A borehole wall oriented coring drill for polar drilling

Abstract

The application discloses a polar drilling hole wall directional coring drill, which comprises a shell, an upper hot melting drill bit, a reverse torsion mechanism, a cable chamber, a control system, a hole positioning mechanism, a supporting mechanism, a reaming mechanism and a coring mechanism, wherein the upper hot melting drill bit is assembled at the top of the shell, the reverse torsion mechanism, the cable chamber, the control system, the hole positioning mechanism, the supporting mechanism, the reaming mechanism and the coring mechanism are sequentially assembled in the shell from top to bottom, and the control system is connected with the upper hot melting drill bit, the reverse torsion mechanism, the hole positioning mechanism, the supporting mechanism, the reaming mechanism and the coring mechanism respectively. The application has the advantages that the coring direction can be accurately controlled, the demand of polar scientific research can be met, the drill is provided with the reaming mechanism, the auxiliary time is greatly shortened, the ice core tube can be telescoped to store the ice core in real time, the loss of the ice core is avoided, the drill adopts the modular design, the structure is simple and compact, the burden of polar logistics guarantee is reduced, and the drill is suitable for coring drilling in a harsh environment.

Description

Technical Field

[0001] This invention relates to a coring tool, and more particularly to a borehole directional coring tool for polar drilling. Background Technology

[0002] Currently, the ice layers hidden deep within glaciers contain invaluable information about ancient climate, environment, and geological history. Analyzing ice cores allows us to understand patterns and trends in global climate change, reveal nature's responses at different times, and help predict future climate change. Furthermore, ice cores provide data on sea-level rise, air pollution, volcanic eruptions, and solar activity, which are crucial for ecosystem health, natural disaster risk assessment, and resource management. Therefore, ice core research not only contributes to the advancement of climate and earth sciences but also provides a scientific basis for developing policies and solutions to address climate change and environmental challenges. In recent years, with the deepening of polar research, drilling additional ice core samples at specific locations has become an important research direction in polar science. This stems from the need for more comprehensive ice core parameter data for ice layers of significant scientific value, leading to a substantial increase in the demand for ice core samples. In addition, additional ice core data not only helps to verify and consolidate existing ice core analysis results but also provides backup resources in response to unforeseen circumstances such as potential loss, damage, or contamination of ice core samples. Therefore, obtaining additional ice core samples from specific ice layer depths is crucial for advancing polar scientific research and ensuring data reliability.

[0003] Faced with the problems of limited core samples, long processing times, and high costs associated with conventional drilling methods for re-drilling on the surface, scientists have proposed a method using eccentric wedges or support arms to deflect the drill bit and extract samples from the borehole wall. However, this method requires multiple drill bit changes to create space within the borehole wall, resulting in long auxiliary times, complex core extraction processes, and poor core azimuth accuracy. In recent years, researchers have proposed a method using a thermomelting drill bit to first melt the ice layer laterally before vertical core extraction. This method offers a simple core extraction process and fast ice drilling speed. However, when drilling into ice layers containing rock particles, the high melting point of the rock makes it difficult for the drill bit to advance. Furthermore, drilling deep ice cores requires low-temperature drilling fluid to stabilize the wellbore, resulting in slow thermomelting drilling speeds. Therefore, there is an urgent need for a borehole core extraction tool that offers a simple core extraction process, accurate core azimuth, and the ability to handle both rock-particle-containing ice layers and deep ice layers. Summary of the Invention

[0004] The main purpose of this invention is to solve the problems of existing methods for drilling ice cores using eccentric wedges or support arms, such as the need to change drill bits multiple times to create space in the borehole wall, long auxiliary time, complex coring process, and poor coring orientation accuracy.

[0005] Another objective of this invention is to solve the problems of existing thermal fusion drill bits, which are difficult to advance when drilling into ice layers containing rock particles due to the high melting point of the rock, and the need for low-temperature drilling fluid to stabilize the well wall when drilling deep ice cores, resulting in slow thermal fusion drilling speed.

[0006] In order to achieve the above objectives and solve the above problems, the present invention provides a borehole wall directional coring tool for polar drilling.

[0007] The polar drilling borehole directional coring tool provided by this invention includes a shell, an upper thermomelting drill bit, a reverse twisting mechanism, a cable chamber, a control system, an in-hole positioning mechanism, a support mechanism, a reaming mechanism, and a coring mechanism. The upper thermomelting drill bit is assembled on the top of the shell. The reverse twisting mechanism, cable chamber, control system, in-hole positioning mechanism, support mechanism, reaming mechanism, and coring mechanism are assembled sequentially inside the shell from top to bottom. The control system is connected to the upper thermomelting drill bit, reverse twisting mechanism, in-hole positioning mechanism, support mechanism, reaming mechanism, and coring mechanism respectively, and controls the operation of the upper thermomelting drill bit, reverse twisting mechanism, in-hole positioning mechanism, support mechanism, reaming mechanism, and coring mechanism.

[0008] The housing includes an upper housing and a lower housing, with the upper housing located above the lower housing. The upper thermoelectric drill bit is mounted on the top of the upper housing. The anti-torsion mechanism, cable chamber, and control system are sequentially mounted inside the upper housing. The support mechanism, reaming mechanism, and core-taking mechanism are mounted inside the lower housing. The in-hole positioning mechanism is mounted at the connection between the upper and lower housings.

