Fish top trimming tool and trimming method

Abstract

The invention discloses a fish top trimming tool and trimming method. The tool is characterized in that a first channel is formed in the side wall of the lower end of a center pipe; the center pipe is sleeved with the guide pipe. The water eye base is of a circular tube structure and arranged at the lower end of the central tube; the sleeve is coaxially and fixedly arranged at the lower end of the guide pipe, and the water eye base is arranged in the sleeve in a penetrating mode. A plurality of cutter plates are arranged at the lower end of the sleeve along the circumference, the section of each cutter plate is arc-shaped, cutter bodies are arranged on the inner arc surfaces of the cutter plates, and guide surfaces protruding inwards are arranged on the inner walls of the upper ends of the cutter plates; an annular cavity is formed among the lower end face of the guide pipe, the upper end face of the water eye base, the outer wall of the center pipe and the inner wall of the sleeve, and the first channel is used for introducing circulating liquid into the annular cavity to push the guide pipe to move upwards relative to the center pipe. According to the scheme, the deformed fish top can be better trimmed, the trimmed fish top can be effectively prevented from forming a pen point shape, iron sheets are prevented from being formed outside the fish, and drill jamming is prevented.

Description

Technical Field

[0001] The invention belongs to the field of drill rod dressing tools used in oil and gas production, and in particular relates to a fish top dressing tool and a dressing method. Background Art

[0002] When the fluid corrosion causes the drill bit to corrode and break off from the wellhead, it breaks at a depth of more than 1000 meters, resulting in a fish drop of more than 300 meters underground. At the same time, the open hole section is pickled many times and the well diameter is expanded, causing the upper and lower sections of the drill bit fracture to cross each other for several meters. When the drill bit breaks, it is accompanied by a large rotational torque. The top of the fish drop, that is, the fracture of the top of the fish drop, is easily deformed, making the fish top form an elliptical structure or a flat mouth structure similar to an ellipse. At the same time, the top of the fish drop will deviate to one side of the open hole, and the whole fish drop will form a twist shape.

[0003] When salvaging fallen fish, conventional grinding and milling tools are limited in size and cannot grind the downhole drill pipe normally. After grinding, eccentric grinding may occur, causing the fish top to become a pen tip shape, and may even cause the drill to drill out sideways during the milling window. If a forging and milling solution is adopted and a conical milling tool is used to grind the drill pipe, it is easy to form banana peel-like lumps of iron sheets and cause drill jamming. The so-called banana peel-like lumps of iron sheets refer to the fact that part of the iron sheets cannot form debris during grinding, but are squeezed by the conical milling tool and spread out to the surroundings and get stuck with the side wall of the wellbore, causing drill jamming. Summary of the invention

[0004] In order to solve the deficiencies of the prior art, the present invention provides a fish top trimming tool and a trimming method, which can better trim the deformed fish top, effectively prevent the trimmed fish top from forming a pen tip shape, avoid the formation of iron sheet on the outside of the fallen fish, and prevent drill jamming.

[0005] In order to achieve the purpose of the present invention, the following scheme is proposed: A fish top trimming tool comprises: a center tube, a guide tube, a water eye base, a sleeve and a knife plate arranged at the lower end of the sleeve.

[0006] A first channel is formed on the side wall of the lower end of the central tube; The guide tube is coaxially sleeved on the middle section outside the central tube; The water eye base is a circular tube structure, which is coaxially fixed to the lower end of the central tube. The outer diameter of the water eye base is larger than the outer diameter of the central tube. The water eye base and the guide tube are all sealed and connected to the central tube. The casing is coaxially fixed to the lower end of the guide tube, and the water eye base is penetrated inside the casing; A plurality of mutually independent blades are arranged in a circular array at the lower end of the casing. The cross section of the blade is arc-shaped, and its inner arc surface faces the middle of the casing. The inner arc surface of the blade is provided with a blade body. The inner wall of the upper end of the blade has a guide surface protruding inwardly, and the guide surface is inclined toward the upper part of the middle of the casing. The outer edge of the lower end surface of the water eye base is located within the range of the guide surface in the projection view of the central pipe axis. An annular chamber is formed between the lower end surface of the guide tube, the upper end surface of the water eye base, the outer wall of the central tube and the inner wall of the sleeve. The first channel is used to introduce circulating liquid into the annular chamber to push the guide tube to move upward relative to the central tube.

