A drilling tool for salt cavern gas storage cavity bottom residue without drilling pressure

Abstract

The present invention relates to the technical field of secondary brine removal in salt cavern underground gas storage, and in particular to a no-drilling pressure drilling tool for removing residue from the bottom of a salt cavern gas storage cavity. The diameter-controllable support mechanism is sleeved on the outer wall of the double-wall drill pipe. The bottom end of the motor assembly is transmission-connected to the top end of an axial impact propeller. The bottom end of the axial impact propeller is transmission-connected to the top end of a no-drilling pressure cleaning and drainage short section. The no-drilling pressure cleaning and drainage short section is provided with a flushing nozzle connected to the axial impact propeller and a suction valve hole connected to an outer pipe flow channel. The flushing nozzle and the suction valve hole are both connected to the outside of the no-drilling pressure cleaning and drainage short section. The bottom end of the no-drilling pressure cleaning and drainage short section is transmission-connected with a conical impact head. The beneficial effects of the present invention are as follows: the present invention can complete the operations of flushing slag, removing brine and removing residue, which can save injection and production time; it can also discharge brine, shorten the dissolution cavity time, effectively expand the salt cavity volume, fully improve the utilization rate of the salt layer, and improve the efficiency of brine removal and slag removal.

Description

Technical Field

[0001] The invention relates to the technical field of secondary brine removal in salt cavern underground gas storage, and in particular to a drilling tool for salt cavern gas storage cavity bottom residue without weight on bit. Background Art

[0002] After a salt cavern underground gas storage is constructed using the water-soluble solution method, the cavity is filled with brine, formed by the dissolution of water-soluble salt rock liquid. This brine must be removed through gas injection and brine removal to maximize the effective storage volume and make natural gas storage more economical. my country has also been developing salt cavern-type gas storage for nearly 20 years, but the design, construction, and operational technologies are still in their early stages. Currently, underground salt cavern gas storage in my country uses a vertical well to create a dissolution cavity. After the cavity is created, gas injection and brine removal tubing are installed. After natural gas is injected, the brine removal tubing is pulled out. Due to the high impurity content and numerous interlayers in my country's salt rock formations, insoluble impurities settle to the bottom of the cavity after creation. Since these impurities are difficult to remove through the tubing, removing the brine contained in the impurities can significantly increase the effective cavity volume. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a salt cavern gas storage cavity bottom residue zero-weight-on-bite drilling tool to overcome the problem that saturated brine is difficult to discharge in the prior art.

[0004] The technical solution of the present invention to solve the above technical problems is as follows: a salt cavern gas storage cavity bottom residue no-biting pressure drilling tool, comprising a double-wall drill pipe, a diameter-controllable support mechanism, a motor assembly, an axial impact thruster, a no-biting pressure cleaning short section and a conical impact head, the space between the inner tube and the outer tube of the double-wall drill pipe forms an outer tube flow channel, the diameter-controllable support mechanism is sleeved on the outer wall of the double-wall drill pipe, and is used to set the double-wall drill pipe at the wellhead; the motor assembly and the axial impact thruster are sequentially arranged in the inner tube of the double-wall drill pipe from top to bottom, and the bottom end of the motor assembly is connected to the inner tube of the double-wall drill pipe. The top transmission connection of the axial impact thruster is used to convert the hydraulic power of the liquid entering the motor assembly into mechanical energy for driving the axial impact thruster to rotate around its central axis; the bottom end of the axial impact thruster is transmission-connected to the top end of the no-bit pressure-on-drilling cleaning and drainage pup joint, and the no-bit pressure-on-drilling cleaning and drainage pup joint is provided with a flushing spray hole connected to the axial impact thruster and a suction valve hole connected to the outer pipe flow channel, the flushing spray hole and the suction valve hole are both connected to the outside of the no-bit pressure-on-drilling cleaning and drainage pup joint, and the bottom end of the no-bit pressure-on-drilling cleaning and drainage pup joint is transmission-connected to the conical impact head.

[0005] The beneficial effects of the present invention are as follows: the diameter-controllable support mechanism is sleeved on the outside of the double-wall drill pipe, and the double-wall drill pipe is set at the wellhead through the diameter-controllable support mechanism; the present invention can complete the slag flushing, brine removal and residue cleaning operations, which can save injection and production time; it can also discharge brine, shorten the dissolution cavity time, effectively expand the salt cavity volume, fully improve the utilization rate of the salt layer, and improve the efficiency of brine removal and slag cleaning. The motor assembly can complete flushing and suction operations during water injection drilling and gas injection brine removal processes, thereby reducing operating costs and saving working time.