[0009] The anti-torsion mechanism includes a cutter head, a pull rod, a lead screw, a pull rod seat, a transmission nut, and a first motor. The pull rod seat is inserted into the inner cavity of the upper housing and is sleeved on the transmission nut and the lead screw. The output shaft of the first motor is connected to the transmission nut via a coupling, enabling the first motor to drive the transmission nut to rotate. The transmission nut is screwed to the lower part of the lead screw. Several splines are mounted on the outer circumference of the upper part of the lead screw, and these splines can engage with the keyways of the pull rod seat. The lead screw is connected to the pull rod seat via the splines and can move up and down along the keyways on the pull rod seat. The rotation of the transmission nut drives the lead screw. The drill bit moves up and down along the keyway on the tie rod seat. The outer side of the transmission nut is connected to the tie rod seat through two rolling bearings. Four cutter heads and tie rods are symmetrically assembled. The protrusion behind each cutter head is pivotally connected to the top of the tie rod, and the bottom of each cutter head is pivotally connected to the top of the lead screw. The bottom of each tie rod is pivotally connected to the top of the tie rod seat. The side wall of the upper housing has a first opening corresponding to the part of each cutter head. During the up and down movement of the lead screw, it can drive the cutter head to extend out of the side wall of the upper housing from the first opening to fix the entire drill bit. The first motor is connected to the control system and is controlled by the control system.

[0010] Armored cables are installed inside the cable compartment. The lower part of the cable compartment is equipped with a male cable connector, a female cable connector, an adjusting nut, and a first load cell. The female cable connector is located on a cable connector mounting base, and the male cable connector is inserted into the female cable connector. The adjusting nut is located on the upper part of the male cable connector to adjust the tightness of the armored cable shell. After the armored cable passes through the upper thermoforming drill bit and the anti-torsion mechanism, the armored cable shell is fixed between the male and female cable connectors. The internal wires of the armored cable are connected to the control system. The first load cell is installed between the female cable connector and the cable connector mounting base to monitor the tensile force on the armored cable. The first load cell is connected to the control system and can transmit the collected data to the control system in real time.

[0011] The borehole positioning mechanism includes a second motor, an upper rotating shaft, a universal joint, a lower rotating shaft, and a gyroscope. The second motor is fixedly installed in the inner cavity of the lower part of the upper housing. The output shaft of the second motor is connected to the upper rotating shaft. The outer side of the upper rotating shaft is connected to the inner wall of the upper housing through a transverse bearing. The lower end of the upper rotating shaft is pivotally connected to the top of the universal joint through a pin. The top of the lower rotating shaft is pivotally connected to the lower end of the universal joint through a pin. The bottom of the lower rotating shaft is screwed to the top of the lower housing. The second motor drives the lower housing to rotate through the upper rotating shaft, the universal joint, and the lower rotating shaft. The gyroscope is fixedly installed in the middle of the upper rotating shaft to monitor the centering position of the borehole wall. Both the second motor and the gyroscope are connected to the control system. The gyroscope can transmit the collected data to the control system in real time, and the control system controls the operation of the second motor.

[0012] The support mechanism is mounted on the upper part of the inner cavity of the lower housing. The support mechanism includes a first electric push rod, a second weighing sensor, and a support block. The top end of the first electric push rod is pivotally connected to the upper rear end of the support block via a pin, and the upper front end of the support block is pivotally connected to the inner wall of the lower housing via a pin. A second opening is provided on the side wall of the lower housing corresponding to the support block. The first electric push rod can drive the support block to rotate and extend out of the side wall of the lower housing through the second opening. The second weighing sensor is mounted on the bottom of the first electric push rod to monitor the supporting force between the support block and the hole wall. Both the second weighing sensor and the first electric push rod are connected to the control system. The second weighing sensor can transmit the collected data to the control system in real time, and the control system controls the operation of the first electric push rod.

[0013] The reaming mechanism is assembled in the inner cavity of the lower housing at the bottom of the support mechanism. The reaming mechanism includes a third load cell, a second electric push rod, and a reaming drill bit. The third load cell is assembled in the inner cavity of the lower housing and is connected to the fixed end of the second electric push rod via a pin. The third load cell is used to monitor the pressure between the reaming drill bit and the ice layer. The reaming drill bit includes an extension shaft, a third motor, and a drill body. The tail end of the output shaft of the second electric push rod is pivotally connected to the front end of the extension shaft. The third motor is assembled inside the extension shaft, and the drill body is sleeved on the extension shaft. The drill body and the extension shaft... A wear-resistant copper sleeve is fitted between the parts. The third motor is connected to the drill bit body through a motor adapter plate and can drive the drill bit body to rotate. Several rows of drill teeth are embedded in the outer circumference of the drill bit body. A third opening is opened on the side wall of the lower housing corresponding to the reaming drill bit part. The second electric push rod can drive the reaming drill bit to extend out of the lower housing from the third opening to perform reaming operations through the extension shaft. The third weighing sensor, the second electric push rod and the third motor are all connected to the control system. The third weighing sensor can transmit the collected data to the control system in real time. The control system controls the operation of the second electric push rod and the third motor.

