Coiled tubing oscillation impact type screw motor

Abstract

The invention discloses a coiled tubing oscillation impact type screw motor, and relates to the technical field of drilling and grinding bridge plugs in oil field coiled tubing operation, the coiled tubing oscillation impact type screw motor comprises an upper joint, an upper outer cylinder and a core shaft outer cylinder, a disc spring is arranged in the upper outer cylinder, a core shaft is arranged in the core shaft outer cylinder, a gap is arranged between the core shaft and the core shaft outer cylinder, and the core shaft outer cylinder is provided with a through hole communicated with the outside; the top of the mandrel is fixedly connected with the disc spring, a piston is arranged at the bottom of the mandrel, and a through hole communicated with the outside is formed in the mandrel outer cylinder, so that a high-pressure area is formed below the piston in the tool and in the mandrel, and a low-pressure area is formed in a gap between the mandrel above the piston and the mandrel outer cylinder. When liquid flows through the instantaneous maximum / minimum staggered area formed between the movable valve plate and the static valve plate, large pressure fluctuation can be generated due to the change of flow resistance to form a water hammer effect. Due to the existence of the through hole which is directly communicated with the underground annulus, the pressure change is converted into the internal and external pressure difference, so that the dynamic response of the whole system is enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of drilling and grinding bridge plugs in oil field continuous tubing operations, and in particular to a continuous tubing oscillating impact type screw motor. Background Art

[0002] The main structural features of existing screw motor tools are generally composed of four major components: the bypass valve assembly, the stator and rotor assembly, the flexible shaft assembly, and the drive shaft assembly. Their basic operating principle is as follows: the mud pump outputs liquid, which enters the motor through the bypass valve. The liquid creates a certain pressure differential between the motor inlet and outlet, driving the motor rotor to rotate. The speed and torque are then transmitted to the grinding shoe via the flexible shaft and drive shaft.

[0003] The current screw motor can provide drilling power and meet basic usage requirements. However, there are the following problems: 1. In horizontal wells, deep wells, and ultra-deep well operations, complex well conditions lead to unstable bit pressure provided by the screw motor to the mill shoe; 2. The screw motor does not fit the bridge plug well enough, resulting in low efficiency in drilling and grinding the bridge plug. 3. To increase the drilling and grinding efficiency of the screw motor, the existing method is to connect a hydraulic oscillator to the screw motor. However, in the case of upturned horizontal wells and poor wellbore trajectories, the combination of the hydraulic oscillator and the motor is difficult to improve the drilling and grinding bridge plug efficiency.

[0004] The invention patent application with publication number CN117328810A discloses a multi-stage pulse oscillation screw, which consists of a bypass valve assembly, a first pulse assembly, a motor assembly, a universal shaft assembly, a second pulse assembly, and a transmission assembly; the bypass valve assembly is used to control the flow direction of the drilling fluid; the first pulse assembly generates a periodic oscillation effect by periodically changing the flow area between the dynamic valve and the static valve, pushing the hammer to compress the second spring to generate axial impact; the motor assembly is used to convert the drilling fluid pressure energy into mechanical energy for the rotation of the motor rotor; the universal shaft assembly is used to convert the eccentric rotation of the motor rotor into fixed axis rotation; the second pulse assembly generates a periodic oscillation effect by periodically changing the flow area between the water cap and the second pulse housing; the transmission assembly is used to transmit the rotational mechanical energy to the drill bit.

[0005] However, this patent pushes the piston through internal pressure difference. Since the liquid inside the tool as a whole is incompressible, the pressure difference formed is small. At the same time, the matching water hammer spring is also small. Therefore, the oscillation force generated by the above structure is very small and cannot be used in drilling and grinding bridge plugs in oil field continuous tubing operations. Summary of the Invention

[0006] The present invention aims to provide a coiled tubing oscillating impact screw motor. Aiming at the actual application conditions of downhole motor tools, the present invention ensures that the motor generates sufficient oscillating force. The motor adopts the principle of internal and external pressure difference and is equipped with a double-piston and multiple sets of disc springs. Through a more practical internal and external pressure difference method and a more reliable double-piston thrust design, as well as a matching multiple sets of disc springs, a stable oscillating force is generated.

