Electrically controlled auxiliary short section for screw drill anti-torque automatic balancing device

Abstract

The application provides an electric control auxiliary short section for a screw drill anti-torque automatic balancing device, which comprises a hollow cylindrical outer shell body, a side wall of the outer shell body is provided with a through hole, a main valve is arranged in the outer shell body, a leakage passage and a valve core are arranged in the main valve, two ends of the leakage passage are communicated with the inside of the outer shell body and the through hole respectively, a sealed cabin is fixedly connected with the main valve body, a motor, a calculation control module, a gravity sensor and a power supply are arranged in the sealed cabin, the calculation control module is signal connected with the gravity sensor and the motor respectively, an output end of the motor is circumferentially fixedly connected with the valve core, wherein the gravity sensor can measure the angular position and the rotating speed of the outer shell body, the calculation control module can collect the measurement data of the gravity sensor in real time, and the motor is controlled to rotate to drive the valve core to move axially to adjust the opening size of the leakage passage, so that the displacement of the drill pipe is automatically controlled.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of directional well and horizontal well directional drilling operation, and particularly relates to an electrically controlled auxiliary short section for a screw rod drilling tool anti-torque automatic balancing device. BACKGROUND

[0002] At present, directional wells and horizontal wells mainly use screw rod drilling tools for borehole trajectory control. When sliding drilling, the drill string does not rotate to ensure the stability of the tool face of the screw rod drilling tool, but this will cause a large axial friction between the drill string and the well wall, especially for long horizontal section horizontal wells and extended reach wells, the huge axial friction will cause the drilling pressure to be not smoothly transmitted, and the mechanical drilling speed is low. In order to solve the low mechanical drilling speed of the screw rod drilling tool sliding directional drilling, various technologies have been developed at home and abroad, the main idea of which is to rotate the drill string to reduce friction, thereby achieving the purpose of improving the mechanical drilling speed.

[0003] There are many schemes in the prior art, for example, by using advanced rotary steering tools, the drill string can be rotated while effectively controlling the borehole trajectory, thereby overcoming the shortcomings of sliding steering technology, and the drilling pressure is smoothly transmitted, the mechanical drilling speed is high, the borehole quality is good, however, since the existing rotary steering tool is a mechanical-electrical-hydraulic integrated device, the use and maintenance cost is high, which is not conducive to the reduction of drilling cost.

[0004] There is also a large-angle screw composite drilling technology that maintains the ability to control the borehole trajectory, reduces the proportion of sliding drilling rigs, and improves drilling speed. The research and application of variable diameter stabilizers and other screw steering tools configuration tools and measures can improve the performance of conventional steering tools as much as possible. However, the failure frequency of large-angle screw drilling tools increases when composite drilling, and the proportion of composite drilling is limited.

[0005] There is also a method of changing the top drive program, when sliding drilling, the top drive first rotates in a positive direction for a certain number of turns, then reverses for the same number of turns, and the above process is continuously repeated, a certain length of drill string is subjected to continuous positive and negative shock, which can reduce the friction between the drill string and the well wall, and the number of positive and negative turns is limited within a certain range. However, the length of the shock is limited, and there is a risk of unhooking

[0006] Chinese patent document ZL201620363357.0 discloses a downhole pipe string rotation control switch which is placed at a position about 300m above the screw drill tool. The switch can be opened by drilling fluid, and the friction force of the drilling string about 300m is used to overcome the counter torque of the screw drill tool when the drilling string rotates, so as to realize the target of rotating the drilling string during directional drilling. However, the downhole pipe string rotation control switch uses the gravity of the drilling string to generate friction force, which is greatly affected by the motion state, and the drilling string about 300m cannot rotate, which reduces the proportion of the drilling string rotation and seriously affects the effect of reducing friction and increasing speed.

[0007] Chinese patent document CN201220454297 discloses an up-and-down sliding drilling friction reduction and torque reduction tool, and proposes a tool for reducing resistance by using an up-and-down control mode. However, there is severe axial vibration in the actual drilling process, which may cause control difficulty, and the design of the transmission part is not involved. For the short section which bears an axial force of about 100KN, rapid wear will occur, so the practicability is poor. SUMMARY

[0008] In view of the above technical problems, the present application aims to provide an electric control auxiliary short section for a screw drill counter torque automatic balancing device, which can automatically adjust the screw drill composite drilling mode and the directional sliding drilling mode. In the composite drilling state, the mechanical drilling speed is high, and the friction mechanism is not worn. In the sliding drilling state, the counter torque automatic balancing device can automatically balance the screw drill counter torque, and can make the friction torque generated by the device always balance the screw counter torque with high efficiency and high precision, greatly reducing the axial friction, thereby greatly improving the mechanical drilling speed while keeping the tool face of the screw drill tool stable.

