Control tool for a screw drill

Abstract

The present application relates to a kind of control tools for screw drill, including inner shaft and shell, the upper end of shell is used to be connected with upper drill string, transmission control part is arranged between inner shaft and shell, transmission control part is used to transmit the torque of upper drill string to the tool face of screw drill to smoothly transmit weight on bit, and for balancing the counter torque acting on the shell of screw drill, so that upper drill string can be normally rotated;The lower end of inner shaft is used to be connected with MWD measuring short section.The embodiment of the present application can regulate and control the size of friction torque to balance the counter torque of the shell of screw drill;Upper drill string and lower screw drill can be rotated throughout to eliminate the situation such as supporting pressure, to achieve the purpose of reducing friction and resistance to speed up;When screw drill directional sliding drilling, the size of friction torque can be controlled to balance the counter torque of the shell of screw drill, to effectively control the tool face rotation angle of screw drill and realize the controllability of wellbore trajectory.

Description

Technical Field

[0001] This invention belongs to the field of oil drilling tool technology, specifically relating to a control tool for screw drills. Background Technology

[0002] Currently, screw drilling tools are widely used in drilling operations of complex well structures such as deep wells, ultra-deep wells, directional wells, extended reach wells, and long horizontal wells. Screw drilling tools are a commonly used downhole power drilling tool in drilling processes in both new and old oil and gas fields.

[0003] During directional sliding drilling with a screw drill string, the drilling fluid drives the rotor of the screw drill string, causing the drill bit to rotate clockwise and generating torque to break the rock. Simultaneously, a counter-clockwise torque is generated on the stator of the screw drill string, acting on its outer casing. Since the outer casing is connected to the upper drill string, this counter-torque causes both the screw drill string and the upper drill string to rotate counter-clockwise by a certain angle. This leads to a change in the tool face angle, causing deviation and affecting wellbore trajectory control. Therefore, to counteract the counter-torque and ensure the tool face remains stable, the upper drill string must be stopped rotating. Stopping the upper drill string results in significant axial friction between the upper drill string and the wellbore, causing severe pressure build-up, especially in long horizontal wells and extended reach wells. This leads to poor pressure on the drill bit (PBT) transmission, low mechanical rate of penetration (MRLP), and significantly reduced drilling efficiency. In addition, the common method for adjusting the tool face angle of conventional screw drills is to adjust the rotation angle of the upper drill string according to actual needs and observe the tool face angle through a measurement while drilling instrument to make the adjusted working face angle equal to the expected angle. This method has the disadvantage of being time-consuming, and because of the presence of pressure, the drilling pressure and torque are difficult to be transmitted to the drill bit, which also makes it difficult to adjust the tool face angle.

[0004] In existing technologies, the inability to autonomously control the pressure and tool face severely restricts the application of conventional screw drills in complex drilling processes. Summary of the Invention

[0005] In order to solve all or part of the above problems, the present invention aims to provide a control tool for screw drills. The control tool for screw drills of the present invention can transmit the torque of the upper drill string to the tool face of the screw drill to smoothly transmit drilling pressure, and can balance the counter-torque acting on the screw drill housing so that the upper drill string can rotate normally.

[0006] According to one aspect of the present invention, a control tool for a screw drill bit is provided, comprising an inner shaft and a housing, the upper end of the housing being connected to an upper drill string, a transmission control portion being disposed between the inner shaft and the housing, the transmission control portion being used to transmit the torque of the upper drill string to the tool face of the screw drill bit to smoothly transmit drilling pressure, and to balance the counter-torque acting on the housing of the screw drill bit so that the upper drill string can rotate normally; the lower end of the inner shaft being connected to an MWD measuring sub.

[0007] Furthermore, the transmission control part includes a buffer spring sleeved on and limited on the inner shaft; a friction assembly is provided between the inner shaft and the housing above the buffer spring, and a rotating cavity is provided above the friction assembly; a movable spline sleeve is sleeved on the inner shaft above the rotating cavity, the movable spline sleeve can transmit the torque of the housing to the inner shaft, and when the movable spline sleeve moves to the rotating cavity, the movable spline sleeve cannot transmit the torque of the housing to the inner shaft;

[0008] The upper end of the inner shaft is fixedly and sealed to a support end, and the lower end of the inner shaft is sealed to the housing. A hydraulic piston is provided in the sealed hydraulic cavity formed by the inner shaft, the support end, and the housing. The upper end of the movable spline sleeve is fixedly connected to the hydraulic piston. A first return spring is provided between the movable spline sleeve and the hydraulic piston. The lower end of the first return spring is limited by the shoulder of the housing.

[0009] The support end is fixedly and sealed to an external structure. A circuit board protection chamber is fixedly and sealed between the support end and the external structure. A drive assembly is fixedly installed on the support end. The drive assembly is located in the cavity formed by the support end, the external structure and the circuit board protection chamber. The drive assembly is connected to a hydraulic control unit. The hydraulic control unit is used to supply oil to the high-pressure oil chamber above the hydraulic piston.

[0010] The friction assembly is used to generate frictional torque under the action of a hydraulic piston.

[0011] Furthermore, a locking piston is sealed within the sealed hydraulic cavity. The locking piston is located between the support end and the hydraulic piston, forming a high-pressure oil cavity. The cavity on the side of the locking piston away from the hydraulic piston and the cavity on the side of the hydraulic piston away from the locking piston are both low-pressure oil cavities. A second return spring is provided between the locking piston and the support end. A locking block is provided within the radial movement hole of the hydraulic piston. When the hydraulic piston moves axially, the locking block moves radially along the inclined surface of the sliding groove on the outer side of the inner shaft. After the locking piston moves to the unlocked position towards the low-pressure oil cavity away from the hydraulic piston, the locking piston disengages from the locking block.

[0012] Furthermore, the lower end of the buffer spring is limited by a shoulder provided on the inner shaft, and the upper end of the buffer spring is limited by a first elastic retaining ring fixed on the inner shaft.

[0013] The friction assembly includes a plurality of moving friction plates, all of which are disposed above the buffer spring. The plurality of moving friction plates are connected to the inner shaft by a key. A stator friction plate is disposed between two adjacent moving friction plates. The plurality of stator friction plates are connected to the housing by a key. The lowermost moving friction plate is limited by a support ring between itself and the buffer spring. The uppermost moving friction plate is limited by a second elastic retaining ring fixed on the inner shaft. The rotating cavity is disposed above the uppermost moving friction plate.

[0014] Furthermore, the external structure includes a protective cylinder disposed on the outside of the support end, the support end being fixedly and sealed to the protective cylinder, the protective cylinder being fixedly and sealed to the upper end of the protective compartment, the circuit board protective compartment being disposed within the inner cavity formed by the support end and the upper end of the protective compartment, the circuit board protective compartment being keyed to both the support end and the upper end of the protective compartment, and the circuit board protective compartment being sealed to both the support end and the upper end of the protective compartment.

[0015] Furthermore, a pressure sensor is fixedly and sealed to the upper end of the protective chamber. The upper end of the protective chamber has a mud pressure tapping chamber, a mud channel, and a mud pressure tapping hole that are connected in sequence. The pressure sensor is inserted into the mud pressure tapping hole. The pressure sensor is used to measure the mud pressure in the central flow channel of the upper end of the protective chamber. A mud screen plate is fixed to the mud pressure tapping chamber by an elastic retaining ring.

[0016] Furthermore, a first thrust bearing assembly is fitted onto the upper end of the protective chamber. The lower end of the inner ring of the first thrust bearing assembly is limited by a shoulder provided on the upper end of the protective chamber. A first fixing ring is threaded onto the upper end of the protective chamber. The first fixing ring is used to limit the upper end of the inner ring of the first thrust bearing assembly. An upper connector is threaded onto the upper end of the housing. The housing and the upper connector are fixedly connected. The upper connector is used to connect with the upper drill string. The upper connector is used to limit the upper end of the outer ring of the first thrust bearing assembly. The lower end of the outer ring of the first thrust bearing assembly is limited by a step provided on the housing.

[0017] Furthermore, the drive assembly includes a motor reduction assembly, which is fixed on a motor reduction assembly mounting bracket. The output shaft of the motor reduction assembly is connected to the hydraulic control unit via a coupling. The cable of the motor reduction assembly is connected to a corresponding connector of a first power sealing connector. The first power sealing connector is fixedly and sealed to a first plug. The first plug is fixedly and sealed to a motor reduction assembly protective sleeve. The motor reduction assembly protective sleeve is fixedly and sealed to one end of a connecting thread, and the other end of the connecting thread is fixedly and sealed to the support end.

