Anti-blocking well drilling sleeve joint

Abstract

The utility model relates to an anti-blocking well drilling sleeve joint, and belongs to the technical field of well drilling sleeve joints. The anti-blocking drilling casing joint comprises a first pipeline, a threaded lantern ring, a first joint, a second joint and a second pipeline, one side of the first pipeline is in meshed connection with the first connector through threads, the connection strength and the sealing performance are guaranteed, the end face of the first connector is machined through a mirror face machining technology, the flatness of the attaching face of the first connector and the second connector is high, and detention of rock debris is effectively reduced, and right-handed spiral flow guide lines are formed in the inner walls of the first pipeline, the second pipeline and the connectors. The thread sleeve ring is made of a duplex stainless steel material, trapezoidal threads matched with external threads of the second connector are machined on the inner wall of the thread sleeve ring, pre-tightening force is applied through rotary meshing, the compression amount of the sealing ring is accurately increased, and the self-cleaning sealing ring is particularly suitable for a shale gas horizontal well. And the rock debris passing efficiency is greatly improved compared with that of a traditional connector.

Description

Technical Field

[0001] This utility model relates to the field of drilling casing joint technology, and in particular to an anti-clogging drilling casing joint. Background Technology

[0002] Casing drilling refers to using casing instead of drill pipe to apply torque and drilling pressure to the drill bit, enabling the drill bit to rotate and drill. The entire drilling process no longer uses drill pipe, drill collars, etc. The drill bit is retrieved using a wire rope and raised and lowered within the casing. This allows for drill bit and drill string replacement without lifting the drill string, reducing tripping, blowouts, stuck pipe, and other accidents, improving drilling safety, and reducing drilling costs.

[0003] When existing casing joints are in use, the axial deviation mainly stems from manufacturing errors (such as thread machining deviations and material deformation differences), installation and operation limitations (such as insufficient torque control accuracy and wellbore trajectory influences), and geological condition interference (such as formation creep and temperature effects). These factors work together to cause axial offset, which in turn leads to serious hazards such as increased rock cuttings impact wear, accumulation and blockage, sealing failure, and decreased cementing quality, affecting the safety and efficiency of drilling operations. Utility Model Content

[0004] Therefore, it is necessary to provide an anti-clogging drilling casing joint to address the serious hazards caused by axial misalignment, such as increased rock cuttings impact and wear, accumulation and blockage, sealing failure, and decreased cementing quality, which affect the safety and efficiency of drilling operations.

[0005] A clog-resistant drilling casing connector includes: a first pipe, a first connector threadedly connected to one side of the first pipe, a second connector fitted to one end of the first connector, and a second pipe threadedly connected to one side of the second connector.

[0006] The first pipe, the second pipe, the first joint, and the second joint are all provided with flow guide patterns inside, and the flow guide patterns are spiral patterns.

[0007] A threaded collar is movably sleeved on the surface of the second connector, and one side of the threaded collar is engaged with the outer wall of the second connector.

[0008] In one embodiment, the threads on the surfaces of the first and second pipes gradually extend toward the side closer to the axis.

[0009] In one embodiment, the pitch of the guide pattern decreases in a stepped manner from the first pipe to the second pipe, and the surface of the guide pattern is coated with a wear-resistant ceramic coating.

[0010] In one embodiment, a rubber sleeve is provided on the surface of the connection between the first connector and one end of the first pipe. Two rubber sleeves are provided, and the other rubber sleeve is provided on the surface of the connection between the second connector and the second pipe.

[0011] In one embodiment, a sealing ring is provided at the contact point between the second connector and the threaded collar, and multiple sealing rings are provided, with the inner diameter of the multiple sealing rings gradually increasing.

[0012] In one embodiment, a limiting ring is fixedly sleeved on the surface of the first connector, and the inner wall of one end of the threaded collar is sleeved on the surface of the limiting ring.

[0013] In one embodiment, one end of the threaded collar gradually narrows radially towards the side of the second connector, and a boss is provided at the point where the second connector fits with the first connector.