[0014] The coring mechanism is assembled inside the lower housing at the bottom of the reaming mechanism. The coring mechanism includes a coring drill bit, a fourth motor, a third electric push rod, and a retractable ice core tube. A drill bit holder is fitted around the lower part of the coring drill bit, and a wear-resistant copper sleeve is sandwiched between the coring drill bit and the drill bit holder. A retaining ring is fitted around the bottom of the wear-resistant copper sleeve to limit its movement. Pins are fitted on both sides of the drill bit holder, and these pins are mounted in grooves on the inner wall of the lower housing via bearings. The drill bit holder drives the coring drill bit to slide synchronously along the grooves. The top of the drill bit holder… The output end of the lower housing is pivotally connected to the third electric push rod via a pin. The third electric push rod can drive the drill bit holder and the core drill bit to slide synchronously along the slide groove. A fourth opening is provided on the outer wall of the lower housing corresponding to the core drill bit. Driven by the third electric push rod, the core drill bit can extend through the fourth opening to the outer wall of the lower housing for core extraction. A belt drive wheel is mounted on the top of the drill bit holder. The belt drive wheel and the belt pulley sleeved around the outer circumference of the core drill bit are connected by a belt for transmission. The top of the belt drive wheel is connected to the lower housing via a retractable flexible shaft. A fourth motor is connected to the inner cavity of the housing. The fourth motor drives the belt drive pulley to rotate the core drill bit synchronously via a retractable flexible shaft. The outer surface of the belt is equipped with serrations for cutting off excess ice. The retractable ice core tube is fixed to the lower part of the drill bit fixing seat by a clamp. The bottom of the retractable ice core tube is fixed to the bottom of the inner cavity of the lower housing. The inlet of the retractable ice core tube is connected to the outlet below the core drill bit. The retractable ice core tube can directly receive the ice core drilled by the core drill bit. The top of the core drill bit is equipped with a cutting tool, and the top surface of the cutting tool is equipped with a pad. The fixed end of the third electric push rod is connected to the fourth weighing sensor via a pin to monitor the drilling pressure of the core drill bit. The output end of the fourth motor is equipped with an encoder to monitor the output speed of the fourth motor. The bottom of the inner cavity of the lower housing is equipped with a displacement sensor to monitor the core length of the core drill bit. The fourth motor, the third electric push rod, the fourth weighing sensor, the encoder, and the displacement sensor are all connected to the control system. The fourth weighing sensor, the encoder, and the displacement sensor can transmit the collected data to the control system in real time. The control system controls the operation of the fourth motor and the third electric push rod.

[0015] The control system is connected to the ground equipment via internal wiring in an armored cable. The control system includes a signal input unit, a signal output unit, and a signal processing unit. The signal input unit is connected to the first, second, third, and fourth load cells, a gyroscope, a displacement sensor, and an encoder. The signal input unit can receive data transmitted from these load cells in real time. The signal output unit is connected to the upper thermo-melting drill bit, the first, second, third, and fourth motors, and the first, second, and third electric actuators. The signal output unit controls the operating status of these components. The signal processing unit receives data from the signal input unit and transmits the processed data to the signal output unit. The signal input and signal output units are also connected to the ground signal unit, enabling the ground system to control the downhole drilling tools.

[0016] The first weighing sensor, second weighing sensor, third weighing sensor, fourth weighing sensor, gyroscope, displacement sensor, encoder, hot melt drill bit, first motor, second motor, third motor, fourth motor, first electric actuator, second electric actuator, third electric actuator, signal input unit, signal output unit, signal processing unit, and ground signal unit mentioned above are all assemblies of existing equipment. Therefore, their specific models and specifications are not detailed.

[0017] Working principle of the invention:

[0018] The polar drilling directional coring tool provided by this invention is used by lowering the drill bit below a predetermined well section using an armored cable. The control system controls a first motor to rotate a transmission nut. With the keyway engagement of the tie rod seat, the lead screw moves upward along the keyway axis, thereby driving the cutter head and tie rod to rotate around the pin. The cutter head extends from the first opening on the side wall of the upper housing and is supported on the borehole wall. Then, the control system commands a second motor to rotate the universal joint and the lower housing until the coring bit extends to the predetermined position. The control system commands a first electric push rod to extend, thereby driving the support block to rotate around the pin until one side of the lower housing is in close contact with the borehole wall. The control system commands a second electric push rod to retract and drive the extension shaft and the reaming bit to rotate around the pin, extending from the third opening on the side wall of the lower housing. The control system commands a third motor to rotate the reaming bit. During the extension of the reaming bit, it rotates to cut the ice layer, achieving borehole enlargement. After reaming is completed, the control system instructs the second electric push rod to extend and retract the extension shaft and reaming drill bit into the drill string. The drill string is then lifted until the core drill bit is positioned within the reaming area. The control system instructs the third electric push rod to retract and extend the drill bit holder and core drill bit outwards along the groove. The control system instructs the fourth motor to rotate the belt drive shaft via a retractable flexible shaft, which in turn rotates the core drill bit, enabling upward core drilling. The drilled ice core is directly stored in the retractable ice core tube below the core drill bit. After core drilling is completed, the control system instructs the fourth motor to stop rotating, and the third electric push rod to extend and retract the drill bit holder and core drill bit into the drill string along the groove. The control system instructs the first electric push rod to retract and retract the support block into the drill string. The control system instructs the first motor to reverse, causing the lead screw to move axially downwards, retracting the cutter head into the drill string. The drill string is then lifted to the surface using an armored cable, completing the core drilling. If borehole diameter reduction occurs during the lifting process, the control system instructs the hot-melt drill bit to operate, achieving diameter reaming.

[0019] The beneficial effects of this invention are:

[0020] The polar drilling tool provided by this invention uses a belt-driven core drill bit to rotate and cut through the ice layer, making it suitable for drilling in ice layers containing rock particles and deep ice layers. The anti-torsion mechanism and the in-hole positioning mechanism work together to precisely control the core orientation, meeting the needs of polar scientific research. The tool is equipped with a hole-reaming mechanism, eliminating the need for additional drilling tools to create cavities beforehand, significantly reducing auxiliary time. The retractable ice core tube can store the ice core in real time, preventing ice core loss accidents. The tool adopts a modular design, with a simple and compact structure, reducing the burden of polar logistics support and making it suitable for core drilling in harsh environments. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the polar drilling borehole directional coring tool described in this invention.

[0022] Figure 2This is a three-dimensional structural diagram of the anti-torsion mechanism described in this invention.

[0023] Figure 3 This is a three-dimensional structural diagram of the hole-expanding mechanism described in this invention.

[0024] Figure 4 This is a schematic diagram of the core drill bit structure described in this invention.

