Hydraulic steering system for an auto-orienting drilling tool

Abstract

The application relates to a liquid control guiding system of an automatic directional drilling tool, which comprises a guiding sleeve and a storage battery, a storage battery storage is arranged on the guiding sleeve, a storage battery is fixedly installed in the storage battery storage, three liquid control guiding single integrated blocks are uniformly distributed along the axis of the guiding sleeve, each liquid control guiding single integrated block is fixedly installed with a liquid control guiding single integrated block, the liquid control guiding single integrated block is installed with a liquid control guiding system, an oil storage rubber bag, a guiding hydraulic cylinder and an anti-pollution micro-flow metal diaphragm pump, the liquid control guiding system is communicated with the oil storage rubber bag, the guiding hydraulic cylinder and the anti-pollution micro-flow metal diaphragm pump through pipelines, and the liquid control guiding system of the automatic directional drilling tool has the characteristics of anti-pollution, anti-leakage, stable thrust under strong vibration, high stability, downhole electric energy extraction and anti-stuck drill.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of oil drilling and geological drilling technology, and particularly relates to a hydraulic control guiding system for an automatic directional drilling tool. BACKGROUND

[0002] Directional drilling technology is one of the most advanced and complex drilling technologies in the field of oil exploration and development in the world today. It is a technology that effectively controls the well trajectory by using a special downhole guiding system, measuring instruments and process technology, and is widely used in various complex working conditions of oil drilling operations such as deviated wells, horizontal wells and butt joint drilling. According to the source of guiding force, the special downhole guiding system is mainly divided into drilling hydraulic differential type, motor driven type and electrically controlled hydraulic type. Their respective characteristics are as follows: the guiding force generated by the drilling hydraulic differential type is affected by the displacement of the drilling pump and the performance of the drilling fluid, etc., resulting in a lower guiding efficiency of the downhole drilling tool. The motor driven type has insufficient driving force and poor stability. Compared with the drilling hydraulic differential type and the motor driven type, the electrically controlled hydraulic type generates more continuous and stable guiding force. However, the existing hydraulic control guiding system (electrically controlled hydraulic type) has many shortcomings such as short working time of the power supply device (downhole storage battery), weak anti-pollution ability, poor guiding thrust stability under strong vibration conditions, etc.

[0003] Chinese patent CN102434508 changes the outlet flow of the pump by adjusting the speed of the speed-regulating motor, changes the pressure value of the hydraulic control guiding system, and then adjusts the output force of the thrust cylinder. However, considering the actual situation of high temperature, high pressure and high vibration in the downhole, the speed-regulating motor also has some shortcomings in controlling the pressure of the system and the thrust cylinder, such as low power efficiency, weak high temperature and high pressure resistance, and weak power supply reliability. Moreover, the capacity and life of the storage battery will rapidly decay with the increase of the temperature in the cavity, resulting in a great reduction of the working time of the storage battery in the downhole.

[0004] Chinese patent CN101858198 provides hydraulic power system with hydraulic energy by using plunger pump, the input signal of the control valve such as electromagnetic valve and safety valve is used to realize the size of the cylinder thrust of the hydraulic control guiding system. Meanwhile, when the cylinder leaks, the accumulator is used to supplement the oil to ensure the stability of the cylinder thrust. But the controllable hydraulic power integrated unit still has the following defects: (1) when facing the poor working environment in the well, some drilling fluid impurities easily flow into the working chamber of the plunger pump, which pollutes the hydraulic source, reduces the sensitivity of the control elements of the hydraulic power system or damages them, affects the size and stability of the cylinder thrust, and even the damage of the hydraulic control elements may occur, which causes the system to work abnormally; (2) due to the high pressure system (such as oil source pressure 30-40Mpa) and the strong vibration working environment in the well, the spring accumulator has poor pressure buffering effect, unstable pressure and slow pressure stability recovery speed, so it is difficult to realize the rapid compensation of the stable pressure of the thrust cylinder; (3) the service life of the power supply (storage battery) for the normal work of the hydraulic elements is short.

[0005] Chinese patent CN2592840 provides pressure energy for the hydraulic control guiding system by using plunger hydraulic pump, and the electromagnetic pressure proportional valve is used to adjust the thrust size of the execution piston, but some defects still exist: some drilling fluid impurities easily flow into the rodless chamber of the plunger cylinder, which pollutes the clean hydraulic oil as the pressure transmission medium; the hydraulic control system only has one pressure control element, i.e. the electromagnetic pressure proportional valve, and the system may appear the phenomenon of sticking.