[0007] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows: A continuous oil tubing oscillating impact screw motor comprises an upper joint, an upper outer tube and a core shaft outer tube. The top of the upper joint is connected to the mud pump, the bottom of the upper joint is connected to the upper outer tube, a disc spring is provided in the upper outer tube, the bottom of the upper outer tube is connected to the core shaft outer tube, a core shaft is provided in the core shaft outer tube, a gap is provided between the core shaft and the core shaft outer tube, the core shaft outer tube is provided with a through hole connected to the outside, the top of the core shaft is fixedly connected to the disc spring, the bottom of the core shaft is provided with a piston, the bottom of the inner side of the core shaft outer tube is provided with an anti-collision ring, the bottom of the core shaft outer tube is connected to the lower joint, the bottom of the lower joint is connected to a valve seat, the bottom of the lower joint is provided with a static valve plate, the top of the valve seat is provided with a rotatable dynamic valve plate, the bottom of the valve seat is connected to the stator and rotor assembly, the bottom of the stator and rotor assembly is connected to the flexible shaft assembly, and the bottom of the flexible shaft assembly is connected to the transmission assembly.

[0008] The central flow channel of the stationary valve disc is an umbrella-shaped structure, while the central flow channel of the movable valve disc is the umbrella-shaped tip portion of the umbrella-shaped structure. The movable valve disc rotates in response to the impact of liquid, and the internal structures of the stationary and movable valve discs intersect with each other as the movable disc rotates. When the internal structures of the stationary and movable valve discs are fully closed (with the instantaneous minimum intersect area), the liquid flow rate through the internal structures is at its highest, and the pressure generated by the liquid passing through the discs is at its highest. When the stationary valve disc rotates to a fully open position with the internal structure of the movable valve disc (with the instantaneous maximum intersect area), the liquid flow rate through the internal structures is at its lowest, and the pressure generated by the liquid passing through the discs is at its lowest.

[0009] The middle flow channel of the static valve plate is a vertical structure, and the middle flow channel of the dynamic valve plate is inclined at 30°. The inclined flow channel of the dynamic valve plate brings resistance when the liquid flows, because the change in the flow area will generate greater fluid pressure, thereby enhancing the oscillation impact effect.

[0010] The movable valve plate and the static valve plate are clearance-matched; The bottom of the valve seat is connected to the stator and rotor assembly through a connector; A gasket is provided between the connector and the valve seat to adjust the gap between the static valve disc and the dynamic valve disc; Depending on the difficulty of drilling and grinding the bridge plug, the thickness of the gasket can be adjusted. The gasket thickness is 0.1mm, 0.3mm or 0.5mm. Adjusting the gap size will affect the pressure drop difference generated by the dynamic valve plate and the static valve plate when they rotate and stagger. The smaller the gap, the greater the pressure drop difference, and the greater the downward impact force generated in the end.

[0011] The movable valve disc is fitted with a valve seat in a clearance, and the movable valve disc and the valve seat are installed by adopting a hot embedding process. The movable valve disc can rotate in the valve seat.

[0012] The top of the core shaft passes through the core shaft outer cylinder and is fixedly connected to the disc spring in the upper outer cylinder. The top of the core shaft slides and seals with the inner wall of the upper outer cylinder. A gap is provided on the side of the core shaft and the inside of the upper outer cylinder. The connection between the upper outer cylinder and the core shaft outer cylinder is sealed with the core shaft. A hole connected to the outside is provided on the side of the core shaft at the gap between the core shaft and the upper outer cylinder. When the internal structure of the dynamic valve plate and the static valve plate changes from a fully open state to a fully closed state, the flow rate of the liquid suddenly decreases and a water hammer effect is generated, that is, the kinetic energy of the fluid is directly converted into pressure energy. The inside of the core shaft is a high-pressure area. The liquid in the high-pressure area flows out through the hole into the gap between the core shaft and the upper outer cylinder. The high-pressure liquid in the gap pushes the top of the core shaft to compress the disc spring, and interacts with the high-pressure liquid at the bottom of the piston to jointly push the core shaft to compress the disc spring, forming a double-piston effect.