[0025] Figure 5 This is a connection diagram of the control system described in this invention.

[0026] Figure 6 This is a schematic diagram of the borehole enlargement principle of the borehole wall orientation coring system described in this invention.

[0027] Figure 7 This is a schematic diagram of the drilling principle of the borehole wall directional coring system described in this invention.

[0028] The annotations in the image above are as follows:

[0029] 1. Top-mounted thermoforming drill bit; 2. Reverse twisting mechanism; 3. Cable compartment; 4. Control system.

[0030] 5. In-hole positioning mechanism; 6. Support mechanism; 7. Hole reaming mechanism; 8. Core sampling mechanism.

[0031] 9. Upper housing; 10. Lower housing; 11. Cutting head; 12. Pull rod; 13. Lead screw.

[0032] 14. Tie rod seat; 15. Transmission nut; 16. First motor; 17. Rolling bearing.

[0033] 18. First opening; 19. Armored cable; 20. Male cable connector; 21. Female cable connector

[0034] 22. Adjusting nut; 23. First load cell; 24. Second motor; 25. Upper rotating shaft.

[0035] 26. Universal joint; 27. Lower rotating shaft; 28. Gyroscope; 29. ​​Lateral bearing.

[0036] 30. First electric push rod; 31. Second weighing sensor; 32. Support block; 33. Second opening.

[0037] 34. Third weighing sensor; 35. Second electric push rod; 36. Reamer bit; 37. Extending shaft.

[0038] 38. Third motor; 39. Drill bit body; 40. Wear-resistant copper sleeve; 41. Drill bit teeth; 42. Third opening.

[0039] 43. Core drill bit; 44. Fourth motor; 45. Third electric actuator; 46. Telescopic ice core tube.

[0040] 47. Drill bit holder; 48. Retaining ring; 49. Slide groove; 50. Fourth opening; 51. Belt drive pulley

[0041] 52. Pulley 53. Belt 54. Flexible shaft 55. Cutting tool 56. Insulating shoe

[0042] 57. Fourth weighing sensor; 58. Encoder; 59. Displacement sensor; 60. Signal input unit.

[0043] 61. Signal output unit; 62. Signal processing unit; 63. Ground signal unit. Detailed Implementation

[0044] Please see Figures 1 to 7 As shown:

[0045] The polar drilling borehole directional coring tool provided by the present invention includes a shell, an upper thermomelting drill bit 1, a reverse twisting mechanism 2, a cable chamber 3, a control system 4, an in-hole positioning mechanism 5, a support mechanism 6, a reaming mechanism 7, and a coring mechanism 8. The upper thermomelting drill bit 1 is assembled on the top of the shell. The reverse twisting mechanism 2, the cable chamber 3, the control system 4, the in-hole positioning mechanism 5, the support mechanism 6, the reaming mechanism 7, and the coring mechanism 8 are assembled sequentially inside the shell from top to bottom. The control system 4 is connected to the upper thermomelting drill bit 1, the reverse twisting mechanism 2, the in-hole positioning mechanism 5, the support mechanism 6, the reaming mechanism 7, and the coring mechanism 8 respectively. The control system 4 controls the operation of the upper thermomelting drill bit 1, the reverse twisting mechanism 2, the in-hole positioning mechanism 5, the support mechanism 6, the reaming mechanism 7, and the coring mechanism 8.

[0046] The housing includes an upper housing 9 and a lower housing 10, wherein the upper housing 9 is located on the upper part of the lower housing 10, the upper hot melt drill bit 1 is assembled on the top of the upper housing 9, the anti-torsion mechanism 2, the cable chamber 3 and the control system 4 are sequentially assembled inside the upper housing 9, the support mechanism 6, the hole reaming mechanism 7 and the core extraction mechanism 8 are assembled inside the lower housing 10, and the hole positioning mechanism 5 is assembled at the connection between the upper housing 9 and the lower housing 10.

[0047] The anti-torsion mechanism 2 includes a cutter head 11, a pull rod 12, a lead screw 13, a pull rod seat 14, a transmission nut 15, and a first motor 16. The pull rod seat 14 is inserted into the inner cavity of the upper housing 9 and is sleeved on the transmission nut 15 and the lead screw 13. The output shaft of the first motor 16 is connected to the transmission nut 15 via a coupling, enabling the first motor 16 to drive the transmission nut 15 to rotate. The transmission nut 15 is screwed to the lower part of the lead screw 13. Several splines are mounted on the outer circumference of the upper part of the lead screw 13, and these splines can engage in the keyways of the pull rod seat 14. The lead screw 13 is connected to the pull rod seat 14 via splines and can move up and down along the keyways on the pull rod seat 14. During rotation, the transmission nut 15... The lead screw 13 moves up and down along the keyway on the tie rod seat 14. The outer side of the transmission nut 15 is connected to the tie rod seat 14 through two rolling bearings 17. Four cutter heads 11 and tie rods 12 are symmetrically assembled. The protrusion behind each cutter head 11 is pivotally connected to the top of the tie rod 12. The bottom of each cutter head 11 is pivotally connected to the top of the lead screw 13. The bottom of each tie rod 12 is pivotally connected to the top of the tie rod seat 14. The side wall of the upper housing 9 has a first opening 18 corresponding to the part of each cutter head 11. During the up and down movement of the lead screw 13, it can drive the cutter head 11 to extend out of the side wall of the upper housing 9 from the first opening 18 to fix the entire drill bit. The first motor 16 is connected to the control system 4 and is controlled by the control system 4.