[0006] Therefore, it is the key to improve the development of automatic directional drilling tool and technology to develop a hydraulic control guiding system with stable and high stability, continuous adjustment, anti-sticking, anti-pollution and automatic extraction of electric energy in the well. SUMMARY

[0007] To solve the above technical problems, the present application provides a hydraulic control guiding system of automatic directional drilling tool, which can realize the high stability and continuous adjustment of the guiding force of the hydraulic control guiding system, thereby effectively improving the guiding performance of the automatic directional drilling tool and the quality of the well trajectory. Meanwhile, the hydraulic control guiding system has the characteristics of anti-sticking, anti-pollution and electric energy extraction, and also improves the service life and reliability, and reduces the occurrence of drilling accidents.

[0008] The technical solution adopted by the present application is as follows:

[0009] A hydraulic control guiding system of automatic directional drilling tool, comprising a guiding sleeve and a storage battery,

[0010] The guide sleeve is provided with a storage battery compartment and a hydraulic control guide single block compartment, the storage battery is fixedly installed in the storage battery compartment, three hydraulic control guide single blocks are evenly distributed along the guide sleeve axis, and each hydraulic control guide single block is fixedly installed with a hydraulic control guide single block,

[0011] The hydraulic control guide system, the oil storage bag, the guide hydraulic cylinder and the anti-pollution micro-flow metal diaphragm pump are installed on the hydraulic control guide single block, the hydraulic control guide system is connected with the oil storage bag, the guide hydraulic cylinder and the anti-pollution micro-flow metal diaphragm pump through pipelines,

[0012] The guide hydraulic cylinder of each hydraulic control guide single block is located on the same horizontal plane perpendicular to the guide sleeve axis, and the front end of the piston rod of each guide hydraulic cylinder is provided with a thrust block.

[0013] Preferably, the hydraulic control guide system comprises a flow distribution oil suction check valve, a direct-acting proportional overflow valve and a safety valve, the oil inlet of the flow distribution oil suction check valve is connected with the oil storage bag, the oil outlet of the flow distribution oil suction check valve is connected with the oil inlet of the anti-pollution micro-flow metal diaphragm pump, the oil outlet of the anti-pollution micro-flow metal diaphragm pump is connected with the oil inlet of the flow distribution oil discharge check valve, the oil outlet of the flow distribution oil discharge check valve is connected with the rodless cavity of the guide hydraulic cylinder through a first throttle valve, the rod cavity of the guide hydraulic cylinder is connected with the oil storage bag, the oil inlets of the direct-acting proportional overflow valve and the safety valve are connected with the oil outlet of the flow distribution oil discharge check valve, the oil outlets of the direct-acting proportional overflow valve and the safety valve are connected with the oil storage bag, the oil inlet and the oil outlet of the spring accumulator are connected with the rodless cavity of the guide hydraulic cylinder through an electromagnetic proportional throttle valve, the leakage oil port of the spring accumulator is connected with the oil storage bag, and the first check valve is connected in parallel at the two ends of the electromagnetic proportional throttle valve.

[0014] Preferably, the anti-pollution micro-flow metal diaphragm pump comprises a base, a metal diaphragm and a ball head spring plunger, the base is fixedly installed on the inner side wall of the guide sleeve, the metal diaphragm is fixedly and sealingly installed on the base to form a closed working cavity, the ball head spring plunger is located in the working cavity and is fixedly installed on the base, the front end of the ball head spring plunger is in contact with the inner side of the metal diaphragm, the outer side of the metal diaphragm is in contact with an eccentric bearing, and the oil inlets and the oil outlets of the anti-pollution micro-flow metal diaphragm pump are formed in the base.

[0015] Preferably, the metal diaphragm is in the shape of a twice convex arc.

[0016] Preferably, the downhole electric energy extraction device is composed of a small impeller generator, a hydraulic reversing valve, a second check valve and a second throttle valve, two ends of the small impeller generator are communicated with the oil storage bag and the oil outlet of the hydraulic reversing valve respectively, the oil inlet of the hydraulic reversing valve is communicated with the oil inlet of the flow distribution and oil discharge check valve, two ends of the second throttle valve are communicated with the oil outlet of the flow distribution and oil discharge check valve and the K port of the hydraulic reversing valve respectively, the second check valve is connected in parallel at two ends of the second throttle valve, the small impeller generator is electrically connected with the storage battery in the storage battery compartment of the guide sleeve, and the storage battery is electrically connected with the electromagnetic proportional throttle valve and the direct-acting proportional overflow valve.