[0007] The beneficial effects of the present invention are as follows: the present scheme utilizes the opened blade to adapt to the deformed fish top and the enlarged naked eye, even if the fish top of the fallen fish is in an eccentric position of the naked eye, it can be covered by the opened blade, thereby avoiding the influence of the naked eye expansion and the eccentricity of the fallen fish on the fish top trimming process, and after the multiple blades are opened, a cone structure will be formed, which can effectively avoid the appearance of a pen tip structure on the fish top, and prevent the formation of banana peel-like iron sheets on the outside of the fallen fish, thereby preventing drill jamming. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present invention.

[0009] Figure 1 A schematic diagram of the overall external structure of the present application is shown after the blade is opened.

[0010] Figure 2 Shows Figure 1 A partial enlarged view of point A in the middle.

[0011] Figure 3 The interface view between the middle part of the stop tube and the center tube is shown.

[0012] Figure 4 Shows an overall cross-sectional view of the present application when the blade is folded.

[0013] Figure 5 Shows Figure 4 A partial enlarged view of point B in the middle.

[0014] Figure 6 Shows an overall cross-sectional view of the present application when the blade is in an open state.

[0015] Figure 7 Shows Figure 6 A partial enlarged view of point C in the middle.

[0016] Markings in the figure: center tube-1, first channel-11, guide tube-2, countersunk hole-21, water eye base-3, step surface-31, second channel-32, sleeve-4, knife plate-5, guide surface-51, limit surface-52, return spring-6, limit tube-7, pin-8, top joint-9. DETAILED DESCRIPTION

[0017] To make the objectives, technical solutions and advantages of the embodiments of the present invention more clear, the implementation modes of the present invention are described in detail below with reference to the accompanying drawings. However, the embodiments described in the present invention are only part of the embodiments of the present invention, rather than all the embodiments.

[0018] like Figure 1 and Figures 4 to 7 As shown, a fish top trimming tool comprises: a central tube 1, a guide tube 2, a water eye base 3, a sleeve 4 and a knife plate 5 arranged at the lower end of the sleeve 4.

[0019] Specifically, Figure 5 , Figure 7 As shown, a first channel 11 is opened on the side wall at the lower end of the central tube 1. As a preferred structure, in order to increase the liquid circulation speed and flow rate, multiple first channels 11 can be opened along the circumference of the side wall of the same cross section of the central tube 1. At the same time, in order to ensure the structural strength of the central tube 1, multiple first channels 11 can be arranged in a circumferential array.

[0020] Specifically, Figure 4 , Figure 6 As shown, the guide tube 2 is coaxially sleeved on the middle section outside the central tube 1 .

[0021] Specifically, Figures 4 to 7 As shown, the water eye base 3 is a circular tube structure, which is coaxially fixed to the lower end of the central tube 1 so that the position of the water eye base 3 along the axis of the central tube 1 remains constant. It can also be understood that the water eye base 3 is fixedly arranged outside the lower end of the central tube 1. The outer diameter of the water eye base 3 is larger than the outer diameter of the central tube. The water eye base 3 and the guide tube 2 are all sealed with the central tube 1. The sealing structure is usually realized by a sealing ring arranged between the inner wall of the guide tube 2 and the outer wall of the central tube 1.

[0022] Specifically, Figure 5 , Figure 7 As shown, the sleeve 4 is coaxially fixed to the lower end of the guide tube 2 , and the water eye base 3 is penetrated into the sleeve 4 .

[0023] Specifically, Figure 1 and Figures 4 to 7As shown, a plurality of independent blades 5 are provided along a circumferential array at the lower end of the sleeve 4. The cross-section of the blade 5 is arc-shaped, and its inner arc surface faces the middle of the sleeve 4. The inner arc surface of the blade 5 is provided with a blade body for grinding the fish top. The specific blade body is cemented carbide particles and is fixed on the inner arc surface of the blade 5 by bonding or welding. The inner wall of the upper end of the blade 5 has an inwardly protruding guide surface 51, and the guide surface 51 is inclined toward the upper part of the middle of the sleeve 4. The outer edge of the lower end surface of the water eye base 3 is located within the range of the guide surface 51 in the projection view of the axis of the center tube 1. It can also be understood that the radius of the water eye base 3 is greater than or equal to the distance between the upper edge of the guide surface 51 and the axis of the center tube 1, and is less than the distance between the lower edge of the guide surface 51 and the axis of the center tube 1.