[0048] An armored cable 19 is installed inside the cable compartment 3. The lower part of the cable compartment 3 is equipped with a male cable connector 20, a female cable connector 21, an adjusting nut 22, and a first weighing sensor 23. The female cable connector 21 is located on the cable connector fixing seat, and the male cable connector 20 is inserted into the female cable connector 21. The adjusting nut 22 is located on the upper part of the male cable connector 20 to adjust the tightness of the armored cable 19 shell. After the armored cable 19 passes through the upper thermoforming drill bit 1 and the anti-torsion mechanism 2, the shell of the armored cable 19 is fixed between the male cable connector 20 and the female cable connector 21. The internal wires of the armored cable 19 are connected to the control system 4. The first weighing sensor 23 is installed between the female cable connector 21 and the cable connector fixing seat to monitor the tension of the armored cable 19. The first weighing sensor 23 is connected to the control system 4 and can transmit the collected data to the control system 4 in real time.

[0049] The in-hole positioning mechanism 5 includes a second motor 24, an upper rotating shaft 25, a universal joint 26, a lower rotating shaft 27, and a gyroscope 28. The second motor 24 is fixedly installed in the inner cavity of the lower part of the upper housing 9. The output shaft of the second motor 24 is connected to the upper rotating shaft 25. The outer side of the upper rotating shaft 25 is connected to the inner wall of the upper housing 9 through a transverse bearing 29. The lower end of the upper rotating shaft 25 is pivotally connected to the top end of the universal joint 26 through a pin. The top end of the lower rotating shaft 27 is pivotally connected to the lower end of the universal joint 26 through a pin. The bottom of the lower rotating shaft 27 is screwed to the top of the lower housing 10. The second motor 24 drives the lower housing 10 to rotate through the upper rotating shaft 25, the universal joint 26, and the lower rotating shaft 27. The gyroscope 28 is fixedly installed in the middle part of the upper rotating shaft 25 to monitor the centering position of the hole wall. Both the second motor 24 and the gyroscope 28 are connected to the control system 4. The gyroscope 28 can transmit the collected data to the control system 4 in real time. The control system 4 controls the operation of the second motor 24.

[0050] The support mechanism 6 is mounted on the upper part of the inner cavity of the lower housing 10. The support mechanism 6 includes a first electric push rod 30, a second weighing sensor 31, and a support block 32. The top end of the first electric push rod 30 is pivotally connected to the upper rear end of the support block 32 by a pin. The upper front end of the support block 32 is pivotally connected to the inner wall of the lower housing 10 by a pin. A second opening 33 is provided on the side wall of the lower housing 10 corresponding to the support block 32. The first electric push rod 30 can drive the support block 32 to rotate and extend out of the side wall of the lower housing 10 through the second opening 33. The second weighing sensor 31 is mounted on the bottom of the first electric push rod 30 to monitor the supporting force between the support block 32 and the hole wall. Both the second weighing sensor 31 and the first electric push rod 30 are connected to the control system 4. The second weighing sensor 31 can transmit the collected data to the control system 4 in real time. The control system 4 controls the operation of the first electric push rod 30.

[0051] The reaming mechanism 7 is assembled in the inner cavity of the lower housing 10 at the bottom of the support mechanism 6. The reaming mechanism 7 includes a third weighing sensor 34, a second electric push rod 35, and a reaming drill bit 36. The third weighing sensor 34 is assembled in the inner cavity of the lower housing 10 and is connected to the fixed end of the second electric push rod 35 via a pin. The third weighing sensor 34 is used to monitor the pressure between the reaming drill bit 36 ​​and the ice layer. The reaming drill bit 36 ​​includes an extension shaft 37, a third motor 38, and a drill body 39. The tail end of the output shaft of the second electric push rod 35 is pivotally connected to the front end of the extension shaft 37. The third motor 38 is assembled inside the extension shaft 37. The drill body 39 is sleeved on the extension shaft 37. The drill body 39 and the extension shaft are connected... Wear-resistant copper sleeves 40 are fitted between 37. The third motor 38 is connected to the drill body 39 through a motor adapter plate and can drive the drill body 39 to rotate. Several rows of drill teeth 41 are embedded on the outer periphery of the drill body 39. The lower housing 10 has a third opening 42 on the side wall corresponding to the reaming drill bit 36. The second electric push rod 35 can drive the reaming drill bit 36 ​​to extend out of the lower housing 10 from the third opening 42 to perform reaming operations through the extension shaft 37. The third weighing sensor 34, the second electric push rod 35 and the third motor 38 are all connected to the control system 4. The third weighing sensor 34 can transmit the collected data to the control system 4 in real time. The control system 4 controls the operation of the second electric push rod 35 and the third motor 38.