[0017] The beneficial effects achieved by the technical solutions of the present application are as follows:

[0018] 1. The anti-pollution micro-flow metal diaphragm pump provides a pollution-proof, leak-proof and micro-flow hydraulic pump for the hydraulic control guide system in the automatic directional drilling tool. The functions of the anti-pollution micro-flow metal diaphragm pump mainly include the following two aspects. On the one hand, the anti-pollution micro-flow metal diaphragm pump is sealed and installed with the base through the metal diaphragm, effectively isolating the clean hydraulic oil in the working cavity from the downhole drilling fluid and other pollution impurities, avoiding the flow of drilling fluid and other impurities into the working cavity of the pump and mixing with the clean hydraulic oil, and playing a role in preventing pollution. At the same time, it also avoids the reduction of sensitivity and control accuracy of the control elements of the hydraulic control guide system due to the pollution of high-pressure oil in the hydraulic control guide system, and even damage. On the other hand, compared with the plunger hydraulic pump mentioned in the background art of the Chinese patent, the metal diaphragm is the only deformation area of the anti-pollution micro-flow metal diaphragm pump, greatly reducing the area where oil leakage may exist. And the metal diaphragm is sealed and fixedly installed on the base, driven by the eccentric bearing pushing the outer convex surface of the metal diaphragm, the metal diaphragm makes small stroke reciprocating convex-concave motion, thereby changing the working cavity volume of the pump, realizing the non-external leakage operation of the anti-pollution micro-flow metal diaphragm pump.

[0019] 2. A B-type energy storage and utilization damping network is provided for a hydraulic control steering system in an automatic directional drilling tool. The network can make the hydraulic control steering system of the drilling tool realize stable steering thrust, high stability and fast recovery of stable steering thrust under strong vibration working conditions. When the hydraulic control steering system is steering in the actual downhole working conditions, the thrust block of the steering hydraulic cylinder vibrates to the right relative to the well wall due to the influence of strong vibration, and the thrust block connected by the piston rod and the well wall jumps. Under the action of the pressure in the rodless cavity of the steering hydraulic cylinder, the piston rod extends to the well wall to compensate for the distance between the thrust block connected by the piston rod and the well wall. At this time, the volume of the rodless cavity of the steering hydraulic cylinder increases, and the anti-pollution micro-flow metal diaphragm pump continuously supplies high-pressure oil to the steering hydraulic cylinder. At this time, the oil resistance-liquid capacity pressure differential network rapidly provides pressure oil in the rodless cavity of the steering hydraulic cylinder, and cooperates with the buffer pressure at the outlet of the first throttle valve in the B-type hydraulic damping half-bridge network to make the oil source pressure in the rodless cavity of the steering hydraulic cylinder recover to stable, thereby realizing the stability of the thrust of the hydraulic control steering system. When the pressure of the high-pressure oil supplied to the rodless cavity of the steering hydraulic cylinder fluctuates above and below the expected stable pressure value (or the expected stable steering thrust), part of the high-pressure oil flows to the spring accumulator through the one-way valve in the one-way throttle valve in the B-type energy storage and utilization damping network, and the pressure energy is stored in the spring accumulator, so that the pressure in the rodless cavity of the steering hydraulic cylinder gradually tends to the expected stable pressure value (or the expected stable steering thrust). When the pressure in the rodless cavity of the steering hydraulic cylinder fluctuates above and below the expected stable pressure value (or the expected stable steering thrust), under the action of the first throttle valve in the B-type hydraulic damping half-bridge, the oil source pressure of the anti-pollution micro-flow metal diaphragm pump is buffered, and under the pressure compensation of the oil resistance-liquid capacity pressure differential network, the pressure in the rodless cavity of the steering hydraulic cylinder tends to the expected stable pressure value (or the expected stable steering thrust). In the process from unstable oil source pressure (the oil supply pressure in the rodless cavity is higher or lower than the expected stable pressure value) to stable oil source pressure in the rodless cavity of the steering hydraulic cylinder, the recovery speed of the process from unstable pressure to stable pressure in the rodless cavity of the steering hydraulic cylinder can be controlled by adjusting the input voltage value of the one-way throttle valve in the B-type energy storage and utilization damping network, thereby shortening the waiting time of the process from unstable pressure to stable pressure in the steering hydraulic cylinder. At the same time, cooperating with the pressure stabilization adjustment process under the above-mentioned strong vibration working conditions, the stable thrust of the steering hydraulic cylinder is quickly compensated.

