Corrosion-resistant and wear-resistant fracturing fluid pipeline

Abstract

The utility model discloses a corrosion-resistant and wear-resistant fracturing fluid pipeline, and belongs to the technical field of petroleum and natural gas extraction equipment. Comprising a pipeline body, and a metal layer, a metal-ceramic layer, a metal-diamond layer and a diamond layer are sequentially arranged on the inner surface of the pipeline body; one end of the pipeline body is provided with an annular first protruding block, and the other end of the pipeline body is provided with an annular inserting groove matched with the first protruding block. Wherein the metal layer provides structural strength and preliminary corrosion resistance, the metal-ceramic layer is combined with high-hardness ceramic and a corrosion-resistant metal matrix to enhance the binding force between the metal layer and the metal-diamond layer, and interface stripping is prevented. The wear resistance of the metal-diamond layer is enhanced through superhard diamond, the diamond layer directly resists corrosion and wear, the tolerance of the pipeline to fracturing fluid is remarkably improved, and the service life is prolonged. Through the synergistic effect of the four protection layers, a gradient protection system can be formed from foundation supporting to surface protection, and the corrosion resistance and wear resistance of the pipeline are effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of oil and natural gas mining equipment, in particular to a corrosion-resistant and wear-resistant fracturing fluid pipeline. Background Art

[0002] In the oil and gas extraction industry, fracturing technology is widely used as a key means to increase oil and gas production.

[0003] When fracturing fluid is transported through pipelines, it often contains corrosive components such as acids and additives. During high-pressure pumping, this not only causes severe chemical corrosion to the inner wall of the pipeline, but also causes severe erosion and wear due to the high-speed flow. Currently, traditional fracturing fluid pipelines mostly use a single metal material or a simple coating structure, which has limited corrosion resistance. When faced with fracturing fluids with complex components, the metal material is easily corroded and the coating is prone to falling off. While some pipelines made of composite materials have improved wear resistance, the combined corrosion and wear resistance still cannot meet the needs of long-term high-intensity operations.

[0004] Based on this, there is an urgent need to develop a new type of pipeline with both high corrosion resistance and high wear resistance. Utility Model Content

[0005] The purpose of the utility model is to provide a corrosion-resistant and wear-resistant fracturing fluid pipeline, which solves the problems of severe corrosion and wear of traditional pipelines and easy peeling of coatings through a four-layer composite protection structure, thereby extending the service life.

[0006] The purpose of this utility model is achieved through the following technical solutions:

[0007] A corrosion-resistant and wear-resistant fracturing fluid pipeline comprises a pipeline body; the inner surface of the pipeline body is sequentially provided with a metal layer, a metal-ceramic layer, a metal-diamond layer and a diamond layer;

[0008] At both ends of the pipe body, one end is provided with a first annular protrusion, and the other end is provided with an annular slot adapted to the first protrusion.

[0009] Preferably, the metal layer includes nickel and iron; the thickness of the metal layer is 1.0-2.0 mm.

[0010] Preferably, the metal-ceramic layer comprises Ni, Cr, and WC-Co; and the thickness of the metal-ceramic layer is 0.3-0.8 mm.

[0011] Preferably, the metal-diamond layer comprises Co, Ni and diamond particles; and the thickness of the metal-diamond layer is 0.2-0.6 mm.

[0012] Preferably, in the metal-diamond layer, the diamond particles have a particle size of 20-50 μm.

[0013] Preferably, in the diamond layer, the diamond particle size is 5-15 μm, and the thickness of the diamond layer is 30-60 μm.

[0014] Preferably, the inner surface of the pipe body is provided with a plurality of pits with a depth of 50-100 μm.

[0015] Preferably, flanges are provided at both ends of the pipe body, and one of the two sides of the flanges at both ends of the pipe body, which are away from each other, is provided with a plurality of second protrusions on one side and grooves adapted to the second protrusions on the other side.