[0052] The coring mechanism 8 is assembled inside the lower housing 10 at the bottom of the reaming mechanism 7. The coring mechanism 8 includes a coring drill bit 43, a fourth motor 44, a third electric push rod 45, and a retractable ice core tube 46. A drill bit fixing seat 47 is fitted onto the lower part of the coring drill bit 43. A wear-resistant copper sleeve 40 is sandwiched between the coring drill bit 43 and the drill bit fixing seat 47. A retaining ring 48 is fitted around the bottom of the wear-resistant copper sleeve 40 and around the periphery of the coring drill bit 43 for limiting the wear-resistant copper sleeve 40. Pins are fitted on both sides of the drill bit fixing seat 47. The pins are mounted in a sliding groove 49 on the inner side wall of the lower housing 10 via bearings. The drill bit fixing seat 47 drives the coring drill bit 43 to slide synchronously along the sliding groove 49. The top of drill bit holder 47 is pivotally connected to the output end of the third electric push rod 45 via a pin. The third electric push rod 45 can drive the drill bit holder 47 and the core drill bit 43 to slide synchronously along the slide groove 49. The lower housing 10 has a fourth opening 50 on the outer wall corresponding to the core drill bit 43. Driven by the third electric push rod 45, the core drill bit 43 can extend out of the outer wall of the lower housing 10 through the fourth opening 50 to perform core extraction. The top of drill bit holder 47 is equipped with a belt drive wheel 51. The belt drive wheel 51 and the belt pulley 52 sleeved around the outer periphery of the core drill bit 43 are connected by a belt 53 for transmission. The top of the belt drive wheel 51 is connected to the fixed base via a retractable flexible shaft 54. A fourth motor 44 is fixed inside the lower housing 10. The fourth motor 44 drives the belt drive pulley 51 to rotate the core drill bit 43 synchronously via a retractable flexible shaft 54. The outer surface of the belt 53 is equipped with serrations for cutting excess ice. The retractable ice core tube 46 is fixed to the lower part of the drill bit fixing seat 47 by a clamp. The bottom of the retractable ice core tube 46 is fixed to the bottom of the lower housing 10. The inlet of the retractable ice core tube 46 is connected to the outlet below the core drill bit 43. The retractable ice core tube 46 can directly receive the ice core drilled by the core drill bit 43. The top of the core drill bit 43 is equipped with a cutting tool 55. The top surface of the cutting tool 55 is equipped with a pad shoe 56. The third electric push... The fixed end of rod 45 is connected to a fourth weighing sensor 57 via a pin to monitor the drilling pressure of the core drill bit 43. The output end of the fourth motor 44 is equipped with an encoder 58 to monitor the output speed of the fourth motor 44. The bottom of the inner cavity of the lower housing 10 is equipped with a displacement sensor 59 to monitor the core length of the core drill bit 43. The fourth motor 44, the third electric push rod 45, the fourth weighing sensor 57, the encoder 58 and the displacement sensor 59 are all connected to the control system 4. The fourth weighing sensor 57, the encoder 58 and the displacement sensor 59 can transmit the collected data to the control system 4 in real time. The control system 4 controls the operation of the fourth motor 44 and the third electric push rod 45.

[0053] The control system 4 is connected to the ground equipment via internal wiring of the armored cable 19. The control system 4 includes a signal input unit 60, a signal output unit 61, and a signal processing unit 62. The signal input unit 60 is connected to the first weighing sensor 23, the second weighing sensor 31, the third weighing sensor 34, the fourth weighing sensor 57, the gyroscope 28, the displacement sensor 59, and the encoder 58. The signal input unit 60 can receive data transmitted in real time from the first weighing sensor 23, the second weighing sensor 31, the third weighing sensor 34, the fourth weighing sensor 57, the gyroscope 28, the displacement sensor 59, and the encoder 58. The signal output unit 61 is connected to the upper thermoforming drill bit 1 and the first motor. 16. The second motor 24, the third motor 38, the fourth motor 44, the first electric push rod 30, the second electric push rod 35, and the third electric push rod 45 are connected. The signal output unit 61 controls the working status of the upper thermomelting drill bit 1, the first motor 16, the second motor 24, the third motor 38, the fourth motor 44, the first electric push rod 30, the second electric push rod 35, and the third electric push rod 45. The signal processing unit 62 receives the data transmitted from the signal input unit 60 and transmits the processed data to the signal output unit 61. The signal input unit 60 and the signal output unit 61 are also connected to the ground signal unit 63 to realize the control of the downhole drilling tools by the ground system.

[0054] The first weighing sensor 23, the second weighing sensor 31, the third weighing sensor 34, the fourth weighing sensor 57, the gyroscope 28, the displacement sensor 59, the encoder 58, the upper thermoforming drill bit 1, the first motor 16, the second motor 24, the third motor 38, the fourth motor 44, the first electric actuator 30, the second electric actuator 35, the third electric actuator 45, the signal input unit 60, the signal output unit 61, the signal processing unit 62, and the ground signal unit 63 mentioned above are all assemblies of existing equipment. Therefore, their specific models and specifications are not described in detail.

[0055] Working principle of the invention:

[0056] The polar drilling directional coring tool provided by this invention is used by lowering the drill string below a predetermined well section using an armored cable 19. The control system 4 controls the first motor 16 to rotate the transmission nut 15. With the keyway engagement of the tie rod seat 14, the lead screw 13 moves upward along the keyway axis, thereby driving the cutter head 11 and the tie rod 12 to rotate around the pin. The cutter head 11 extends out from the first opening 18 on the side wall of the upper housing 9 and is supported on the borehole wall. Then, the control system 4 commands the second motor 24 to rotate the universal joint 26 and the lower housing 10 until the coring drill bit 43 extends to the predetermined position. Control system 4 instructs the first electric push rod 30 to extend, thereby driving the support block 32 to rotate around the pin until one side of the lower housing 10 is in close contact with the hole wall; control system 4 instructs the second electric push rod 35 to retract and drive the extension shaft 37 and the reaming drill bit 36 ​​to rotate around the pin, extending from the third opening 42 on the side wall of the lower housing 10; control system 4 instructs the third motor 38 to drive the reaming drill bit 36 ​​to rotate, and during the extension of the reaming drill bit 36, it rotates to cut the ice layer, thereby achieving hole reaming. After hole reaming is completed, control system 4 instructs the second electric push rod 35 to extend and retract the extension shaft 37 and the reaming drill bit 36 ​​into the drill bit, and then lifts the drill bit until the core drill bit 43 is in the reaming area. Control system 4 instructs the third electric push rod 45 to retract, causing the drill bit holder 47 and the core drill bit 43 to extend outward along the slide groove 49. Control system 4 instructs the fourth motor 44 to drive the belt drive shaft to rotate via the retractable flexible shaft 54, which in turn drives the core drill bit 43 to rotate, achieving upward core drilling. The drilled ice core is directly stored in the retractable ice core tube 46 below the core drill bit 43. After core drilling is completed, control system 4 instructs the fourth motor 44 to stop rotating, and the third electric push rod 45 extends, causing the drill bit holder 47 and the core drill bit 43 to retract into the drill string along the slide groove 49. Control system 4 instructs the first electric push rod 30 to retract, causing the support block 32 to retract into the drill string. Control system 4 instructs the first motor 16 to reverse, causing the lead screw 13 to move downward along the axial direction, and the cutter head 11 to retract into the drill string. The drill string is then lifted to the surface using the armored cable 19, completing the core drilling. If borehole diameter reduction occurs during the lifting process, control system 4 instructs the upper thermoforming drill bit 1 to operate, achieving diameter expansion.