[0020] 3. The hydraulic guidance system of the present invention is equipped with a downhole power extraction device. Under normal operation of the hydraulic guidance system, the high-pressure oil at the outlet of the anti-pollution micro-flow metal diaphragm pump can be converted from hydraulic energy to electrical energy through the small impeller generator, thereby realizing downhole power extraction to charge the battery in the automatic directional drilling tool, thus solving the problem of insufficient power supply from downhole batteries.

[0021] 4. The hydraulic control guidance system of this invention is equipped with a safety valve, which can reduce the risk of stuck drill bits in automatic directional drilling tools.

[0022] 5. The hydraulic steering system in the automatic directional drilling tool of the present invention improves wellbore quality, the smoothness of the wellbore surface, and reduces the degree of helical bending of the wellbore during the drilling process.

[0023] 6. The hydraulic guidance system has a simple structure, is easy to maintain, and is safe and reliable. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the guide sleeve structure of the present invention;

[0025] Figure 2 This is a schematic diagram of the working principle of the guide sleeve cross section of the present invention;

[0026] Figure 3 This is a schematic diagram of the principle and structure of the hydraulic guidance system of the present invention;

[0027] Figure 4 This is a schematic diagram of the anti-pollution micro-flow metal diaphragm pump of the present invention.

[0028] 1. Guide sleeve; 2. Battery; 3. Oil reservoir bladder; 4. Guide hydraulic cylinder; 5. Anti-pollution micro-flow metal diaphragm pump; 6. Distribution suction check valve; 7. Oil inlet; 8. Oil outlet; 9. Distribution discharge check valve; 10. First throttle valve; 11. Direct-acting proportional relief valve; 12. Safety valve; 13. Spring accumulator; 14. Electromagnetic proportional throttle valve; 15. First check valve; 16. Base; 17. Metal diaphragm; 18. Ball-head spring plunger; 19. Working chamber; 20. Eccentric bearing; 21. Downhole power extraction device; 22. Small impeller generator; 23. Hydraulic directional valve; 24. Second check valve; 25. Second throttle valve; 26. Drill string; 27. Type B energy storage and utilization damping network; 28. Thrust block; 29. ​​Wellbore; 30. Hydraulically controlled guide unit integrated block. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings:

[0030] Depend on Figures 1 to 4 As shown, the hydraulic steering system of an automated directional drilling tool.

[0031] The application discloses a hydraulic control guiding system of an automatic directional drilling tool, which is characterized by comprising a guiding sleeve 1 and a battery storage 2,

[0032] The guiding sleeve 1 is provided with a battery storage bin and a hydraulic control guiding monomer integrated block bin, the battery storage 2 is fixedly installed in the battery storage bin, and three hydraulic control guiding monomer integrated block bins are evenly distributed along the axis of the guiding sleeve 1.

[0033] The hydraulic control guiding monomer integrated block 30 is provided with a hydraulic control guiding system, an oil storage rubber bag 3, a guiding hydraulic cylinder 4 and an anti-pollution micro-flow metal diaphragm pump 5, the hydraulic control guiding system is connected with the oil storage rubber bag 3, the guiding hydraulic cylinder 4 and the anti-pollution micro-flow metal diaphragm pump 5 through pipelines.

[0034] The guiding hydraulic cylinder 4 on each hydraulic control guiding monomer integrated block 30 is located on the same horizontal plane perpendicular to the axis of the guiding sleeve 1, and the front end of the piston rod of each guiding hydraulic cylinder 4 is provided with a thrust block 28.