[0013] A sealing ring is sleeved on the top of the core shaft, and a sliding sealing fit is achieved between the top of the core shaft and the inner wall of the upper outer cylinder through the sealing ring.

[0014] The disc springs are multiple groups of disc springs connected end to end in sequence to ensure the generation of a stable oscillating force.

[0015] The disc spring is pre-stressed during installation and has an initial compression force. The size of the initial pre-tightening force can be set according to the actual flow rate to ensure that the elastic force of the disc spring can push the piston to collide with the anti-collision ring.

[0016] Beneficial effects of the present invention: 1. In this invention, the periodic opening and closing of the dynamic and static valve discs creates a water hammer effect, generating both upward thrust and downward impact. Combined with the stator and rotor assembly, this dual power of "rotation + impact" effectively improves drilling efficiency when drilling bridge plugs in oilfield coiled tubing operations.

[0017] 2. In this invention, by providing a through-hole connecting the core shaft outer tube to the outside, a distinct high-pressure zone (below the piston and inside the core shaft) and a low-pressure zone (above the piston, between the core shaft and the core shaft outer tube) are formed inside the tool. When liquid flows through the instantaneous maximum / minimum intersection area formed between the moving and stationary valve discs, the change in flow resistance produces large pressure fluctuations, leading to a water hammer effect. The presence of a through-hole directly connecting to the downhole annulus allows these pressure fluctuations to be more effectively converted into an internal-external pressure differential, thereby enhancing the dynamic response of the entire system.

[0018] 3. The present invention involves the top of the mandrel passing through the mandrel outer cylinder and fixedly connected to the disc spring within the upper outer cylinder. The top of the mandrel forms a sliding, sealed engagement with the interior of the upper outer cylinder. A gap is defined between the side of the mandrel and the interior of the upper outer cylinder. The upper outer cylinder is sealed to the mandrel at the junction with the mandrel outer cylinder, and a connecting hole is provided on the side of the mandrel at the gap between the mandrel and the upper outer cylinder. This separates the mandrel into an independent pressure chamber, giving the mandrel a piston function. When the dynamic and static valve discs transition from fully open to fully closed, high pressure is generated within the mandrel. Fluid pressure initially pushes the piston upward. Simultaneously, high-pressure fluid enters a second high-pressure zone formed by the mandrel and the upper outer cylinder, generating an upward force at the top of the mandrel, creating a high-pressure zone-low-pressure zone-high-pressure zone pattern. This generates a double thrust to compress the disc spring. This superimposed bidirectional thrust, while maintaining the overall structure of the tool, addresses the issues of conventional fluid-driven devices that rely on a dual-piston structure for bidirectional thrust, resulting in a complex and bulky structure, and a single-piston structure that can only output thrust in one direction, resulting in low efficiency.

[0019] 4. The dynamic valve plate and static valve plate of the present invention are designed with an "umbrella-shaped" structure. The "umbrella-shaped" dynamic and static valve plate structure design achieves a maximum and minimum interleaving area ratio of 4.7:1 through the interleaving of the "umbrella tip" and the "umbrella handle", which is equivalent to doubling the pulse energy generated by this application under the same displacement and specifications.