Claims

1. A polar drilling hole wall directional coring drill tool, comprising a shell, an upper hot melting drill head, a reverse torsion mechanism, a cable chamber, a control system, a hole positioning mechanism, a supporting mechanism, a reaming mechanism and a coring mechanism, wherein the upper hot melting drill head is assembled at the top of the shell, the reverse torsion mechanism, the cable chamber, the control system, the hole positioning mechanism, the supporting mechanism, the reaming mechanism and the coring mechanism are sequentially assembled in the shell from top to bottom, the control system is connected with the upper hot melting drill head, the reverse torsion mechanism, the hole positioning mechanism, the supporting mechanism, the reaming mechanism and the coring mechanism respectively, and the control system controls the work of the upper hot melting drill head, the reverse torsion mechanism, the hole positioning mechanism, the supporting mechanism, the reaming mechanism and the coring mechanism, characterized in that: The reverse torsion mechanism comprises a cutter head, a pull rod, a lead screw, a pull rod seat, a transmission nut and a first motor, wherein the pull rod seat is inserted into the inner cavity of the upper shell, the pull rod seat is sleeved on the transmission nut and the lead screw, the output shaft of the first motor is connected with the transmission nut through a shaft coupling, the first motor can drive the transmission nut to rotate, the transmission nut is screwed with the lower part of the lead screw, the outer periphery of the upper part of the lead screw is provided with a plurality of splines, the plurality of splines can be clamped in the key groove of the pull rod seat, the lead screw is connected with the pull rod seat through the splines, the lead screw can move up and down along the key groove on the pull rod seat, the transmission nut drives the lead screw to move up and down along the key groove on the pull rod seat during the rotation of the transmission nut, the outer side of the transmission nut is connected with the pull rod seat through two upper and lower rolling bearings, the cutter head and the pull rod are both symmetrically provided with four, the protrusion behind each cutter head is pivoted with the top end of the pull rod, the bottom of each cutter head is pivoted with the top end of the lead screw, and the bottom of each pull rod is pivoted with the top end of the pull rod seat, the side wall of the upper shell is provided with a first opening corresponding to the position of each cutter head, the lead screw can drive the cutter head to stretch out of the side wall of the upper shell to fix the whole drilling tool during the up and down movement of the lead screw, and the first motor is connected with the control system and controlled by the control system.The coring mechanism is assembled in the lower shell at the bottom of the reaming mechanism, and the coring mechanism comprises a coring bit, a fourth motor, a third electric push rod and a retractable ice core tube, wherein the lower part of the coring bit is sleeved with a bit fixing seat, a wear-resistant copper sleeve is clamped between the coring bit and the bit fixing seat, a retaining ring is arranged on the circumference of the bottom of the coring bit for limiting the wear-resistant copper sleeve, pin shafts are arranged on both sides of the bit fixing seat, the pin shafts are installed in the sliding groove in the inner side wall of the lower shell through bearings, the bit fixing seat drives the coring bit to slide synchronously along the sliding groove, the top of the bit fixing seat is pivotally connected with the output end of the third electric push rod through the pin shafts, the third electric push rod can drive the bit fixing seat and the coring bit to slide synchronously along the sliding groove, a fourth opening is formed in the outer side wall of the lower shell corresponding to the coring bit, the coring bit can be extended out of the outer side wall of the lower shell through the fourth opening to perform coring operation under the driving of the third electric push rod, a belt driving wheel is arranged on the top of the bit fixing seat, the belt driving wheel and the belt pulley sleeved with the outer circumference of the coring bit are connected through a belt for transmission, the top end of the belt driving wheel is connected with the fourth motor fixed in the inner cavity of the lower shell through a retractable flexible shaft, the fourth motor drives the belt driving wheel to drive the coring bit to rotate synchronously through the retractable flexible shaft, sawteeth are arranged on the outer surface of the belt for cutting excess ice layer, the retractable ice core tube is fixed to the lower part of the bit fixing seat through a clamping fixture, the bottom of the retractable ice core tube is fixed to the bottom of the inner cavity of the lower shell, the inlet of the retractable ice core tube is communicated with the outlet below the coring bit, the retractable ice core tube can directly accommodate the ice core drilled by the coring bit, a cutting tool is arranged on the top end of the coring bit, a pad shoe is arranged on the top surface of the cutting tool, a fourth load sensor is connected to the fixed end of the third electric push rod through a pin shaft for monitoring the drilling pressure of the coring bit, an encoder is arranged on the output end of the fourth motor for monitoring the output rotating speed of the fourth motor, a displacement sensor is arranged on the bottom of the inner cavity of the lower shell for monitoring the coring length of the coring bit, the fourth motor, the third electric push rod, the fourth load sensor, the encoder and the displacement sensor are connected with a control system, the fourth load sensor, the encoder and the displacement sensor can transmit the collected data to the control system in real time, and the control system controls the working of the fourth motor and the third electric push rod.