[0035] The hydraulic control guiding system comprises a flow distribution oil suction one-way valve 6, a direct-acting proportional overflow valve 11 and a safety valve 12, the oil inlet of the flow distribution oil suction one-way valve 6 is connected with the oil storage rubber bag 3, the oil outlet of the flow distribution oil suction one-way valve 6 is connected with the oil inlet 7 of the anti-pollution micro-flow metal diaphragm pump 5, the oil outlet 8 of the anti-pollution micro-flow metal diaphragm pump 5 is connected with the oil inlet of a flow distribution oil discharge one-way valve 9, the oil outlet of the flow distribution oil discharge one-way valve 9 is connected with the rodless cavity of the guiding hydraulic cylinder 4 through a first throttle valve 10, the rod cavity of the guiding hydraulic cylinder 4 is connected with the oil storage rubber bag 3, the oil inlets of the direct-acting proportional overflow valve 11 and the safety valve 12 are connected with the oil outlet of the flow distribution oil discharge one-way valve 9, the oil outlets of the direct-acting proportional overflow valve 11 and the safety valve 12 are connected with the oil storage rubber bag 3, the oil inlet and the oil outlet of a spring accumulator 13 are connected with the rodless cavity of the guiding hydraulic cylinder 4 through an electromagnetic proportional throttle valve 14, the leakage oil port of the spring accumulator 13 is connected with the oil storage rubber bag 3, and a first one-way valve 15 is connected in parallel at the two ends of the electromagnetic proportional throttle valve 14. The safety valve 12 is only opened when a fault occurs in the hydraulic control guiding system, for example, when a pipe sticking phenomenon occurs, and under other conditions, the valve ports of the safety valve 12 are in a closed state.

[0036] The plurality of components of the hydraulic control guiding system are integrated and installed on the hydraulic control guiding monomer integrated block, which is beneficial to the machining and assembly in the early stage and is also beneficial to the direct installation of the hydraulic control guiding monomer integrated block on the guiding sleeve 1 in the later stage.

[0037] The first throttle valve 10, the electromagnetic proportional throttle valve 14, the first check valve 15 and the spring accumulator 13 constitute a B-type energy storage and utilization damping network 27.

[0038] The electromagnetic proportional throttle valve 14 and the first check valve 15 constitute a check throttle valve.

[0039] The electromagnetic proportional throttle valve 14, the flow distribution and oil discharge check valve 9 and the first throttle valve 10 constitute a B-type hydraulic damping half-bridge network.

[0040] The electromagnetic proportional throttle valve 14 and the spring accumulator 13 constitute a liquid resistance-liquid capacity pressure differential network.

[0041] The spring accumulator 13, the electromagnetic proportional throttle valve 14, the first throttle valve 10 and the flow distribution and oil discharge check valve 9 constitute a dynamic pressure feedback network.

[0042] The B-type hydraulic damping half-bridge network plays a buffering and compensating role for the oil source pressure or the guiding thrust of the guiding hydraulic cylinder 4. The liquid resistance-liquid capacity pressure differential network can improve the static stiffness and the stability of the guiding hydraulic cylinder 4 thrust of the liquid-controlled guiding system and reduce the steady-state error of the liquid-controlled guiding system and the guiding hydraulic cylinder 4 thrust. The dynamic pressure feedback network is also jointly constituted by the B-type hydraulic damping half-bridge network and the liquid resistance-liquid capacity pressure differential network, and has the ability of the liquid-controlled guiding system to resist strong vibration or external environmental interference underground.

[0043] By adjusting the input voltage of the check throttle valve, the waiting time for the pressure of the guiding hydraulic cylinder 4 to become stable from unstable can be changed.

[0044] The B-type hydraulic damping half-bridge network, the liquid resistance-liquid capacity pressure differential network, the dynamic pressure feedback network and the check throttle valve jointly constitute a B-type energy storage and utilization damping network 27. The B-type energy storage and utilization damping network 27 has the sum of the functions and effects of the above-mentioned networks and the check throttle valve.

[0045] The anti-pollution micro-flow metal diaphragm pump 5 comprises a base 16, a metal diaphragm 17 and a ball head spring plunger 18. The base 16 is fixedly installed on the inner side wall of the guiding sleeve 1. The metal diaphragm 17 is sealingly and fixedly installed on the base 16 to form a closed working cavity 19. The ball head spring plunger 18 is located in the working cavity 19 and is fixedly installed on the base 16. The front end of the ball head spring plunger 18 is in contact with the inner side of the metal diaphragm 17. The outer side of the metal diaphragm 17 is in contact with an eccentric bearing 20. The oil inlet 7 and the oil outlet 8 of the anti-pollution micro-flow metal diaphragm pump 5 are respectively formed in the base 16. In use, the guiding sleeve 1 is in contact with the inner surface of the well wall 29 and is installed on the outer side of the drill string 26. The eccentric bearing 20 is fixed on the drill string 26 and is in contact with the outer side of the metal diaphragm 17.

[0046] Through the rotation of the drill string 26, the mechanical energy is extracted from the rotating drill string 26 by the eccentric bearing 20 and the anti-pollution micro-flow metal diaphragm pump 5 under the action of the eccentric bearing 20, and is converted into the hydraulic pressure energy of the hydraulic control guiding system for the operation of the hydraulic control guiding system.