[0006] On the basis of the above technical solution, the present invention can also be improved as follows.

[0007] Furthermore, the double-wall drill pipe includes an outer tube and an inner tube fixed inside the outer tube, the inner wall of the outer tube and the outer wall of the inner tube are spaced apart to form the outer tube flow channel, and the inner wall of the outer tube and the outer wall of the inner tube are fixedly connected by a support.

[0008] The beneficial effect of adopting the above further solution is: the outer tube and the inner tube are spaced apart by the support member so that an outer tube flow channel is formed between the outer tube and the inner tube, which facilitates the simultaneous realization of gas injection into the inner tube and brine discharge through the outer tube flow channel during brine discharge.

[0009] Furthermore, the diameter-controllable support mechanism includes a support tube body, a plurality of arc rods are provided in the support tube body, and the plurality of arc rods are arranged in a circular matrix. The two ends of the arc rods are extended along the length direction of the support tube body, and the transverse cross-section of the arc rods is arc-shaped. The inner wall of the support tube body and the outer wall of the arc rod are fixedly connected by a spring, and the inner walls of the plurality of arc rods are pressed against the outer wall of the double-wall drill pipe.

[0010] The beneficial effect of adopting the above further solution is that the arc-shaped rod with an arc-shaped cross section facilitates the straightening of the double-wall drill pipe. At the same time, due to the elasticity of the spring, it can be applied to double-wall drill pipes with different outer diameters.

[0011] Furthermore, a plurality of fan-shaped embedding holes are spaced apart circumferentially in the middle of the support tube body, and an embedding block matching the shape of the embedding hole is slidably provided in the embedding hole, and the arc rods are fixedly connected to the inner wall of the embedding block through the spring in a one-to-one correspondence.

[0012] The beneficial effect of adopting the above-mentioned further scheme is that the sliding fit between the insert and the insert hole enables the insert to slide in the insert hole. When the inner wall of the arc rod presses against the outer wall of the double-wall drill pipe, the insert slides outward under the action of the spring, and can more firmly abut the inner wall of the wellhead, making the connection between the diameter-controllable support mechanism and the inner wall of the wellhead more stable.

[0013] Furthermore, both top and bottom ends of the arc-shaped rod are fixedly connected to the inner wall of the support tube body through elastic connecting pieces.

[0014] The beneficial effect of adopting the above further solution is that the setting of the elastic connecting piece can support the two ends of the arc rod, avoiding the two ends of the arc rod from tilting when the arc rod and the inner tube of the double-wall drill pipe are connected by spring alone, which makes it inconvenient to install the double-wall drill pipe.

[0015] Furthermore, the motor assembly includes a stator with conductive top and bottom ends and a rotor that rotates inside the stator. A motor flow channel is provided between the inner wall of the stator and the outer wall of the rotor. The outer wall of the stator is connected to the inner wall of the inner tube of the double-wall drill pipe, and the bottom end of the rotor is transmission-connected to the top end of the axial impact thruster.

[0016] The beneficial effect of adopting the above further solution is that a motor flow channel is provided between the inner wall of the stator and the outer wall of the rotor, and when water flows through, the motor flow channel drives the rotor to rotate, thereby driving the rotor.

[0017] Furthermore, the axial impact thruster includes a bearing joint housing, a main shaft, a butterfly spring group and a rolling bearing group. The bearing joint housing is sleeved on the outside of the main shaft, and the rolling bearing group is fixedly sleeved on the outer wall of the main shaft. The outer peripheral wall of the rolling bearing group is slidingly connected to the inner wall of the bearing joint housing. The interior of the main shaft is provided with a center hole running through both ends of the main shaft. The top of the main shaft is transmission-connected to the bottom end of the rotor through an upper connector. The outer wall of the upper connector is provided with a guide hole for connecting the center hole and the motor flow channel. The bottom end of the bearing joint housing is threadedly connected with a lower locking nut. The bottom end of the main shaft passes through the lower locking nut and is transmission-connected and communicated with the drilling pressure-free cleaning short section. The butterfly spring group is sleeved on the outer wall of the main shaft between the rolling bearing group and the lower locking nut.

[0018] The beneficial effect of adopting the above further scheme is that the main shaft rotates under the drive of the motor assembly, thereby driving the no-bit pressure-on-drilling cleaning and drainage short section and the conical impact head to rotate. At the same time, under the impact of the water flow, the no-bit pressure-on-drilling cleaning and drainage short section and the conical impact head are driven to drill downward, thereby improving the drilling efficiency.