2. A borehole wall oriented coring drill tool for polar drilling as claimed in claim 1, characterized in that: The shell comprises an upper shell and a lower shell, wherein the upper shell is arranged on the upper part of the lower shell, the upper hot melting drill bit is arranged on the top of the upper shell, the reverse torsion mechanism, the cable chamber and the control system are sequentially arranged in the upper shell, the supporting mechanism, the reaming mechanism and the coring mechanism are arranged in the lower shell, and the in-hole positioning mechanism is arranged at the connecting position of the upper shell and the lower shell.

3. A borehole wall oriented coring drill tool for polar drilling as defined in claim 1, characterized by: The cable chamber is provided with an armored cable, and the lower part of the cable chamber is provided with a cable connector male end, a cable connector female end, an adjusting nut and a first weighing sensor. The cable connector female end is arranged on the cable connector fixed seat, the cable connector male end is inserted into the cable connector female end, the adjusting nut is arranged on the upper part of the cable connector male end to adjust the tightness of the armored cable shell, the armored cable passes through the inside of the upper hot melting drill bit and the reverse torsion mechanism, and the shell of the armored cable is fixed between the cable connector male end and the cable connector female end. The internal wire of the armored cable is connected with the control system. The first weighing sensor is arranged between the cable connector female end and the cable connector fixed seat to monitor the tension of the armored cable. The first weighing sensor is connected with the control system, and can transmit the collected data to the control system in real time.

4. A borehole wall oriented coring drill tool for polar drilling as defined in claim 1 wherein: The in-hole positioning mechanism comprises a second motor, an upper rotating shaft, a universal joint, a lower rotating shaft and a gyroscope. The second motor is fixedly installed in the inner cavity of the lower part of the upper shell, the output shaft of the second motor is connected with the upper rotating shaft, the outer side of the upper rotating shaft is connected with the inner wall of the upper shell through a horizontal bearing, the lower end of the upper rotating shaft is pivotally connected with the top end of the universal joint through a pin shaft, the top end of the lower rotating shaft is pivotally connected with the lower end of the universal joint through a pin shaft, and the bottom of the lower rotating shaft is screw-connected with the top of the lower shell. The second motor drives the lower shell to rotate through the upper rotating shaft, the universal joint and the lower rotating shaft. The gyroscope is fixedly installed at the middle part of the upper rotating shaft to monitor the coring direction of the hole wall. The second motor and the gyroscope are connected with the control system, and the gyroscope can transmit the collected data to the control system in real time. The control system controls the working of the second motor.

5. A borehole wall oriented coring drill tool for polar drilling as defined in claim 1 wherein: The supporting mechanism is arranged in the upper part of the inner cavity of the lower shell, and comprises a first electric push rod, a second weighing sensor and a supporting block. The top end of the first electric push rod is pivotally connected with the upper rear end of the supporting block through a pin shaft, the upper front end of the supporting block is pivotally connected with the inner wall of the lower shell through a pin shaft, the side wall of the lower shell is provided with a second opening corresponding to the position of the supporting block, the first electric push rod can drive the supporting block to rotate and extend out of the side wall of the lower shell through the second opening, and the second weighing sensor is arranged at the bottom of the first electric push rod to monitor the supporting force between the supporting block and the hole wall. The second weighing sensor and the first electric push rod are connected with the control system, and the second weighing sensor can transmit the collected data to the control system in real time. The control system controls the working of the first electric push rod.

6. A borehole wall oriented coring drill tool for polar drilling as defined in claim 1 wherein: The reaming mechanism is assembled in the lower cavity of the lower shell at the bottom of the supporting mechanism, and comprises a third load sensor, a second electric push rod and a reaming drill bit. The third load sensor is assembled in the lower cavity of the lower shell, and is connected with the fixed end of the second electric push rod through a pin shaft. The third load sensor is used for monitoring the pressure of the reaming drill bit and the ice layer. The reaming drill bit comprises an extension shaft, a third motor and a drill bit body. The tail end of the output shaft of the second electric push rod is pivotally connected with the front end of the extension shaft. The third motor is assembled in the extension shaft. The drill bit body is sleeved on the extension shaft. A wear-resistant copper sleeve is assembled between the drill bit body and the extension shaft. The third motor is connected with the drill bit body through a motor adapter plate and can drive the drill bit body to rotate. A plurality of rows of drill teeth are embedded on the outer periphery of the drill bit body. A third opening is formed in the side wall of the lower shell corresponding to the position of the reaming drill bit. The second electric push rod can drive the reaming drill bit to extend out of the lower shell through the third opening for reaming operation. The third load sensor, the second electric push rod and the third motor are connected with the control system. The third load sensor can transmit the collected data to the control system in real time. The control system controls the working of the second electric push rod and the third motor.

7. A borehole wall oriented coring drill tool for polar drilling as claimed in claim 1 or 3 or 4 or 5 or 6, characterized by: The control system is connected with the ground equipment through the internal wires of the armored cable. The control system comprises a signal input unit, a signal output unit and a signal processing unit. The signal input unit is connected with the first load sensor, the second load sensor, the third load sensor, the fourth load sensor, the gyroscope, the displacement sensor and the encoder. The signal input unit can receive the data transmitted by the first load sensor, the second load sensor, the third load sensor, the fourth load sensor, the gyroscope, the displacement sensor and the encoder in real time. The signal output unit is connected with the upper hot melting drill bit, the first motor, the second motor, the third motor, the fourth motor, the first electric push rod, the second electric push rod and the third electric push rod. The signal output unit controls the working state of the upper hot melting drill bit, the first motor, the second motor, the third motor, the fourth motor, the first electric push rod, the second electric push rod and the third electric push rod. The signal processing unit receives the data transmitted by the signal input unit. The signal processing unit transmits the processed data to the signal output unit. The signal input unit and the signal output unit are also connected with the ground signal unit, so that the ground system can control the downhole drilling tools.

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