[0047] The metal diaphragm 17 is in the shape of a secondary convex arc. The metal diaphragm 17 has a small outward convex trend at the part near the sealing fixing position, and has a large outward convex trend at the middle part. This is beneficial to increase the force receiving area of the metal diaphragm 17 in tangential contact with the eccentric bearing 20, thereby reducing the stress on the metal diaphragm 17, and effectively preventing the metal diaphragm 17 from being broken due to the gradually increasing force generated by the eccentric bearing 20.

[0048] The downhole electric energy extraction device 21 is composed of a small impeller generator 22, a hydraulic directional valve 23, a second check valve 24 and a second throttle valve 25. The two ends of the small impeller generator 22 are respectively connected with the oil storage bag 3 and the oil outlet of the hydraulic directional valve 23. The oil inlet of the hydraulic directional valve 23 is connected with the oil inlet of the flow distribution and oil discharge check valve 9. The two ends of the second throttle valve 25 are respectively connected with the oil outlet of the flow distribution and oil discharge check valve 9 and the K port of the hydraulic directional valve 23. The second check valve 24 is connected in parallel at the two ends of the second throttle valve 25. The small impeller generator 22 is electrically connected with the storage battery 2 in the storage battery compartment of the guide sleeve 1. The storage battery 2 is electrically connected with the electromagnetic proportional throttle valve 14 and the direct-acting proportional overflow valve 11. The second check valve 24 and the second throttle valve 25 are connected in parallel to form a damper. The second check valve 24 is used to ensure the smooth oil inlet of the end surface of the hydraulic directional valve 23. The second throttle valve 25 is used for throttling the oil return of the end surface of the hydraulic directional valve 23, so as to realize the smooth switching of the hydraulic directional valve 23. The hydraulic directional valve 23 is a two-position two-way directional valve. One end of the valve core is connected with the damper. The other end of the valve core is provided with a return spring. The return force of the return spring is the maximum stable thrust when the piston rod of the guide hydraulic cylinder 4 is fully extended.

[0049] The direct-acting proportional overflow valve 11 uses an analog signal to continuously control and adjust the guiding force of the hydraulic control guiding system downhole. By adjusting the input voltage of the direct-acting proportional overflow valve 11 online, the electromagnetic force acting on the valve core is changed, and compared with the hydraulic pressure acting on the valve core through the outlet oil of the flow distribution and oil discharge check valve 9 of the anti-pollution micro-flow metal diaphragm pump 5, so as to control the opening degree of the direct-acting proportional overflow valve 11, and then discharge the excess oil in the dry cavity of the guide hydraulic cylinder 4, so as to achieve the purpose of adjusting the guiding force of the hydraulic control guiding system. By changing the input voltage of the direct-acting overflow valve 11, the continuous adjustment of the guiding thrust of the hydraulic control guiding system can be realized.