[0009] To this end, the present application provides an electric control auxiliary short section for a screw drill counter torque automatic balancing device, which comprises: an outer shell body configured as a hollow cylinder, a side wall of the outer shell body being provided with a through hole; a main valve arranged in the outer shell body, the main valve being provided with a flow discharge channel and a valve core, two ends of the flow discharge channel being in communication with the inside of the outer shell body and the through hole respectively; a sealed cabin fixedly connected with the main valve body, a motor, a calculation control module, a gravity sensor and a power supply being arranged in the sealed cabin, the calculation control module being signal connected with the gravity sensor and the motor respectively, an output end of the motor being in circumferential fixed connection with the valve core; wherein the gravity sensor can measure the angular position and the rotating speed of the outer shell body, the calculation control module can collect the measurement data of the gravity sensor in real time, and control the motor to rotate to drive the valve core to move axially, so as to adjust the opening size of the flow discharge channel, thereby automatically controlling the displacement of the drilling pipe.

[0010] In one embodiment, the electrically controlled auxiliary short section further comprises a pressure sensor for measuring pressure in the drill string.

[0011] In one embodiment, the main valve comprises an outer cylinder, an inner cylinder concentrically arranged in the outer cylinder, and a connecting portion for connecting the outer cylinder and the inner cylinder, the outer cylinder is fixedly connected with the inner wall of the outer housing, and the sealed cabin is arranged at the axial end of the inner cylinder.

[0012] In one embodiment, the connecting portion is configured as a radially symmetrical wing rib, and the wing rib is arranged in a radial direction so as to form a drilling fluid flow channel between the inner cylinder and the outer cylinder.

[0013] In one embodiment, a threaded hole is arranged in the inner cylinder along the central axis, and the valve core is installed in the threaded hole, and the valve core can rotate under the action of the motor to move axially along the inner cylinder.

[0014] In one embodiment, the drainage channel is configured to include a first flow channel, a second flow channel and a third flow channel connected in sequence,

[0015] The first flow channel penetrates the side wall of the inner cylinder to communicate with the drilling fluid flow channel of the corresponding side, the second flow channel is arranged inside the inner cylinder along the central axis, and the third flow channel extends radially and penetrates the inner cylinder, the connecting portion of the corresponding side and the outer cylinder in sequence, and communicates with the through hole on the outer housing.

[0016] In one embodiment, one end of the second flow channel communicates with the threaded hole, and the valve core can control the size of the communication port between the second flow channel and the first flow channel through axial movement, so as to adjust the opening size of the drainage channel.

[0017] In one embodiment, the output shaft of the motor is configured as an inner polygonal torque transmission surface, one end of the valve core is configured as an outer polygonal torque transmission surface, and the valve core and the output shaft of the motor are connected through the outer polygonal torque transmission surface.

[0018] In one embodiment, two gravity sensors are arranged, and the two gravity sensors are arranged perpendicular to each other.

[0019] In one embodiment, a connecting portion is arranged at the upper end of the outer housing, the outer diameter of the connecting portion is smaller than the outer diameter of the outer housing, and the connecting portion is used to connect the hollow shaft in the screw drill anti-torque automatic balancing device.

[0020] Compared with the prior art, the application has the following advantages:

[0021] The electric control auxiliary short section for the screw drill reverse torque automatic balancing device according to the present application can control the leakage flow to adjust the drilling fluid discharge, so as to realize the automatic adjustment of the screw drill composite drilling mode and the directional sliding drilling mode. The screw drill reverse torque automatic balancing device can realize the switching of the drill string-rotary sliding drilling and the composite drilling by using the specific switch pump program, which is simple in operation and high in efficiency. In the composite drilling state, the mechanical drilling speed is high, and the friction stator and the friction rotor in the friction mechanism are not worn. In the sliding drilling state, the reverse torque automatic balancing device can automatically balance the screw drill reverse torque, so that the screw drill can rotate the drill string to smoothly transfer the drilling pressure when sliding drilling, and can effectively control the tool of the tool face, and greatly reduce the axial friction resistance, thereby greatly improving the mechanical drilling speed while keeping the screw drill tool face stable, and effectively solving the problems of sliding drilling pressure bearing and low mechanical drilling speed. Moreover, the electric control auxiliary short section is used to control the leakage flow to adjust the drilling fluid discharge, so that the friction torque generated by the friction mechanism is always balanced with the screw reverse torque with high efficiency and high precision, which greatly improves the efficiency and precision of the discharge adjustment. The reverse torque automatic balancing device enables the screw drill to automatically switch the working state according to the actual working condition, greatly improves the drilling construction efficiency, and significantly enhances the drilling construction effect. BRIEF DESCRIPTION OF DRAWINGS

[0022] The present application will be described below with reference to the accompanying drawings.

[0023] Figure 1 The structure of the electric control auxiliary short section installed in the reverse torque automatic balancing device according to the present application is shown.

[0024] Figure 2 The structure of the electric control auxiliary short section for the screw drill reverse torque automatic balancing device according to the present application is shown.

[0025] Figure 3 is Figure 2 is a sectional view along line A-A in FIG.

