rod 3, and the air inlet channel 103 of double-channel steam and water tap 1 are connected; the exhaust channel 607 of drill bit 6, the exhaust channel 507 of three-channel drill rod 5, the exhaust channel 407 of air lift mixer 4, and the air inlet mixing chamber 404 of air lift mixer 4 are connected.

[0048] In this embodiment, the reverse circulation large-diameter bundled down-the-hole hammer fully crushing drill bit 6, three-channel drill rod 5, air lift mixer 4, and dual-channel drill rod 3 (including active drill rod) are connected sequentially from bottom to top and then lowered into the borehole. Finally, a dual-channel steam and water tap 1 is connected to the outside of the hole.

[0049] In this invention, regardless of the depth to which the large-diameter, bundled down-the-hole hammer (DHH) fully fractured drill bit is lowered into the well, during drilling in medium-hard formations, the DHH hammer's inlet pressure is approximately 1.4–1.7 MPa, and its exhaust pressure is approximately 1.0–1.3 MPa. The increase in the DHH hammer's back pressure is related to the depth of the mixer within the hydrostatic column, but not to the borehole depth. Only after the mixer is buried at a depth of 100 meters does the DHH hammer's "air lift" pressure increase with increasing depth, leading to an increase in the DHH hammer's inlet pressure. Therefore, during drilling, within a hydrostatic column depth range of 70–120 meters, the DHH hammer's inlet and exhaust pressures remain within a certain range. This ensures that the air compressor stably maintains the basic impact work of the DHH hammer while also ensuring that the exhaust gas from the DHH hammer provides a continuous and efficient power source for air lift and reverse circulation drilling.

[0050] In the example of preventing fluid leakage within the borehole, the exhaust gas from the down-the-hole hammer is discharged to a depth of approximately 100 meters from the borehole opening. A special mixer utilizes this exhaust gas to achieve air-lift reverse circulation. This technical solution uses a large-diameter, bundled down-the-hole hammer fully reaming drill bit with reverse circulation as an example, but it is not limited to this; it can also be applied to large-diameter, bundled down-the-hole hammer reaming drill bits with reverse circulation to achieve continuous, efficient reaming drilling.

[0051] Example 2 Based on Example 1, the present invention also provides a drilling method for a large-diameter bundled down-the-hole hammer drill bit with air lift reverse circulation.

[0052] In the example of preventing liquid leakage in the borehole, the exhaust gas from the down-the-hole hammer is discharged to a depth of about 100 meters from the borehole opening, and the exhaust gas is used to achieve air-lift reverse circulation through an air-lift mixer.

[0053] This embodiment takes a reverse circulation large-diameter bundled down-the-hole hammer full-break drill bit as an example. It uses the exhaust gas after the down-the-hole hammer has done work to achieve a drilling process structure of air lift reverse circulation through an independent exhaust channel at a position close to the borehole opening (within about 100 meters).

[0054] The drilling method specifically includes the following steps: S1: High-pressure air source start-up and primary air supply: High-pressure air enters the intake chamber 612 for energy concentration through the first downhole hammer air intake channel 103 of the dual-channel steam-water tap 1, the second downhole hammer air supply channel 305 of the dual-channel drill rod 3, the third downhole hammer air intake channel 405 of the air lift mixer 4, and the fourth downhole hammer air intake channel 505 of the three-channel drill rod 5. S2: Down-the-hole hammer breaking rock: After the high-pressure air is charged in the intake chamber 612, it opens the check valve on the rear connector 614 of the downhole hammer, driving the piston of the downhole hammer impactor 613 to impact the high-frequency hammer head 615 to break the rock 901. The exhaust gas after doing work enters the exhaust chamber 620 through the side outlet on the downhole hammer impactor 613. S3: Cuttings Collection and Reverse Circulation Slag Removal: The exhaust gas in the exhaust chamber 620 passes through the third down-the-hole hammer exhaust channel 607 on the drill bit 6 and the second down-the-hole hammer exhaust channel 507 on the three-channel drill rod 5 to reach the first down-the-hole hammer exhaust channel 407 of the gas lift mixer 4, and pushes open the check valve to enter the mixing chamber 404. The exhaust gas enters through the exhaust gas inlet on the mixer center tube 402 of the gas lift mixer 4. The bubbles mix with the liquid in the mixer center tube 402 to form a bubble state and return to the ground surface by pressure to achieve gas lift. The circulating medium carrying rock cuttings 902 returns to the surface and passes through the sedimentation tank 801, where the gas, liquid, and solid phases are separated. The liquid then enters the borehole through the circulation tank 802 for continuous reverse circulation cuttings removal drilling.

[0055] Specifically, the high-pressure air required for the down-the-hole hammer to perform its work passes through the first down-the-hole hammer air inlet channel 103 of the dual-channel steam-water tap 1, the second down-the-hole hammer air supply channel 305 of the dual-channel drill rod 3, the third down-the-hole hammer air inlet channel 405 of the air lift mixer 4, and the fourth down-the-hole hammer air inlet channel 505 of the three-channel drill rod 5. Finally, it enters the air inlet chamber 612 for energy concentration through the fifth down-the-hole hammer air inlet channel 605 of the reverse circulation large-diameter bundled down-the-hole hammer comprehensive crushing drill bit 6.