[0019] Furthermore, the axial impact thruster also includes an upper radial thrust bearing and a lower radial thrust bearing, the upper radial thrust bearing and the lower radial thrust bearing are both fixedly mounted on the main shaft, and the upper radial thrust bearing and the lower radial thrust bearing are respectively arranged on both sides of the rolling bearing group, the outer peripheral walls of the upper radial thrust bearing and the lower radial thrust bearing are slidingly connected to the inner wall of the bearing section housing, and the butterfly spring group is mounted on the outer wall of the main shaft between the lower radial thrust bearing and the lower locking nut.

[0020] The beneficial effect of adopting the above further solution is that the arrangement of the upper radial thrust bearing and the lower radial thrust bearing can improve the stability of the main shaft rotation.

[0021] Furthermore, a limiting portion for blocking the upper radial thrust bearing is provided on the inner wall of the bearing joint housing at one end close to the upper connector, and the upper radial thrust bearing, the rolling bearing group, the lower radial thrust bearing and the butterfly spring group are arranged between the limiting portion and the lower locking nut.

[0022] The beneficial effect of adopting the above further solution is that the setting of the limiting portion and the lower locking nut can limit the upper radial thrust bearing, the rolling bearing group, the lower radial thrust bearing and the butterfly spring group, facilitate installation and prevent separation.

[0023] Furthermore, the no-drilling pressure cleaning and drainage short section includes an upper joint, a cleaning and drainage outer tube, a cleaning and drainage inner tube and a lower joint. The bottom end of the cleaning and drainage inner tube is fixedly connected and communicated with the bottom end of the main shaft through the upper joint, and the bottom end of the cleaning and drainage inner tube is fixedly connected with the conical impact head through the lower joint. The lower part of the cleaning and drainage inner tube is provided with the flushing spray hole for communicating with the outside; the cleaning and drainage outer tube is provided on the outside of the cleaning and drainage inner tube, the top end of the cleaning and drainage outer tube is communicated with the outer tube flow channel, and the lower part of the cleaning and drainage outer tube is provided with a suction valve hole communicating with the outside.

[0024] The beneficial effect of adopting the above further scheme is: the rotation of the main shaft drives the rotation of the no-pressure-on-drilling cleaning and drainage short section, thereby driving the rotation of the conical impact head. At the same time, during drilling, clean water passes through the motor assembly and the axial impact propeller in sequence and is ejected from the flushing nozzles on the cleaning and drainage inner tube to flush away the slag around the conical impact head; during the brine discharge process, the gas passes through the motor assembly and the axial impact propeller in sequence and is ejected from the flushing nozzles on the cleaning and drainage inner tube. The brine at the insoluble residue in the salt cavity is sucked into the cleaning and drainage outer tube of the no-pressure-on-drilling cleaning and drainage combination short section, and then passes through the axial impact propeller to the motor assembly. The torque generated by the brine impacting the motor assembly will increase the suction force of the suction valve hole of the no-pressure-on-drilling cleaning and drainage combination short section, and the sucked brine is finally discharged through the outer tube flow channel of the double-wall drill pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the present invention;

[0026] Figure 2 is a cross-sectional view of the diameter-controllable support mechanism of the present invention;

[0027] Figure 3 for Figure 2 AA section view in the figure;

[0028] Figure 4 is a schematic structural diagram of the motor assembly of the present invention;

[0029] Figure 5 Schematic diagram of the structure of the axial impact thruster in the present invention;

[0030] Figure 6 It is a structural diagram of the no-pressure-on-drilling cleaning and drainage sub in the present invention;

[0031] Figure 7 It is a schematic diagram of the present invention during drilling;

[0032] Figure 8 It is a schematic diagram of the present invention when removing brine.

[0033] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0034] 1. Double-wall drill pipe; 11. Outer pipe flow channel; 12. Outer pipe; 13. Inner pipe; 2. Diameter-controllable support mechanism; 21. Support pipe body; 22. Curved rod; 23. Spring; 24. Embedded hole; 25. Embedded block; 26. Elastic connector; 3. Motor assembly; 31. Stator; 32. Rotor; 4. Axial impact thruster; 41. Bearing housing; 42. Spindle; 43. Belleville spring assembly; 44. Rolling bearing assembly; 45. Center hole; 46. Diversion hole; 47. Lower locking nut; 48. Upper radial thrust bearing; 49. Lower radial thrust bearing; 410. Limiting part; 411. Upper locking nut; 412. Centralizer; 413. Upper connector; 5. No-pressure drilling cleaning and drainage short section; 51. Upper joint; 52. Cleaning and drainage outer pipe; 53. Cleaning and drainage inner pipe; 54. Lower joint; 55. Flushing spray hole; 56. Suction valve hole; 6. Conical impact head. DETAILED DESCRIPTION