[0026] Figure 4 is Figure 2 is a sectional view along line B-B in FIG.

[0027] Figure 5 is Figure 2 is a sectional view along line C-C in FIG.

[0028] In this application, all the drawings are schematic drawings, which are only used to illustrate the principles of the present application, and are not drawn according to the actual proportions. DETAILED DESCRIPTION

[0029] The present application will be described below with reference to the accompanying drawings.

[0030] In the present application, it is to be noted that the lower end of the electrically controlled auxiliary sub for the anti-torque automatic balancing device of the screw drill according to the present application is defined as the lower end or similar terms, which is lowered into the wellbore away from the wellhead, and the end close to the wellhead is defined as the upper end or similar terms. In addition, in the present application, the term "radial" refers to the vertical direction in Figure 1 , and the term "axial" refers to the horizontal direction in Figure 1 .

[0031] Figure 1 The structure of the electrically controlled auxiliary sub 5 according to the present application installed in the anti-torque automatic balancing device 100 is shown. As shown in Figure 1 , the anti-torque automatic balancing device 100 includes a cylindrical housing 2, a hollow mandrel 3, a friction mechanism 4, and an electrically controlled auxiliary sub 5. The hollow mandrel 3 is arranged concentrically in the housing 2, and the inside of the hollow mandrel 3 is formed with a central flow passage extending in the axial direction for the flow of drilling fluid. The friction mechanism 4 is arranged between the housing 2 and the hollow mandrel 3 in the radial direction, and the friction mechanism 4 is capable of generating a friction torque. The electrically controlled auxiliary sub 5 is fixedly connected to the lower end of the hollow mandrel 3, and the electrically controlled auxiliary sub 5 is capable of automatically controlling the displacement of the drill pipe, thereby adjusting the size of the friction torque generated by the friction mechanism 4. The anti-torque automatic balancing device 100 is capable of balancing the friction torque generated by the friction mechanism 4 with the anti-torque of the screw drill through the electrically controlled auxiliary sub 5 under the condition of reaching a certain displacement, thereby automatically balancing the anti-torque of the screw drill to enable the drill string to perform directional sliding drilling operation. Moreover, the electrically controlled auxiliary sub 5 is capable of closing the passage inside and outside the drill string, and making the certain displacement smaller than the normal drilling displacement, so that the friction torque generated by the friction mechanism 4 is higher than the anti-torque of the screw drill, thereby enabling the drill string to perform composite drilling operation.

[0032] The anti-torque automatic balancing device 100 is capable of automatically adjusting according to the actual working condition, thereby selecting to perform directional sliding drilling operation or composite drilling operation. Moreover, in the state of directional sliding drilling operation, the friction torque generated by the friction mechanism 4 is capable of automatically balancing the anti-torque of the screw drill, so that the screw drill housing does not rotate but the drill string rotates, thereby achieving the effect of reducing the axial friction and improving the rate of penetration during directional drilling. In the state of composite drilling, the friction torque generated by the friction mechanism 4 is higher than the anti-torque of the screw drill, thereby driving the screw drill stator (housing) to rotate, and the drill string is also in a rotating state, thereby greatly improving the rate of penetration in the state of composite drilling operation. This is very beneficial to improve the performance of the screw drill, and is conducive to enhancing the drilling operation effect and improving the construction efficiency.

[0033] The anti-torque automatic balancing device 100 is installed at a certain position above the screw drill, and the drill string-rotary sliding drilling and composite drilling can be realized by using a specific switch pump program. For example, the anti-torque automatic balancing device 100 can be installed at a position about 50 m above the upper part of the screw drill.

[0034] like Figure 1 As shown, an upper connector 1 is fixedly connected to the upper end of the housing 2. The upper connector 1 is used to connect the upper drill string and the drilling pump (not shown). In one embodiment, the housing 2 is fixedly connected to the upper connector 1 via a stepped threaded connection. Furthermore, the upper end face of the housing 2 extends to the axial inner side of the upper connector 1. The upper connector 1 is configured with a special thread type for connection to the upper drill string. This connection method of the upper connector 1 not only effectively ensures the reliability of the connection between components but also facilitates convenient and quick installation and disassembly.

[0035] The hollow mandrel 3 is rotatably connected to the housing 2 via a bearing assembly 7. For example... Figure 1 As shown, the hollow mandrel 3 is concentrically arranged inside the housing 2 via a bearing assembly 7. A step with its end face facing downwards is provided on the inner wall of the upper connector 1. The bearing assembly 7 is positioned between the step and the housing 2, and the axial end face of the outer ring of the bearing assembly 7 contacts both the end face of the step and the upper end face of the housing 2, thus forming an axial limit. Therefore, the hollow mandrel 3 can rotate freely relative to the housing 2 and the upper connector 1 via the bearing assembly 7, while simultaneously withstanding axial forces such as drilling pressure.

