A washpipe assembly for a petroleum drilling rig swivel

Abstract

The utility model discloses a kind of washpipe assembly for petroleum drilling rig faucet, belong to petroleum drilling equipment technical field;Including washpipe body, and the packing of sliding sleeve being set in the washpipe body outside;The outer wall of the washpipe body is sequentially provided with metal ceramic layer, transition layer and diamond layer from inside to outside;The packing inside is provided with annular cavity, annular cavity is provided with shape memory alloy in.The metal ceramic layer bears the continuous impact of cuttings in slurry, and insulates corrosive medium, transition layer relieves and avoids coating cracking and falling off, diamond layer blocks chemical erosion by virtue of superhardness and chemical inertia.Three layers of coating closely cooperate, effectively improve the overall wear resistance and corrosion resistance of washpipe.Shape memory alloy is set to realize dynamic sealing between packing and washpipe, and then effectively improve sealing property.The utility model optimizes washpipe outer wall coating and sealing structure, effectively improves the corrosion resistance and wear resistance of washpipe outer wall and improves sealing property.

Description

Technical Field

[0001] This utility model relates to the field of oil drilling equipment technology, and in particular to a flushing pipe assembly for an oil drilling rig swivel. Background Technology

[0002] As the core hub of oil drilling operations, the performance of the swivel on an oil drilling rig directly determines drilling efficiency and safety, and the flushing assembly is a key load-bearing component of the swivel. In actual drilling processes, the outer wall of the flushing assembly is directly exposed to a harsh environment, not only withstanding the continuous scouring of high-pressure drilling mud (up to 50 MPa), but also dealing with the high-frequency impact of rock cuttings (hardness 800-1200 HV) in the mud, and Cl... - Chemical corrosion from highly corrosive media such as H2S is a significant concern. Therefore, the corrosion resistance and wear resistance of the outer wall of the flushing pipe directly affect the lifespan of the faucet and drilling efficiency. Furthermore, traditional packing relies on pre-tightening force for sealing, which cannot dynamically adjust pressure according to changes in operating conditions. When drilling depth increases or mud parameters change, the pre-tightened packing may become too tight, leading to a surge in frictional power consumption and overheating of components, or too loose, causing leakage. This makes it difficult to meet the sealing requirements under complex operating conditions, reducing the stability and efficiency of drilling operations.

[0003] Therefore, optimizing the coating system on the outer wall of the pipe and the sealing system in the contact area between the pipe and the packing has become the key to breaking through the bottleneck of oil drilling technology and improving operational efficiency and safety. Utility Model Content

[0004] The purpose of this utility model is to provide a flushing pipe assembly for a swivel tap in an oil drilling rig. By optimizing the coating structure of the outer wall of the flushing pipe and the sealing structure of the contact area between the flushing pipe and the packing, the corrosion resistance and wear resistance of the outer wall of the flushing pipe and the sealing performance are effectively improved.

[0005] The objective of this utility model is achieved through the following technical solution:

[0006] A flushing assembly for a swivel tap in an oil drilling rig includes a flushing body and a packing that is slidably sleeved on the outside of the flushing body; the outer wall of the flushing body is provided with a metal-ceramic layer, a transition layer and a diamond layer from the inside to the outside; the packing has an annular cavity inside, and a shape memory alloy is disposed in the annular cavity.

[0007] Preferably, the metal-ceramic layer is tungsten carbide-cobalt-based metal-ceramic.

[0008] Preferably, the thickness of the metal-ceramic layer is 0.3-0.8 mm.

[0009] Preferably, the transition layer is a titanium alloy, and the thickness of the transition layer is 10-30 μm.

[0010] Preferably, the thickness of the diamond layer is 50-100 μm.

[0011] Preferably, the shape memory alloy has a spring-like structure, and the shape memory alloy and the punch body are coaxial.

[0012] Preferably, the annular cavity is a cylindrical cavity, and both the inner and outer walls of the annular cavity are provided with a first thermally conductive silicone layer.

[0013] Preferably, a second thermally conductive silicone layer is provided between the two ends of the shape memory alloy and the top and bottom walls of the annular cavity.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0015] 1. This invention features a three-layer composite coating on the outer wall of the punching pipe, forming a robust barrier against wear and corrosion. The innermost metal-ceramic layer, with its excellent hardness and toughness, withstands the continuous impact of rock debris in the mud and isolates it from corrosive media. The middle transition layer effectively alleviates the stress caused by the difference in thermal expansion between the coating layers, preventing cracking and peeling and ensuring structural stability. The outermost diamond layer, with its ultra-high hardness and chemical inertness, further reduces mud friction loss, blocks chemical erosion, and prevents mud adhesion and scaling. The three coating layers work closely together to effectively improve the overall wear resistance and corrosion resistance of the punching pipe.