[0020] 5. In this invention, the central flow channel of the stationary valve disc is vertical, while the central flow channel of the movable valve disc is inclined at a 30° angle. The difference in fluid forces between the straight and inclined channels directly affects flow characteristics and energy loss. The straight channel exhibits pronounced axisymmetry, resulting in high velocity at the center and a sharp drop in velocity near the walls due to boundary layer effects. Furthermore, longitudinal vortices are more likely to form in the straight sections, increasing turbulent energy consumption. An inclined channel, where the channel axis is angled with the mainstream direction, alters the mainstream direction, inducing centrifugal force through the normal velocity component, balancing the axial pressure gradient, reducing boundary layer separation, and suppressing the formation of secondary vortices. However, directional changes in the two inclined sections (for example, a 30° left turn followed by a 60° right turn) can cause repeated changes in the direction of the centrifugal force, triggering flow oscillations and indirectly increasing driving energy consumption. In a straight channel combined with an inclined channel, the straight section allows for full boundary layer development, reducing the impact of inlet disturbances in the straight inclined section. The inclined section only undergoes a single directional adjustment, balancing centrifugal force and pressure gradients and preventing the superposition of secondary flows. At the same Reynolds number, the "direct current + inclined" combination consumes 15% to 30% less energy than the dual-inclined combination. When the angle between the inclined section and the direct current section is acute (θ = 30° to 60°), the centrifugal force component exerted on the fluid during the diversion process forms a dynamic balance with the axial pressure gradient, preventing flow separation. The centrifugal force component is directly proportional to the change in the acute angle, while the axial pressure gradient is inversely proportional to the change in the acute angle. Therefore, the smaller the angle, the smaller the centrifugal force contribution, and the flow moves closer to the axial direction. When θ = 30°, centrifugal force effectively guides the flow diversion while avoiding excessive fluid disturbance.

[0021] 6. In the present invention, the movable valve disc and the static valve disc are fitted with a gap, and a gasket for adjusting the gap size between the static valve disc and the movable valve disc is provided between the connector and the valve seat; the gasket specifications include 0.1mm, 0.3mm and 0.5mm. The gap between the valve discs is set to ensure the rotation of the movable valve disc, avoid motion hysteresis caused by friction or rigid contact, and thermal seizure of the valve disc material caused by temperature changes. The flow resistance of the gap between the movable and static valve discs is related to the gap size. Within a certain range, when the gap decreases, the flow becomes laminar and the flow resistance increases sharply, resulting in an increase in the pressure difference on both sides of the movable and static valve discs. When the gap increases, the flow turns into turbulent flow, the flow resistance decreases relatively, and the pressure difference on both sides of the movable and static valve discs decreases. The three gap ranges given in this application can adapt to the pressure drop difference requirements of different well conditions by adjusting the gap without changing other parameters while ensuring the above functions; the gap setting is mainly aimed at well conditions with too long horizontal sections. The longer the horizontal section, the greater the pressure drop requirement. Specifically: 0.1mm is suitable for horizontal sections with a length greater than 3000 meters, 0.3mm is suitable for horizontal sections with a length of 2000 meters to 3000 meters, and 0.5mm is suitable for horizontal sections with a length of 1000 meters to 2000 meters.

[0022] 7. The dynamic transformation of the high-pressure area of ​​the dynamic and static valve discs in the present invention is combined with the disc spring and through-hole linkage design to realize the oscillation impact function. When the dynamic and static valve discs are turned from the fully open state to the fully closed state, the inside of the core shaft is a high-pressure area, and the fluid pressure pushes the piston upward to compress the disc spring. When the dynamic and static valve discs are turned from the fully closed state to the fully open state, the high-pressure area is transformed into a low-pressure area, and the disc spring resets downward to push the core shaft and the piston. The downward fluid also exerts a downward force on the top of the core shaft. At the same time, the annular space liquid acts on the upper end face of the piston through the through-hole. The three thrusts work together to cause the piston to generate a downward impact force. Due to the periodic change of high pressure formed by the water hammer effect, even when parameters such as the displacement and pressure of the mud are constant, this high pressure can be guaranteed to change periodically. In this application, the dynamic and static valve discs, disc springs, and through-holes are all core structures to ensure the push of the piston. Without any one of them, no axial impact force can be generated. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic structural diagram of the coiled tubing oscillating impact screw motor of the present invention.

[0024] Figure 2 This is a schematic diagram of the upper outer cylinder structure of the coiled tubing oscillating impact screw motor of the present invention.

[0025] Figure 3 This is a schematic diagram of the core shaft and outer cylinder structure of the coiled tubing oscillating impact screw motor of the present invention.

[0026] Figure 4 Schematic diagram of the valve seat structure of the coiled tubing oscillating impact screw motor of the present invention.