[0036] In one embodiment, an annular protrusion 31 is provided on the outer wall of the hollow mandrel 3, preferably located near the upper end of the hollow mandrel 3. The bearing assembly 7 is fixedly connected to the hollow mandrel 3 by fasteners 32 and the annular protrusion 31. The bearing assembly 7 is fitted onto the hollow mandrel 3, and the axial inner end face of the inner ring of the bearing assembly 7 abuts against the upper end face of the annular protrusion 31. The fasteners 32 are installed on the axial outer end face of the inner ring of the bearing assembly 7, thereby securing the bearing assembly 7. In one embodiment, the fastener 32 may be a fixing nut.

[0037] like Figure 1 As shown, the friction mechanism 4 includes an annular piston 41 sleeved on a hollow spindle 3, and several friction stators 42 and friction rotors 43 alternately sleeved on the hollow spindle 3. The friction stators 42 and friction rotors 43 can be made of, for example, hard alloy material. Figure 1 As shown, the annular piston 41 is positioned below the bearing assembly 7, and the friction stator 42 and friction rotor 43 are located at the lower end of the annular piston 41. The friction stator 42 is circumferentially fixedly connected to the inner wall of the housing 2, and the friction rotor 43 is circumferentially fixedly connected to the hollow spindle 3. The lower end face of the annular piston 41 abuts against the upper end face of the uppermost friction stator 42.

[0038] During actual operation, the annular piston 41 generates an axial downward thrust under hydraulic pressure, which acts on the uppermost friction stator 42, thereby pushing the friction stator 42 to fit tightly against the friction rotor 43. This allows the friction mechanism 4 to generate friction torque when the housing 2 rotates relative to the hollow spindle 3. The friction torque generated by the friction mechanism 4 is related to the number of friction stators 42 and friction rotor 43, the coefficient of friction, their dimensions, and the force of the annular piston 41. In actual operation, the friction torque value generated by the friction mechanism 4 can be adjusted as needed according to the above parameters.

[0039] The friction stator 42 is constructed in an annular shape, and its inner ring is clearance-fitted with the hollow mandrel 3. Several limiting grooves (not shown) are provided on the inner wall of the housing 2, and several limiting protrusions (not shown) are provided on the outer circumferential surface of the friction stator 42. The limiting protrusions can be fitted into the limiting grooves, thereby forming a circumferentially fixed connection between the friction stator 42 and the housing 2. Preferably, the limiting grooves are evenly spaced apart circumferentially on the housing 2, and correspondingly, the limiting protrusions are evenly spaced apart circumferentially on the friction stator 42.

[0040] The friction rotor 43 is also constructed in an annular shape, and a gap is left between the friction rotor 43 and the housing 2. A first involute tooth (not shown) is provided on the outer wall of the hollow mandrel 3, and a second involute tooth (not shown) is provided on the inner wall of the friction rotor 43. The first involute tooth can be fitted and installed with the second involute tooth, thereby forming a circumferential fixed connection between the friction rotor 43 and the hollow mandrel 3. Both the first and second involute teeth are arranged to be densely distributed circumferentially. The tooth height of both the first and second involute teeth is set to be less than 3 mm. This forms a shallow and dense involute tooth connection structure. This not only allows for the transmission of a larger torque but also reduces the impact on the strength of the hollow mandrel 3.

[0041] like Figure 1 As shown, a hydraulic channel 6 is formed at the upper end of the annular piston 41, and the hydraulic channel 6 is located radially between the housing 2 and the hollow mandrel 3. The hydraulic channel 6 is connected to the central flow channel of the hollow mandrel 3, and the hydraulic channel 6 can transmit the hydraulic pressure in the hollow mandrel 3 to the upper end face of the annular piston 41, thereby causing the annular piston to generate an axial thrust and act on the friction stator 42 at the uppermost end, thereby pushing the friction stator 42 to fit tightly against the friction rotor 43.

[0042] In this embodiment, to ensure that the hydraulic pressure can effectively act on the annular piston 41, a first seal 411 is provided between the annular piston 41 and the outer wall of the hollow mandrel 3, and a second seal 412 is provided between the annular piston 41 and the inner wall of the hollow mandrel 3 housing 2. This effectively ensures the sealing between the annular piston 41, the hollow mandrel 3, and the housing 2, thereby ensuring the sealing of the hydraulic passage 6. The first seal 411 and the second seal 412 can be wear-resistant Glyd ring seals.

[0043] like Figure 1 As shown, an anti-drop ring 8 is also fixedly connected to the lower end of the hollow mandrel 3. Preferably, the anti-drop ring 8 can be fixedly connected to the housing 2 by a threaded connection. During operation, when the bearing assembly 7 malfunctions, the anti-drop ring 8 can support the hollow mandrel 3, the annular piston 41, and the friction stator 42 and friction rotor 43, thereby preventing the hollow mandrel 3, the annular piston 41, and the friction stator 42 and friction rotor 43 from falling into the well.