[0014] In one embodiment, the rubber sleeve has chamfered sides that extend toward the side closer to the axis, and the inner wall of the rubber sleeve has cross anti-slip textures.

[0015] Beneficial effects

[0016] 1. The first pipe is connected to the first connector by a thread on one side to ensure connection strength and sealing. The end face of the first connector is mirror-finished, and the flatness of the mating surface with the second connector is high, effectively reducing rock cuttings retention. The second connector is connected to the second pipe by a special tapered thread with a hard chrome plated surface for improved wear resistance. Right-hand spiral flow guides are opened on the inner walls of the first and second pipes and the connector. The pitch decreases linearly from the inlet to the outlet, forming a self-cleaning flow field. The threaded collar is made of duplex stainless steel and has a trapezoidal thread on the inner wall that matches the external thread of the second connector. Pre-tightening force is applied by rotational engagement to precisely increase the compression of the sealing ring. It is particularly suitable for shale gas horizontal wells, and the rock cuttings passage efficiency is significantly improved compared with traditional connectors.

[0017] 2. The limiting ring on the surface of the first joint adopts a double-step axial limiting design. The outer chamfer and the inner wall of the threaded collar form a wedge-shaped mating surface. When subjected to axial tensile force, the mechanical interlocking effect prevents the threaded collar from accidentally falling off. Utilizing the pre-tightening torque generated by the elastic deformation of the metal, the tapered contraction section of the threaded collar adopts a streamlined curved surface transition, forming a negative pressure drainage effect when the fluid passes through, which increases the boundary layer flow velocity and significantly reduces rock cuttings deposition. The end boss of the second joint is processed with laser-textured texture on the mating surface of the first joint. Through the micro-locking effect, the contact stress of the sealing surface is increased. The chamfered extension of the rubber sleeve forms a 30° angle with the pipe body. Combined with the cross-textured design of the inner wall, the friction coefficient is increased, effectively resisting drilling fluid erosion. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0020] Figure 2 This is a schematic diagram of the overall side cross-sectional structure of this utility model;

[0021] Figure 3 This is a schematic diagram of the overall splicing structure of this utility model;

[0022] Figure 4 This is a schematic diagram of the overall spliced ​​side sectional structure of this utility model;

[0023] Figure 5 This is a three-dimensional cross-sectional view of the overall assembly of this utility model.

[0024] Figure label:

[0025] 100, First pipe; 101, Guide line; 200, Second pipe; 201, Rubber sleeve; 300, First connector; 301, Limiting ring; 400, Second connector; 500, Threaded collar; 600, Sealing ring. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0027] The following is combined Figures 1-5 This invention describes an anti-clogging drilling casing connector.

[0028] In one embodiment, an anti-clogging drilling casing joint includes: a first pipe 100 and a threaded collar 500. A first connector 300 is threadedly connected to one side of the first pipe 100. A second connector 400 is attached to one end of the first connector 300. A second pipe 200 is threadedly connected to one side of the second connector 400. The first pipe 100, the second pipe 200, the first connector 300, and the second connector 400 are all provided with flow guide patterns 101, which are spiral patterns. The threaded collar 500 is movably sleeved on the surface of the second connector 400, and one side of the threaded collar 500 is engaged with the outer wall of the second connector 400.

[0029] In this embodiment, one side of the first pipe 100 is connected to the first connector 300 by a thread to ensure connection strength and sealing. The end face of the first connector 300 is made of mirror finish, and the flatness of the mating surface with the second connector 400 is high, which effectively reduces rock debris retention. The second connector 400 is connected to the second pipe 200 by a special tapered thread, and the thread surface is plated with a hard chrome layer to improve wear resistance.

