A downhole nipple for double-stage high-frequency flapping to trim the borehole wall while drilling

Abstract

The present invention discloses a downhole sub for trimming the wellbore with double-stage high-frequency flapping while drilling, which includes a main body structure, a double-stage power mechanism, and a push rod flapping mechanism. The main body structure is provided with an upper joint and a lower joint for connecting downhole drilling tools such as drill pipes and drill collars, and two stages of stepped through holes arranged in a staggered manner are provided on the outer wall in the circumferential direction, with three holes evenly distributed in the circumferential direction for each stage. The protective sleeve is sleeved outside the housing and fixed at both ends in the protective sleeve installation groove; the push rod flapping mechanism is assembled in the stepped through holes on the outer wall of the main body structure to form a double-stage radial flapping-resetting structure; the double-stage power mechanism adopts an impact block + double-cone piston design and is installed inside the main body structure to provide power for the radial flapping-resetting structure. This device utilizes the vibration and impact during drilling to drive the impact block to impact upward. The double-stage power mechanism moves upward, pushing the push rod flapping mechanism to flap the wellbore at a high frequency, playing a role in trimming the wellbore and reducing the risk of drilling accidents such as wellbore collapse during the processes of pulling up, lowering, and drilling.

Description

Technical Field

[0001] The present invention relates to the technical field related to oil drilling technology, and particularly to a downhole sub for double-stage high-frequency flapping and trimming the wellbore while drilling. Background Art

[0002] Maintaining wellbore trimming is a crucial link in drilling engineering, which is directly related to the safety and efficiency of drilling operations and the smooth progress of subsequent oil and gas production. During the drilling process, due to the influence of various factors such as formation rock properties, geological conditions, and drilling fluid performance, the wellbore may become unstable, such as wellbore collapse and lost circulation, posing great challenges to drilling operations. Therefore, in-depth research on wellbore trimming, understanding its influencing factors and laws, is of great significance for improving the safety and efficiency of drilling operations. Currently, the main reasons for wellbore collapse are: imbalance of liquid column pressure, formation water sensitivity reaction, formation vulnerability, swabbing phenomenon caused by pulling out the drill string, decrease of liquid column pressure in the well due to failure to refill drilling fluid in time during the process of pulling out the drill string, and large-displacement circulation of drilling fluid in the open hole section for a long time may erode the wellbore.

[0003] A variable-diameter joint with the patent number CN201620447721.1 has a main structure consisting of a joint body, a wear-resistant belt, a support block, wear-resistant block I, and wear-resistant block II. The support block provided on the through-hole can extend or retract, changing the outer diameter of the joint and thus trimming the wellbore. However, it is difficult to repair the wear-resistant blocks after they are worn out, resulting in high usage costs. Moreover, when the support block extends, the grinding force of the wear-resistant blocks cannot be guaranteed, which may lead to a decline in the effect of trimming the wellbore. This patent uses a grinding method and cannot play a role in strengthening the wellbore, nor can it reduce the risk of wellbore instability. A variable-diameter drill stabilizer with the patent number CN202211387882.2 has a main structure consisting of upper and lower joints, a central tube, a centralizer strip, upper and lower pistons, upper and lower outer sleeves, a dovetail groove guide rail, upper and lower ball seat holes, upper and lower liquid inlet holes, cutting strips, support strips, a rake angle, a back rake angle, a clearance angle, an opening groove, a cutting edge, and a cone. It enlarges the hole by changing the position of the centralizer strip, with the centralizer strip extending or retracting. However, the design of this stabilizer includes multiple precision components and complex mechanical structures (such as dovetail groove guide rails, upper and lower ball seat holes, etc.). The manufacturing and processing of these components require high-precision equipment and technology, resulting in high manufacturing costs and the need to provide additional power for expansion and contraction. Similarly, this patent uses a cutting method and cannot play a role in strengthening the wellbore, nor can it reduce the risk of wellbore instability. A telescopic hole enlarging tool while drilling with the patent number CN202222689364.8 has a main structure consisting of a transmission shaft, an upper joint, a disc spring group, a housing, cutting teeth, a guide shaft, a pin, a wedge-shaped guide surface, a piston, an hole enlarging blade, a blade groove, an end cap, and a lower joint. When the guide shaft moves downward, the wedge-shaped guide surface pushes the hole enlarging blade radially outward to cut the wellbore. However, the structure of this patent is complex, increasing the difficulty of manufacturing and processing. Moreover, due to the use of cutting and grinding methods, cutting components such as hole enlarging blades are prone to wear during long-term use and need to be replaced regularly, increasing the usage costs and maintenance difficulties. Similarly, this patent using cutting or grinding methods also cannot play a role in strengthening the wellbore, nor can it reduce the risk of wellbore instability.