[0044] According to the present invention, such as Figure 2 and Figure 2 As shown, the electronically controlled auxiliary sub 5 includes an outer casing 50, a main valve 51 disposed within the outer casing 50, a drain channel 52 and a valve core 53 disposed within the main valve 51, a sealed chamber 54 fixedly connected to the main valve body 51, and a motor 55, a calculation and control module 56, a gravity sensor 57, and a power supply 58 disposed within the sealed chamber. The calculation and control module 56 is connected to the gravity sensor 57 and the motor 55 respectively, and the output end of the motor 55 is fixedly connected to the valve core 53. The power supply 58 is connected to the motor 55, the calculation and control module 56, and the gravity sensor 57 respectively to provide electrical energy. The electronically controlled auxiliary sub 5 can measure the angular position and rotational speed of the outer casing 50 through the gravity sensor 57. The calculation and control module 56 can collect the measurement data of the gravity sensor 57 in real time and control the motor 55 to rotate, thereby driving the valve core 53 to move axially to adjust the opening size of the drain channel 52, thereby automatically controlling the drill pipe discharge rate.

[0045] According to one embodiment of the present invention, the upper end of the outer casing 50 is constructed with a standard thread for fixed connection with the hollow mandrel 3. The upper end of the outer casing 50 extends upward to the axial inner side of the housing 2, and the upper end face of the outer casing 50 contacts the friction rotor 43 at the lowermost end, thereby forming an axial limit on the friction rotor 43. In addition, the outer diameter of the upper end connecting portion of the outer casing 50 is set to be smaller than the outer diameter of the main structure of the outer casing 50, and a gap is left between the outer wall surface of the upper end connecting portion and the anti-drop ring 8. The lower end of the outer casing 50 is constructed with a special snap-fit ​​type for connection with the lower drill string (drill rod). For example, the lower end of the outer casing 50 is sequentially connected to the lower drill string, the screw drill tool, and the drill bit.

[0046] likeFigure 5 and Figure 2 As shown, the main valve 51 includes an outer cylinder 511 and an inner cylinder 512, with the inner cylinder 512 concentrically distributed inside the outer cylinder 511. The inner cylinder 512 is connected to the outer cylinder 511 via radially symmetrically distributed connecting portions 513. Thus, two axially extending drilling fluid channels 514 are formed between the inner cylinder 512 and the outer cylinder 511, and these two drilling fluid channels 514 are radially symmetrically distributed. Preferably, the axial length of the inner cylinder 512 can be set to be less than the axial length of the outer cylinder 511, and one end of the inner cylinder 512 is flush with one end of the outer cylinder 511. The connecting portions 513 are located radially between the outer cylinder 511 and the inner cylinder 512 and are arranged radially, while also extending a portion axially. The outer cylinder 511 is used for fixed connection to the inner wall of the outer casing 50, and the sealing chamber 54 is located at the axial end of the inner cylinder 512. Figure 2 In the illustrated embodiment, the lower end face of the inner cylinder 512 is flush with the lower end face of the outer cylinder 511, and the sealing chamber 54 is disposed at the upper axial end of the inner cylinder 512. Of course, it can be understood that the upper end face of the inner cylinder 512 can be flush with the upper end face of the outer cylinder 511, and the sealing chamber 54 can also be disposed at the lower axial end of the inner cylinder 512.

[0047] like Figure 3 and Figure 4 As shown, the sealed chamber 54 is cylindrical, with its upper end closed and its lower end open. The lower end of the sealed chamber 54 is fixedly connected to the axial end of the inner cylinder 512 of the main valve 51, forming a seal. The motor 55, the calculation and control module 56, the gravity sensor 57, and the power supply 58 are all arranged inside the sealed chamber 54. The motor 55, the calculation and control module 56, and the gravity sensor 57 are all powered by the power supply 58. A mounting plate is also provided on the inner wall of the sealed chamber 54 near the lower end. The motor 55 is mounted on the mounting plate, and the output shaft 551 of the motor 55 passes through the mounting plate axially and extends outward to connect to the valve core 53.

[0048] According to the present invention, the output shaft 551 of the motor 55 is configured as an inner polygonal torque transmission surface, and one end of the valve core 53 is configured as an outer polygonal torque transmission surface. The valve core 53 and the output shaft 551 of the motor 55 are adapted to be connected through the outer polygonal torque transmission surface. This allows the valve core 53 to rotate under the drive of the motor 55 and to move axially relative to the output shaft 551 of the motor 55, thereby moving axially along the inner cylinder 512.

[0049] In one embodiment, such as Figure 2 As shown, the output shaft 551 of the motor 55 is constructed with an internal hexagonal structure. Meanwhile, one end of the valve core 53 ( Figure 2The left end of the valve core 53 is constructed with an external hexagonal structure. The valve core 53 and the output shaft 551 of the motor 55 are connected circumferentially through the external and internal hexagonal structures, while allowing axial sliding relative to the output shaft 551. A threaded hole is provided along the central axis in the inner cylinder 512 of the main valve 51. The valve core 53 is axially mounted in the threaded hole and forms a threaded connection with the threaded hole of the inner cylinder 512. The motor 55 can rotate forward or reverse under the control of the calculation and control module 56. Thus, the motor 55 can drive the valve core 53 to rotate, causing the valve core 53 to move axially along the inner cylinder 512.