[0024] As a preferred solution, the knife plate 5 can be rotatably connected to the lower end of the sleeve 4 via a pin, and the axis of the pin is consistent with the tangent direction of the sleeve 4 and the knife plate 5.

[0025] Specifically, Figure 7 As shown, an annular chamber is formed between the lower end surface of the guide tube 2, the upper end surface of the water eye base 3, the outer wall of the center tube 1, and the inner wall of the sleeve 4. The first channel 11 is located within the range of the annular chamber along the axial direction of the center tube 1, and is used to introduce circulating liquid into the annular chamber to push the guide tube 2 to move upward relative to the center tube 1.

[0026] As a preferred structural layout, no matter when the guide tube 2 moves to the upper limit or the lower limit, in order to ensure that the first channel 11 is always within the range of the annular chamber, the first channel 11 can be set at a position close to the upper end surface of the water eye base 3.

[0027] In order to ensure that the circulating liquid can generate an upward thrust on the guide tube 2 at the initial stage of entry, a countersunk hole 21 can be opened on the inner wall of the lower end of the guide tube 2. The depth of the countersunk hole 21 is greater than the distance between the top of the first channel 11 and the top surface of the water eye base 3. With this structural design, even if the lower end surface of the guide tube 2 is in contact with the upper end surface of the water eye base 3, the circulating liquid can smoothly enter between the guide tube 2 and the water eye base 3, thereby smoothly pushing the guide tube 2 to move upward.

[0028] As a preferred solution, the first channel 11 can be a through hole structure, and can also be formed by using a nozzle installed in the through hole. As a further preferred solution, the nozzle is installed in the through hole in a detachable manner. By replacing the nozzle, a first channel 11 with different channel diameters can be formed to adjust the maximum pressure inside the annular chamber.

[0029] The method for performing fish top trimming using the above-mentioned fish top trimming tool comprises the following steps: S1: Use the drill rod to lower the fish top trimming tool to a predetermined depth, or lower it until the fish top trimming tool abuts against the fish top and the drill rod cannot be lowered further.

[0030] S2: Start the liquid circulation, push the blade 5 outward along the circumference, and cover the blade 5 on the fish top. The specific operation is to start the ground water pump, pump liquid into the center pipe 1 through the drill pipe, the liquid passes through the fish top finishing tool, and then is discharged back to the ground from the annulus, thus forming a circulating liquid; the opening principle of the blade 5 is as follows: when the liquid starts to circulate, the internal pressure of the center pipe 1 will increase, and part of the liquid will go out through the pipe opening at the lower end of the water eye base 3, and then return to the ground through the annulus. According to actual needs, the pipe opening at the lower end of the water eye base 3 can be closed by throwing a ball into the center pipe 1. When liquid circulation is required, there is no need to throw a ball; some liquid will enter the annular chamber through the first channel 11, and the liquid entering the annular chamber will push the guide pipe 2 to move upward along the center pipe 1, and At the same time, the sleeve 4 and the blade 5 are driven to rise together; during the rising process of the blade 5, the pressure between the guide surface 51 and the outer edge of the lower end of the water eye base 3 will gradually increase, so that the water eye base 3 is used to push the blade 5 outward to expand the circular contour surrounded by the lower ends of all the blades 5, so as to adapt to the deformed fish top and the enlarged naked eye, even if the fish top of the fallen fish is in an eccentric position of the naked eye, it can be covered by the opened blade 5, so as to avoid the influence of the naked eye expansion and the eccentricity of the fallen fish on the fish top trimming process, and multiple blades 5 will form a cone structure after opening, which can effectively avoid the appearance of a pen tip structure on the fish top, and prevent the formation of banana peel-like iron sheets on the outside of the fallen fish, thereby preventing drill jamming.

[0031] S3: trimming the fish top, rotating the drill rod through the ground equipment, the drill rod drives the fish top trimming tool to rotate, and the cutter body on the inner wall of the cutter plate 5 is used to grind the fish top, and trim the fish top into a truncated cone structure, so as to facilitate the subsequent process of making a buckle at the upper end of the fish. This scheme finally makes a buckle to form an external thread structure.