[0050] Working principle: the eccentric bearing 20 is installed on the drill string 26, and the eccentric bearing 20 is in tangential contact with the metal diaphragm 17 of the anti-pollution micro-flow metal diaphragm pump 5. When the drill string 26 rotates, the eccentric bearing 20 also rotates, and the anti-pollution micro-flow metal diaphragm pump 5 extracts mechanical energy from the drill string 26 through the eccentric bearing 20, and converts it into hydraulic pressure energy through the extrusion and release of the metal diaphragm 17 to provide hydraulic pressure for the hydraulic guiding system. When the drill string 26 rotates one revolution, the eccentric bearing 20 completes the extrusion and release process of the metal diaphragm 17, and the working chamber 19 of the anti-pollution micro-flow metal diaphragm pump 5 completes one expansion and compression motion. As the eccentricity of the eccentric bearing 20 installed on the drill string 26 gradually decreases, the metal diaphragm 17 gradually changes from the extrusion state to the release state under the action of the ball head spring plunger 18. When the working chamber 19 expands, the volume of the working chamber 19 increases, a negative pressure is formed in the chamber, and the flow distribution oil suction one-way valve 6 opens to suck low-pressure oil from the oil storage bag 3. When the eccentricity of the eccentric bearing 20 installed on the drill string 26 gradually increases, the metal diaphragm 17 changes from the release state to the extrusion state, and the volume of the working chamber 19 decreases, forming a high pressure in the chamber. The high-pressure oil pushes away the flow distribution oil discharge one-way valve 9, and the high-pressure oil is sent into the rodless chamber of the guide hydraulic cylinder 4. The drill string 26 rotates continuously, the eccentricity of the eccentric bearing 20 increases and then decreases repeatedly, the metal diaphragm 17 completes multiple extrusion and release cycles, the anti-pollution micro-flow metal diaphragm pump 5 continuously completes multiple expansion and compression motions, and continuously inputs high-pressure oil source into the rodless chamber of the guide hydraulic cylinder 4, and the piston rod of the guide hydraulic cylinder 4 continuously extends outward. By adjusting the input voltage value of the direct-acting proportional overflow valve 11 online, the opening degree of the direct-acting proportional overflow valve 11 is changed, and the lifting and lowering of the guide hydraulic cylinder 4 piston rod thrust is realized. When the guide hydraulic cylinder 4 thrust is unstable due to strong vibration working conditions underground, the outlet oil pressure of the anti-pollution micro-flow metal diaphragm pump 5 is buffered, the rodless chamber of the guide hydraulic cylinder 4 is compensated by high-pressure oil, and the oil pressure in the rodless chamber of the guide hydraulic cylinder 4 is stabilized under the joint action of the B-type hydraulic damping half-bridge, the liquid resistance-liquid capacity pressure differential network and the dynamic feedback network of the B-type energy storage and utilization damping network 27. By adjusting the input voltage value of the electromagnetic proportional throttle valve 14 in the B-type energy storage and utilization damping network 27, the opening degree of the variable throttle valve 14 is changed, thereby shortening the waiting time for the oil source pressure in the rodless chamber of the guide hydraulic cylinder 4 to stabilize from unstable, and achieving the effect of rapid compensation of the rodless chamber pressure of the guide hydraulic cylinder 4. In addition, while the hydraulic guiding system realizes the guiding function, the downhole electric energy extraction device 21 can convert hydraulic energy and electric energy without affecting the normal operation of the guide hydraulic cylinder 4, and charge the downhole storage battery 2 in the guide sleeve 1.When the pressure in the rodless chamber of the guide hydraulic cylinder 4 is lower than the spring return force of the hydraulic reversing valve 23, the hydraulic reversing valve 23 does not reverse, the valve port is not opened, the small impeller generator 22 in the downhole electric energy extraction device 21 does not work, the anti-pollution micro-flow metal diaphragm pump 5 supplies oil to the guide hydraulic cylinder 4, and the thrust block 28 of the guide hydraulic cylinder 4 gradually extends outward; when the pressure in the rodless chamber of the guide hydraulic cylinder 4 is higher than or equal to the spring return force of the hydraulic reversing valve 23, which is the maximum thrust of the guide hydraulic cylinder, that is, the guide hydraulic cylinder 4 piston rod is fully extended and the thrust reaches the maximum, the valve port of the hydraulic reversing valve 23 is opened, and the outlet oil of the anti-pollution micro-flow metal diaphragm pump 5 flows to the oil inlet of the small impeller generator 22 through the hydraulic reversing valve 23, and the oil flows back to the oil storage bladder 3 from the oil outlet. The kinetic energy between the high-pressure oil source entering the oil inlet and flowing back to the oil storage bladder 3 drives the impeller of the small impeller generator 22 to rotate, so that the small impeller generator 22 works and generates electric energy to charge the downhole storage battery 2. Due to the reverse blocking effect of the flow distribution and oil discharge one-way valve 9, the oil source pressure in the rodless chamber of the guide hydraulic cylinder 4 is kept, the thrust block 28 connected to the piston rod continuously and stably pushes against the well wall 29, and when the pressure in the rodless chamber of the guide hydraulic cylinder 4 is lower than the spring return force of the hydraulic reversing valve, the valve port of the hydraulic reversing valve 23 is closed, and the anti-pollution micro-flow metal diaphragm pump 5 continuously supplies oil to the rodless chamber of the guide hydraulic cylinder 4. The extraction of downhole electric energy is realized, so that the small impeller generator 22 charges the downhole storage battery 2.

[0051] In addition, when the hydraulic control guide system fails or other factors cause the automatic directional drilling tool to be stuck, the drill string 26 stops working, the anti-pollution micro-flow metal diaphragm pump 5 stops supplying oil to the rodless chamber of the guide hydraulic cylinder 4, and under the reaction force of the well wall 29 on the thrust block 28 during the lifting of the drilling tool, the high-pressure oil in the rodless chamber of the guide hydraulic cylinder 4 gradually flows to the oil storage bladder 3 through the safety valve 12.