[0050] According to one embodiment of the present invention, two gravity sensors 57 are provided, and the two gravity sensors 57 are distributed perpendicularly to each other. The two gravity sensors 57 can measure the angular position and rotational speed of the outer shell 50, and can transmit the collected measurement data to the computing and control module 56 in real time.

[0051] like Figure 5 and Figure 2 As shown, a radially extending through hole 501 is provided on the side wall of the outer casing 50. The two ends of the drain channel 52 are respectively connected to the internal channel of the outer casing 50 and the through hole 501. The drain channel 52 includes a first flow channel 521, a second flow channel 522, and a third flow channel 523 connected in sequence. The first flow channel 521 penetrates the side wall of the inner cylinder 512 and communicates with the drilling fluid flow channel 514 on the corresponding side. The second flow channel 522 extends along the central axis of the inner cylinder 512 and is distributed inside the inner cylinder 512, with one end connected to the threaded hole for mounting the valve core 53. The third flow channel 523 extends radially and sequentially penetrates the inner cylinder 512, the connecting portion 513, and the outer cylinder 511, and communicates with the through hole 501 on the side wall of the outer casing 50. The valve core 53 can control the size of the connection between the second flow channel 522 and the first flow channel 521 through axial movement, thereby adjusting the opening size of the discharge channel 52 and thus controlling the drill pipe discharge rate.

[0052] like ​ As shown, the electronically controlled auxiliary section 5 also includes a pressure sensor 59 for measuring the pressure inside the drill string. The pressure sensor 59 is located on the outside of the sealed chamber 54 and is connected to the calculation and control module 56 and the power supply 58.

[0053] An automatic anti-torque balancing device 100 for screw drill bits is installed at a certain position above the screw drill bit. When the screw drill bit is drilling normally, pressure loss occurs in the screw drill bit and drill bit, with the screw drill bit accounting for the majority of the pressure loss. This results in a pressure difference between the hydraulic channel 6 between the hollow mandrel 3 and the housing 2 and the annular space outside the housing 2. Consequently, the upper end face of the annular piston 41 is connected to the high-pressure area formed by the hydraulic channel 6, while the lower end is connected to the low-pressure area outside the housing 2 through the friction stator 42 and the friction rotor 43. Therefore, the annular piston 41 is subjected to liquid pressure. When the rotor outputs torque of the screw drill bit, the stator (housing) is subjected to an equal and opposite counter-torque, which is counterclockwise. According to the working characteristics of the screw drill bit, the greater the output torque of the screw, the greater the pressure loss generated by the screw, and the two are directly proportional. The greater the axial thrust generated by the annular piston 41, the greater the axial thrust. The turntable drives the upper connector 1 and the housing 2 to rotate, resulting in a greater frictional torque between the friction stator 42 and the friction rotor 43. The direction of the frictional torque is clockwise. Therefore, as long as the magnitude of the frictional torque is the same as the counter-torque of the screw drill bit, the stator of the screw drill bit is in a state of torque balance, thus maintaining a non-rotating state, allowing the screw drill bit to perform directional sliding drilling operations. At this time, the automatic counter-torque balancing device 100 is in the first state. In this state, the frictional torque generated by the friction mechanism 4 can automatically balance the counter-torque of the screw drill bit, so that the screw drill bit housing does not rotate but the drill string rotates, thereby achieving the effect of reducing axial friction and increasing mechanical drilling speed during directional drilling.

[0054] In its first state, the anti-torque automatic balancing device 100 adjusts the displacement via the electronically controlled auxiliary sub 5. When the displacement is adjusted to a specific displacement Q0, this specific displacement is sufficient for normal drilling. The friction torque is equal to the screw anti-torque, and even when encountering complex formations or changes in drilling pressure cause screw anti-torque, the two remain balanced. This achieves the effect of automatically balancing the anti-torque of the screw drill bit. Due to the force balance, the screw drill bit housing remains in a non-rotating state, allowing for directional sliding drilling. The specific displacement Q0 is related to the screw characteristics and the wear of the friction stator 42 and friction rotor 43. In field use, repeated testing via the electronically controlled auxiliary sub 5 is required to determine the specific displacement Q0, and tool placement also takes a considerable amount of time. The electronically controlled auxiliary sub 5 significantly improves the efficiency and accuracy of displacement adjustment.

[0055] When the drilling fluid discharge increases and deviates from the specific discharge rate Q0, the friction torque generated by the friction mechanism 4 will be greater than the torque generated by the screw drill bit. The two are no longer in balance, and the stator (casing) of the screw drill bit will rotate with the drill string, thus enabling the screw drill bit to perform composite drilling operations. At this time, the anti-torque automatic balancing device 100 is in its second state. In this state, the mechanical drilling rate during composite drilling operations can be greatly improved, which is highly beneficial for increasing the drilling efficiency of the screw drill bit.

