Metal clad spoolable non-metallic coated pipe and method of manufacture

Abstract

The present application belongs to the technical field of non-metal composite pipe processing, and particularly relates to a metal armored coiled non-metal cable coated pipe and a processing method. The metal armored coiled non-metal cable coated pipe comprises, from inside to outside, an inner pipe, a composite layer and an armored layer. The inner pipe is made of general plastic or engineering plastic. The composite layer is uniformly provided with a plurality of capillary tubes, cables and optical cables along the circumference. The armored layer is provided with an outer coating. The present application has high tensile strength and compressive strength, is not easy to be pulled apart or crushed in downhole operation, is corrosion resistant, scale resistant and wax resistant, and can meet the requirements of high tensile strength, high pressure resistance, electric passage, signal acquisition and transmission passage for downhole oil production or water injection. The present application can perform downhole gas injection and liquid injection operation, and the coiled pipe form can effectively improve the downhole operation efficiency, save operation time and reduce cost.

Description

Technical Field

[0001] This invention belongs to the field of non-metallic composite pipe processing technology, and specifically relates to a metal-armored coilable non-metallic cable-laying pipe and its processing method. Background Technology

[0002] In recent years, with the energy conservation and consumption reduction in oil and gas extraction, the construction of intelligent well sites, submersible pump oil production, quantitative injection, and downhole monitoring have developed rapidly in the field of oil and gas extraction.

[0003] Current cable-laying oil production methods involve binding power cables, deploying / retrieval cables, and non-metallic cables to the outside of metal pipes. The method of binding power cables to the outside of metal pipes inevitably leads to collisions and cable jamming in the wellbore, resulting in a high accident rate. For example, cable collisions can cause performance degradation, cable jamming of the pump, and even well abandonment, while also reducing the efficiency of well access operations. The method of deploying / retrieval cables, where the pump is lowered with the tubing before the cable is lowered from the pipe opening, is prone to misalignment and poor sealing at the cable connection point during well access, making operations impossible. Furthermore, due to the material properties of metal pipes, corrosion, wax buildup, and scaling can easily occur inside the tubing during extraction, causing pipe failure and pipeline blockage. While existing non-metallic cable-laying pipes have solved the problems of impact and connection, and reduced corrosion, waxing, and scaling, the pipes themselves have insufficient tensile and compressive strength, making them prone to breakage and crushing during downhole operations, which affects oil and gas extraction. Moreover, most existing non-metallic cable-laying pipes are used for setting up downhole power and signal acquisition channels, and there are currently no non-metallic cable-laying pipes that can be used for downhole gas injection and fluid injection operations. Summary of the Invention

[0004] To address the aforementioned problems, the purpose of this invention is to provide a metal-armored, coilable non-metallic cable-laying pipe and its processing method. This invention has high tensile and compressive strength, making it less prone to breakage and crushing during downhole operations. It is also corrosion-resistant, scale-resistant, and wax-resistant, meeting the requirements for high tensile strength, high pressure resistance, electrical channels, signal acquisition, and transmission channels for downhole oil production or water injection. It is also capable of downhole gas injection operations. Furthermore, the coilable pipe design effectively improves downhole operation efficiency, saves operation time, and reduces costs.

[0005] The technical solution of the present invention is as follows: a metal-armored coilable non-metallic cable-laying tube, comprising, from the inside out, an inner tube, a composite layer, and an armor layer, wherein multiple capillaries, multiple electrical cables, and multiple optical cables are uniformly arranged circumferentially within the composite layer, and an outer coating is provided on the outer side of the armor layer.

[0006] The inner tube and the composite layer are made of the same material, specifically one or more of modified polyethylene, polyvinylidene fluoride, polyketone, and polyimide.

[0007] The capillary tube is a metal tube or a plastic tube with a diameter ≤ 4 mm. Specifically, the metal tube is a 316L metal tube, and the plastic tube is a PTFE plastic tube.

[0008] The capillary tube, cable, and optical fiber are laid on the outer wall of the inner tube by winding or vertically adhering to it, and the cross-section of the cable is ≤4mm. 2 .

[0009] The armor layer material is carbon steel or stainless steel of the CT series, and the armor layer wall thickness is ≥2.5mm.

[0010] The outer coating is made of epoxy anti-corrosion coating, and the thickness of the outer coating is 50um~500um.

[0011] A method for processing a metal-armored, coilable, non-metallic cable conduit, comprising the following steps: S1: A composite layer is formed on the outside of the inner tube. The specific process is as follows: Using a cable winding machine, capillary tubes, cables, and optical fibers are evenly distributed on the outer wall of the inner tube using a low-tension spiral or straight-line method (0-3 kgf). An extruder is used to fill the inner tube with a material of the same type as the inner tube. After hot-melting, the tube is formed into an integral, bonded, equal-wall-thickness composite continuous tube through a mold. S2: An armor layer is formed on the outside of the composite layer. The specific process is as follows: S21: Metal armor layer forming: The carbon steel or unrepaired steel coil of the CT series is cut into a continuous length of longitudinal strip by a slitting machine according to the coiling direction. The longitudinal strip is then continuously formed along the width direction by a multi-roll forming machine using the UOE method to form a longitudinal butt joint. S22: Combination of metal armor layer and composite layer: The uniform wall thickness composite continuous tube obtained in S1 is inserted into the armor layer multi-roll forming machine at an angle of 0~45° through a transverse and longitudinal movable four-roll rounding machine to form a metal armor covering structure. The butt joint maintains a gap of 1mm~4mm with the outer wall of the uniform wall thickness composite continuous tube. The covering is completed by welding the butt joint with laser or argon arc welding. S23: Pipe sizing, the armored continuous pipe is passed through a 10~60° tapered sizing hole to form a tight physical bond between metal and non-metal, with an extrusion amount of 1.5mm~5mm, forming a seamless integrated mechanical pressing structure; S3: Coating: After shot blasting or sandblasting, the armor layer of the continuous tube is coated with a 50um~500um coating by spraying or brushing. S4: Measurement and inspection, including pipe diameter, welding quality, inner pipe deformation, coating thickness, to complete the processing of metal-armored coilable non-metallic cable-laying pipes.