[0018] Furthermore, the hydraulic control unit includes a hydraulic pump fixedly connected to the coupling. The hydraulic oil outlet of the hydraulic pump is fixedly and sealed to one end of the oil outlet pipe. The oil outlet pipe is provided with a central hole. The first electric sealing connector, the first plug, the motor reduction assembly protection cylinder, the oil outlet pipe, the threaded connection, and the support end form a closed hydraulic oil tank. The hydraulic pump is fixed on the motor reduction assembly mounting bracket. A three-position four-way directional valve is sealed in the hydraulic reversing through hole of the support end. An overflow valve is fixedly and sealed in the overflow hole of the support end. A fixedly and sealed connection is provided on the support end. A check valve is provided, wherein the hydraulic oil outlet of the hydraulic pump is connected to the third connecting hole of the three-position four-way directional valve, the check valve is disposed between the hydraulic oil outlet of the hydraulic pump and the third connecting hole, the low-pressure oil chamber is connected to the fourth connecting hole of the three-position four-way directional valve, the first connecting hole of the three-position four-way directional valve is connected to the hydraulic oil tank, one end of the relief valve is connected between the first connecting hole and the hydraulic oil tank, the other end of the relief valve is connected between the inlet of the check valve and the hydraulic oil outlet of the hydraulic pump, and the second connecting hole of the three-position four-way directional valve is connected to the high-pressure oil chamber.

[0019] Furthermore, a high-pressure sensor is fixedly and sealed to the support end, which is used to detect the pressure of the high-pressure oil chamber; a low-pressure sensor is fixedly and sealed to the support end, which is used to test the liquid pressure of the low-pressure oil chamber; a high-pressure oil main channel and a high-pressure oil through hole are provided on the support end, and the second connecting hole of the three-position four-way reversing valve is connected to the high-pressure oil chamber through the high-pressure oil main channel and the high-pressure oil through hole.

[0020] Furthermore, it also includes a control circuit: the control circuit includes a motor drive circuit protection cylinder, one end of which is fixedly and sealed to a second power sealing connector, and the other end of which is fixedly and sealed to a second plug. The second plug is fixedly and sealed to a third power sealing connector. The motor drive circuit protection cylinder is fixedly connected to the circuit board protection compartment. A circuit support plate is fixedly connected inside the motor drive circuit protection cylinder, and a motor drive circuit is fixedly connected to the circuit support plate. The second power sealing connector and the third power sealing connector are electrically connected to the motor drive circuit.

[0021] The circuit board protection compartment is fixedly connected to a power supply battery, a wireless communication circuit, and an intelligent control circuit. The low-pressure sensor, the high-pressure sensor, the three-position four-way reversing valve motor drive circuit, and the power supply battery are all connected to the intelligent control circuit.

[0022] Furthermore, a drive shaft is fixedly connected to the lower end of the inner shaft. The drive shaft is used to connect with the MWD measuring short section. A lower housing is fixedly connected to the lower end of the housing. An upper moving ring housing, an upper moving ring alloy sleeve, a second thrust bearing assembly, a half ring, a lower stationary alloy, a lower moving alloy, a spacer ring, a pressure ring, an upper stationary ring housing, an upper stationary ring alloy sleeve, and a lower moving housing are sleeved on the drive shaft. The upper moving ring housing and the lower moving housing are fixedly connected to the drive shaft. The upper moving ring alloy sleeve is fixed on the upper moving ring housing. The upper stationary ring alloy sleeve is sleeved outside the upper moving ring alloy sleeve, and a dynamic friction pair structure is formed between the two. The upper stationary ring alloy sleeve is fixedly connected to the upper stationary ring housing. The lower moving alloy is fixed on the lower moving housing. The lower stationary alloy is fixed on the lower stationary housing. The lower stationary housing is fixedly connected to the lower housing. A dynamic friction pair structure is formed between the lower moving alloy and the lower stationary alloy.

[0023] A second thrust bearing assembly is provided between the drive shaft and the lower housing. The inner ring of the second thrust bearing assembly is limited by a bearing ring and an upper moving ring housing, and the outer ring of the second thrust bearing assembly is limited by a spacer ring and an upper stationary ring housing.

[0024] As can be seen from the above technical solution, the control tool for screw drills provided by the present invention has the following beneficial effects:

[0025] The embodiments of this invention can adjust the magnitude of frictional torque to balance the counter-torque of the screw drill tool housing; enable the upper drill string and the lower screw drill tool to rotate throughout the entire process to eliminate pressure build-up and other issues, thereby achieving the purpose of reducing friction, decreasing resistance, and increasing speed; when the screw drill tool is directionally sliding, it can control the magnitude of frictional torque to balance the counter-torque of the screw drill tool housing, thereby effectively controlling the rotation angle of the screw drill tool's tool face to achieve controllable wellbore trajectory; and the upper drill string can rotate forward to smoothly transmit drilling pressure, effectively solving the problems of pressure build-up and low mechanical drilling speed caused by conventional screw drill tool sliding drilling. Attached Figure Description

[0026] Figure 1 This is a front view of a control tool for a screw drill according to an embodiment of the present invention;

[0027] Figure 2 This is a left view of a control tool for a screw drill according to an embodiment of the present invention;

[0028] Figure 3 yes Figure 2 Sectional view along axis AA;

[0029] Figure 4 yes Figure 3 A magnified view of a section at point M;

[0030] Figure 5 yes Figure 2 The upper part of the BB-directed sectional view;

[0031] Figure 6 yes Figure 2 The upper part of the CC-direction sectional view;

[0032] Figure 7 yes Figure 2 The middle part of the DD-direction sectional view;

[0033] Figure 8 yes Figure 1 EE-directed sectional view;

[0034] Figure 9 yes Figure 1 FF section view;

[0035] Figure 10 yes Figure 1 GG-direction sectional view;

[0036] Figure 11 yes Figure 1 HH-direction sectional view;

[0037] Figure 12 yes Figure 1 Sectional view in direction II;

[0038] Figure 13 This is a schematic diagram of the hydraulic control unit. Detailed Implementation

[0039] To better understand the purpose, structure, and function of this invention, a control tool for screw drills according to this invention will be described in further detail below with reference to the accompanying drawings.

[0040] like Figure 1 , Figure 2 As shown, this invention illustrates a control tool for a screw drill bit, comprising an inner shaft 48 and a housing. The upper end of the housing is used to connect to an upper drill string. A transmission control section is provided between the inner shaft 48 and the housing. The transmission control section is used to balance the counter-torque acting on the screw drill bit housing so that the upper drill string can rotate normally to smoothly transmit drilling pressure. The lower end of the inner shaft is used to connect to an MWD measuring sub.

[0041] The housing in this embodiment includes a protective shell 3, a connecting section 5, and an upper shell 7. The connecting section 5 is connected to the upper shell 7 via a tapered pipe thread, and the two are sealed by two O-rings. The connecting section 5 and the upper shell 7 are also connected by four first locking pins 6 to prevent the upper shell 7 from loosening. The protective shell 3 is connected to the connecting section 5 via a flat thread, and the two are sealed by two O-rings. The protective shell 3 and the connecting section 5 are also connected by four second locking pins 4 to prevent the protective shell 3 from loosening.

[0042] Regarding the transmission control section: such as Figure 3 , Figure 4 As shown, it includes a buffer spring 34 that is sleeved on and limited on the inner shaft 48; specifically, the lower end of the buffer spring 34 is limited by a shoulder provided on the inner shaft 48, and the upper end of the buffer spring after pre-compression is limited by a first elastic retaining ring 33 fixed on the inner shaft 48; in specific installation, after the buffer spring 34 is pre-compressed, it is sleeved on the inner shaft 48 together with the retaining ring 50, and the first elastic retaining ring 33 is locked in a slot on the inner shaft 48 to limit the buffer spring 34 and the retaining ring 50.

[0043] A friction assembly is provided between the inner shaft 48 above the buffer spring 34 and the housing. A rotating cavity 016 is provided above the friction assembly. A movable spline sleeve is fitted on the inner shaft 48 above the rotating cavity 016. The movable spline sleeve can transmit the torque of the housing to the inner shaft 48. When the movable spline sleeve 31 moves to the rotating cavity 016, the movable spline sleeve 31 cannot transmit the torque of the housing to the inner shaft 48.

[0044] In practice, the inner side of the movable spline sleeve 31 is machined with eight keyways that mate with the eight long keys on the outer side of the inner shaft 48, and the outer side of the movable spline sleeve 31 is machined with ten long keys that mate with the ten keyways on the inner side of the connecting short section 5. The movable spline sleeve 31 is threaded onto the inner shaft 48. The eight keyways on the inner side of the movable spline sleeve 31 can move freely axially along the eight long keys on the outer side of the inner shaft 48, and the ten long keys on the outer side of the movable spline sleeve 31 can move freely axially along the ten keyways on the inner side of the connecting short section 5. Therefore, the movable spline sleeve 31 can move relative to the inner shaft and the housing along the axial direction of the inner shaft 48. When the connecting short section 5 is rotated again, the movable spline sleeve 31 can transmit the torque of the connecting short section 5 to the inner shaft 48, causing the inner shaft 48 to rotate together. However, when the movable spline sleeve 31 moves to the rotating cavity 016, since there are no long keys in the rotating cavity, the movable spline sleeve 31 cannot transmit the torque of the housing to the inner shaft 48.

[0045] The upper end of the inner shaft 48 is fixedly and sealed with a support end 25, and the lower end of the inner shaft 48 is sealed to the housing. A hydraulic piston is provided in the sealed hydraulic cavity formed by the inner shaft 48, the support end 25 and the housing. The upper end of the movable spline sleeve 31 is fixedly connected to the hydraulic piston 27. A first return spring 30 is provided between the movable spline sleeve 31 and the hydraulic piston 27. The lower end of the first return spring 30 is limited by the shoulder of the housing.