[0027] Figure 5It is a partial schematic diagram of the coiled tubing oscillating impact screw motor disc spring being compressed according to the present invention.

[0028] Figure 6 It is a partial schematic diagram of the coiled tubing oscillating impact screw motor piston colliding with the anti-collision ring of the present invention.

[0029] Figure 7 This is a schematic diagram of the structure of the movable valve plate of the coiled tubing oscillating impact screw motor of the present invention.

[0030] Figure 8 This is a schematic diagram of the static valve plate structure of the coiled tubing oscillating impact screw motor of the present invention.

[0031] Figure 9 This is a schematic diagram of the minimum interleaving area between the dynamic valve plate and the static valve plate of the coiled tubing oscillating impact screw motor of the present invention.

[0032] Figure 10 This is a schematic diagram of the maximum interleaving area between the dynamic valve plate and the static valve plate of the coiled tubing oscillating impact screw motor of the present invention.

[0033] Among them, 1. upper joint; 2. upper outer tube; 3. core shaft outer tube; 4. disc spring; 5. core shaft; 6. through hole; 7. piston; 8. anti-collision ring; 9. lower joint; 10. valve seat; 11. static valve plate; 12. dynamic valve plate; 13. stator and rotor assembly; 14. flexible shaft assembly; 15. transmission assembly; 16. connector. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below with reference to the examples, but the embodiments of the present invention are not limited thereto.

[0035] Example 1 like Figures 1 to 6 As shown, this embodiment provides a continuous tubing oscillating impact screw motor, including an upper outer tube 2 and a core shaft outer tube 3. The top of the upper joint 1 is connected to the mud pump, and the bottom of the upper joint 1 is connected to the upper outer tube 2. A disc spring 4 is provided in the upper outer tube 2. The bottom of the upper outer tube 2 is connected to the core shaft outer tube 3. A core shaft 5 is provided in the core shaft outer tube 3. A gap is provided between the core shaft 5 and the core shaft outer tube 3. The core shaft outer tube 3 is provided with a through hole 6 connected to the outside. The top of the core shaft 5 is fixedly connected to the disc spring 4. A piston 7 is provided at the bottom of the core shaft 5. An anti-collision ring 8 is provided at the bottom inside the inner side of the core shaft outer tube 3. The bottom of the core shaft outer tube 3 is connected to the lower joint 9. The bottom of the lower joint 9 is connected to a valve seat 10. A static valve plate 11 is provided at the bottom of the lower joint 9. A rotatable dynamic valve plate 12 is provided at the top of the valve seat 10. The bottom of the valve seat 10 is connected to the stator and rotor assembly 13. The bottom of the stator and rotor assembly 13 is connected to the flexible shaft assembly 14. The bottom of the flexible shaft assembly 14 is connected to the transmission assembly 15.

[0036] In this embodiment, the liquid output by the mud pump passes through the disc spring 4, core shaft 5, piston 7, anti-collision ring 8, and lower joint 9 to reach the static valve plate 11. The static valve plate 11 is fixed in position, and the dynamic valve plate 12 rotates in the valve seat 10 due to the impact of the liquid. The flow channel between the static valve plate 11 and the dynamic valve plate 12 produces staggered contact as the dynamic valve plate 12 rotates. When the internal structure of the static valve plate 11 and the dynamic valve plate 12 is in the middle flow channel (instantaneous minimum staggered area), the flow rate of the liquid flowing through the middle flow channel is the largest, and the pressure generated by the liquid passing through the valve plate is the largest. When the static valve plate 11 rotates to the fully open state (instantaneous maximum staggered area) between the static valve plate 11 and the dynamic valve plate 12, the flow rate of the liquid flowing through the internal structure is the smallest, and at this time, the pressure generated by the liquid passing through the valve plate is the smallest; Because the movable valve disc 12 is constantly rotating, the liquid flows downward in the water hole. When the internal structure of the movable valve disc 12 and the static valve disc 11 changes from a fully open state to a fully closed state, the flow rate of the liquid suddenly decreases, which will produce a water hammer effect. That is, the kinetic energy of the fluid is directly converted into pressure energy to form a high-pressure area. This fluid pressure acts on the piston 7. The contact area between the liquid pressure and the piston 7 will generate a thrust on the piston 7. The area below the piston 7 and inside the core shaft 5 are high-pressure areas. Because the through hole 6 of the core shaft outer tube 3 is connected to the downhole annulus, the gap between the core shaft 5 and the core shaft outer tube 3 above the piston 7 is a low-pressure area, while the inside of the core shaft 5 is a high-pressure area. The thrust generated by the piston 7 in the high-pressure area squeezes the liquid in the low-pressure area. The piston 7 further pushes the core shaft 5 upward and transmits the thrust to the disc spring 4. At this time, because the thrust of the piston 7 is greater than the preload of the disc spring 4, the disc spring 4 is compressed. Figure 5 As shown; like Figure 6 As shown, when the internal structure of the static valve plate 11 and the dynamic valve plate 12 changes from a fully closed state to a fully open state, the liquid will continue to flow downward, the generated fluid high-pressure area disappears, and an oscillation effect is formed inside the screw motor.