[0035] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0036] like Figure 1As shown, an embodiment of the present invention includes a double-wall drill pipe 1, a diameter-controllable support mechanism 2, a motor assembly 3, an axial impact thruster 4, a zero-pressure drilling cleaning short section 5, and a conical impact head 6. The space between the inner tube 13 and the outer tube 12 of the double-wall drill pipe 1 forms an outer tube flow channel 11. The diameter-controllable support mechanism 2 is sleeved on the outer wall of the double-wall drill pipe 1 to set the double-wall drill pipe 1 at the drilling head; the motor assembly 3 and the axial impact thruster 4 are sequentially arranged in the inner tube 13 of the double-wall drill pipe 1 from top to bottom, and the bottom end of the motor assembly 3 is connected to the top end of the axial impact thruster 4. The transmission connection is used to convert the hydraulic power of the liquid entering the motor assembly 3 into mechanical energy for driving the axial impact thruster 4 to rotate around its central axis; the bottom end of the axial impact thruster 4 is transmission-connected to the top end of the no-bit pressure cleaning and drainage sub 5, and the no-bit pressure cleaning and drainage sub 5 is provided with a flushing spray hole 55 connected to the axial impact thruster 4 and a suction valve hole 56 connected to the outer pipe flow channel 11. The flushing spray hole 55 and the suction valve hole 56 are both connected to the outside of the no-bit pressure cleaning and drainage sub 5, and the bottom end of the no-bit pressure cleaning and drainage sub 5 is transmission-connected to the conical impact head 6.

[0037] Specifically, the double-wall drill pipe 1 includes an outer tube 12 and an inner tube 13 fixedly disposed within the outer tube 12. The inner wall of the outer tube 12 and the outer wall of the inner tube 13 are spaced apart to form the outer tube flow channel 11. The inner wall of the outer tube 12 and the outer wall of the inner tube 13 are fixedly connected by a support member. The outer tube 12 and the inner tube 13 are spaced apart by the support member, so that the outer tube flow channel 11 is formed between the outer tube 12 and the inner tube 13. This facilitates simultaneous gas injection into the inner tube 13 and brine discharge from the outer tube flow channel 11 during brine discharge. In this embodiment, the support member may be a support rod, a support ring, etc., and the support member does not block the outer tube flow channel 11, thereby ensuring that liquid can pass through the outer tube flow channel 11.

[0038] like Figure 2 、 Figure 3As shown, in an embodiment of the invention, the diameter-controllable support mechanism 2 includes a support tube body 21, the support tube body 21 is vertically arranged, the support tube body 21 is in the shape of a circular tube, and the outer wall of the support tube body 21 abuts the inner wall of the wellhead, and a plurality of arc rods 22 are arranged in a circular matrix, the matrix center line of the plurality of arc rods 22 coincides with the center line of the support tube body 21, and the two ends of the arc rods 22 extend along the length direction of the support tube body 21. The arc rod 22 is extended, and the transverse cross-section of the arc rod 22 is arc-shaped. The inner wall of the support tube body 21 and the outer wall of the arc rod 22 are fixedly connected by a spring 23. One end of the spring 23 is fixedly connected to the outer wall of the arc rod 22. The inner walls of multiple arc rods 22 all press against the outer wall of the double-wall drill pipe 1 to wrap the double-wall drill pipe 1. The arc rod 22 with an arc-shaped cross-section is convenient for straightening the double-wall drill pipe 1. At the same time, due to the elasticity of the spring 23, it can be applicable to double-wall drill pipes 1 with different outer diameters.