[0056] The working process of the electronically controlled auxiliary section 5 according to the present invention applied to the anti-torque automatic balancing device 100 of the screw drill bit is briefly described below.

[0057] In actual construction operations, the pressure inside the drill string is low when the pump is turned off and high when the pump is turned on. Therefore, the pump switching status can be determined by the pressure sensor 59, and the pump can be controlled by a pump-turn-off-turn-on program through programming.

[0058] During on-site operations, when compound drilling is required, the pump shut-off time is set to be longer than 30 seconds. Then, the rotary table is started, and the calculation control module 56 commands the motor 55 to drive the valve core 53 to rotate forward. The valve core 53 moves downward until the discharge channel 52 is closed, thus closing the internal and external channels of the drill string. At this time, the displacement of the lower screw drill bit and drill string is the drilling pump displacement. Due to the design of the sealing pre-tightening degree, the specific displacement is less than the normal drilling displacement. Therefore, under normal displacement conditions, the friction mechanism 4 generates a friction torque much higher than the screw reverse torque, and the screw drill bit enters the compound drilling state.

[0059] When directional sliding drilling is required, the tool face is first rotated to the designed position according to the conventional directional procedure. Then, the pump is shut off for less than 30 seconds. After restarting the pump, the calculation and control module 56 first collects data from the gravity sensor 57 and automatically records the angle position. Then, it commands the motor 55 to move the valve core 53 to the middle position. A portion of the drilling fluid is discharged into the annulus through the drain channel 52, reducing the flow rate through the screw drill bit. Two minutes after starting the pump, the rotary table is started, and the drilling pressure is gradually increased to the designed value. The calculation and control module 56 collects data from the gravity sensor 57 in real time. The calculation and control module 56 determines the rotation direction by the angle change of the outer casing 50. The specific process is as follows:

[0060] If the outer casing 50 rotates forward, it indicates that the torque generated by the anti-torque automatic balancing device 100 is too large. Then, the calculation control module 56 commands the motor 55 to rotate in reverse by 0.5 turns, which drives the valve core 53 to move upward. The opening of the discharge channel 52 becomes larger, the discharge flow increases, the discharge volume through the screw drill decreases, and the friction torque generated by the friction mechanism 4 becomes smaller.

[0061] If the outer casing 50 reverses, it indicates that the torque generated by the anti-torque automatic balancing device 100 is too small. Then, the calculation control module 56 commands the motor 55 to rotate forward 0.5 revolutions, driving the valve core 53 to move downwards. The opening of the discharge channel 52 becomes smaller, the discharge flow decreases, the discharge volume through the screw drill increases, and the friction torque generated by the friction mechanism 4 increases.

[0062] If the outer casing 50 does not rotate, then the motor 55 and the valve core 53 will not move.

[0063] Therefore, by continuously and automatically adjusting the displacement through the electronically controlled auxiliary sub 5 until the outer casing 50 stops rotating, it indicates that the friction torque of the automatic anti-torque balancing device 100 is the same as the anti-torque of the screw drill bit. At this time, the displacement flowing through the screw drill bit and drill bit is a specific displacement Q0, that is, the drilling pump displacement minus the discharge flow through the discharge channel 52. The friction torque generated by the friction mechanism 4 is always equal to the screw anti-torque, and the screw drill bit casing is in a non-rotating state. The screw drill bit enters the directional sliding drilling state.

[0064] During drilling operations, the automatic anti-torque balancing device 100 is installed at a certain length above the screw drill bit. When the screw drill bit is lowered into the well to begin drilling, if the wellbore trajectory meets the design requirements, the rotary table and pump are started, then the pump is turned off, and restarted after more than 30 seconds. At this time, the friction torque generated by the friction mechanism 4 is higher than the anti-torque of the screw drill bit. The screw drill bit stator is rotating, and the drill string is also rotating. The screw drill bit is in a combined drilling state, with a high mechanical drilling speed, and no wear on the friction stator 42 and friction rotor 43. The screw drill bit lacks the ability to control the wellbore trajectory.

[0065] After drilling a certain distance, if the wellbore trajectory deviates from the design and directional drilling is required, the tool face is first positioned at the design location. The pump start-up-stop time is less than 30 seconds, then the pump is started again. The rotary table is then activated, and the drill string displacement is automatically adjusted to a specific displacement Q0 via the electronically controlled auxiliary sub 5, allowing the screw drilling to enter a directional sliding state. At this time, the friction torque generated by the friction mechanism 4 automatically balances the reverse torque of the screw drill string. Therefore, the screw drill string housing does not rotate, but the drill string rotates, achieving the effect of reducing axial friction and increasing mechanical drilling speed during directional drilling. After drilling for a period of time, the drill string returns to the wellbore trajectory design target, and the drilling fluid displacement is again adjusted to a composite drilling state via the electronically controlled auxiliary sub 5.