[0046] The hydraulic piston 27 is mounted on the inner shaft 48 and can move freely axially along the optical axis of the inner shaft 48. A movable spline sleeve 31 is connected to the hydraulic piston 27 via a flat thread. A first return spring 30 is installed between the movable spline sleeve 31 and the hydraulic piston 27. The movable spline sleeve 31 and the hydraulic piston 27 are also connected by four fourth locking pins 29 to prevent the hydraulic piston 27 from loosening. Two first Chappell piston rod seals 28 are installed in the inner groove of the hydraulic piston 27 to form a dynamic seal between the hydraulic piston 27 and the inner shaft 48. Two second Chappell piston seals 26 are installed in the outer groove of the hydraulic piston 27 to form a dynamic seal between the hydraulic piston 27 and the support end 25. The inner shaft 48 and the support end 25 are fixedly connected by a flat thread. Two O-rings are installed before and after the flat thread to form a static seal between the inner shaft 48 and the support end 25. The hydraulic piston 27 can move freely axially within the hydraulic cylinder structure formed by the inner shaft 48 and the support end 25.

[0047] The support end 25 is fixedly and sealed to an external structure. A circuit board protection chamber 21 is fixedly and sealed between the support end 25 and the external structure. A drive assembly is fixedly installed on the support end 25. The drive assembly is located in the cavity formed by the support end 25, the external structure and the circuit board protection chamber 21. The drive assembly is connected to a hydraulic control unit. The hydraulic control unit is used to supply oil to the high-pressure oil chamber 059 above the hydraulic piston 27.

[0048] The friction assembly in this embodiment is used to generate frictional torque under the action of the hydraulic piston 27.

[0049] Specifically, the friction assembly includes several moving friction plates 52, all of which are disposed above the buffer spring 34. The moving friction plates 52 are connected to the inner shaft 48 by a key. A stator friction plate 32 is disposed between two adjacent moving friction plates 52. The stator friction plates 32 are connected to the housing by a key. The lowermost moving friction plate 52 is limited by a support ring 51 between it and the buffer spring 34, and the support ring 51 can compress the buffer spring 34 and move it downward after being subjected to force. The uppermost moving friction plate 52 is limited by a second elastic retaining ring 53 fixed on the inner shaft.

[0050] For the friction assembly: eight long keys are machined on the outer side of the inner shaft 48, and eight keyways are machined on the inner side of each moving friction plate 52. The keyways of the moving friction plate 52 cooperate with the long keys on the inner shaft 48, so that the inner shaft 48 and the moving friction plate 52 rotate together; ten long keys are machined on the outer side of the stator friction plate 32, and ten keyways are machined on the inner side of the connecting short section 5. The long keys of the stator friction plate 32 cooperate with the keyways on the connecting short section 5, so that the stator friction plate 32 and the connecting short section 5 rotate together; three stator friction plates 32 and four moving friction plates 52 are arranged alternately and are threaded onto the inner shaft 48 together with the support ring 51. The second elastic retaining ring 53 is locked in the slot on the inner shaft 48 to position the uppermost moving friction plate 52.

[0051] The rotating cavity 016 is located above the uppermost moving friction plate 52. In a specific implementation, the rotating cavity 016 can be formed by removing the aforementioned keyway at the middle position of the connecting short section 5.

[0052] The control tool for screw drills according to the embodiments of the present invention is described again as follows: the drive assembly is used to drive the hydraulic control unit, which is used to pump high-pressure oil into the high-pressure oil chamber. The high-pressure oil causes the hydraulic piston 27 to move towards the low-pressure oil chamber. After the hydraulic piston 27 moves to the rotating chamber, it continues to move downward, which will cause the friction assembly to generate friction torque. This friction torque causes the inner shaft 48 to be in a critical equilibrium state of stopping rotation, thereby keeping the tool face stationary. Alternatively, the friction torque can cause the inner shaft 48 to rotate clockwise or counterclockwise, thereby realizing the adjustment of the tool face.

[0053] The embodiments of this invention can adjust the magnitude of frictional torque to balance the counter-torque of the screw drill tool housing; enable the upper drill string and the lower screw drill tool to rotate throughout the entire process to eliminate pressure build-up and other issues, thereby achieving the purpose of reducing friction, decreasing resistance, and increasing speed; when the screw drill tool is directionally sliding, it can control the magnitude of frictional torque to balance the counter-torque of the screw drill tool housing, thereby effectively controlling the rotation angle of the screw drill tool's tool face to achieve controllable wellbore trajectory; and the upper drill string can rotate forward to smoothly transmit drilling pressure, effectively solving the problems of pressure build-up and low mechanical drilling speed caused by conventional screw drill tool sliding drilling.

[0054] During composite drilling, the screw drill housing is locked to the upper drill string for normal composite drilling.

[0055] In one embodiment, such as Figure 5 As shown, a locking piston 74 is sealed inside the hydraulic chamber. The locking piston 74 is located between the support end 25 and the hydraulic piston 27, forming a high-pressure oil chamber 059 between the locking piston 74 and the hydraulic piston 27. The chambers on the side of the locking piston 74 away from the hydraulic piston 27 and the chambers on the side of the hydraulic piston away from the locking piston 74 are both low-pressure oil chambers 041. A second return spring 71 is provided between the locking piston 74 and the support end 25. A locking block 75 is provided in the radial movement hole of the hydraulic piston 27. When the hydraulic piston 27 moves axially, the locking block 75 moves radially along the inclined surface of the sliding groove on the outer side of the inner shaft 48. After the locking piston 74 moves to the unlocking position in the direction away from the low-pressure oil chamber 041 of the hydraulic piston 27, the locking piston 74 disengages from the locking block 75.

[0056] The locking piston 74 and the second return spring 71 are inserted into the piston lock hole of the support end 25. The locking piston 74 can move freely axially. The stop ring 73 is installed in the piston lock hole of the support end 25 through a flat thread. The locking block 75 is inserted into the radial movement hole of the hydraulic piston 27. When the hydraulic piston 27 moves axially, the locking block 75 can move radially along the inclined surface of the slide groove on the outer side of the inner shaft 48. When the locking piston 74 moves to the unlock position, the baffle of the locking piston 74 disengages from the locking block 75, and the locking piston 74 disengages from the locking block 75.

[0057] The external structure includes a protective cylinder 20 disposed on the outside of the support end 25. The support end 25 and the protective cylinder 20 are fixedly and sealed together. The protective cylinder 20 is fixedly and sealed together with the upper end 15 of the protective chamber. The circuit board protective chamber 21 is disposed in the inner cavity formed by the support end 25 and the upper end 15 of the protective chamber. The circuit board protective chamber 21 is connected to the support end 25 and the upper end 15 of the protective chamber by keys. The circuit board protective chamber 21 is sealed to the support end 25 and the upper end 15 of the protective chamber.

[0058] Specifically, the support end 25 and the protective cylinder 20 are connected by a flat thread, and a static seal is formed between them by two O-rings; the other end of the protective cylinder 20 is connected to the upper end 15 of the protective chamber by a flat thread, and a static seal is formed between them by two O-rings; the support end 25 and the protective cylinder 20, and the protective cylinder 20 and the upper end 15 of the protective chamber are respectively connected by four locking pins 57 to prevent the protective cylinder 20 from loosening; the two ends of the circuit board protective chamber 21 are respectively inserted into the inner cavity of the upper end 15 of the protective chamber and the support end 25, and the keys at both ends of the circuit board protective chamber 21 are respectively inserted into the keyways in the inner cavity of the upper end 15 of the protective chamber and the support end 25 to transmit torque, and a static seal is formed between the circuit board protective chamber 21 and the upper end 15 of the protective chamber, and between the circuit board protective chamber 21 and the support end 25 by two O-rings.

[0059] like Figure 5 As shown, a pressure sensor 83 is fixedly and sealed to the upper end 15 of the protective chamber. The upper end 15 of the protective chamber has a mud pressure tapping chamber 046, a mud channel 047, and a mud pressure tapping hole 048 connected in sequence. The pressure sensor 83 is inserted into the mud pressure tapping hole 048. The pressure sensor 83 is used to measure the mud pressure in the central flow channel of the upper end 15 of the protective chamber. A mud screen plate 86 is fixed at the mud pressure tapping chamber 046 by an elastic retaining ring 84.

[0060] Specifically, the pressure sensor 83 is installed on the upper end 15 of the protective chamber via a flat thread, and a static seal is formed between the two by two O-rings. The upper end 15 of the protective chamber has a mud pressure tapping chamber 046, a mud channel 047, and a mud pressure tapping hole 048 connected in sequence. The mud pressure tapping hole 048 is an axial through-hole penetrating the upper end 15 of the protective chamber, and the end of the mud pressure tapping hole 048 away from the central flow channel is sealed by a sealing plug 85. The sealing plug 85 is installed on the upper end 15 of the protective chamber via a flat thread, and a static seal is formed between the two by an O-ring. An elastic retaining ring 84 fixes the mud screen plate 86 to the upper end 15 of the protective chamber. The mud screen plate 86 is used to ensure that only mud enters the mud pressure tapping chamber 046 to prevent blockage. The pressure sensor 83 is used to measure the pressure of the mud passing through the central channel of the upper end 15 of the protective chamber through the mud pressure tapping chamber 046, the mud channel 047, and the mud pressure tapping hole 048.