[0039] Furthermore, the middle part of the support tube body 21 is provided with a plurality of fan-shaped embedded holes 24 at intervals along the circumference. The embedded holes 24 penetrate the inner and outer walls of the support tube body 21. The embedded holes 24 are slidably provided with an embedded block 25 that matches the shape of the embedded hole 24. That is, the embedded block 25 is fan-shaped and slidably arranged in the embedded hole 24. The arc rods 22 are fixedly connected to the inner wall of the embedded block 25 through the spring 23 in a one-to-one correspondence. Specifically, one end of the spring 23 is fixedly connected to the outer wall of the middle part of the arc rod 22, and the other end of the spring 23 is fixedly connected to the embedded block 25. The inner wall of the block 25 is fixedly connected, and the sliding fit between the insert 25 and the insert hole 24 enables the insert 25 to slide in the insert hole 24. When the inner wall of the arc rod 22 presses against the outer wall of the double-wall drill pipe 1, the arc rod 22 is pushed outward by the double-wall drill pipe 1, so that the spring 23 is compressed and has elastic potential energy. Under the action of the elastic potential energy of the spring 23, the insert 25 slides outward after being subjected to the outward force, thereby increasing the pressure on the inner wall of the wellhead, and can more firmly abut the inner wall of the wellhead, so that the connection between the diameter-controllable support mechanism 2 and the inner wall of the wellhead is more stable. Preferably, the top and bottom ends of the arc rod 22 are fixedly connected to the inner wall of the support tube body 21 through elastic connectors 26. The setting of the elastic connector 26 can support the two ends of the arc rod 22, avoiding the two ends of the arc rod 22 from tilting when the arc rod 22 and the inner tube 13 of the double-wall drill pipe 1 are connected by the spring 23 alone, which is inconvenient for the installation of the double-wall drill pipe 1. In an embodiment of the present invention, the elastic connector 26 can be a compression spring 23 or an elastic rod set at an angle, etc.

[0040] like Figure 4As shown, in an embodiment of the present invention, the motor assembly 3 includes a stator 31 with conductive ends at both ends, and a rotor 32 rotatably disposed within the stator 31. A motor flow channel is provided between the inner wall of the stator 31 and the outer wall of the rotor 32. The outer wall of the stator 31 is connected to the inner wall of the inner tube 13 of the double-wall drill pipe 1, and the bottom end of the rotor 32 is transmission-connected to the top end of the axial impact thruster 4. A motor flow channel is provided between the inner wall of the stator 31 and the outer wall of the rotor 32. When water flows through, it drives the rotor 32 to rotate, thereby driving the rotor 32. The specific structure of the motor assembly 3 is prior art in this field, and its specific structure and working principle will not be described in detail here.

[0041] like Figure 5 As shown, in an embodiment of the present invention, the axial impact thruster 4 includes a bearing joint housing 41, a main shaft 42, a butterfly spring group 43 and a rolling bearing group 44, the bearing joint housing 41 is sleeved on the outside of the main shaft 42, and the top end of the bearing joint housing 41 is threadedly connected with an upper locking nut 411, and the rolling bearing group 44 is fixedly sleeved on the outer wall of the main shaft 42, and the outer peripheral wall of the rolling bearing group 44 is slidably connected to the inner wall of the bearing joint housing 41, and the interior of the main shaft 42 is provided with a center hole 45 that passes through both ends of the main shaft 42, and the top end of the main shaft 42 is transmission-connected to the bottom end of the rotor 32 through an upper connector 413, and the bottom end of the upper connector 413 is fixedly connected to the top end of the main shaft 42 by threads, and the top end of the upper connector 413 is circumferentially fixedly connected to the bottom end of the rotor 32 by a cylindrical spline, so that the rotation of the rotor 32 can drive the rotation of the main shaft 42 through the upper connector 413, and will not limit the movement of the main shaft 42 along its axial direction. The outer wall of the body 413 is provided with a guide hole 46 for connecting the central hole 45 and the motor flow channel. A sealing ring is fixedly sleeved on the outer wall of the upper connecting body 413. The sealing ring is slidably connected to the inner wall of the bearing section housing 41. The sealing ring is arranged on the side of the guide hole 46 close to the main shaft 42. The bottom end of the bearing section housing 41 is threadedly connected to a lower locking nut 47. The bottom end of the main shaft 42 passes through the lower locking nut 47 and is connected to the no-drilling pressure cleaning short section 5 for transmission. The butterfly spring group 43 is sleeved on the outer wall of the main shaft 42 between the rolling bearing group 44 and the lower locking nut 47. The main shaft 42 rotates under the drive of the motor assembly 3, thereby driving the no-bit pressure cleaning and drainage short section 5 and the conical impact head 6 to rotate. At the same time, under the impact of the water flow, it enters the upper connector 413 and the main shaft 42 from the guide hole 46 and impacts the main shaft 42, driving the main shaft 42 to move downward, driving the no-bit pressure cleaning and drainage short section 5 and the conical impact head 6 to drill downward, thereby improving the drilling efficiency.