[0066] The electrically controlled auxiliary section 5 for the automatic anti-torque balancing device of the screw drill bit according to the present invention can control the discharge flow to adjust the drilling fluid discharge, thereby realizing automatic adjustment of the screw drill bit's composite drilling mode and directional sliding drilling mode. It can use a specific pump switching program to enable the automatic anti-torque balancing device to switch between drill string-rotation sliding drilling and composite drilling, which is simple to operate and highly efficient. In composite drilling mode, the mechanical drilling rate is high, and there is no wear on the friction stator 42 and friction rotor 43 in the friction mechanism 4. In sliding drilling mode, the automatic anti-torque balancing device 100 can automatically balance the anti-torque of the screw drill bit, allowing the screw drill bit to rotate the drill string to smoothly transmit drilling pressure during sliding drilling, effectively controlling the tool face, and greatly reducing axial friction. This significantly improves the mechanical drilling rate while maintaining the stability of the screw drill bit's tool face, effectively solving problems such as pressure buildup and low mechanical drilling rate in sliding drilling. Furthermore, the use of the electrically controlled auxiliary sub 5 to control the discharge flow rate adjusts the drilling fluid discharge volume, ensuring that the friction torque generated by the friction mechanism 4 is always in high-efficiency and high-precision balance with the screw counter-torque. This greatly improves the efficiency and accuracy of discharge volume adjustment. The automatic counter-torque balancing device 100 enables the screw drill bit to automatically switch working states according to actual working conditions, greatly improving drilling efficiency and significantly enhancing drilling performance.

[0067] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0068] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0069] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0070] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An electrically controlled auxiliary sub for an automatic anti-torque balancing device for screw drills, comprising: An outer shell (50) is constructed in the shape of a hollow cylinder, and the side wall of the outer shell is provided with a through hole (501); The main valve (51) is disposed in the outer shell. The main valve is provided with a discharge channel (52) and a valve core (53). The two ends of the discharge channel are respectively connected to the interior of the outer shell and the through hole. The main valve includes an outer cylinder (511) and an inner cylinder (512) concentrically distributed in the outer cylinder. A threaded hole is provided in the inner cylinder along the central axis direction. The valve core is installed in the threaded hole. The sealed chamber (54) is fixedly connected to the main valve. Inside the sealed chamber are a motor (55), a calculation and control module (56), a gravity sensor (57), and a power supply (58). The calculation and control module is connected to the gravity sensor and the motor respectively. The output end of the motor is circumferentially fixedly connected to the valve core. The valve core can rotate under the action of the motor to move along the axial direction of the inner cylinder. The gravity sensor can measure the angular position and rotation speed of the outer shell. The calculation and control module can collect the measurement data of the gravity sensor in real time and control the motor to rotate and drive the valve core to move axially, so as to adjust the opening size of the discharge channel and thus automatically control the drill rod discharge rate. The main valve includes a connecting part (513) for connecting the outer cylinder and the inner cylinder. The outer cylinder is fixedly connected to the inner wall of the outer shell. The sealing chamber is disposed at the axial end of the inner cylinder. The connecting part is configured with radially symmetrical ribs. The ribs extend radially, thereby forming a drilling fluid flow channel (514) between the inner cylinder and the outer cylinder. The discharge channel is configured to include a first flow channel (521), a second flow channel (522), and a third flow channel (523) connected in sequence. The first flow channel penetrates the side wall of the inner cylinder and communicates with the drilling fluid flow channel on the corresponding side. The second flow channel extends along the central axis and is disposed inside the inner cylinder. The third flow channel extends radially and penetrates the inner cylinder, the connecting part on the corresponding side, and the outer cylinder in sequence, and communicates with a through hole on the outer shell. One end of the second flow channel communicates with the threaded hole. The valve core can control the size of the communication port between the second flow channel and the first flow channel by axial movement, thereby adjusting the opening size of the discharge channel.

2. The electronically controlled auxiliary sub according to claim 1, characterized in that, The electronically controlled auxiliary sub also includes a pressure sensor (59) for measuring the pressure inside the drill string.

3. The electronically controlled auxiliary sub according to claim 1 or 2, characterized in that, The output shaft (551) of the motor is configured as an inner polygonal torque transmission surface, and one end of the valve core is configured as an outer polygonal torque transmission surface. The valve core and the output shaft of the motor are adapted to each other through the outer polygonal torque transmission surface.

4. The electronically controlled auxiliary sub according to claim 1, characterized in that, The gravity sensor is provided in two parts, and the two gravity sensors are distributed perpendicularly to each other.

5. The electronically controlled auxiliary sub according to claim 1, characterized in that, A connecting part is provided at the upper end of the outer shell. The outer diameter of the connecting part is set to be smaller than the outer diameter of the outer shell. The connecting part is used to connect the hollow mandrel (3) in the screw drill anti-torque automatic balancing device.

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