[0004] In the existing related patented technologies for wellbore trimming, most wellbore trimming tools adopt structures with cutting teeth or other cutting functions installed to trim the wellbore. The drill pipe drives the device body to rotate, and the cutting teeth trim the wellbore. However, the sizes of the cylindrical body and the cutting teeth are fixed, and the diameter of the drilling hole that a wellbore trimming tool can trim is also fixed, which cannot meet the requirements for trimming wellbores of various diameters. Moreover, the commonly used wellbore trimming devices are disposable items, and it is difficult to repair them after wear and damage, resulting in high usage costs. Another part uses other methods such as rolling to trim the wellbore, which also has the disadvantage of not being able to meet the requirements for trimming wellbores of various diameters. In addition, the amount of shaping in one time is relatively small. Therefore, during the shaping process, it is necessary to frequently trip the drill string and replace the tools, which increases the workload and time cost of the operation. And when the force is uneven, the rolling components are easily flattened, resulting in the scrapping of the device and a corresponding increase in the workover cost.

[0005] Therefore, there is an urgent need to propose a device that can reinforce and trim the wellbore in other ways while the drill bit penetrates the formation to solve the problems raised in the above background technology. Summary of the Invention

[0006] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a downhole sub for trimming the wellbore with double-stage high-frequency slapping while drilling, which can reinforce the wellbore while drilling, reduce the risk of wellbore instability and the accident rate, and improve the safety of drilling.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] A downhole sub for trimming the wellbore with double-stage high-frequency slapping while drilling trims and reinforces the wellbore by slapping. The device includes a main structure, a double-stage power mechanism, and a push rod slapping mechanism. Utilizing the vibration and impact during drilling, it drives the impact block to impact upward, causing the double-stage conical piston to displace, and pushing the push rod slapping mechanism to slap the wellbore at a relatively high frequency to complete the trimming of the wellbore.

[0009] In the preferred embodiment, the main body structure includes an upper joint, a lower joint, a double-stage stepped hole, a retaining ring, a protective sleeve mounting groove, and a protective sleeve. The upper and lower joints are used to connect downhole drilling tools such as drill pipes and drill collars. The inner wall of the upper part of the lower joint is provided with threads for installing the retaining ring, which is an axial limiting part of the double-stage power mechanism. Since designing a single-stage six stepped holes will result in insufficient strength of the main body structure, a double-stage stepped hole is provided circumferentially on the outer wall of the main body structure. Each stage has three holes evenly distributed circumferentially, and a total of six stepped through-holes in two stages are evenly arranged with a dislocation; the three holes in the first stage are respectively at 0°, 120°, and 240° azimuths, and the three holes in the second stage are respectively at 60°, 180°, and 300° azimuths; the inner wall of the hole with the middle diameter of each stepped hole is provided with threads for installing the spring base. The outer wall of the main body structure is also provided with two protective sleeve mounting grooves for fixing the protective sleeve. The protective sleeve is sleeved outside the main body structure and is an integrally designed elastic sleeve. It is provided with six holes at the same positions as the double-stage stepped holes for isolating the parts wrapped inside from external fluids, rock cuttings, etc., preventing premature failure of the device caused by corrosion and wear, and also playing a part in preventing the push rod beating mechanism from falling off.