[0016] Preferably, sealing gaskets are provided in both the annular slot and the groove, and the sealing gaskets are made of polytetrafluoroethylene.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] 1. The metal layer provides structural strength and initial corrosion resistance. The metal-ceramic layer combines high-hardness ceramic with a corrosion-resistant metal matrix, strengthening the bond between the metal layer and the metal-diamond layer and preventing interfacial delamination. The metal-diamond layer utilizes ultra-hard diamond particles to enhance wear resistance. The innermost diamond layer directly resists corrosion and wear, significantly improving the pipeline's tolerance to fracturing fluids and significantly extending its service life. The four-layer composite structure of metal, metal-ceramic, metal-diamond, and diamond layers forms a gradient protection system from foundation support to surface protection, effectively addressing the severe corrosion and wear problems and coating shedding associated with traditional pipelines and extending their service life.

[0019] 2. By providing an annular first protrusion, an annular slot and a sealing gasket at both ends of the pipe body, the first protrusion can be inserted into the annular slot when the pipe bodies are connected, and the sealing gasket is compressed at the same time to achieve preliminary positioning of the pipe body and enhance axial stability. At the same time, a tighter sealing structure is formed between adjacent pipe bodies, effectively preventing fracturing fluid leakage and ensuring safety and reliability during high-pressure transportation.

[0020] 3. By providing a second protrusion and a groove on the flange and a sealing gasket in the groove, the second protrusion can be precisely fitted into the groove when the flange is connected, limiting the radial displacement of the pipeline. At the same time, the sealing gasket is compressed, cooperating with the first pipeline and the annular slot to achieve double connection reinforcement, forming a tighter sealing structure, effectively preventing fracturing fluid leakage, and ensuring safety and reliability during high-pressure transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic cross-sectional view of the embodiment 1 in the front view direction;

[0022] Figure 2 for Figure 1 A schematic diagram of a cross-sectional structure viewed from the side;

[0023] Figure 3 for Figure 1 Schematic diagram of the structure in the right-view direction;

[0024] Figure 4 for Figure 1 Schematic diagram of the structure in the front view after the flange is set;

[0025] Figure 5 for Figure 4 Schematic diagram of the structure in the left viewing direction;

[0026] In the figure: 1-pipe body, 2-metal layer, 3-metal-ceramic layer, 4-metal-diamond layer, 5-diamond layer, 6-first bump, 7-annular slot, 9-flange, 10-second bump. DETAILED DESCRIPTION

[0027] Example 1

[0028] A corrosion-resistant and wear-resistant fracturing fluid pipeline, such as Figure 1-Figure 3 As shown, it includes a pipe body 1; the inner surface of the pipe body 1 is sequentially provided with a metal layer 2, a metal-ceramic layer 3, a metal-diamond layer 4 and a diamond layer 5; at both ends of the pipe body 1, one end is provided with a first annular protrusion 6, and the other end is provided with an annular slot 7 adapted to the first protrusion 6. Figure 4 and Figure 5 As shown, flanges 9 are provided at both ends of the pipe body 1. Two surfaces of the flanges 9, facing away from each other, are provided with multiple second protrusions 10 on one side and grooves (not shown in the prior art) that mate with the second protrusions 10 on the other side. Furthermore, sealing gaskets (not shown in the prior art) are provided in both the annular slot 7 and the grooves. These gaskets are made of polytetrafluoroethylene.

[0029] It is worth noting that the filled area of each coating layer in the accompanying drawings is not the actual thickness of the coating.

[0030] Working Principle: When the fracturing fluid is transported within the pipeline body 1, the innermost diamond layer 5 first comes into direct contact with the fracturing fluid. Its extremely high hardness and chemical stability effectively resist the erosion of corrosive components in the fracturing fluid and the wear caused by high-speed flow. In the metal-diamond layer 5, diamond particles embedded in the metal matrix further enhance erosion resistance, dispersing the impact of the fracturing fluid on the inner wall of the pipeline and reducing wear. The ceramic particles in the metal-ceramic layer, with their high hardness, resist the erosion of the fracturing fluid, while the metal matrix ensures the bonding strength and corrosion resistance of the coating, working together with the metal-diamond layer 5 to exert a protective effect. The metal layer 2 serves as a foundation layer, providing structural support and tightly bonding with subsequent coatings to evenly distribute external pressure.