[0061] The upper end 15 of the protective chamber is fitted with a first thrust bearing assembly 14. The lower end of the inner ring of the first thrust bearing assembly 14 is limited by a shoulder provided on the upper end 15 of the protective chamber. A first fixing ring 13 is threadedly connected to the upper end 15 of the protective chamber. The first fixing ring 13 is used to limit the upper end of the inner ring of the first thrust bearing assembly 14. The upper end of the housing is threadedly connected to an upper connector 1. The housing and the upper connector 1 are fixedly connected. The upper connector 1 is used to connect with the upper drill string. The upper connector 1 is used to limit the upper end of the outer ring of the first thrust bearing assembly 14. The lower end of the outer ring of the first thrust bearing assembly 14 is limited by a step provided on the housing.

[0062] For the upper connector 1: the upper connector 1 is connected to the protective shell 3 by a flat thread, and the two are connected by two O-rings to form a static seal. There are also four sixth locking pins 2 between them to prevent the upper connector 1 from loosening. The upper connector 1 is connected to the upper drill string by a tapered pipe thread.

[0063] A second fixing ring 16 is also provided between the upper end 15 of the protective chamber and the protective shell 3. The second fixing ring 16 is used to limit the first Chevron sealing spacer 17, O-ring 18 and first Chevron rotary sealing ring 19 below it.

[0064] The first thrust bearing assembly 14 is mounted on the upper end 15 of the protective chamber. A first retaining ring 13 is connected to the upper end 15 of the protective chamber via a flat thread to secure the upper end of the inner ring of the first thrust bearing assembly 14. The first retaining ring 13 is secured to the upper end 15 of the protective chamber by four fifth locking pins 12 to prevent the first retaining ring 13 from loosening. The upper connector 1 is used to limit the upper end of the outer ring of the first thrust bearing assembly 14. The lower end of the outer ring of the first thrust bearing assembly 14 is limited by a step on the protective shell 3, and the lower end of the inner ring of the first thrust bearing assembly 14 is limited by a shoulder on the upper end 15 of the protective chamber. In this embodiment, the first thrust bearing assembly 14 can counteract the axial and radial vibrations transmitted by the upper end 15 of the protective chamber.

[0065] Among them, such as Figure 5 As shown, the drive assembly includes a motor reduction assembly 62, which is fixed on a motor reduction assembly mounting bracket 65. The output shaft of the motor reduction assembly 62 is connected to the hydraulic control unit via a coupling 64. The cable of the motor reduction assembly 62 is connected to the corresponding connector of the first power sealing connector 59. The first power sealing connector 59 is fixedly and sealed to the first plug 60. The first plug 60 is fixedly and sealed to the motor reduction assembly protective cylinder 63. The motor reduction assembly protective cylinder 63 is fixedly and sealed to one end of the connecting wire 68, and the other end of the connecting wire 68 is fixedly and sealed to the support end 25.

[0066] Specifically, the motor reduction assembly 62 is fixed to the motor reduction assembly mounting bracket 65 by four screws. The first plug 60 is connected to the motor reduction assembly protective sleeve 63 by a flat thread, and the two are statically sealed by two O-rings. The first plug 60 is axially fixed to the motor reduction assembly 62 by the support tube 61 to prevent the motor reduction assembly 62 from moving axially. The first power sealing connector 59 is connected to the first plug 60 by a flat thread, and the two are statically sealed by two O-rings. The eight pins on the inner side of the first power sealing connector 59 are connected to the eight flexible cables of the motor reduction assembly 62. The output shaft of the motor reduction assembly 62 is connected to the hydraulic pump 66 of the hydraulic control unit by a coupling 64. The motor reduction assembly 62 and the coupling 64 are locked by locking pins. The other end of the motor reduction assembly mounting bracket 65 is connected to the hydraulic pump 66 by a flat thread.

[0067] Among them, such as Figure 13 As shown, the hydraulic control unit includes a hydraulic pump 66 fixedly connected to the coupling 64. The hydraulic oil outlet of the hydraulic pump 66 is fixedly and sealed to one end of the oil outlet pipe 67. The oil outlet pipe 67 is provided with an oil outlet pipe center hole 037. The first electric sealing connector 59, plug 60, motor reduction assembly protection cylinder 63, oil outlet pipe 67, and threaded connector 68 form a closed hydraulic oil tank with the support end 25. The hydraulic pump 66 is fixed on the motor reduction assembly mounting bracket 65. A three-position four-way directional valve 22 is sealed in the hydraulic reversing through hole of the support end 25. An overflow valve 96 is fixedly and sealed in the overflow hole of the support end 25. A one-way valve 69 is connected to the fixed seal. The hydraulic oil outlet of the hydraulic pump 66 is connected to the third connecting hole 08 of the three-position four-way directional valve 22. The one-way valve is located between the hydraulic oil outlet of the hydraulic pump 66 and the third connecting hole 08. The low-pressure oil chamber 041 is connected to the fourth connecting hole 05 of the three-position four-way directional valve 22. The first connecting hole 011 of the three-position four-way directional valve 22 is connected to the hydraulic oil tank. One end of the relief valve is connected between the first connecting hole 011 and the hydraulic oil tank. The other end of the relief valve is connected between the inlet of the one-way valve 69 and the hydraulic oil outlet of the hydraulic pump 66. The second connecting hole 09 of the three-position four-way directional valve 22 is connected to the high-pressure oil chamber 059.

[0068] Specifically, for the hydraulic pump and coupling, the keyway at the input end of the hydraulic pump 66 is inserted into the keyway at the other end of the coupling 64. The connection between the hydraulic pump 66, the coupling 64 and the motor reduction assembly 62 enables the motor reduction assembly 62 to drive the hydraulic pump 66 to work normally.

[0069] like Figure 10 As shown, the support end 25 is provided with a high-pressure oil main channel 051 and a high-pressure oil through hole 052. The second connecting hole 09 of the three-position four-way reversing valve 22 is connected to the high-pressure oil chamber 059 through the high-pressure oil main channel 051 and the high-pressure oil through hole 052.

[0070] The hydraulic oil outlet of the hydraulic pump 66 is connected to the oil outlet pipe 67 via a flat thread, and a static seal is formed between them by an O-ring seal. The other end of the motor reduction assembly protective cylinder 63 is connected to the mating thread 68 via a flat thread, and a static seal is formed between them by two O-ring seals. The other end of the mating thread 68 is installed on the support end 25 via a flat thread, and a static seal is formed between them by two O-ring seals. The oil outlet pipe 67 is installed on the oil outlet of the support end 25 via a flat thread, and a static seal is formed between them by... Two O-rings form a static seal; the first power sealing connector 59, the first plug 60, the motor reduction assembly protection cylinder 63, the oil outlet pipe 67, the threaded connection 68, and the support end 25 form a miniature hydraulic oil tank and are filled with hydraulic oil; the one-way valve 69 is installed on the support end 25 through a flat thread, and the two are connected by an O-ring to form a static seal; the plug 70 is installed in the main oil supply channel of the support end 25 through a flat thread, and the plug 70 and the main oil supply channel of the support end 25 are connected by two O-rings to form a static seal.

[0071] For the sealed hydraulic chamber, the cavity between the hydraulic piston 27 and the locking piston 74 is the high-pressure oil chamber 059 of the sealed hydraulic chamber. When injecting oil into the high-pressure chamber, hydraulic oil is injected into the high-pressure oil chamber 059 through the first oil injection hole 042 of the support end 25. The first NPT sealing plug 76 is used to seal the first oil injection hole 042. During the oil injection process through the first oil injection hole 042, the high-pressure oil main channel 051 and the high-pressure oil through hole 052 are the vent holes.

[0072] For the low-pressure oil chamber 041 of the sealed hydraulic chamber, hydraulic oil is filled into the low-pressure oil chamber 041 such as the inner cavity 18 of the moving spline sleeve and the rotating cavity 016 through the second oil injection hole 030 on the upper end of the protective chamber 15, the transition oil chamber 031, and the oil passage groove 029 on the outside of the protective cylinder. During the oil injection process, the air is vented through the vent hole 049 on the upper end of the protective chamber 15, and sealed through the second NPT sealing plug 58 and the third NPT sealing plug 87 respectively.

[0073] The overflow valve 96 is installed on the support end 25 by a flat thread, and the two are connected by an O-ring to form a static seal; the overflow valve 96 is inserted into the overflow hole of the support end 25, and the two are connected by an O-ring to form a static seal.

[0074] The three-position four-way directional valve is an electromagnetic three-position four-way directional threaded cartridge valve. The three-position four-way directional valve 22 is inserted into the hydraulic directional through hole of the support end 25, and the two are connected by a flat thread and form a static seal through an O-ring; such as Figure 12As shown, a first support end connecting hole 04 is provided on the support end. The first support end connecting hole 04 and the second support end connecting hole 07 on the support end are statically sealed to the protective cylinder 20 by two O-ring seals on both sides. The four hydraulic channels of the three-position four-way reversing valve 22, namely the fourth connecting hole 05, the third connecting hole 08, the second connecting hole 09 and the first connecting hole 011, are statically sealed to the support end 25 by O-ring seals on both sides.