[0037] At this point, the thrust generated by the piston 7 disappears, and the thrust exerted on the core shaft 5 and the disc spring 4 disappears. The disc spring 4 generates a downward elastic force, which acts on the core shaft 5 and is transmitted to the piston 7, pushing the piston 7 downward, and eventually pushing the piston 7 to collide with the anti-collision ring 8. The impact force of the collision between the piston 7 and the anti-collision ring 8 is transmitted downward, causing an oscillation effect on the screw motor. Under the action of the liquid, the movable valve plate 12 is in a continuous rotation process. The internal structures of the movable valve plate 12 and the static valve plate 11 will periodically be in a fully open and fully closed state, so a periodic downward oscillating impact force will be generated inside the screw motor. Liquid exiting the movable valve disc 12 continues through the valve seat 10 and connector 16 into the stator-rotor assembly 13. The pressure differential created by the liquid at the inlet and outlet of the stator-rotor assembly 13 drives the rotor to rotate, transmitting torque and speed to the flexible shaft assembly 14. The rotor rotates eccentrically, and the flexible shaft converts the eccentric rotation into concentric motion of the drive shaft. The flexible shaft assembly 14 then transmits the torque and speed to the drive shaft assembly. Ultimately, the screw motor combining the movable valve disc 12 and the stationary valve disc 11 outputs the dual power of "rotation + impact."

[0038] In this embodiment, Figure 7 and Figure 8 As shown, the middle flow channel of the static valve plate 11 is an umbrella-shaped structure, and the middle flow channel of the dynamic valve plate 12 is the umbrella tip part structure of the umbrella-shaped structure; the middle flow channel of the static valve plate 11 is a vertical structure, and the middle flow channel of the dynamic valve plate 12 is inclined at 30°.

[0039] In this embodiment, the flow channel between the movable and stationary valve discs is innovatively designed in an "umbrella-shaped" structure to adjust the maximum and minimum flow areas. The movable valve disc 12 rotates under the impact of the liquid, and the internal structures of the stationary valve disc 11 and the movable valve disc 12 intersect with each other as the movable valve disc 12 rotates. When the internal structures of the stationary valve disc 11 and the movable valve disc 12 are in the fully closed state (instantaneous minimum intersect area), as shown in FIG. Figure 9 As shown, Figure 9 The shaded area in the middle is the instantaneous interleaving area; the liquid flows through the internal structure at the highest velocity, and the pressure generated by the liquid passing through the valve plate is the highest. When the static valve plate 11 rotates to the point where the internal structure of the movable valve plate 12 is in the fully open state (instantaneous maximum interleaving area), Figure 10 As shown, Figure 10 The shaded area is the instantaneous interlaced area; the flow rate of the liquid through the internal structure is the smallest, and the pressure generated by the liquid passing through the valve plate is the smallest at this time.

[0040] In this embodiment, the inclined flow channel of the movable valve plate 12 brings resistance when the liquid flows, because the change in the flow area will generate greater fluid pressure, thereby enhancing the oscillation impact effect; ensuring a larger pressure drop difference between the movable valve plate 12 and the static valve plate 11, and obtaining a more practical oscillation force.