[0030] The first pipe 100, the second pipe 200, and the inner wall of the joint are all provided with right-hand spiral guide lines 101. The pitch decreases linearly from the inlet to the outlet, forming a self-cleaning flow field. The threaded collar 500 is made of duplex stainless steel and has a trapezoidal thread on its inner wall that matches the external thread of the second joint 400. The pre-tightening force is applied by rotational engagement, which precisely increases the compression of the sealing ring 600. It is particularly suitable for shale gas horizontal wells, and the cuttings passage efficiency is greatly improved compared with traditional joints.

[0031] like Figure 1 , Figure 2 and Figure 3 As shown, the threads on the surfaces of the first pipe 100 and the second pipe 200 gradually extend toward the side closer to the axis. The pitch of the guide pattern 101 decreases in a stepwise manner from the first pipe 100 to the second pipe 200, and the surface of the guide pattern 101 is coated with a wear-resistant ceramic coating.

[0032] In this embodiment, the threads on the surfaces of the first pipe 100 and the second pipe 200 adopt a variable pitch design, and the thread angle narrows in a stepwise manner from the root to the end of the pipe body at 15°, which makes the contact stress distribution more uniform when the threads are engaged and improves the anti-slip performance.

[0033] The pitch of the guide ring 101 decreases in a stepwise manner from the first pipe 100 to the second pipe 200. Combined with the right-hand helix angle, it forms a three-dimensional spiral flow field, which can increase the speed of rock cuttings transportation. In particular, a pitch change zone is set in the outlet section of the second pipe 200. The sudden reduction of pitch generates the Venturi effect, forming a local high-speed zone to achieve secondary acceleration of rock cuttings and effectively prevent rock cuttings from accumulating at the joint diameter change.

[0034] like Figure 2 , Figure 3 and Figure 4 As shown, a rubber sleeve 201 is fitted on the surface of the connection between the first connector 300 and the first pipe 100. There are two rubber sleeves 201. Another rubber sleeve 201 is fitted on the surface of the connection between the second connector 400 and the second pipe 200. A sealing ring 600 is provided at the contact point between the second connector 400 and the threaded collar 500. There are multiple sealing rings 600, and the inner diameter of the multiple sealing rings 600 gradually increases.

[0035] In this embodiment, the connection between the first connector 300 and the first pipe 100 adopts a double-conical rubber sleeve 201 sealing structure. The rubber sleeve 201 is made of hydrogenated nitrile rubber. Three carbon fiber reinforced polyetheretherketone sealing rings 600 are provided between the second connector 400 and the threaded collar 500. The sealing rings 600 adopt a trapezoidal cross-section design. The inner diameter of the multi-stage sealing rings 600 increases in a gradient of 0.2mm to form a labyrinth-like sealing barrier. In particular, a diamond-like carbon film is deposited on the surface of the sealing rings 600, which has a low coefficient of friction and significantly improves the durability of the connector in a hydrogen sulfide-containing environment.

[0036] like Figure 2 , Figure 4 and Figure 5 As shown, a limiting ring 301 is fixedly sleeved on the surface of the first connector 300. The inner wall of one end of the threaded collar 500 is sleeved on the surface of the limiting ring 301 and rotates. The outer radial direction of one end of the threaded collar 500 gradually narrows towards the side of the second connector 400. A boss is provided at the contact point between one end of the second connector 400 and the first connector 300. The two sides of the rubber sleeve 201 are chamfered and extend towards the side closer to the axis. The inner wall of the rubber sleeve 201 is provided with cross anti-slip texture.

[0037] In this embodiment, the limiting ring 301 sleeved on the surface of the first connector 300 adopts a double-step axial limiting design. The outer chamfer and the inner wall of the threaded collar 500 form a wedge-shaped mating surface. When subjected to axial tensile force, the mechanical interlocking effect prevents the threaded collar 500 from accidentally falling off. Utilizing the pre-tightening torque generated by the elastic deformation of the metal, the tapered contraction section of the threaded collar 500 adopts a streamlined curved surface transition, forming a negative pressure drainage effect when the fluid passes through, thereby increasing the boundary layer flow velocity and significantly reducing rock cuttings deposition. The end boss of the second connector 400 and the mating surface of the first connector 300 are processed with laser-textured patterns. Through the micro-locking effect, the contact stress of the sealing surface is increased. The chamfered extension of the rubber sleeve 201 forms a 30° angle with the pipe body. Combined with the cross-textured design of the inner wall, the friction coefficient is increased, effectively resisting drilling fluid erosion.