[0075] Regarding the flow of hydraulic oil: Hydraulic pump 66 starts under the drive of motor reduction assembly 62. After starting, hydraulic pump 66 draws in hydraulic oil from its suction port 033. The drawn-in hydraulic oil is pressurized by hydraulic pump 66 and pumped out from its outlet port 034. The high-pressure hydraulic oil enters the main supply port 039 through the center hole 037 of the outlet pipe, opens the check valve 69, and then enters the high-pressure oil main channel 051 through the annular hydraulic channel 043, the second support end connecting hole 07, the third connecting hole 08, and the second connecting hole 09. Finally, the high-pressure hydraulic oil enters the high-pressure oil chamber 059 through the high-pressure oil through hole 052. The hydraulic return oil in the low-pressure oil chambers 041, such as the reset spring chamber 013, the rotating chamber 016, and the inner cavity of the moving spline sleeve 018, enters from the second row of hydraulic radial connecting holes 017 on the inner shaft. It then passes sequentially through the inner shaft hydraulic through hole 019, the first row of hydraulic radial connecting holes 020 on the inner shaft, the support end hydraulic radial connecting hole 021, the support end hydraulic through hole 024, the conversion head center hole 025, the conversion head radial hole 027, the support end connecting hole 026, and the first support end connecting hole 04 before entering the fourth connecting hole 05. Subsequently, it passes sequentially through the return oil radial main through hole 012, the return oil main through hole 057, the return oil radial through hole 058, the return oil channel 036, and the return oil transition chamber 035 before entering the oil storage chamber 032. One end of the inner shaft hydraulic through hole 019 is equipped with an NPT sealing plug 47, and the upper end of the return oil main through hole 057 is equipped with a seal, such as... Figure 11 As shown, the main oil return through hole 057 and the radial oil return through hole 058 are provided on the support end 25.

[0076] The support end 25 is fixedly and sealed with a high-pressure sensor 93, which is used to detect the pressure of the high-pressure oil chamber 059; the support end 25 is fixedly and sealed with a low-pressure sensor 56, which is used to test the liquid pressure of the low-pressure oil chamber 041.

[0077] Specifically, the high-pressure sensor 93 is connected to the first adapter 94 via a flat thread, and the two are sealed by two O-rings. The first adapter 94 is mounted on the support end 25 via a flat thread, and the two are sealed by two O-rings. The low-pressure sensor 56 is connected to the second adapter 55 via a flat thread, and the two are sealed by two O-rings. The second adapter 55 is mounted on the support end 25 via a flat thread, and the two are sealed by two O-rings.

[0078] The control tool for screw drills of the present invention also includes a control circuit, which is used to control the drive assembly, etc.

[0079] Specifically, the control circuit includes a motor drive circuit protection cylinder 79. One end of the motor drive circuit protection cylinder 79 is fixedly and sealed to a second power sealing connector 77, and the other end of the motor drive circuit protection cylinder 79 is fixedly and sealed to a second plug 78. The second plug 78 is fixedly and sealed to the second power sealing connector 82. The motor drive circuit protection cylinder 79 is fixedly connected to the circuit board protection compartment 21. A circuit support plate 81 is fixedly connected inside the motor drive circuit protection cylinder 79. A motor drive circuit 80 is fixedly connected to the circuit support plate 81. The second power sealing connector 77 and the third power sealing connector 82 are electrically connected to the motor drive circuit 80.

[0080] The second power sealing connector 77 is installed on the second plug 78 via a flat thread, and the two are sealed by two O-rings. The second plug 78 is connected to the motor drive circuit protection cylinder 79 via a flat thread, and the two are sealed by two O-rings. The motor drive circuit 80 is fixed to the circuit support plate 81 by four fixing screws. The circuit support plate 81 is connected to the motor drive circuit protection cylinder 79 via a flat thread, and the two are sealed by two O-rings. The third power sealing connector 82 is installed on the circuit support plate 81 via a flat thread, and the two are sealed by two O-rings. The inner pins of the third power sealing connector 82 and the second power sealing connector 77 are connected to the motor drive circuit 80 via a flexible cable. The motor drive circuit 80 is located in the drive circuit protection cavity 045. The motor drive circuit protection cylinder 79 is filled with encapsulating adhesive and is fixed to the circuit board protection chamber 21 by eight fixing screws. The first power sealing connector 59 and the second power sealing connector 77 are connected by a flexible cable.

[0081] The circuit board protection compartment 21 is fixedly connected to a power supply battery 91, a wireless communication circuit 97, and an intelligent control circuit 98. The low-pressure sensor 56, the high-pressure sensor 93, the three-position four-way reversing valve 22, the motor drive circuit 80, and the power supply battery 91 are all connected to the intelligent control circuit 98.

[0082] Specifically, such as Figure 6 As shown, two fourth power sealing connectors 89 are installed on the circuit board protection chamber 21 via flat threads, and the two fourth power sealing connectors 89 and the circuit board protection chamber 21 are respectively statically sealed by two O-rings; the circuit board protection chamber 21 has mounting holes for placing the intelligent control circuit 98, and a cover plate 98 is connected to the mounting holes; the power supply battery 91 is fixed to the circuit board protection chamber 21 by four fixing screws and filled with encapsulating glue, and the five pins on the inner side of the two fourth power sealing connectors 89 are connected to the power supply battery 91 via flexible cables; the first cover plate 92 is fixed to the circuit board protection chamber 21 by multiple fixing screws, and the two are statically sealed by an O-ring; four fifth power sealing connectors 100 are installed on the circuit board protection chamber 21 via flat threads. The upper part of the circuit board protection chamber 21 is sealed by two O-rings. The wireless communication circuit 97 and the intelligent control circuit 98 are connected by a flexible cable and fixed to the circuit board protection chamber 21 by fixing screws. The five pins on the inner side of the four fifth power sealing connectors 100 are connected to the intelligent control circuit 98 by flexible cables and filled with encapsulating glue. The second cover plate 98 is fixed to the circuit board protection chamber 21 by multiple fixing screws and the two are sealed by an O-ring. The low pressure sensor 56, pressure sensor 83, high pressure sensor 93, three-position four-way reversing valve 22, motor drive circuit 80 and power supply battery 91 are all connected to the intelligent control circuit 98 by flexible cables. The upper end 15 of the protection chamber has an oil injection hole 050 for injecting oil into the circuit board chamber annulus 02. The oil injection hole 050 is sealed by a sealing plug. The circuit board chamber annulus 02 is filled with anti-vibration oil, which can both buffer vibration and transfer the heat generated by electronic components.

[0083] When the control tool for the screw drill bit in this embodiment of the invention is used to detect the working status at the wellhead, the tool detection signal can be transmitted in real time through the wireless communication circuit 97. That is, the wireless communication circuit 97 is used for communication between the wellhead and the intelligent control circuit 98. The intelligent control circuit 98 is used to control the three-position four-way reversing valve 22 and the motor drive circuit 80. The intelligent control circuit 98 is also used to adjust the output pump pressure of the hydraulic pump.

[0084] Furthermore, a drive shaft 11 is fixedly connected to the lower end of the inner shaft. The drive shaft is used to connect with the MWD measurement short section. A lower housing 8 is fixedly connected to the lower end of the housing. An upper moving ring housing 37, an upper moving ring alloy sleeve 38, a second thrust bearing assembly 39, a half ring 40, a lower stationary alloy 41, a lower moving alloy 42, a spacer ring 43, a pressure ring 44, an upper stationary ring housing 45, an upper stationary ring alloy sleeve 46, and a lower moving housing 10 are fitted onto the drive shaft 11. The upper moving ring housing 37 and the lower moving housing 10 are also fitted together. The upper moving ring alloy sleeve 38 is fixedly connected to the drive shaft 11 and is fixed on the upper moving ring housing 37. The upper stationary ring alloy sleeve 46 is sleeved on the upper moving ring alloy sleeve 38 and the two form a dynamic friction pair structure. The upper stationary ring alloy sleeve 46 is fixedly connected to the upper stationary ring housing 45. The lower moving alloy 42 is fixed on the lower moving housing 10 and the lower stationary alloy 41 is fixed on the lower stationary housing 9. The lower stationary housing 9 is fixedly connected to the lower housing 8 and a dynamic friction pair structure is formed between the lower moving alloy 42 and the lower stationary alloy 41.

[0085] A second thrust bearing assembly 39 is provided between the drive shaft 11 and the lower housing 8. The inner ring of the second thrust bearing assembly 39 is limited by the bearing ring 44 and the upper moving ring housing 37, and the outer ring of the second thrust bearing assembly 39 is limited by the spacer ring 43 and the upper stationary ring housing 45.