[0032] S4: Recover the fish top trimming tool, stop the liquid circulation, use the reset spring 6 to push the guide tube 2 downward, so that the water eye base 3 retracts the casing 4, removes the outward squeezing force of the knife plate 5, and lifts the fish top trimming tool upward through the drill pipe. Because the knife plate 5 is a downwardly arranged structure, even if it is not retracted in time, it does not affect the lifting of the fish top trimming tool, and it will not get stuck in the well.

[0033] Preferably, Figure 1 , Figure 4 and Figure 6 As shown, the upper end of the center tube 1 and the sleeve are provided with a return spring 6, and the lower end of the return spring 6 is pressed against the top surface of the guide tube 2. When the circulating liquid in the annular chamber is discharged and the pressure inside the annular chamber is reduced, the return spring 6 will push the guide tube 2 to move downward relative to the center tube 1, so that the water eye base 3 is retracted into the sleeve 4, thereby removing the thrust on the guide surface 51.

[0034] Preferably, Figure 5As shown, the outer wall of the lower end of the water eye base 3 is formed with a downwardly arranged step surface 31, and the upper end of the guide surface 51 has a limit surface 52 protruding from the inner wall of the sleeve 4. The step surface 31 abuts against the limit surface 52 to limit the extreme position of the upward movement of the guide tube 2 relative to the center tube 1, and is also used to limit the extreme angle of the outward opening of the knife plate 5, thereby controlling the maximum working diameter of the knife plate 5.

[0035] Preferably, the blade 5 is integrally formed with the sleeve 4. It can also be understood that a plurality of slits are provided at the lower end of the sleeve 4, thereby forming the blade 5 using the solid parts between adjacent slits. The blade 5 having an integral structure with the sleeve 4 can automatically retract toward the middle under the elastic deformation of the metal material after the outward thrust of the water eye base 3 is lost.

[0036] Preferably, Figure 2 , Figure 5 and Figure 7 As shown, the side walls of the water eye base 3 are provided with second channels 32 corresponding to adjacent blade plates 5, which are used to spray circulating liquid between the blade plates 5 to prevent debris from being stuck between adjacent blade plates 5 and hindering the recovery of the blade plates 5, and the second channel 32 is inclined toward the lower part of the outside of the water eye base 3; as a preferred solution, the second channel 32 can be a through hole structure, and can also be formed by a tubular nozzle installed in the through hole; similarly, a tubular nozzle is provided inside the pipe opening at the lower end of the water eye base 3.

[0037] As a further preference, the tubular nozzles are all installed in a detachable manner. By replacing the tubular nozzles, a second channel 32 with a different channel diameter can be formed to adjust the pressure of the circulating water injection, and the flow rate of the circulating liquid discharged from the lower end of the water eye base 3 can also be controlled, thereby balancing the pressure inside the central tube 1 and the annular chamber.

[0038] Preferably, Figure 1 , Figure 3 , Figure 4 and Figure 6 As shown, a limiting tube 7 is coaxially fixed to the upper end of the guide tube 2. Commonly used fixed connection structures include threaded connection, bolt connection, riveting or pin connection. In this embodiment, a threaded connection is adopted between the lower end of the limiting tube 7 and the upper end of the guide tube 2 to achieve the purpose of fixing. The limiting tube 7 is sleeved on the outside of the center tube 1. The inner wall of the limiting tube 7 and the center tube 1 are provided with limiting grooves extending along the axis. The limiting tube 7 and the limiting grooves of the center tube 1 are arranged in pairs. A pin 8 is provided in each pair of limiting grooves for preventing the limiting tube 7 and the center tube 1 from rotating relative to each other, thereby preventing the guide tube 2 from rotating relative to the center tube 1. The reset spring 6 is located above the limiting tube 7.

[0039] Preferably, Figure 1 , Figure 4 and Figure 6As shown, the upper end of the central tube 1 is coaxially connected with a top joint 9, the upper end of the top joint 9 is used to connect the drill pipe, and the return spring 6 is pressed between the top joint 9 and the limit tube 7.

[0040] The above description is only a preferred embodiment of the present invention, and is not intended to be the only one or to limit the present invention. Those skilled in the art should understand that various changes or equivalent substitutions made to the present invention without departing from the scope of the present invention are within the scope of protection of the present invention.