[0031] When connecting multiple pipe bodies 1, the annular first protrusion 6 at one end is inserted into the annular slot 7 at the end of the adjacent pipe, and the sealing gasket in the annular slot 7 is compressed to a certain extent to achieve preliminary positioning, sealing and axial fixation; when connected through the flange 9, the second protrusion 10 and the groove are engaged with each other to further enhance the connection stability. At the same time, the tightening bolts compress the sealing gasket in the groove to form a reliable sealing structure, ensuring that the fracturing fluid will not leak during high-pressure transportation and ensuring the stable operation of the entire transportation system.

[0032] Example 2

[0033] Based on Example 1, the metal layer 2 comprises nickel and iron; the thickness of the metal layer 2 is 1.0-2.0 mm. This metal layer 2 provides the pipeline with basic structural strength and preliminary corrosion resistance. The combination of nickel and iron can resist corrosion from fracturing fluid to a certain extent, while also serving as a good adhesion foundation for subsequent coatings.

[0034] Furthermore, the metal-ceramic layer 3 comprises Ni, Cr, and WC-Co; its thickness is 0.3-0.8 mm. The WC-Co ceramic has high hardness and good wear resistance, while the Ni and Cr metal matrix enhances the coating's bonding strength and corrosion resistance. This layer effectively resists erosion and chemical corrosion from fracturing fluids.

[0035] Furthermore, the metal-diamond layer 4 comprises Co, Ni, and diamond particles; the thickness of the metal-diamond layer 4 is 0.2-0.6 mm. The diamond particles have a particle size of 20-50 μm. The diamond particles have extremely high hardness and are embedded in the metal matrix composed of Co and Ni, forming an extremely hard and erosion-resistant surface, further improving the wear resistance of the pipeline.

[0036] Furthermore, the diamond particle size in the diamond layer 5 is 5-15 μm, and the thickness of the diamond layer 5 is 30-60 μm. The innermost diamond layer 5 directly contacts the fracturing fluid, and its high hardness and chemical stability can effectively resist the wear and corrosion of the fracturing fluid, extending the service life of the pipeline.

[0037] Furthermore, the inner surface of the pipe body 1 is provided with a plurality of pits with a depth of 50-100 μm (existing technology, not shown in the figure) to enhance the adhesion of the metal layer 2 and prevent the coating from peeling off.

[0038] Example 3

[0039] Based on Example 1, the thickness, processing method, and component dosage of the four protective layers are further limited as follows:

[0040] Metal layer 2: prepared by electroplating process, the material is nickel-iron alloy with a mass ratio of 7:3, and the thickness of metal layer 2 is 1.2mm.

[0041] The metal-ceramic layer is produced using thermal spraying technology. Its composition is Ni, Cr, and WC-Co, with the WC-Co content reaching 60% by weight and a Ni:Cr mass ratio of 3:2. The 0.5mm thick metal-ceramic layer effectively resists erosion and corrosion from fracturing fluids by leveraging the high hardness of the WC-Co ceramic and the corrosion resistance of the Ni and Cr metal matrix.

[0042] Metal-diamond layer 5: Produced using chemical vapor deposition (CVD), the material consists of Co, Ni, and 30μm diamond particles. The mass fraction of diamond particles is 30%, and the Co and Ni are mixed in a 1:1 ratio. Metal-diamond layer 5 is 0.4mm thick. During fabrication, a metal alloy molten pool is first created by laser cladding. Diamond particles are then simultaneously supersonic sprayed (at a speed of ≥1500m / s). This embeds the diamonds into the molten pool, creating a "pinning effect." By embedding the diamond particles within the metal matrix, a "hard particle-tough matrix" structure is formed, providing both impact and wear resistance.