[0010] In the preferred embodiment, the double-stage power mechanism includes an upper sealing section, an annular sealing ring groove, a double-stage conical piston, a lower sealing section, an impact block, and a spring II. Both the upper and lower sealing sections are provided with annular sealing ring grooves for installing annular sealing rings to prevent fluids or solid particles carried by them from entering the space formed between the double-stage power mechanisms of the main body structure, resulting in jamming or excessive wear between components; the inner surface of the upper sealing section is a circular conical surface with a certain taper. The double-stage conical piston is hollow and is a fluid flow channel. When the high-speed fluid reaches this surface and is about to enter the flow channel, it can make the fluid pressure greater and the flow rate faster. The upper sealing section and the double-stage conical piston are integrated. The lower part of the double-stage conical piston is provided with threads for installing the lower sealing section. The upper surface of the lower sealing section contacts one end of the spring II; the impact block is in the shape of a circular cylinder for transmitting vibration and impact; the spring II is sleeved on the double-stage conical piston to play a role in resetting. The conical surface of the double-stage conical piston converts the axial movement of the double-stage power mechanism into the radial movement of the push rod beating mechanism. When the radial beating stroke of the push rod beating mechanism is fixed, if the taper of the conical surface is large, the double-stage conical piston only needs a short axial displacement, but the required impact force is also greater, and the maximum outer diameter of the double-stage conical piston is certain, and the diameter of the internal flow channel decreases; if the taper of the conical surface is small, the double-stage conical piston needs a longer axial displacement, but the required impact force is also smaller, and the maximum outer diameter of the double-stage conical piston is certain, and the diameter of the internal flow channel is larger. Therefore, the taper of the conical surface should not be too large or too small. Since the conical surface of the double-stage conical piston contacts the push rod beating mechanism and rubs against each other, materials with good wear resistance should be used and smooth anti-wear treatment should be carried out. The retaining ring is provided with threads and is fixed inside the main body structure by cooperating with the threads on the inner wall of the upper part of the lower joint to play an axial limiting role.

[0011] In the preferred solution, the push rod slapping mechanism includes an upper slapping piece, a lower slapping piece, a connecting screw, a push rod, Spring I, and a spring base. There are six push rod slapping mechanisms, which are installed in the double-stage stepped holes on the main structure. The six slapping pieces cooperate with each other to completely cover the well wall circumferentially. The upper slapping piece is provided with a stepped through hole. The lower slapping piece and the push rod are integrated, and a threaded hole is provided in the upper part. The upper threaded hole is used to install the connecting screw. The two sides of the upper slapping piece are rounded to prevent sticking of the drill string during hoisting, lowering or drilling, and to avoid damaging the reinforced well wall. The contact part between the lower part of the contact surface and the piston conical surface is a concave conical arc surface. The thickness of the slapping piece should not be too thick. A too thick slapping piece will increase the weight, resulting in increased wear between the push rod slapping device and the spring base and affecting the service life of the entire slapping device. Therefore, a thinner slapping piece should be selected as much as possible under the condition of ensuring the slapping effect and the stiffness of the slapping piece. Spring I is a variable-diameter spring, and the diameter ratio of the upper and lower ends is greater than that of the middle part. There is a boss at the junction of the lower slapping piece and the push rod, and a spring clamping groove is provided inside to fix one end of Spring I. The outer bottom end of the spring base is provided with a thread and is installed on the double-stage stepped hole. A spring clamping groove is also provided inside to fix the other end of Spring I. A protective sleeve is sandwiched between the upper slapping piece and the lower slapping piece, and the three are connected by connecting screws. A large force is required for the push rod slapping mechanism to slap the well wall. The push rod slapping mechanism may be prone to deformation. Therefore, materials with light weight and high strength and stiffness should be selected. Since the lower slapping piece of the push rod slapping mechanism is attached to the outer surface of the main structure, and the upper and lower slapping pieces have a certain thickness, the diameter of the overall device can still be designed to be smaller than the drill bit to avoid sticking of the drill string.

[0012] In the preferred solution, in the initial state, the double-stage power mechanism is located at the lower end, the lower surface of the lower sealing section is closely attached to the upper surface of the impact block, and the upper surface of the impact block is closely attached to the upper surface of the retaining ring. When the vibration impact is transmitted to the impact block, the impact block impacts upward, the double-stage power mechanism moves upward, and the conical surface contacts the push rod slapping mechanism. When slapping, as the double-stage power mechanism moves upward, the push rod slapping mechanism moves from contacting the small-diameter part of the conical surface apex to contacting the large-diameter part of the conical surface bottom. At this time, Spring I is in a stretched state, and Spring II is in a compressed state. All six push rod slapping mechanisms are in the slapping state. When resetting, as Spring II pushes the double-stage power mechanism to move downward, the pulling force of Spring I causes the push rod slapping mechanism to reset. The push rod slapping mechanism moves from contacting the large-diameter part of the conical surface bottom to contacting the small-diameter part of the conical surface apex, and all six push rod slapping mechanisms are in the reset state. One slapping cannot complete the slapping reinforcement and trimming of the entire well wall. However, this device rotates with the drill. After rotation, the slapping and resetting processes are repeated. Therefore, it can slap the circumferential well wall without dead angles and complete the circumferential full-well wall slapping and trimming. Considering the influence of drilling fluid and annulus fluid, all components of this device should be made of corrosion-resistant materials. There is relative movement between parts, and they are relatively easy to wear. Metal materials with good wear resistance should be selected.