[0038] Working principle:

[0039] After the drilling fluid enters, the right-hand spiral guide 101 transforms the linear flow into a spiral flow. The stepped pitch reduction design creates a pressure gradient in the direction from the first pipe 100 to the second pipe 200. Combined with the Venturi effect caused by the sudden pitch change at the outlet section of the second pipe 200, a local high-speed jet zone is formed, which applies a dual acceleration effect to the cuttings. Actual measurements show that it can increase the terminal velocity of the cuttings.

[0040] The tapered contraction section of the threaded collar 500 generates negative pressure to guide the flow of fluid, increasing the near-wall velocity and effectively suppressing cuttings deposition. The double-conical rubber sleeve 201 forms an elastic seal through the pipe body, and the cross anti-slip texture design increases the coefficient of friction while maintaining good elongation under certain pressure. The triple carbon fiber reinforced polyetheretherketone sealing ring 600 adopts a trapezoidal cross-section and a 0.2mm inner diameter gradient design to form a labyrinthine sealing barrier. Combined with a diamond-like carbon film coating, the coefficient of friction is reduced and durability is improved in hydrogen sulfide-containing environments. The laser-textured sealing surface at the end of the second joint 400 constructs a dual mechanical locking sealing system to ensure reduced leakage under complex working conditions, effectively prevent casing blockage, and improve drilling efficiency.

[0041] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A clog-resistant drilling casing joint, characterized in that, include: A first pipe (100) is threadedly connected to a first connector (300) on one side, and a second connector (400) is attached to one end of the first connector (300), and a second pipe (200) is threadedly connected to one side of the second connector (400). The first pipe (100), the second pipe (200), the first connector (300), and the second connector (400) are all provided with flow guide patterns (101), and the flow guide patterns (101) are spiral patterns. A threaded collar (500) is movably sleeved on the surface of the second connector (400), and one side of the threaded collar (500) is engaged with the outer wall of the second connector (400).

2. The anti-clogging drilling casing joint according to claim 1, characterized in that, The threads on the surfaces of the first pipe (100) and the second pipe (200) gradually extend toward the side closer to the axis.

3. The anti-clogging drilling casing joint according to claim 2, characterized in that, The pitch of the guide pattern (101) decreases in a stepwise manner from the first pipe (100) to the second pipe (200), and the surface of the guide pattern (101) is coated with a wear-resistant ceramic coating.

4. The anti-clogging drilling casing joint according to claim 1, characterized in that, A rubber sleeve (201) is provided on the surface of the connection between the first connector (300) and the first pipe (100). There are two rubber sleeves (201), and the other rubber sleeve (201) is provided on the surface of the connection between the second connector (400) and the second pipe (200).

5. The anti-clogging drilling casing joint according to claim 3, characterized in that, A sealing ring (600) is provided at the contact point between the second connector (400) and the threaded collar (500). Multiple sealing rings (600) are provided, and the inner diameter of the multiple sealing rings (600) gradually increases.

6. The anti-clogging drilling casing joint according to claim 1, characterized in that, A limiting ring (301) is fixedly sleeved on the surface of the first connector (300), and one end of the threaded collar (500) is sleeved on the surface of the limiting ring (301) and rotates.

7. The anti-clogging drilling casing joint according to claim 6, characterized in that, The outer radial direction of one end of the threaded collar (500) gradually narrows towards the side of the second connector (400), and a boss is provided at the contact point between one end of the second connector (400) and the first connector (300).

8. The anti-clogging drilling casing joint according to claim 4, characterized in that, The rubber sleeve (201) has chamfered sides that extend toward the side closer to the axis, and the inner wall of the rubber sleeve (201) is provided with cross anti-slip texture.

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