[0016] 2. This invention incorporates a shape memory alloy within the packing, which expands to generate additional radial pressure when the slurry temperature rises, compensating for packing wear and loosening. Conversely, it contracts when the temperature decreases, preventing excessive packing compression that increases frictional power consumption. This effectively improves the seal between the packing and the flushing pipe, preventing reduced sealing that could lead to slurry leakage and accelerated wear and corrosion on the flushing pipe surface. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of Example 1 from the front view.

[0018] Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure viewed from above;

[0019] Figure 3 for Figure 1 A cross-sectional view of the structure with the first thermally conductive silicone layer in the center, viewed from the front.

[0020] Figure 4 for Figure 3 A cross-sectional view of the structure after the second thermally conductive silicone layer is installed in the middle, viewed from the front.

[0021] In the figure: 1-Punching tube body, 2-Packing, 3-Metal-ceramic layer, 4-Transition layer, 5-Diamond layer, 6-Annular cavity, 7-Shape memory alloy, 8-First thermally conductive silicone layer, 9-Second thermally conductive silicone layer. Detailed Implementation

[0022] Example 1

[0023] During drilling, the outer wall of the casing is directly exposed to a harsh environment, having to withstand not only the continuous scouring of high-pressure drilling mud, but also the high-frequency impact of rock cuttings in the mud, and Cl... - Chemical corrosion from highly corrosive media such as H2S is a significant concern. Therefore, the corrosion resistance and wear resistance of the outer wall of the flushing pipe directly affect the lifespan of the faucet and drilling efficiency. Furthermore, traditional packing relies on pre-tightening force for sealing, which cannot dynamically adjust pressure according to changes in operating conditions. When drilling depth increases or mud parameters change, the pre-tightened packing may become too tight, leading to a surge in frictional power consumption and overheating of components, or too loose, causing leakage. This makes it difficult to meet the sealing requirements under complex operating conditions, reducing the stability and efficiency of drilling operations.

[0024] Based on this, the present invention provides a flushing pipe assembly for a swivel tap on an oil drilling rig, such as... Figure 1-2 As shown, it includes a punch tube body 1 and a packing 2 slidably sleeved on the outside of the punch tube body 1; the outer wall of the punch tube body 1 is provided with a metal-ceramic layer 3, a transition layer 4, and a diamond layer 5 from the inside to the outside; the packing 2 has an annular cavity 6 inside, and a shape memory alloy 7 (such as...) is disposed in the annular cavity 6. Figure 1 As shown, Figure 2 (Not shown). Packing 2 is housed within a packing 2 box, which is fixedly connected to the faucet housing. Since the packing box itself is existing technology, and its connection to packing 2 is also existing technology, the packing box is not shown in the figure; only packing 2, the flushing pipe, and their connection are shown.

[0025] Working Principle: Of the three coating layers on the exterior of the punch pipe body 1, the innermost metal-ceramic layer 3, with its excellent hardness and toughness, withstands the continuous impact of rock debris in the mud and isolates it from corrosive media. The middle transition layer 4 effectively alleviates the stress caused by the difference in thermal expansion between the coating layers, preventing cracking and peeling, and ensuring structural stability. The outermost diamond layer 5, with its ultra-high hardness and chemical inertness, further reduces mud friction loss. It also reduces surface roughness, decreases mud adhesion and flow resistance, enhances the punch pipe's surface resistance to fouling and corrosion, and effectively blocks chemical erosion. The three coating layers work closely together to effectively improve the overall wear resistance and corrosion resistance of the punch pipe.

[0026] Furthermore, during drilling, the shape memory alloy 7 expands as the mud temperature rises, generating additional radial pressure to compensate for the wear and loosening of the packing 2. As the temperature decreases, the shape memory alloy 7 contracts, preventing excessive compression of the packing 2 and resulting in increased frictional power consumption. This effectively improves the sealing performance between the packing 2 and the flushing pipe.

[0027] This invention effectively improves the corrosion and wear resistance of the outer wall of the punch pipe and the sealing structure of the contact area between the punch pipe and the packing 2 by optimizing the coating structure of the outer wall of the punch pipe and the sealing structure of the contact area between the punch pipe and the packing 2.

[0028] Example 2

[0029] Based on Example 1, the cermet layer 3 is a tungsten carbide-cobalt-based cermet. This tungsten carbide-cobalt-based cermet is composed of tungsten carbide particles (86 wt%) and cobalt (14 wt%), and is prepared using a supersonic flame spraying process. The tungsten carbide-cobalt-based cermet possesses high hardness (HV 1200-1500) and good toughness. The tungsten carbide particles provide wear resistance, while the cobalt enhances structural stability, effectively resisting the erosion of rock debris in the slurry. Furthermore, the tungsten carbide-cobalt-based cermet can resist the erosion of acidic and alkaline substances and corrosive ions in the slurry, effectively extending the service life of the pipe-flush system.