[0013] Compared with the existing methods and devices for reinforcing and trimming the wellbore, a downhole sub for trimming the wellbore with double-stage high-frequency slapping while drilling in the present invention utilizes the vibration and impact during drilling to push the impact block upward to impact, causing the double-stage conical piston to displace, and pushing the push rod slapping mechanism to slap the wellbore at a higher frequency to complete the trimming of the wellbore. By using this slapping method to trim the wellbore, the requirements for trimming wellbores of various diameters of drilling holes can be met, and the failure of the device caused by cutting wear during trimming the wellbore by cutting is avoided. The overall structure of the device is simple, with strong operability. The diameter can be designed to be smaller than the drill bit, without sticking the drill and having very little frictional force with the wellbore, and with a large gap, providing a spacious flow path for fluid circulation. Brief Description of the Drawings

[0014] For ease of explanation, the present invention will be described in detail by the following specific embodiments and the accompanying drawings.

[0015] Figure 1 is the structural diagram of a downhole sub for trimming the wellbore with double-stage high-frequency slapping while drilling in this application;

[0016] Figure 2 is the comparative cross-sectional view of slapping and resetting of a downhole sub for trimming the wellbore with double-stage high-frequency slapping while drilling in this application;

[0017] Figure 3 is the cross-sectional view of the main structure of a downhole sub for trimming the wellbore with double-stage high-frequency slapping while drilling in this application;

[0018] Figure 4 is the cross-sectional view of the double-stage power mechanism of a downhole sub for trimming the wellbore with double-stage high-frequency slapping while drilling in this application;

[0019] Figure 5 is the structural diagram of the push rod slapping piece group of a downhole sub for trimming the wellbore with double-stage high-frequency slapping while drilling in this application;

[0020] Figure 6 is the cross-sectional view of the push rod slapping mechanism of a downhole sub for trimming the wellbore with double-stage high-frequency slapping while drilling in this application;

[0021] In the figures: 1 - main structure; 2 - double-stage power mechanism; 3 - push rod slapping mechanism; 101 - upper sub; 102 - lower sub; 103 - double-stage stepped hole; 104 - retaining ring; 105 - protective sleeve installation groove; 106 - protective sleeve; 201 - upper sealing section; 202 - annular sealing ring groove; 203 - double-stage conical piston; 204 - lower sealing section; 205 - impact block; 206 - spring II; 301 - upper slapping piece; 302 - lower slapping piece; 303 - connecting screw; 304 - push rod; 305 - spring I; 306 - spring base. Detailed Embodiment

[0022] An embodiment of this application provides a downhole sub for trimming the wellbore with double-stage high-frequency slapping while drilling.

[0023] To enable those skilled in the art to better understand the technical solutions in this application, the following will clearly and completely describe the technical solutions in the embodiments of this application in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0024] Figure 1 As shown, in this embodiment, a downhole sub for double-stage high-frequency percussion and wellbore trimming while drilling is used to percussion, reinforce, and trim the wellbore. It includes 1. the main structure; 2. the double-stage power mechanism; 3. the push rod percussion mechanism. The number of the push rod percussion mechanisms 6 is six, three for each of the upper and lower stages, and each can circumferentially cover nearly 1 / 6 of the wellbore. The double-stage power mechanism 2 is installed inside the main structure 1, and the hollow part is a fluid flow channel, and the fluid flows in from the upper joint 101. The protective sleeve 106 is an elastic sleeve and is sleeved outside the main structure 1. This downhole sub utilizes the vibration and impact during drilling to drive the double-stage power mechanism 2 to generate displacement, and push the push rod percussion mechanism 3 to percussion the wellbore at a relatively high frequency to complete the trimming of the wellbore.