[0042] Preferably, the axial impact thruster 4 further includes an upper radial thrust bearing 48 and a lower radial thrust bearing 49, both of which are fixedly mounted on the main shaft 42 and are respectively arranged on either side of the rolling bearing group 44. The outer circumferential walls of the upper radial thrust bearing 48 and the lower radial thrust bearing 49 are slidably connected to the inner wall of the bearing segment housing 41, and the butterfly spring group 43 is mounted on the outer wall of the main shaft 42 between the lower radial thrust bearing 49 and the lower locking nut 47. The provision of the upper radial thrust bearing 48 and the lower radial thrust bearing 49 can improve the rotational stability of the main shaft 42. As the main shaft 42 moves downward, both the upper and lower radial thrust bearings 48 and 49 move downward. The lower radial thrust bearing 49 presses downward on the butterfly spring assembly 43, causing the butterfly spring assembly 43 to generate a downward thrust force on the lower locking nut 47, thereby driving the entire axial impact thruster 4 downward, thereby driving the conical impact head 6 downward. In this embodiment, a centralizer 412 is provided on the main shaft 42 between the upper connector 413 and the upper radial thrust bearing 48 to further improve the rotational stability of the main shaft 42.

[0043] Further preferably, a limiting portion 410 for blocking the upper radial thrust bearing 48 is provided on the inner wall of the bearing joint housing 41 near one end of the upper connector 413, and the limiting portion 410 has a stepped structure. The upper radial thrust bearing 48, the rolling bearing group 44, the lower radial thrust bearing 49 and the butterfly spring group 43 are arranged between the limiting portion 410 and the lower locking nut 47. The stepped limiting portion 410 blocks and limits the upper radial thrust bearing 48. The setting of the limiting portion 410 and the lower locking nut 47 can limit the upper radial thrust bearing 48, the rolling bearing group 44, the lower radial thrust bearing 49 and the butterfly spring group 43, which is convenient for installation and prevents separation.

[0044] like Figure 6As shown, in an embodiment of the present invention, the no-bit-pressure-drilling short section 5 includes an upper joint 51, a drainage outer tube 52, a drainage inner tube 53 and a lower joint 54. The bottom end of the drainage inner tube 53 is fixedly connected and communicated with the bottom end of the main shaft 42 through the upper joint 51, and the bottom end of the drainage inner tube 53 is fixedly connected to the conical impact head 6 through the lower joint 54. The lower part of the drainage inner tube 53 is provided with the flushing spray hole 55 for communicating with the outside; the drainage outer tube 52 is provided on the outside of the drainage inner tube 53, and the top of the drainage outer tube 52 is communicated with the outer tube flow channel 11. The lower part of the drainage outer tube 52 is provided with a suction valve hole 56 communicated with the outside. The rotation of the main shaft 42 drives the no-bit-pressure-drilling The rotation of the short section 5 drives the rotation of the conical impact head 6. At the same time, during drilling, clean water passes through the motor assembly 3 and the axial impact propeller 4 in sequence and is ejected from the flushing nozzle 55 on the cleaning and drainage inner tube 53 to flush away the slag around the conical impact head 6. During the brine discharge process, the gas passes through the motor assembly 3 and the axial impact propeller 4 in sequence and is ejected from the flushing nozzle 55 on the cleaning and drainage inner tube 53. The brine at the insoluble residue in the salt cavity is sucked into the outer tube 12 of the no-biting pressure cleaning and drainage short section 5, and then through the axial impact propeller 4 to the motor assembly 3. The torque generated by the brine impacting the motor assembly 3 will increase the suction force of the suction valve hole 56 of the no-biting pressure cleaning and drainage short section 5, and the sucked brine is finally discharged through the outer tube flow channel 11 of the double-wall drill pipe 1.

[0045] In an embodiment of the present invention, the upper connecting body is a hollow tubular structure, the bottom end of the upper connecting body is fixedly connected to the top end of the cleaning inner tube 53 and is in sealed communication, the top end of the upper connecting body is fixedly connected to the bottom end of the main shaft 42 and is in sealed communication with the center hole 45. The top end of the lower connecting body is fixedly connected to the bottom end of the cleaning inner tube 53 and blocks the bottom end of the cleaning inner tube 53, the bottom end of the lower connecting body is fixedly connected to the top end of the conical impact head 6, and the specific connection method is the existing technology in the field, such as threaded connection or bayonet fixation, etc., which are all within the scope of protection of this application. The cleaning outer tube 52 is fixedly arranged on the outer wall of the cleaning inner tube 53, the outer wall of the top of the cleaning outer tube 52 is slidingly and sealingly connected to the inner wall of the outer tube 12, and the bottom end of the cleaning outer tube 52 is sealed.