[0086] Specifically, the upper moving ring housing 37, the upper moving ring alloy sleeve 38, the second thrust bearing assembly 39, the half ring 40, the lower stationary alloy 41, the lower moving alloy 42, the spacer ring 43, the pressure ring 44, the upper stationary ring housing 45, and the upper stationary ring alloy sleeve 46 are fitted onto the drive shaft 11; the lower moving ring housing 10 is fixed to the drive shaft 11 by a flat thread, the upper moving ring housing 37 is fixed to the drive shaft 11 by a flat thread, the upper moving ring alloy sleeve 38 is installed on the upper moving ring housing 37, and the upper stationary ring alloy sleeve 46 is fitted over the upper moving ring alloy sleeve 38. The upper moving ring alloy sleeve 38 and the upper stationary ring alloy sleeve 46 form a dynamic friction pair structure; the lower moving alloy 42 is installed on the lower moving housing 10, and the lower stationary alloy 41 is installed on the lower stationary housing 9. The lower stationary alloy 41 and the lower moving alloy 42 form a dynamic friction pair structure; the lower stationary housing 9 is fixed to the lower housing 8 by a flat thread, and the upper stationary ring housing 45 is installed at the stepped surface of the lower housing 8; the second thrust bearing assembly 39, the half ring 40 and the pressure ring 44 are fixedly sandwiched in the middle to effectively counteract the axial and radial vibration of the drive shaft 11.

[0087] The upper housing 7 is connected to the housing 8 via a tapered pipe thread, and the inner shaft 48 is connected to the drive shaft 11 via a flat thread. Furthermore, the upper housing 7 is provided with a radial connecting hole 01, which connects to the central flow channel of the lower housing 8. A sealing structure is provided above the radial connecting hole (01) to prevent mud from flowing upward. Regarding the sealing structure: four second Chevron sealing spacers 35 and second Chevron rotary sealing rings 36 are threaded onto the inner shaft 48 to form a rotary dynamic seal. The four second Chevron sealing spacers 35 and second Chevron rotary sealing rings 36 are fixed to the inner cavity of the upper housing 7 by a third fixing ring 49. The four second Chevron sealing spacers 35 and the inner cavity of the upper housing 7 are connected to the static seal by four O-rings. The radial connecting hole 01 allows the circulating mud in the wellbore annulus to flow into the central flow channel of the lower shell 8, thereby providing lubrication and cooling for components such as the upper moving ring shell 37, the upper moving ring alloy sleeve 38, the second thrust bearing assembly 39, the half ring, the lower stationary alloy 41, the lower moving alloy 42, the spacer ring 43, the pressure bearing ring 44, the upper stationary ring shell 45, the upper stationary ring alloy sleeve 46, and the inner shaft 48.

[0088] The control tool for screw drills according to embodiments of the present invention comprises an outer shell structure consisting of components such as an upper connector 1, a protective shell 3, a connecting short section 5, an upper housing 7, a housing 8, and a lower stationary outer shell 9, which can rotate together with the upper drill string; and a transmission shaft structure consisting of components such as a lower moving outer shell 10, a transmission shaft 11, an upper end of a protective chamber 15, a protective cylinder 20, a circuit board protective chamber 21, a support end 25, an upper moving ring outer shell 37, and an inner shaft 48, which can rotate together with the MWD measuring short section and the outer shell of the screw drill.

[0089] The working principle of the control tool for screw drills according to embodiments of the present invention is described below:

[0090] (1) Automatic balancing anti-torque working principle:

[0091] The upper connector 1 is connected to the upper drill string, the drive shaft 11 is connected to the MWD measuring sub, the MWD measuring sub is connected to the outer shell of the screw drill bit, the counter-torque of the drill bit acts on the outer shell of the screw drill bit, and the counter-torque of the drill bit is transferred to the drive shaft 11 through the MWD measuring sub.

[0092] During directional drilling, after the MWD measuring sub detects that the tool face of the screw drill bit has reached the predetermined directional drilling position I, the wellhead sends a balanced torque pressure pulse command A. The pressure sensor 83 detects this pressure pulse command and transmits it to the intelligent control circuit 98. The intelligent control circuit 98 automatically issues a command to the three-position four-way directional valve 22 to switch positions, moving it from the leftmost position I to the middle position II. The intelligent control circuit 98 then automatically issues a motor drive command to the motor drive circuit 80, which energizes the motor reduction assembly 62 to rotate. The hydraulic pump 66 is driven by the coupling 64. The high-pressure hydraulic oil pumped out by the hydraulic pump enters the high-pressure oil chamber 059 (the path of the hydraulic oil entering the high-pressure oil chamber has been described before and will not be repeated here). The hydraulic oil in the high-pressure oil chamber 059 drives the locking piston 74 to compress the second return spring 71 and move it towards the low-pressure oil chamber 041. When the locking piston 74 moves to the unlock position, the locking piston 74 disengages from the locking block 75. The hydraulic piston 27 continues to compress the return spring 30 under the action of the hydraulic oil in the high-pressure oil chamber 059, which drives the moving spline sleeve 31 to move towards the rotating chamber 016.

[0093] When the movable spline sleeve 31 moves along the inner shaft 48 and the connecting short section 5 to the rotating cavity 016, the inner shaft 48 and the connecting short section 5 disengage from the torque transmission of the upper drill string. The movable spline sleeve 31 continues to move along the inner shaft 48, pushing against the first moving friction plate 52. The first moving friction plate 52 transmits pressure to the first stator friction plate 32. The first stator friction plate 32 moves along the connecting short section 5, sequentially transmitting pressure to the mating moving friction plate 52 and the stator friction plate 32. The contact surfaces between the moving friction plate 52 and the stator friction plate 32 generate friction under pressure. The moving friction plate 52 rotates together with the inner shaft 48 and the drive shaft 11, and the stator friction plate 32 rotates together with the upper drill string along with the connecting short section 5. The friction between the contact surfaces of the moving friction plate 52 and the stator friction plate 32... The friction torque is converted into friction torque. The moving friction plate 52 and the stator friction plate 32 move towards the buffer spring 34 under the action of the moving spline sleeve 31. The fourth moving friction plate 52 moves against the support ring 51, and the support ring 51 moves against the retaining ring 50 while compressing the buffer spring 34. The intelligent control circuit 98 adjusts the friction torque on the moving friction plate 52 and the stator friction plate 32 by adjusting the output pump pressure of the hydraulic pump 66. The greater the pressure of the hydraulic piston 27 on the moving friction plate 52 and the stator friction plate 32, the greater the friction torque generated. The moving friction plate 52 and the stator friction plate 32 can move to the position of the first elastic retaining ring 33. This buffer distance can prevent the hydraulic pump 66 from instantly increasing the hydraulic pressure, which would cause a sudden increase in the friction torque of the moving friction plate 52 and the stator friction plate 32.

[0094] After this, the moving friction plate 52 and the stator friction plate 32 stop moving, and the friction torque increases with the increase of the output pressure of the hydraulic pump 66. Hydraulic oil can flow through the spline keyway 015 and the connecting groove 060 in the connecting short section. Figure 8 As shown, the connecting groove 060 is set on the inner shaft 48. During the movement of the hydraulic piston 27 towards the rotating cavity 016, the hydraulic return oil in the low-pressure cavities such as the return spring cavity 013, the rotating cavity 016, and the inner cavity 018 of the moving spline sleeve enters from the second row of hydraulic radial connecting holes 017 on the inner shaft, and passes sequentially through the inner shaft hydraulic through hole 019, the inner shaft first row of hydraulic radial connecting holes 020, the support end hydraulic radial connecting hole 021, the support end hydraulic through hole 024, the conversion head center hole 025, the conversion head radial hole 027, the support end connecting hole 026, and the support end connecting hole 04 before entering the fourth connecting hole 05 of the three-position four-way reversing valve; the low-pressure pressure sensor 56 can measure the hydraulic oil pressure in the low-pressure oil cavity 041, and the hydraulic return oil enters the return oil radial main through hole 012, and then... Figure 7 , Figure 9 As shown, the oil flows sequentially through the main return oil through-hole 057, the radial return oil through-hole 058, the center hole of the outlet pipe 037, the return oil channel 036, and the return oil transition chamber 035 before entering the oil storage chamber 032. The working principle diagram of the hydraulic control system is as follows. Figure 13 As shown.

[0095] The intelligent control circuit 98 can measure the rotation angle of the inner shaft 48 in real time. Based on the mechanical transmission structure, the intelligent control circuit 98 can also measure the tool face angle of the screw drill bit in real time. The intelligent control circuit 98 controls the motor reduction assembly 62 to drive the hydraulic pump 66 to continuously increase the pressure on the moving friction plate 52 and the stator friction plate 32 until the friction torque of the moving friction plate 52 and the stator friction plate 32 brings the inner shaft 48 to a critical equilibrium state where it stops rotating, i.e., the equilibrium torque. At this time, for example, the equilibrium hydraulic oil pressure at the outlet of the hydraulic pump 66 is P. A At this time, the intelligent control circuit 98 monitors that the inner shaft 48 remains stationary, that is, the tool face remains stationary at a°.

[0096] In other words, the present invention can pump high-pressure oil into the high-pressure oil chamber through a hydraulic pump, so that the frictional torque between the moving friction plate 52 and the stator friction plate 32, which is converted from the force exerted by the hydraulic piston 27 on the moving friction plate 52 and the stator friction plate 32, can balance the aforementioned counter-torque, thereby keeping the tool surface stationary.