[0025] Figure 2 As shown, in this embodiment, the fluid flows in from the upper joint 101, passes through the hollow flow channel of the double-stage power mechanism 2, and flows out from the lower joint 102. In the initial state, the double-stage power mechanism 2 is located at the lower end, the lower surface of the lower sealing section 204 is closely attached to the upper surface of the impact block 205, and the lower surface of the impact block 205 is closely attached to the upper surface of the retaining ring 104. When the vibration and impact are transmitted to the impact block 205, the impact block 205 impacts upward, and the double-stage power mechanism 2 moves upward, and the conical surface contacts the push rod percussion mechanism 2; during percussion, as the double-stage power mechanism 2 moves upward, the push rod percussion mechanism 3 moves from contacting the small-diameter part at the apex of the conical surface to contacting the large-diameter part at the bottom of the conical surface. At this time, the spring I 305 is in a stretched state, and the spring II 206 is in a compressed state, and all six push rod percussion mechanisms 3 are in the ejected state; during reset, as the spring II 206 pushes the double-stage power mechanism 2 to move downward, the pulling force of the spring I 305 causes the push rod percussion mechanism 3 to reset, and the push rod percussion mechanism 3 moves from contacting the large-diameter part at the bottom of the conical surface to contacting the small-diameter part at the apex of the conical surface, and all six push rod percussion mechanisms 3 are in the reset state; one percussion cannot complete the percussion, reinforcement, and trimming of the entire wellbore, but this device rotates while drilling, and the percussion and reset processes are repeated after rotation. Therefore, it can percussion the circumferential wellbore without dead angles and complete the percussion trimming of the entire circumferential wellbore.

[0026] Figure 3As shown in the figure, in this embodiment, the main structure 1 is of an integral design. Double-stage stepped holes are evenly distributed circumferentially on the outer part of the housing. The upper sub 101 and the lower sub 102 are used to connect downhole drilling tools such as drill pipes and drill collars. The inner wall of the upper part of the lower sub 102 is provided with threads for installing and fixing the retaining ring 7. Double-stage stepped holes 103 are provided circumferentially on the outer wall, with three holes evenly distributed circumferentially in each stage, and a total of six stepped through-holes in two stages are evenly arranged in a staggered manner, equally divided circumferentially by 360°; threads are provided on the inner wall of the hole of the second stage of each stepped hole. The retaining ring 104 is a circular ring metal plate with threads on the outside, which is used for axially limiting the internal parts of the main structure 1; the protective sleeve 106 is an integral elastic sleeve, on which there are six holes at the same positions as the double-stage stepped holes 103, and both sides are fixed on the protective sleeve mounting groove 105 on the outer wall of the main structure 1.

[0027] Figure 4 As shown in the figure, in this embodiment, the double-stage power mechanism 2 includes an upper sealing section 201, an annular sealing ring groove 202, a double-stage conical piston 203, a lower sealing section 204, an impact block 205, and a spring II 206. Annular sealing ring grooves 202 are sleeved on both the upper sealing section 201 and the lower sealing section 204, which are used to prevent fluids or solid particles carried by them from entering the space formed between the double-stage power mechanisms of the main structure, resulting in jamming or excessive wear between various components; one side of the upper sealing section 201 is a circular conical surface with a certain taper, which can make the fluid pressure greater and the flow rate faster. The upper sealing section 201 and the double-stage conical piston 203 are of an integral design, while the lower sealing section 204 and the double-stage conical piston 203 are connected by threads. The double-stage conical piston 203 is hollow and is a fluid flow channel. The upper conical surface on the double-stage conical piston 203 converts the axial movement of the double-stage power mechanism into the radial movement of the push rod slapping mechanism. When the radial slapping stroke of the push rod slapping mechanism is certain, the taper of the conical surface should not be too large or too small. The taper of the conical surface is initially set to 20°. The coaxiality of the two conical surfaces can ensure that a total of six slapping pieces in two stages slap and retract simultaneously. The radius difference between the large radius at the bottom of the conical surface and the small radius at the top of the conical surface is the maximum slapping stroke of the push rod slapping mechanism 6. In this embodiment, the radius difference between the bottom and the top of the cone is 15 mm. The impact block 205 is a cylindrical ring, and a metal material with a relatively large density is selected. The spring II 206 has a diameter of 140 mm, 5 turns, an initial height of 53 mm, and a cross-sectional diameter of about 4 mm.