[0056] After the high-pressure air is charged in the intake chamber 612, it opens the check valve on the rear connector 614 of the downhole hammer, driving the piston of the downhole hammer impactor 613 to impact the high-frequency hammer head 615 to break the rock 901. The exhaust gas after doing work enters the exhaust chamber 620 through the side outlet on the downhole hammer impactor 613.

[0057] The exhaust gas in the exhaust chamber 620 has a certain pressure. The pressurized exhaust gas passes through the third down-the-hole hammer exhaust channel 607 on the breaker bit 6 and the second down-the-hole hammer exhaust channel 507 on the three-channel drill rod 5 to reach the first down-the-hole hammer exhaust channel 407 of the air lift mixer 4. It pushes open the check valve and enters the mixing chamber 404. Through the exhaust gas inlet on the mixer center tube 402 of the air lift mixer 4, it mixes with the liquid in the center tube in the form of countless bubbles to form a bubble state. It relies on pressure to return to the surface to achieve air lift. According to the principle of communicating vessels, the pressure difference formed by the annular gap between the drill tool center channel and the drill tool and the borehole wall continuously realizes reverse circulation. The circulating medium carrying rock cuttings 902 returns to the surface and after sedimentation in the sedimentation tank 801, the liquid enters the borehole through the circulation tank 802 to replenish the constant pressure difference and achieve efficient cuttings removal drilling.

[0058] In this embodiment, the basic reverse circulation power source for the air-lift reverse circulation large-diameter bundled down-the-hole hammer full-break drill bit and drilling process is the exhaust gas of the down-the-hole hammer.

[0059] The down-the-hole hammer exhaust gas-driven air-lift reverse circulation drilling process described in this embodiment is capable of achieving air-lift reverse circulation of large-diameter bundled down-the-hole hammer drill bits when drilling to a medium-shallow hole depth (hole depth less than 800 meters) and the mixer is buried at a depth of about 100 meters.

[0060] This invention proposes a large-diameter bundled down-the-hole hammer fully crushing drill bit with air-guided air lift reverse circulation. It breaks away from the conventional thinking of sealing the drill bit with the borehole wall and establishes a system that utilizes the exhaust gas of the large-diameter bundled down-the-hole hammer through the air guide channel to fully utilize the exhaust gas pressure to provide a reverse circulation power source for the air lift reverse circulation, realizing continuous and efficient reverse circulation drilling of the large-diameter bundled down-the-hole hammer. At the same time, the exhaust gas of the down-the-hole sub-hammers on the bundled body is collected and introduced into the center channel of the drill rod for reverse circulation discharge, overcoming the technical problem of the down-the-hole hammer being unable to do work due to high back pressure.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A gas-guided air-lift reverse circulation large-diameter bundled in-hole hammer drill system, characterized in that, Comprise: a drill bit (6); a three-channel drill rod (5) for medium transmission arranged on the upper part of the drill bit (6); an air-lift mixer (4) for forming bubbles to realize air-lifting arranged on the upper part of the three-channel drill rod (5); a double-channel drill rod (3) for inputting high-pressure air and outputting reverse circulation fluid arranged on the upper part of the air-lift mixer (4); and a double-channel water and gas faucet (1) for inputting high-pressure air and outputting reverse circulation fluid arranged on the upper part of the double-channel drill rod (3).

2. The air-foiled reverse circulation large-diameter bundled down- hole hammer drill system of claim 1, wherein, Further comprise: a double-channel gas box (2) for inputting high-pressure air and outputting reverse circulation fluid arranged on the upper part of the double-channel drill rod (3); the double-channel gas box (2) is connected with the center channel output reverse circulation fluid of the rig power head.

3. The air-vented gas-lift reverse circulation large-diameter bundled down- hole hammer drill system of claim 1, wherein, The double-channel water and gas faucet (1) comprises: a faucet body (101); a deslagging channel (102) arranged on the upper part of the faucet body (101) for changing the flow direction in the medium flow path and realizing the deslagging function; a first down-the-hole hammer air inlet channel (103) for introducing gas into the subsequent gas supply channel; and a double-channel water and gas faucet connecting flange (104) arranged on the lower part of the faucet body (101) for connecting the double-channel drill rod (3).

4. The air-vented gas-lift reverse circulation large-diameter bundled down- hole hammer drill system according to claim 3, characterized in that, The double-channel drill rod (3) comprises: a double-channel drill rod upper connecting flange (301) connected with the double-channel water and gas faucet connecting flange (104); a double-channel drill rod pipe body (302) arranged on the lower part of the double-channel drill rod upper connecting flange (301) for transmitting torque and anti-tension stress and returning medium through the center channel; a double-channel drill rod lower connecting flange (308) arranged on the lower part of the double-channel drill rod pipe body (302) for connecting the air-lift mixer (4); and a second down-the-hole hammer gas supply channel (305) arranged between the double-channel drill rod upper connecting flange (301) and the double-channel drill rod lower connecting flange (308) for introducing gas into the subsequent gas supply channel.