[0046] Working principle: Figure 7 As shown, during water injection drilling, clean water is injected from the inner tube 13 of the double-wall drill pipe 1, and the clean water impacts the motor assembly 3 through the inner tube 13. The motor assembly 3 generates torque to drive the axial impact propeller 4. The clean water passes through the center hole 45 of the main shaft 42 and enters the drainage inner tube 53 of the no-bit pressure drainage short section 5, and is sprayed out from the flushing spray hole 55 to flush away the slag around the conical impact head 6. The no-bit pressure drainage short section 5 and the conical impact head 6 drill toward the bottom of the insoluble residue under the thrust of the axial impact propeller 4.

[0047] like Figure 8 As shown, when gas injection is used to produce brine, the suction valve hole 56 of the no-drilling pressure cleaning and drainage short section 5 draws the brine from the insoluble residue into the drainage outer pipe 52 of the no-drilling pressure cleaning and drainage short section 5, and then to the motor assembly 3 via the axial impact thruster 4. The torque generated by the brine impacting the motor assembly 3 will increase the suction force of the suction valve hole 56 of the no-drilling pressure cleaning and drainage short section 5, and the sucked brine will finally be discharged through the outer pipe flow channel 11 of the double-wall drill pipe 1.

[0048] The beneficial effects of the present invention are as follows: the diameter-controllable support mechanism 2 is sleeved on the outside of the double-wall drill pipe 1, and the double-wall drill pipe 1 is set at the wellhead through the diameter-controllable support mechanism 2; the present invention can complete the slag flushing, brine removal and residue cleaning operations, which can save injection and production time; it can also discharge brine, shorten the dissolution cavity time, effectively expand the salt cavity volume, fully improve the salt layer utilization rate, and improve the efficiency of brine removal and slag cleaning. The motor assembly 3 can complete flushing and suction operations during water injection drilling and gas injection brine removal, thereby reducing operating costs and saving working time.

[0049] In the description of the present invention, it should be understood that the terms "center", "length", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "inside", "outside", "peripheral", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred system or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0050] In the description of the present invention, “a plurality of” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0051] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0052] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A salt cavern gas storage cavity bottom residue no-biting pressure drilling tool, characterized in that: The invention comprises a double-wall drill pipe (1), a diameter-controllable support mechanism (2), a motor assembly (3), an axial impact thruster (4), a pressure-free drilling cleaning nipple (5), and a conical impact head (6); the space between the inner pipe (13) and the outer pipe (12) of the double-wall drill pipe (1) forms an outer pipe flow channel (11); the diameter-controllable support mechanism (2) is sleeved on the outer wall of the double-wall drill pipe (1) and is used to set the double-wall drill pipe (1) at the wellhead; the motor assembly (3) and the axial impact thruster (4) are sequentially arranged in the inner pipe (13) of the double-wall drill pipe (1) from top to bottom; the bottom end of the motor assembly (3) and the top end of the axial impact thruster (4) are connected to each other. The transmission connection is used to convert the hydraulic power of the liquid entering the motor assembly (3) into mechanical energy for driving the axial impact propeller (4) to rotate around its central axis; the bottom end of the axial impact propeller (4) is transmission-connected to the top end of the no-bit pressure cleaning and drainage short section (5), and the no-bit pressure cleaning and drainage short section (5) is provided with a flushing spray hole (55) communicating with the axial impact propeller (4) and a suction valve hole (56) communicating with the outer tube flow channel (11), the flushing spray hole (55) and the suction valve hole (56) are both connected to the outside of the no-bit pressure cleaning and drainage short section (5), and the bottom end of the no-bit pressure cleaning and drainage short section (5) is transmission-connected to the conical impact head (6); The motor assembly (3) includes a stator (31) with conductive top and bottom ends and a rotor (32) rotatably arranged in the stator (31), a motor flow channel is provided between the inner wall of the stator (31) and the outer wall of the rotor (32), the outer wall of the stator (31) is connected to the inner wall of the inner tube (13) of the double-wall drill pipe (1), and the bottom end of the rotor (32) is transmission-connected to the top end of the axial impact thruster (4); The axial impact thruster (4) comprises a bearing joint housing (41), a main shaft (42), a butterfly spring group (43) and a rolling bearing group (44), wherein the bearing joint housing (41) is sleeved outside the main shaft (42), the rolling bearing group (44) is fixedly sleeved on the outer wall of the main shaft (42), the outer peripheral wall of the rolling bearing group (44) is slidably connected to the inner wall of the bearing joint housing (41), the interior of the main shaft (42) is provided with a center hole (45) penetrating through both ends of the main shaft (42), and the top end of the main shaft (42) is connected to the upper connector ( 413) is in transmission connection with the bottom end of the rotor (32); a guide hole (46) for connecting the center hole (45) and the motor flow channel is provided on the outer wall of the upper connector (413); a lower locking nut (47) is threadedly connected to the bottom end of the bearing section housing (41); the bottom end of the main shaft (42) passes through the lower locking nut (47) and is in transmission connection and communication with the no-drilling pressure cleaning short section (5); the butterfly spring group (43) is sleeved on the outer wall of the main shaft (42) between the rolling bearing group (44) and the lower locking nut (47); The no-pressure-on-drilling short joint (5) comprises an upper joint (51), a drainage outer pipe (52), a drainage inner pipe (53) and a lower joint (54); the bottom end of the drainage inner pipe (53) is fixedly connected and communicated with the bottom end of the main shaft (42) through the upper joint (51); the bottom end of the drainage inner pipe (53) is fixedly connected to the conical impact head (6) through the lower joint (54); the lower part of the drainage inner pipe (53) is provided with the flushing spray hole (55) for communicating with the outside; the drainage outer pipe (52) is provided outside the drainage inner pipe (53); the top end of the drainage outer pipe (52) is communicated with the outer pipe flow channel (11); the lower part of the drainage outer pipe (52) is provided with the suction valve hole (56) for communicating with the outside.