[0097] (2) Working principle of automatic balancing of tool face at 0±5°:

[0098] When the tool face angle a° is within the clockwise range of 0 to 180°, the intelligent control circuit 98 automatically controls the motor reduction assembly 62 to drive the hydraulic pump 66 to automatically reduce the output pump pressure to P. BTo reduce the frictional torque between the moving friction plate 52 and the stator friction plate 32, this frictional torque is less than the balance torque, causing the inner shaft 48 to rotate counterclockwise until the intelligent control circuit 98 monitors the tool face rotation to approximately 0±5°. At this point, the intelligent control circuit 98 automatically controls the motor reduction assembly 62 to drive the hydraulic pump 66, automatically increasing the output pump pressure to the balance hydraulic oil pressure P. A The intelligent control circuit 98 measures the tool face at 0±5° and keeps it stationary. The intelligent control circuit 98 automatically controls the motor reduction assembly 62 to drive the hydraulic pump 66 to continuously output pump pressure P. A .

[0099] When the tool face angle a° is within the clockwise range of 180° to 360°, the intelligent control circuit 98 automatically controls the motor reduction assembly 62 to drive the hydraulic pump 66 to automatically increase the output pump pressure to the hydraulic oil pressure P. C This increases the frictional torque between the moving friction plate 52 and the stator friction plate 32. This frictional torque is greater than the balance torque, causing the inner shaft 48 to rotate clockwise. When the intelligent control circuit 98 monitors the tool face rotation to around 0±5°, the intelligent control circuit 98 automatically controls the motor reduction assembly 62 to drive the hydraulic pump 66 to automatically reduce the output pump pressure to the balance hydraulic oil pressure P. A And continue to supply pressure.

[0100] (3) Working principle of automatic tool face adjustment to b°:

[0101] The MWD (Measuring Tool Window) sub-section monitors the current tool face angle of the screw drill bit, which is around 0±5°, and transmits this monitoring signal to the ground. The tool face angle of the screw drill bit needs to be adjusted to b°.

[0102] When the adjusted angle b° is within the clockwise range of 0 to 180°, the wellhead sends an angle adjustment pressure pulse command B, each command adjusting the clockwise rotation by X° (X = 5°). After the pressure sensor 83 detects the command, it transmits the command to the intelligent control circuit 98. The intelligent control circuit 98 automatically controls the motor reduction assembly 62 to drive the hydraulic pump 66 to automatically increase the output pump pressure to P. C The pressure is continuously supplied, increasing the frictional torque between the moving friction plate 52 and the stator friction plate 32. This frictional torque is greater than the balance torque, causing the inner shaft 48 to rotate clockwise. When the intelligent control circuit 98 monitors the tool face rotation to around X°, the intelligent control circuit 98 automatically controls the motor reduction assembly 62 to drive the hydraulic pump 66 to automatically reduce the output pump pressure to the balance hydraulic oil pressure P. AThe pressure is continuously supplied to keep the tool face near X°. The MWD measuring sub monitors the current tool face angle of the screw drill bit and it is located near X°. The "send angle adjustment pressure pulse command B from the wellhead" is repeated (b / X-1) times until the tool face intelligent monitoring circuit 27 monitors the tool face angle of the screw drill bit and it is located near b°. The MWD measuring sub monitors the current tool face angle of the screw drill bit and it is located near b°. The monitoring signal is then transmitted to the surface, and directional drilling begins.

[0103] When the adjusted angle b° is within the clockwise range of 180° to 360°, the wellhead sends an angle adjustment pressure pulse command C. Each command reverses the adjustment direction by X° (X = 5°). After the pressure sensor 83 detects the command, it transmits the command to the intelligent control circuit 98. The intelligent control circuit 98 automatically controls the motor reduction assembly 62 to drive the hydraulic pump 66 to automatically reduce the output pump pressure to P. B The system continuously supplies pressure, reducing the frictional torque between the moving friction plate 52 and the stator friction plate 32. This frictional torque is less than the balance torque, causing the inner shaft 48 to rotate counterclockwise. When the intelligent control circuit 98 monitors the tool face rotation to around -X°, the intelligent control circuit 98 automatically controls the motor reduction assembly 62 to drive the hydraulic pump 66 to automatically increase the output pump pressure to the balance hydraulic oil pressure P. A The pressure is continuously supplied to keep the tool face near -X°. The MWD measuring sub monitors the current tool face angle of the screw drill string and is located near -X°. It repeats the "send angle adjustment pressure pulse command C from the wellhead" (b / X-1) times until the intelligent control circuit 98 monitors the tool face angle of the screw drill string and is located near b°. The MWD measuring sub monitors the current tool face angle of the screw drill string and is located near b°. It then transmits this monitoring signal to the surface and begins directional drilling.

[0104] (4) Working principle of composite drilling:

[0105] When directional drilling is completed and composite drilling is required for stabilization, the MWD measuring sub monitors that after the tool face of the screw drill bit reaches the predetermined position II of the composite drilling, a reset pressure pulse command D is sent from the wellhead. After the pressure sensor 83 detects this command, it transmits the command to the intelligent control circuit 98. The intelligent control circuit 98 automatically sends a hydraulic reversal from the leftmost position I to the rightmost position III to the three-position four-way directional valve 22. The intelligent control circuit 98 automatically controls the motor reduction assembly 62 to drive the hydraulic pump 66 to automatically reduce the output pump pressure to the hydraulic oil pressure P. DWith continuous pressure supply, the hydraulic piston 27 drives the movable spline sleeve 31 to move towards the high-pressure oil chamber 059, and the locking piston 74 moves towards the high-pressure oil chamber 059. The movable spline sleeve 31 continues to move to the initial position and engages with the inner spline groove of the connecting short section 5, which can transmit the torque of the upper drill string to the tool face of the screw drill. At this time, the locking block 75 moves along the inclined surface of the locking piston 74 baffle and the inclined surface of the outer side of the inner shaft 48 to the initial locking position. The buffer spring 34 returns to the initial position and pushes the moving friction plate 52 and the stator friction plate 32 back to the initial position. At this time, the moving friction plate 52 and the stator friction plate 32 are in a free state and there is no friction torque between them. The intelligent control circuit 98 rotates clockwise continuously for 20 seconds or more as the upper drill string rotates. Circuit 98 automatically sends a hydraulic reversing command from position III to position II to the three-position four-way directional valve 22, and simultaneously sends a motor stop command. The intelligent control circuit 98 enters an automatic sleep mode until it reaches the next directional position, at which point it exits the sleep mode and enters the working mode. At this time, the three-position four-way directional valve 22 is in the middle position II. This position makes the hydraulic pressure on both sides of the locking piston 74 and the hydraulic piston 27 the same. The return spring 30 and the return spring 71 can ensure that the locking piston 74 and the hydraulic piston 27 return to their initial positions. The relief valve 96 ensures that the hydraulic control system can release pressure after an abnormal increase in pressure, ensuring the normal operation of the hydraulic control system. The MWD measuring sub monitors that the tool face of the screw drill bit rotates continuously in the positive direction with the upper drill string, and compound drilling begins.

[0106] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A control tool for screw drills, characterized in that, It includes an inner shaft (48) and a housing. The upper end of the housing is used to connect with the upper drill string. A transmission control part is provided between the inner shaft (48) and the housing. The transmission control part is used to transmit the torque of the upper drill string to the tool face of the screw drill to smoothly transmit the drilling pressure, and to balance the counter-torque acting on the screw drill housing so that the upper drill string can rotate normally. The lower end of the inner shaft is used to connect with the MWD measuring sub. The transmission control part includes a buffer spring (34) sleeved on the inner shaft (48) and limited on the inner shaft (48); a friction assembly is provided between the inner shaft (48) above the buffer spring (34) and the housing, and a rotating cavity (016) is provided above the friction assembly; a movable spline sleeve (31) is sleeved on the inner shaft (48) above the rotating cavity (016), and the movable spline sleeve (31) can transmit the torque of the housing to the inner shaft (48), and when the movable spline sleeve (31) moves to the rotating cavity (016), the movable spline sleeve (31) cannot transmit the torque of the housing to the inner shaft (48). The upper end of the inner shaft (48) is fixedly and sealed to a support end (25). A hydraulic piston (27) is provided in the sealed hydraulic cavity formed by the inner shaft (48), the support end (25) and the housing. An external structure is fixedly and sealed to the support end (25). A circuit board protection chamber (21) is fixedly and sealed between the support end (25) and the external structure. A drive assembly is fixedly provided on the support end (25). The drive assembly is connected to a hydraulic control unit. The hydraulic control unit is used to supply oil to the high-pressure oil chamber (059) above the hydraulic piston (27). The friction assembly is used to generate friction torque under the action of the hydraulic piston (27). A locking piston (74) is sealed inside the sealed hydraulic cavity. A high-pressure oil cavity (059) is formed between the locking piston (74) and the hydraulic piston (27). The cavity on the side of the locking piston (74) away from the hydraulic piston (27) and the cavity on the side of the hydraulic piston away from the locking piston (74) are both low-pressure oil cavities (041). A second return spring (71) is provided between the locking piston (74) and the support end (25). A locking block (75) is provided in the radial movement hole of the hydraulic piston (27). When the hydraulic piston (27) moves axially, the locking block (75) moves radially along the inclined surface of the sliding groove on the outer side of the inner shaft (48). After the locking piston (74) moves to the unlocking position in the direction away from the low-pressure oil cavity (041) of the hydraulic piston (27), the locking piston (74) disengages from the locking block (75). The hydraulic control unit includes a hydraulic pump (66) fixedly connected to the coupling (64). The hydraulic oil outlet of the hydraulic pump (66) is fixedly and sealed to one end of the oil outlet pipe (67). The oil outlet pipe (67) is provided with an oil outlet pipe center hole (037). The first electric sealing connector (59), the first plug (60), the motor reduction assembly protection cylinder (63), the oil outlet pipe (67), the threaded connection (68), and the support end (25) form a closed hydraulic oil tank. A three-position four-way directional valve (22) is sealed in the hydraulic reversing through hole of the support end (25). An overflow valve (96) is fixedly and sealed in the overflow hole of the support end (25). A one-way valve (69) is fixedly and sealed on the support end (25). The hydraulic pump (66) The hydraulic oil outlet of the hydraulic pump (66) is connected to the third connecting hole (08) of the three-position four-way directional valve (22). The check valve is located between the hydraulic oil outlet of the hydraulic pump (66) and the third connecting hole (08). The low-pressure oil chamber (041) is connected to the fourth connecting hole (05) of the three-position four-way directional valve (22). The first connecting hole (011) of the three-position four-way directional valve (22) is connected to the hydraulic oil tank. One end of the relief valve is connected between the first connecting hole (011) and the hydraulic oil tank. The other end of the relief valve is connected between the inlet of the check valve (69) and the hydraulic oil outlet of the hydraulic pump (66). The second connecting hole (09) of the three-position four-way directional valve (22) is connected to the high-pressure oil chamber (059).