5. The air-vented gas-lift reverse circulation large-diameter bundled down- hole hammer drill system, according to claim 1, wherein, The three-channel drill rod (5) comprises: a three-channel drill rod upper connecting flange (501) for connecting the air-lift mixer (4) and a three-channel drill rod lower connecting flange (508) for connecting the drill bit (6); a three-channel drill rod pipe body (502) arranged axially between the three-channel drill rod upper connecting flange (501) and the three-channel drill rod lower connecting flange (508) for transmitting torque, meeting anti-tension stress and center deslagging; a fourth down-the-hole hammer air inlet channel (505) arranged on the outer side of the three-channel drill rod pipe body (502) for introducing gas into the subsequent gas supply channel and a second down-the-hole hammer exhaust channel (507) for exhaust.

6. The air-vented gas-lift reverse circulation large-diameter bundled down- hole hammer drill system of claim 1, wherein, The drill bit (6) is a reverse circulation large-diameter bundled down-the-hole hammer full-face breaking drill bit or a reverse circulation large-diameter bundled down-the-hole hammer reaming drill bit.

7. The air-vented gas-lift reverse circulation large-diameter bundled down- hole hammer drill system, according to claim 1, wherein, The drill bit (6) comprises: a drill bit upper connecting flange (601) for connecting the three-channel drill rod (5); a drill bit center pipe (602) arranged axially on the lower part of the drill bit upper connecting flange (601) for transmitting torque, rotational speed, anti-tension and anti-compression stress and deslagging; A fifth down-the-hole hammer air inlet channel (605) for introducing gas into the subsequent down-the-hole hammer and a third down-the-hole hammer air outlet channel (607) for discharging tail gas are arranged outside the drill bit central pipe (602); An air inlet chamber (612) for containing compressed air is arranged at the lower part of the fifth down-the-hole hammer air inlet channel (605); A plurality of down-the-hole hammer impactors (613) for driving the internal piston to reciprocate and generate impact force by using the energy of compressed air are arranged at the lower part of the air inlet chamber (612); And a tail gas discharge chamber (620) for containing the tail gas discharged by the down-the-hole hammer impactor (613) is arranged at the lower part of the third down-the-hole hammer air outlet channel (607).

8. The air-vented gas-lift reverse circulation large-diameter bundled down- hole hammer drill system, according to claim 7, wherein, The drill bit (6) further comprises: An outer flow guide groove (604) is arranged on the peripheral cylinder (610) of the air inlet chamber (612), and the outer flow guide groove (604) is a concave semicircular groove.

9. The air-vented gas-lift reverse circulation large-diameter bundled down- hole hammer drill system, according to claim 7, wherein, The drill bit (6) further comprises: A residue discharge channel (603) is arranged between the plurality of down-the-hole hammer impactors (613), and the residue discharge channel (603) penetrates through the air inlet chamber (612) and converges at the drill bit central pipe (602).

10. A method of drilling with a gas-guided reverse circulation large-diameter bundled down-the-hole hammer drill, characterized in that, The air-guided air-lift reverse circulation large-diameter bundled down-the-hole hammer drill system of any one of claims 1-9 comprises the following steps: S1: High-pressure air source start and primary delivery: After the high-pressure air passes through the first down-the-hole hammer air inlet channel (103) of the double-channel air and water swivel (1), the second down-the-hole hammer air inlet channel (305) of the double-channel drill rod (3), the third down-the-hole hammer air inlet channel (405) of the air-lift mixer (4), and the fourth down-the-hole hammer air inlet channel (505) of the three-channel drill rod (5), the high-pressure air enters the air inlet chamber (612) for energy concentration through the fifth down-the-hole hammer air inlet channel (605) of the drill bit (6); S2: Down-the-hole hammer works to break rocks: The high-pressure air after energy concentration in the air inlet chamber (612) opens the check valve on the down-the-hole hammer rear connector (614), drives the piston of the down-the-hole hammer impactor (613) to impact the hammer head (615) at a high frequency to break rocks (901), and the tail gas after work is discharged through the side air outlet of the down-the-hole hammer impactor (613) into the tail gas discharge chamber (620); S3: Rock debris collection and reverse circulation residue discharge: The tail gas in the tail gas discharge chamber (620) passes through the third down-the-hole hammer air outlet channel (607) of the drill bit (6), the second down-the-hole hammer air outlet channel (507) of the three-channel drill rod (5), reaches the first down-the-hole hammer air outlet channel (407) of the air-lift mixer (4), pushes open the check valve to enter the mixing chamber (404), passes through the tail gas inlet hole of the mixer central pipe body (402) of the air-lift mixer (4), and the bubbles are mixed with the liquid in the mixer central pipe body (402) to form a bubble state and return to the surface by pressure to realize air-lift; The circulating medium carrying the rock debris (902) returns to the surface, separates into gas, liquid, and solid phases after sedimentation in the sedimentation tank (801), and the liquid enters the drill hole through the circulating groove (802) to continuously perform reverse circulation residue discharge drilling.

Images