[0041] Example 2 Compared with Example 1, the present embodiment differs in that, in the present embodiment, the movable valve disc 12 and the static valve disc 11 are clearance-matched; the bottom of the valve seat 10 is connected to the stator and rotor assembly 13 via a connector 16; the movable valve disc 12 and the valve seat 10 are clearance-matched, and a gasket for adjusting the size of the gap between the static valve disc and the movable valve disc is provided between the connector and the valve seat; the movable valve disc 12 and the valve seat 10 are installed by a hot-mounting process; the remaining structure is the same as that of Example 1.

[0042] In this embodiment, the clearance between the movable valve plate 12 and the static valve plate 11 ensures that the movable valve plate 12 can rotate relative to the static valve plate 11, and the liquid will not escape from between the movable valve plate 12 and the static valve plate 11, resulting in pressure drop difference loss. According to the difficulty of drilling and grinding the bridge plug, the thickness of the gasket can be adjusted. Adjusting the size of the gap will affect the pressure drop difference generated by the movable valve plate 12 and the static valve plate 11 when they rotate and stagger. The smaller the gap, the greater the pressure drop difference, and the greater the downward impact force generated in the end.

[0043] In this embodiment, the thickness of the gasket can be adjusted to suit the difficulty of drilling the bridge plug. The gasket thickness is 0.1mm, 0.3mm, or 0.5mm. Adjusting the gap size affects the differential pressure drop generated by the rotating and interlaced discs. A smaller gap increases the differential pressure drop, ultimately generating a greater downward impact force. Different gaps are suitable for different horizontal sections: 0.1mm is suitable for horizontal sections longer than 3000 meters, 0.3mm for sections between 2000 and 3000 meters, and 0.5mm for sections between 1000 and 2000 meters.

[0044] Example 3 The present embodiment differs from the embodiment 1 in that, in the present embodiment, the disc springs 4 are multiple groups of disc springs 4 connected end to end in sequence, the disc springs 4 are pre-compressed during installation, and the disc springs 4 have an initial pressing force; the rest of the structure is the same as that of the embodiment 1.

[0045] In this embodiment, disc springs 4 utilize multiple sets of disc springs 4 connected end-to-end to ensure a stable oscillating force is generated when pushing core shaft 5. Disc springs 4 are preloaded during installation, providing an initial compressive force. This initial preload can be adjusted based on the actual flow rate to ensure that the elastic force of disc springs 4 can push piston 7 into collision with anti-collision ring 8.

[0046] Example 4 Compared with Example 1, this embodiment differs in that the top of the core shaft 5 passes through the core shaft outer tube 3 and is fixedly connected to the disc spring 4 inside the upper outer tube 2. The top of the core shaft 5 slides and seals with the inner wall of the upper outer tube 2. A gap is provided between the side of the core shaft 5 and the interior of the upper outer tube 2. The connection between the upper outer tube 2 and the core shaft outer tube 3 and the core shaft 5 are sealed. A hole communicating with the outside is provided on the side of the core shaft 5 at the gap between the core shaft 5 and the upper outer tube 2. A sealing ring is provided on the top of the core shaft 5, which realizes a sliding and sealing fit between the top of the core shaft 5 and the inner wall of the upper outer tube 2. The remaining structure is the same as that of Example 1.

[0047] In this embodiment, when the internal structure of the movable valve disc 12 and the static valve disc 11 transitions from a fully open state to a fully closed state, the liquid flow rate suddenly decreases, generating a water hammer effect. This is when the kinetic energy of the fluid is directly converted into pressure energy. This creates a high-pressure zone within the core shaft 5. The liquid in this high-pressure zone flows through the holes into the gap between the core shaft 5 and the upper outer tube 2. The high-pressure liquid in this gap pushes the top of the core shaft 5 to compress the disc spring 4. This interacts with the high-pressure liquid at the bottom of the piston 7, jointly pushing the core shaft 5 to compress the disc spring 4, creating a double piston 7 effect. A sealing ring is used to achieve a sliding seal between the top of the core shaft 5 and the interior of the upper outer tube 2.