Claims

1. A fish top trimming tool, characterized in that: include: A central tube (1) having a first passage (11) formed on a side wall at a lower end thereof; A guide tube (2) is coaxially sleeved on the middle section outside the center tube (1); The water eye base (3) is a circular tube structure, which is coaxially fixed to the lower end of the central tube (1). The outer diameter of the water eye base (3) is larger than the outer diameter of the central tube. The water eye base (3) and the guide tube (2) are all sealedly connected to the central tube (1). The sleeve (4) is coaxially fixed to the lower end of the guide tube (2), and the water eye base (3) is inserted into the sleeve (4); A plurality of mutually independent blades (5) are arranged in a circular array at the lower end of the sleeve (4); the cross section of the blade (5) is arc-shaped, and the inner arc surface thereof faces the middle of the sleeve (4); a blade body is arranged on the inner arc surface of the blade (5); the inner wall of the upper end of the blade (5) has an inwardly protruding guide surface (51); the guide surface (51) is inclined toward the upper middle of the sleeve (4); and the outer edge of the lower end surface of the water eye base (3) is located within the range of the guide surface (51) in a projection view of the axis of the central tube (1); An annular chamber is formed between the lower end surface of the guide tube (2), the upper end surface of the water eye base (3), the outer wall of the central tube (1), and the inner wall of the sleeve (4), and the first channel (11) is used to pass circulating liquid into the annular chamber to push the guide tube (2) to move upward relative to the central tube (1).

2. A fish top trimming tool according to claim 1, characterized in that: The upper end and sleeve of the center tube (1) are provided with a return spring (6), and the lower end of the return spring (6) is pressed tightly against the top surface of the guide tube (2).

3. A fish top trimming tool according to claim 1 or 2, characterized in that: The outer wall of the lower end of the water eye base (3) is formed with a step surface (31) arranged downward, and the upper end of the guide surface (51) has a limit surface (52) protruding from the inner wall of the sleeve (4). The step surface (31) abuts against the limit surface (52) to limit the limit position of the upward movement of the guide tube (2) relative to the center tube (1).

4. A fish top trimming tool according to claim 1, characterized in that: The knife plate (5) and the sleeve (4) are integrally formed.

5. A fish top trimming tool according to claim 1, characterized in that: A countersunk hole (21) is formed on the inner wall of the lower end of the guide tube (2), and the depth of the countersunk hole (21) is greater than the distance between the top of the first channel (11) and the top surface of the water eye base (3).

6. A fish top trimming tool according to claim 1, characterized in that: Second channels (32) are provided between the side walls of the water eye base (3) and the adjacent knife plates (5), and the second channels (32) are inclined downward toward the outside of the water eye base (3).

7. A fish top trimming tool according to claim 2, characterized in that: A limiting tube (7) is coaxially fixedly provided at the upper end of the guide tube (2). The limiting tube (7) is sleeved on the outside of the central tube (1). The inner wall of the limiting tube (7) and the central tube (1) are both provided with limiting grooves extending along the axis. The limiting tube (7) and the limiting grooves of the central tube (1) are arranged in pairs. A latch pin (8) is provided in each pair of limiting grooves. A return spring (6) is located above the limiting tube (7).

8. A fish top trimming tool according to claim 7, characterized in that: The upper end of the center tube (1) is coaxially connected to a top joint (9), the upper end of the top joint (9) is used to connect a drill pipe, and a return spring (6) is pressed between the top joint (9) and the limit tube (7).

9. A method for trimming a fish top, implemented using the fish top trimming tool according to any one of claims 1 to 8, the method comprising the following steps: S1: Use the drill rod to lower the fish top trimming tool to a predetermined depth; S2: Start the liquid circulation, push the knife plate (5) outward along the circumference, and cover the knife plate (5) on the top of the fish; S3: trimming the fish top, rotating the drill rod through the ground equipment, the drill rod drives the fish top trimming tool to rotate, and the cutter body on the inner wall of the cutter plate (5) is used to grind the fish top, so that the fish top is trimmed into a truncated cone structure; S4: Recover the fish top trimming tool, stop the liquid circulation, use the return spring (6) to push the guide tube (2) downward, so that the water eye base (3) retracts the casing (4), removes the outward squeezing force of the knife plate (5), and lifts the fish top trimming tool upward through the drill pipe.

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