2. The salt cavern gas storage cavity bottom residue no-weight-on-bit drilling tool according to claim 1, characterized in that: The double-wall drill pipe (1) comprises an outer pipe (12) and an inner pipe (13) fixedly arranged in the outer pipe (12), the inner wall of the outer pipe (12) and the outer wall of the inner pipe (13) are spaced apart to form the outer pipe flow channel (11), and the inner wall of the outer pipe (12) and the outer wall of the inner pipe (13) are fixedly connected via a support member.

3. The salt cavern gas storage cavity bottom residue no-weight-on-bit drilling tool according to claim 1, characterized in that: The diameter-controllable support mechanism (2) comprises a support tube body (21), wherein a plurality of arc-shaped rods (22) are provided in the support tube body (21), wherein the plurality of arc-shaped rods (22) are arranged in a circular matrix, wherein both ends of the arc-shaped rods (22) extend along the length direction of the support tube body (21), and the transverse cross-section of the arc-shaped rods (22) is arranged in an arc shape, wherein the inner wall of the support tube body (21) and the outer wall of the arc-shaped rods (22) are fixedly connected via a spring (23), and the inner walls of the plurality of arc-shaped rods (22) all press against the outer wall of the double-wall drill pipe (1).

4. The salt cavern gas storage cavity bottom residue no-weight-on-bit drilling tool according to claim 3, characterized in that: A plurality of fan-shaped embedded holes (24) are provided at intervals along the circumference of the middle portion of the support tube body (21), and embedded blocks (25) matching the shape of the embedded holes (24) are slidably provided in the embedded holes (24), and the arc-shaped rods (22) are fixedly connected to the inner walls of the embedded blocks (25) via the springs (23) in a one-to-one correspondence.

5. The salt cavern gas storage cavity bottom residue no-weight-on-bit drilling tool according to claim 3, characterized in that: Both the top and bottom ends of the arc-shaped rod (22) are fixedly connected to the inner wall of the support tube body (21) via elastic connecting pieces (26).

6. The salt cavern gas storage cavity bottom residue no-weight-on-bit drilling tool according to claim 1, characterized in that: The axial impact thruster (4) further includes an upper radial thrust bearing (48) and a lower radial thrust bearing (49), both of which are fixedly sleeved on the main shaft (42), and the upper radial thrust bearing (48) and the lower radial thrust bearing (49) are respectively arranged on both sides of the rolling bearing group (44), the outer peripheral walls of the upper radial thrust bearing (48) and the lower radial thrust bearing (49) are slidably connected to the inner wall of the bearing section housing (41), and the butterfly spring group (43) is sleeved on the outer wall of the main shaft (42) between the lower radial thrust bearing (49) and the lower locking nut (47).

7. The salt cavern gas storage cavity bottom residue no-weight-on-bit drilling tool according to claim 6, characterized in that: A limiting portion (410) for blocking the upper radial thrust bearing (48) is provided on the inner wall of one end of the bearing joint housing (41) close to the upper connector (413), and the upper radial thrust bearing (48), the rolling bearing group (44), the lower radial thrust bearing (49) and the butterfly spring group (43) are arranged between the limiting portion (410) and the lower locking nut (47).

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