[0030] Furthermore, the thickness of the metal-ceramic layer 3 is 0.3-0.8 mm. This thickness range ensures sufficient wear and corrosion resistance while avoiding reduced adhesion or excessive cost due to excessive coating thickness.

[0031] Furthermore, the transition layer 4 is a titanium alloy with a thickness of 10-30 μm. The titanium alloy composition includes titanium (90-95 wt%), aluminum (3-5 wt%), and vanadium (2-5 wt%). The coefficient of thermal expansion of the titanium alloy is between that of the cermet layer 3 and the diamond layer 5, which can effectively alleviate the stress caused by the difference in thermal expansion between the two layers, reduce the risk of coating cracking, and effectively improve the overall thermal shock resistance of the coating. Furthermore, the 10-30 μm thickness achieves good stress transition without affecting the overall structural dimensions and performance, ensuring a tight bond between the coating layers.

[0032] Furthermore, the diamond layer 5 has a thickness of 50-100 μm. The diamond layer 5 has extremely high hardness, and its thickness of 50-100 μm provides durable wear-resistant protection, significantly reducing wear on the punched pipe surface.

[0033] Furthermore, such as Figure 1As shown, the shape memory alloy 7 has a spring-like structure (a prior art technology), and the shape memory alloy 7 and the punch body 1 are coaxial. The spring-like structure facilitates the uniform radial pressure applied to the packing 2 when the shape memory alloy 7 expands due to heat, achieving adaptive sealing. The coaxial arrangement ensures uniform pressure distribution, avoids localized wear of the packing 2, and improves the sealing performance of the packing 2, effectively extending the sealing life of the packing 2. Figure 1 As shown, the shape memory alloy 7 is in contact with the outer wall and inner wall of the annular cavity 6, respectively.

[0034] Example 3

[0035] Based on Example 2, such as Figure 3 As shown, the annular cavity 6 is a cylindrical cavity, and both the inner and outer walls of the annular cavity 6 are provided with a first thermally conductive silicone layer 8. The first thermally conductive silicone layer 8 can rapidly conduct the heat generated by the shape memory alloy 7 to the punch and packing 2, accelerating the thermal response speed of the shape memory alloy 7. In addition, the elasticity of the first thermally conductive silicone can buffer the friction and collision between the shape memory alloy 7 and the inner wall of the cavity, protecting the shape memory alloy 7 and extending its service life.

[0036] Furthermore, such as Figure 4 As shown, a second thermally conductive silicone layer 9 is respectively disposed between the two ends of the shape memory alloy 7 and the top and bottom walls of the annular cavity 6. The second thermally conductive silicone layer can position and fix the shape memory alloy 7, preventing it from shifting during operation. In addition, the second thermally conductive silicone layer 9, in conjunction with the first thermally conductive silicone layer 8, can achieve omnidirectional heat conduction of the shape memory alloy 7, further improving heat transfer efficiency and ensuring its temperature uniformity.

Claims

1. A flushing pipe assembly for a swivel in an oil drilling rig, comprising a flushing pipe body (1) and a packing (2) slidably sleeved on the outside of the flushing pipe body (1); characterized in that, The outer wall of the punch body (1) is provided with a metal ceramic layer (3), a transition layer (4) and a diamond layer (5) from the inside to the outside; the packing (2) is provided with an annular cavity (6), and a shape memory alloy (7) is provided in the annular cavity (6).

2. The flushing pipe assembly for a swivel tap on an oil drilling rig according to claim 1, characterized in that, The metal-ceramic layer (3) is a tungsten carbide-cobalt-based metal-ceramic.

3. The flushing pipe assembly for a swivel tap on an oil drilling rig according to claim 2, characterized in that, The thickness of the metal-ceramic layer (3) is 0.3-0.8 mm.

4. The flushing pipe assembly for a swivel in an oil drilling rig according to claim 3, characterized in that, The transition layer (4) is a titanium alloy and the thickness of the transition layer (4) is 10-30 μm.

5. The flushing pipe assembly for a swivel tap on an oil drilling rig according to claim 1, characterized in that, The thickness of the diamond layer (5) is 50-100 μm.

6. The flushing pipe assembly for a swivel in an oil drilling rig according to claim 1, characterized in that, The shape memory alloy (7) has a spring-like structure, and the shape memory alloy (7) and the punch body (1) are coaxial.

7. A flushing pipe assembly for a swivel tap on an oil drilling rig according to claim 6, characterized in that, The annular cavity (6) is a cylindrical cavity, and the inner and outer walls of the annular cavity (6) are provided with a first thermally conductive silicone layer (8).

8. The flushing pipe assembly for a swivel in an oil drilling rig according to claim 7, characterized in that, A second thermally conductive silicone layer (9) is provided between the two ends of the shape memory alloy (7) and between the top and bottom walls of the annular cavity (6).

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