[0043] Diamond Layer 5: During preparation, pure diamond powder (8μm in diameter) is applied using a supersonic flame spraying process. High-pressure fuel gas (propane + oxygen) accelerates the diamond powder to a speed exceeding 1200 m / s, forming Diamond Layer 5 on the surface of Metal-Diamond Layer 4. Diamond Layer 5, 40μm thick, comes into direct contact with the fracturing fluid, providing a final protective barrier for the pipeline with its high hardness and chemical stability.

[0044] Pit preparation: Laser engraving technology is used to process multiple pits with a depth of 60 μm on the inner surface of the pipe body 1.

[0045] The pipe body is made of stainless steel with a thickness of 15mm.

[0046] Connect the prepared pipe to other pipes of the same specification by first inserting the annular first protrusion 6 at one end into the annular slot 7 at the other end to complete the initial docking. Then connect through flange 9, insert the second protrusion 10 into the groove, and tighten flange 9 with bolts. After the connection is completed, perform a pressure test.

[0047] Inject simulated fracturing fluid into the pipeline, gradually increase the pressure to 35MPa, maintain the pressure for 30 minutes, and check that there is no leakage at the pipeline connection, proving that the connection structure is well sealed.

[0048] Subsequently, a long-term corrosion and wear resistance test was carried out. After continuously transporting simulated fracturing fluid for 180 hours, it was found through inner wall inspection that there was no obvious wear and corrosion on the inner surface coating of the pipeline, proving that the pipeline has excellent corrosion and wear resistance.

Claims

1. A corrosion-resistant and wear-resistant fracturing fluid pipeline, comprising a pipeline body (1); characterized in that: The inner surface of the pipe body (1) is provided with a metal layer (2), a metal-ceramic layer (3), a metal-diamond layer (4) and a diamond layer (5) in sequence; At both ends of the pipe body (1), one end is provided with a first annular protrusion (6), and the other end is provided with an annular slot (7) adapted to the first protrusion (6).

2. The corrosion-resistant and wear-resistant fracturing fluid pipeline according to claim 1, characterized in that: The metal layer (2) comprises nickel and iron; the metal layer (2) has a thickness of 1.0-2.0 mm.

3. The corrosion-resistant and wear-resistant fracturing fluid pipeline according to claim 1, characterized in that: The metal-ceramic layer (3) comprises Ni, Cr, and WC-Co; the thickness of the metal-ceramic layer (3) is 0.3-0.8 mm.

4. The corrosion-resistant and wear-resistant fracturing fluid pipeline according to claim 3, characterized in that: The metal-diamond layer (4) comprises Co, Ni and diamond particles; the thickness of the metal-diamond layer (4) is 0.2-0.6 mm.

5. The corrosion-resistant and wear-resistant fracturing fluid pipeline according to claim 4, characterized in that: In the metal-diamond layer (4), the particle size of the diamond particles is 20-50 μm.

6. The corrosion-resistant and wear-resistant fracturing fluid pipeline according to claim 1, characterized in that: In the diamond layer (5), the particle size of diamond is 5-15 μm, and the thickness of the diamond layer (5) is 30-60 μm.

7. The corrosion-resistant and wear-resistant fracturing fluid pipeline according to claim 1, characterized in that: The inner surface of the pipe body (1) is provided with a plurality of pits with a depth of 50-100 μm.

8. The corrosion-resistant and wear-resistant fracturing fluid pipeline according to claim 1, characterized in that: Both ends of the pipe body (1) are provided with flanges (9), and the flanges (9) at both ends of the pipe body (1) are two surfaces away from each other, one of which is provided with a plurality of second protrusions (10), and the other is provided with grooves adapted to the second protrusions (10).

9. The corrosion-resistant and wear-resistant fracturing fluid pipeline according to claim 8, characterized in that: Sealing gaskets are provided in both the annular slot (7) and the groove, and the sealing gaskets are made of polytetrafluoroethylene.

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