[0028] Figure 5 、 6As shown in the figure, in this embodiment, the number of the push rod slapping mechanisms 3 is six, and the six slapping pieces cooperate with each other to circumferentially and slightly cover the wellbore wall with a small gap. The upper slapping piece 301 is a thin cylindrical surface. The upper slapping piece 301 and the lower slapping piece 302 are connected and fixed by a connecting screw 303, and a clamping protective sleeve 106 is installed between the upper and lower pieces. The actual slapping part of the upper slapping piece 301 has a width of 70 mm, and there are rounded corners on both sides to prevent sticking of the drill string during hoisting, lowering or drilling, and to avoid damaging the reinforced wellbore wall. There is a boss at the lower part of the lower slapping piece 302, and a spring clamping groove is arranged inside. The spring base 306 also has a spring clamping groove inside. The two clamping grooves are used to fix the spring I 305, and the spring I 305 can play a role in resetting and preventing falling. There is a threaded structure on the outer side of the lower part of the spring base 306, which is matched with the thread on the main body structure housing to fix the spring base 306 on the double-stage stepped hole 103 of the main body structure 1. The maximum diameter at the non-threaded part of the upper part is 48 mm. The thread on the outer side of the lower part of the spring base 4 is M10×1.5, with a height of 15 mm and a right-handed thread.

[0029] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0030] In addition, it should be noted that, in the various specific technical features described in the above specific embodiments, without contradiction, they can be combined in any appropriate way. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods. In addition, any combination can be made between various different embodiments of the present invention, as long as it does not violate the idea of the present invention, it should also be regarded as the content disclosed by the present invention.

Claims

1. A downhole sub for double-stage high-frequency slapping and trimming the wellbore while drilling, which slaps and reinforces the wellbore. It includes a main structure (1), a double-stage power mechanism (2), and a push rod slapping mechanism (3); the main structure (1) includes an upper joint (101), a lower joint (102), a double-stage stepped hole (103), a retaining ring (104), a protective sleeve installation groove (105), and a protective sleeve (106); the double-stage power mechanism (2) includes an upper sealing section (201), an annular sealing ring groove (202), a double-stage conical piston (203), a lower sealing section (204), an impact block (205), and a spring II (206); the push rod slapping mechanism (3) includes an upper slapping piece (301), a lower slapping piece (302), a connecting screw (303), a push rod (304), a spring I (305), and a spring base (306); the device utilizes the vibration and impact during drilling to push the impact block (205) to impact upward, causing the double-stage conical piston (203) to displace, and pushing the push rod slapping mechanism (3) to slap the wellbore at a higher frequency to complete the trimming of the wellbore; The upper joint (101) and the lower joint (102) in the main structure (1) are used to connect downhole drilling tools such as drill strings and drill collars. The inner wall of the upper part of the lower joint (102) is provided with threads for installing the retaining ring (104), and the stepped part above the threads contacts one end of the spring II (206); the outer wall of the main structure (1) is circumferentially provided with a double-stage stepped hole (103), with three holes evenly distributed in each stage, and a total of six stepped through holes in two stages are evenly arranged in a staggered manner, circumferentially equally divided by 360°. The inner wall of the second-stage stepped hole of each stepped hole is provided with threads for mating with the spring base (306); the outer wall of the main structure (1) is also provided with two protective sleeve installation grooves (105) for fixing the protective sleeve (106).

2. The downhole sub according to claim 1 for downhole short connection of double-stage high-frequency slapping to trim the wellbore while drilling, characterized in that, The retaining ring (104) is a circular ring metal plate with threads on the outside, used for axially limiting the internal parts of the main structure (1); the protective sleeve (106) is an integrally designed elastic sleeve, with six holes at the same positions as the double-stage stepped hole (103), and both sides are fixed on the protective sleeve installation grooves (105) on the outer wall of the main structure (1), used to isolate the internally wrapped parts from external fluids, cuttings, etc., to prevent the device from jamming or premature failure caused by corrosion and wear.