Claims

1. A hydraulic guidance system for an automatic directional drilling tool, characterized in that, Includes a guide sleeve (1) and a storage battery (2), The guide sleeve (1) has a battery compartment and a hydraulically controlled guide unit integrated block compartment. The battery (2) is fixedly installed in the battery compartment. There are three hydraulically controlled guide unit integrated block compartments evenly distributed along the axis of the guide sleeve (1). Each hydraulically controlled guide unit integrated block compartment is fixedly installed with a hydraulically controlled guide unit integrated block (30). The hydraulically controlled guide unit integrated block (30) is equipped with a hydraulically controlled guide system, an oil reservoir (3), a guide hydraulic cylinder (4), and a contamination-resistant micro-flow metal diaphragm pump (5). The hydraulically controlled guide system is connected to the oil reservoir (3), the guide hydraulic cylinder (4), and the contamination-resistant micro-flow metal diaphragm pump (5) through pipelines. The oil outlet (8) of the contamination-resistant micro-flow metal diaphragm pump (5) is connected to the oil inlet of the distribution and discharge check valve (9). The inlet of the direct-acting proportional relief valve (11) is connected to the outlet of the distribution and discharge check valve (9). The outlet of the direct-acting proportional relief valve (11) is connected to the oil reservoir (3). The inlet and outlet of the spring accumulator (13) are connected to the rodless chamber of the guide hydraulic cylinder (4) through the electromagnetic proportional throttle valve (14). The leakage port of the spring accumulator (13) is connected to the oil reservoir (3). The guide hydraulic cylinders (4) on each hydraulically controlled guide unit integrated block (30) are respectively located on the same cross section of the vertical guide sleeve (1) axis, and each guide hydraulic cylinder (4) has a thrust block (28) installed at the front end of the piston rod. It also includes a downhole power extraction device (21), which consists of a small impeller generator (22), a hydraulic directional valve (23), a second check valve (24), and a second throttle valve (25). The two ends of the small impeller generator (22) are connected to the oil storage bladder (3) and the oil outlet of the hydraulic directional valve (23), respectively. The oil inlet of the hydraulic directional valve (23) is connected to the oil inlet of the distribution and discharge check valve (9). The two ends of the second throttle valve (25) are connected to the oil outlet of the distribution and discharge check valve (9) and the K port of the hydraulic directional valve (23), respectively. The second check valve (24) is connected in parallel to the two ends of the second throttle valve (25). The small impeller generator (22) is electrically connected to the battery (2) in the battery compartment on the guide sleeve (1). The battery (2) is electrically connected to the electromagnetic proportional throttle valve (14) and the direct-acting proportional overflow valve (11).

2. The hydraulic guidance system for an automatic directional drilling tool according to claim 1, characterized in that: The hydraulic control system includes a flow-distribution suction check valve (6) and a safety valve (12). The inlet of the flow-distribution suction check valve (6) is connected to the oil reservoir (3), and the outlet of the flow-distribution suction check valve (6) is connected to the inlet (7) of the anti-pollution micro-flow metal diaphragm pump (5). The outlet of the flow-distribution discharge check valve (9) is connected to the rodless chamber of the guide hydraulic cylinder (4) through the first throttle valve (10). The rod chamber of the guide hydraulic cylinder (4) is connected to the oil reservoir (3). The inlet of the safety valve (12) is connected to the outlet of the flow-distribution discharge check valve (9), and the outlet of the safety valve (12) is connected to the oil reservoir (3). The first check valve (15) is connected in parallel to both ends of the electromagnetic proportional throttle valve (14).

3. The hydraulic guidance system for an automatic directional drilling tool according to claim 1, characterized in that: The anti-pollution micro-flow metal diaphragm pump (5) includes a base (16), a metal diaphragm (17), and a ball spring plunger (18). The base (16) is fixedly installed on the inner wall of the guide sleeve (1). The metal diaphragm (17) is sealed and fixedly installed on the base (16) to form a closed working chamber (19). The ball spring plunger (18) is located in the working chamber (19) and is fixedly installed on the base (16). The front end of the ball spring plunger (18) is in contact with the inner side of the metal diaphragm (17), and the outer side of the metal diaphragm (17) is in contact with the eccentric bearing (20). The oil inlet (7) and oil outlet (8) of the anti-pollution micro-flow metal diaphragm pump (5) are respectively opened on the base (16).

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