[0048] It will be understood that the present invention is described by way of some embodiments, and it will be appreciated by those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

Claims

1. A coiled tubing oscillating impact screw motor, characterized by: The invention comprises an upper joint (1), an upper outer tube (2) and a core shaft outer tube (3), wherein the bottom of the upper joint (1) is connected to the upper outer tube (2), a disc spring (4) is provided in the upper outer tube (2), the bottom of the upper outer tube (2) is connected to the core shaft outer tube (3), a core shaft (5) is provided in the core shaft outer tube (3), a gap is provided between the core shaft (5) and the core shaft outer tube, the core shaft outer tube (3) is provided with a through hole (6) connected to the outside, the top of the core shaft (5) is in contact with the disc spring (4), the bottom of the core shaft (5) is provided with a piston (7), the bottom of the core shaft outer tube (3) is provided with an anti-collision ring (8), and the core shaft outer tube (3) is provided with a through hole (6) connected to the outside. The bottom of the cylinder (3) is connected to the lower joint (9), the bottom of the lower joint (9) is connected to the valve seat (10), the bottom of the lower joint (9) is provided with a static valve disc (11), the top of the valve seat (10) is provided with a rotatable movable valve disc (12), the bottom of the valve seat (10) is connected to the stator and rotor assembly (13), the bottom of the stator and rotor assembly (13) is connected to the flexible shaft assembly (14), and the bottom of the flexible shaft assembly (14) is connected to the transmission assembly (15); the middle flow channel of the static valve disc (11) is an umbrella-shaped structure, and the middle flow channel of the movable valve disc (12) is an umbrella tip part structure of the umbrella-shaped structure.

2. The coiled tubing oscillating impact screw motor according to claim 1, characterized in that: The top of the core shaft (5) passes through the core shaft outer tube (3) and abuts against the disc spring (4) in the upper outer tube (2). The top of the core shaft (5) is in sliding and sealing cooperation with the interior of the upper outer tube (2). A gap is provided between the side of the core shaft (5) and the interior of the upper outer tube (2). The connection between the upper outer tube (2) and the core shaft outer tube (3) is sealed with the core shaft (5). A connecting hole is provided on the side of the core shaft (5) at the gap between the core shaft (5) and the upper outer tube (2).

3. The coiled tubing oscillating impact screw motor according to claim 2, characterized in that: The top of the core shaft (5) is sleeved with a sealing ring, and a sliding seal is achieved between the top of the core shaft (5) and the interior of the upper outer cylinder (2) through the sealing ring.

4. The coiled tubing oscillating impact screw motor according to claim 1, characterized in that: The middle flow channel of the static valve plate (11) is a vertical structure, and the middle flow channel of the dynamic valve plate (12) is inclined at 30 degrees.

5. The coiled tubing oscillating impact screw motor according to claim 1, characterized in that: The movable valve plate (12) and the static valve plate (11) are clearance-matched; the bottom of the valve seat (10) is connected to the stator and rotor assembly (13) via a connector (16).

6. The coiled tubing oscillating impact screw motor according to claim 5, characterized in that: A gasket is provided between the connector and the valve seat for adjusting the gap between the static valve plate and the dynamic valve plate.

7. The coiled tubing oscillating impact screw motor according to claim 6, characterized in that: The thickness of the gasket is 0.1mm, 0.3mm or 0.5mm.

8. The coiled tubing oscillating impact screw motor according to claim 1, characterized in that: The movable valve plate (12) and the valve seat (10) are clearance-matched, and the movable valve plate (12) and the valve seat (10) are installed using a hot-mounting process.

9. The coiled tubing oscillating impact screw motor according to claim 1, characterized in that: The disc springs (4) are multiple groups of disc springs (4) connected end to end in sequence.

10. The coiled tubing oscillating impact screw motor according to claim 1, characterized in that: The disc spring (4) is pre-compressed during installation, and the disc spring (4) has an initial pressing force.

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