3. The downhole nipple for trimming the wellbore with double-stage high-frequency flapping while drilling according to claim 1, characterized in that, An annular sealing ring groove (202) is provided on the upper sealing section (201) of the two-stage power mechanism (2) to prevent fluid or solid particles carried by it from entering the space formed between the main structure (1) and the two-stage power mechanism (2), which may cause jamming or excessive wear between components; the bottom of the two-stage conical piston (203) is provided with threads and is of an integral design. Each stage is composed of a conical surface + a cylindrical surface. The conical surface is used to convert the axial movement of the two-stage power mechanism (2) into the radial slapping movement of the push rod slapping mechanism (3); an annular sealing ring groove (202) is also provided at the lower end of the lower sealing section (204), and threads are provided on the inner wall of the upper end, which is threadedly connected with the bottom thread of the two-stage conical piston (203). The upper surface of the lower sealing section (204) contacts the other end of the spring II (206); the impact block (205) is in the shape of a circular cylinder and is used to transmit vibration shock; the spring II (206) is sleeved on the two-stage conical piston (203) and plays a role in resetting.

4. The downhole nipple for downhole wellbore trimming with double-stage high-frequency slapping while drilling according to claim 1, characterized in that, The number of the push rod slapping mechanisms (3) is six, which are installed in the two-stage stepped holes (103) on the main structure (1). The six pieces cooperate with each other to circumferentially cover the wellbore with a micro-gap; among them, the upper slapping piece (301) is provided with a stepped through hole, the lower slapping piece (302) and the push rod (304) are integrated and a threaded hole is provided in the upper part. The upper threaded hole is used to install the connecting screw (303); there is a boss at the junction of the lower slapping piece (302) and the push rod (304), and a spring clamping groove is arranged inside to fix one end of the spring I (305); a protective sleeve (106) is clamped between the upper slapping piece (301) and the lower slapping piece (302), and the three are connected by the connecting screw (303); the bottom surface of the push rod (304) is an inner concave conical surface, which contacts and completely fits with the conical surface of the two-stage conical piston (203); the outer bottom end of the spring base (306) is provided with threads and is installed on the two-stage stepped hole (103), and a spring clamping groove is arranged inside to fix the other end of the spring I (305).

5. The downhole sub for the downhole wellbore trimming with double-stage high-frequency slapping while drilling according to claim 1, wherein When the vibration shock is transmitted to the impact block (205), the impact block (205) impacts upward, and the two-stage power mechanism (2) moves upward, and the conical surface contacts the push rod slapping mechanism (3); during slapping, as the two-stage power mechanism (2) moves upward, the push rod slapping mechanism (3) contacts the conical surface from the small-diameter part of the cone top and moves to the large-diameter part of the cone bottom. At this time, the spring I (305) is in a stretched state, and the spring II (206) is in a compressed state. All six push rod slapping mechanisms (3) are in the slapping state; during resetting, as the spring II (206) pushes the two-stage power mechanism (2) to move downward, the pulling force of the spring I (305) causes the push rod slapping mechanism (3) to reset. The push rod slapping mechanism (3) contacts the conical surface from the large-diameter part of the cone bottom and moves to the small-diameter part of the cone top. All six push rod slapping mechanisms (3) are in the reset state; one slapping cannot complete the slapping reinforcement and trimming of the entire wellbore, but the device rotates with the drill. After rotation, the slapping and resetting processes are repeated, so it can slap the circumferential wellbore without dead angles and complete the circumferential slapping and trimming of the entire wellbore.

6. A downhole nipple for downhole double-stage high-frequency flapping to trim the wellbore according to claim 1, characterized in that Considering the influence of drilling fluid and annulus fluid, all components of this device should be made of corrosion-resistant materials. Since there is relative movement between parts and they are prone to wear, metal materials with better wear resistance should be selected. At the same time, a large force is required when slapping against the wellbore wall, and the push rod slapping mechanism (3) may be prone to deformation. Therefore, materials with relatively light weight and high strength and stiffness should be selected. The slapping piece of the push rod slapping mechanism (3) is attached to the outer surface of the main structure (1) and has a certain thickness. However, the overall diameter of the device can still be designed to be smaller than the drill bit to avoid sticking of the drill.

Images