2. The control tool for screw drills according to claim 1, characterized in that, The lower end of the inner shaft (48) is sealed to the housing, the upper end of the movable spline sleeve (31) is fixedly connected to the hydraulic piston (27), and a first return spring (30) is provided between the movable spline sleeve (31) and the hydraulic piston (27). The lower end of the first return spring (30) is limited by the shoulder of the housing. The drive assembly is located within the cavity formed by the support end (25), the external structure, and the circuit board protection compartment (21).

3. The control tool for screw drills according to claim 2, characterized in that, The locking piston (74) is located between the support end (25) and the hydraulic piston (27).

4. The control tool for screw drills according to claim 2, characterized in that, The lower end of the buffer spring (34) is limited by a shoulder provided on the inner shaft (48), and the upper end of the buffer spring is limited by a first elastic retaining ring (33) fixed on the inner shaft (48). The friction assembly includes a plurality of moving friction plates (52), all of which are disposed above the buffer spring (34). The plurality of moving friction plates (52) are connected to the inner shaft (48) by a key. A stator friction plate (32) is disposed between two adjacent moving friction plates (52). The plurality of stator friction plates (32) are connected to the housing by a key. The lowermost moving friction plate (52) is limited by a support ring (51) between it and the buffer spring (34). The uppermost moving friction plate (52) is limited by a second elastic retaining ring (53) fixed on the inner shaft. The rotating cavity (016) is disposed above the uppermost moving friction plate (52).

5. The control tool for screw drills according to claim 2, characterized in that, The external structure includes a protective cylinder (20) disposed on the outside of the support end (25). The support end (25) is fixedly and sealed to the protective cylinder (20). The protective cylinder (20) is fixedly and sealed to the upper end (15) of the protective chamber. The circuit board protective chamber (21) is disposed in the cavity formed by the support end (25) and the upper end (15) of the protective chamber. The circuit board protective chamber (21) is connected to the support end (25) and the upper end (15) of the protective chamber by a key. The circuit board protective chamber (21) is sealed to the support end (25) and the upper end (15) of the protective chamber.

6. The control tool for screw drills according to claim 5, characterized in that, A pressure sensor (83) is fixedly and sealed on the upper end (15) of the protective chamber. The upper end (15) of the protective chamber is provided with a mud pressure tapping chamber (046), a mud channel (047), and a mud pressure tapping hole (048) connected in sequence. The pressure sensor (83) is inserted into the mud pressure tapping hole (048). The pressure sensor (83) is used to measure the mud pressure in the central flow channel of the upper end (15) of the protective chamber. A mud screen plate (86) is fixed at the mud pressure tapping chamber (046) by an elastic retaining ring (84).

7. The control tool for screw drills according to claim 5, characterized in that, The upper end (15) of the protective chamber is fitted with a first thrust bearing assembly (14). The lower end of the inner ring of the first thrust bearing assembly (14) is limited by a shoulder provided on the upper end (15) of the protective chamber. A first fixing ring (13) is threaded on the upper end (15) of the protective chamber. The first fixing ring (13) is used to limit the upper end of the inner ring of the first thrust bearing assembly (14). The upper end of the housing is threaded with an upper connector (1). The housing and the upper connector (1) are fixedly connected. The upper connector (1) is used to connect with the upper drill string. The upper connector (1) is used to limit the upper end of the outer ring of the first thrust bearing assembly (14). The lower end of the outer ring of the first thrust bearing assembly (14) is limited by a step provided on the housing.

8. The control tool for screw drills according to claim 3, characterized in that, The drive assembly includes a motor reduction assembly (62), which is fixed on a motor reduction assembly mounting bracket (65). The output shaft of the motor reduction assembly (62) is connected to the hydraulic control unit via a coupling (64). The cable of the motor reduction assembly (62) is connected to the corresponding connector of the first power sealing connector (59). The first power sealing connector (59) is fixedly and sealed to the first plug (60). The first plug (60) is fixedly and sealed to the motor reduction assembly protective sleeve (63). The motor reduction assembly protective sleeve (63) is fixedly and sealed to one end of the threaded wire (68). The other end of the threaded wire (68) is fixedly and sealed to the support end (25).

9. The control tool for screw drills according to claim 8, characterized in that, The hydraulic pump (66) is fixed on the motor reduction assembly mounting bracket (65).

10. The control tool for screw drills according to claim 9, characterized in that, The support end (25) is fixedly and sealed with a high pressure sensor (93), which is used to detect the pressure of the high pressure oil chamber (059); the support end (25) is fixedly and sealed with a low pressure sensor (56), which is used to test the liquid pressure of the low pressure oil chamber (041); the support end (25) is provided with a high pressure oil main channel (051) and a high pressure oil through hole (052), and the second connecting hole (09) of the three-position four-way reversing valve (22) is connected to the high pressure oil chamber (059) through the high pressure oil main channel (051) and the high pressure oil through hole (052).

11. The control tool for screw drills according to claim 10, characterized in that, It also includes control circuitry: The control circuit includes a motor drive circuit protection cylinder (79), one end of which is fixedly and sealed with a second power sealing connector (77), and the other end of which is fixedly and sealed with a second plug (78). The second plug (78) is fixedly and sealed with a third power sealing connector (82). The motor drive circuit protection cylinder (79) is fixedly and sealed with the circuit board protection compartment (21). A circuit support plate (81) is fixedly connected inside the motor drive circuit protection cylinder (79). A motor drive circuit (80) is fixedly connected on the circuit support plate (81). The second power sealing connector (77) and the third power sealing connector (82) are electrically connected to the motor drive circuit (80). The circuit board protection compartment (21) is fixedly connected to a power supply battery (91), a wireless communication circuit (97) and an intelligent control circuit (98). The low-pressure sensor (56), the high-pressure sensor (93), the three-position four-way reversing valve (22), the motor drive circuit (80) and the power supply battery (91) are all connected to the intelligent control circuit (98).

12. The control tool for screw drills according to any one of claims 1-11, characterized in that, The lower end of the inner shaft is fixedly connected to a drive shaft (11), which is used to connect with the MWD measuring section. The lower end of the housing is fixedly connected to a lower housing (8). The drive shaft (11) is fitted with an upper moving ring housing (37), an upper moving ring alloy sleeve (38), a second thrust bearing assembly (39), a half ring (40), a lower stationary alloy (41), a lower moving alloy (42), a spacer ring (43), a pressure ring (44), an upper stationary ring housing (45), an upper stationary ring alloy sleeve (46), and a lower moving housing (10). The upper moving ring housing (37) and the lower moving housing (10) are connected to the drive shaft (11). The upper moving ring alloy sleeve (38) is fixed on the upper moving ring outer shell (37), the upper stationary ring alloy sleeve (46) is sleeved on the upper moving ring alloy sleeve (38) and a dynamic friction pair structure is formed between the two, the upper stationary ring alloy sleeve (46) is fixedly connected to the upper stationary ring outer shell (45), the lower moving alloy (42) is fixed on the lower moving outer shell (10), the lower stationary alloy (41) is fixed on the lower stationary outer shell (9), the lower stationary outer shell (9) is fixedly connected to the lower shell (8), and a dynamic friction pair structure is formed between the lower moving alloy (42) and the lower stationary alloy (41). A second thrust bearing assembly (39) is provided between the drive shaft (11) and the lower housing (8). The inner ring of the second thrust bearing assembly (39) is limited by the bearing ring (44) and the upper moving ring housing (37), and the outer ring of the second thrust bearing assembly (39) is limited by the spacer ring (43) and the upper stationary ring housing (45).

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