[0012] The composite pipe of the metal-armored coilable non-metallic cable-laying pipe has a yield load range of 15~30 tons, a tensile load range of 20~50 tons, a continuous working internal pressure resistance range of 25~110Mpa, an outer diameter range of 25mm~90mm, and a single length range of 1000~7000m.

[0013] The technical advantages of this invention are as follows: 1. This invention, by uniformly distributing multiple capillaries, cables, and optical fibers along the circumference of the composite layer, can meet the requirements of electrical channels, signal acquisition, and transmission channels for downhole oil production, gas injection, or fluid injection; 2. The armor layer of this invention uses CT series carbon steel or stainless steel with high tensile strength and high pressure resistance, and can be coiled, which can effectively improve the efficiency of downhole operations, save operation time, and reduce costs; 3. The outer side of the armor layer of this invention is provided with an outer coating, which uses epoxy anti-corrosion coating to effectively prevent corrosion of the armor layer.

[0014] The following will provide further explanation in conjunction with the accompanying drawings. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a metal-armored, coilable non-metallic cable conduit structure according to an embodiment of the present invention.

[0016] Reference numerals: 1-Inner tube; 2-Capillary tube; 3-Cable; 4-Optical cable; 5-Armor layer; 6-Composite layer; 7-Outer coating. Detailed Implementation

[0017] Example 1 like Figure 1 As shown, a metal-armored coilable non-metallic cable conduit includes, from the inside out, an inner tube 1, a composite layer 6, and an armor layer 5. Multiple capillary tubes 2, multiple electrical cables 3, and multiple optical cables 4 are evenly distributed circumferentially within the composite layer 6. An outer coating 7 is provided on the outer side of the armor layer 5.

[0018] This invention employs a composite pipe with a three-layer armored structure, embedding a cable 3, optical fiber 4, or capillary tube 2 between the inner pipe 1 and the armor layer 5. This provides protection for the cable or optical fiber, solves the problem of insufficient pipe strength, facilitates the connection of the cable and downhole power or information acquisition devices, enables injection-production separation, and solves the problems of wear and insufficient strength in traditional rodless lifting oil production pipeline equipment. This reduces accidents during oil and gas extraction and improves recovery efficiency.

[0019] The inner tube 1 and the composite layer 6 are made of the same material, specifically one or more of modified polyethylene, polyvinylidene fluoride, polyketone, and polyimide, to improve the corrosion resistance, scale prevention, and wax prevention performance of the inner tube. The inner tube 1 and the composite layer 6 are made of the same material, and the composite layer 6 is bonded to the inner tube 1 by heating the composite layer 9 to form an integral adhesive.

[0020] The capillary tube 2 is a metal tube or a plastic tube with a diameter ≤ 4mm. Specifically, the metal tube is a 316L metal tube, and the plastic tube is a PTFE plastic tube. The capillary tube can realize the injection of gas or liquid from the wellhead to the well, achieving injection-production separation and precision.

[0021] The capillary tube 2, cable 3, and optical cable 4 are laid on the outer wall of the inner tube 1 by winding or vertically adhering to it. The cross-section of the cable 3 is ≤4mm. 2 .

[0022] The armor layer 5 is made of carbon steel or stainless steel of the CT series, and its wall thickness is ≥2.5mm. During the coating process, the armor layer 5 undergoes mechanical extrusion to form a seamless interface with the composite layer 6, thereby improving the strength of the pipe.

[0023] The outer coating 7 is made of epoxy anti-corrosion coating, and the thickness of the outer coating 7 is 50um~500um.

[0024] Example 2 A method for processing a metal-armored, coilable, non-metallic cable conduit, comprising the following steps: S1: A composite layer 6 is formed on the outside of the inner tube 1. The specific process is as follows: Using a cable winding machine, capillary tube 2, cable 3 and optical cable 4 are evenly distributed on the outer wall of inner tube 1 in a low-tension spiral or straight-line manner (0~3 kgf). Then, an extruder is used to fill the inner tube 1 with a material of the same material as the inner tube 1. After hot melting, the material is formed into an integral bonded structure of equal wall thickness composite continuous tube through a mold. S2: An armor layer 5 is formed on the outside of the composite layer 6, the specific process of which is as follows: S21: Metal armor layer forming: The carbon steel or unrepaired steel coil of the CT series is cut into a continuous length of longitudinal strip by a slitting machine according to the coiling direction. The longitudinal strip is then continuously formed along the width direction by a multi-roll forming machine using the UOE method to form a longitudinal butt joint. S22: Combination of metal armor layer and composite layer: The uniform wall thickness composite continuous tube obtained in S1 is inserted into the armor layer multi-roll forming machine at an angle of 0~45° through a transverse and longitudinal movable four-roll rounding machine to form a metal armor covering structure. The butt joint maintains a gap of 1mm~4mm with the outer wall of the uniform wall thickness composite continuous tube. The covering is completed by welding the butt joint with laser or argon arc welding. S23: Pipe sizing, the armored layer 5 continuous pipe is passed through a 10~60° tapered sizing hole to form a tight physical bonding layer between metal and non-metal, with an extrusion amount of 1.5mm~5mm, forming a seamless integrated mechanical pressing structure; S3: Coating: After shot blasting or sandblasting, the armor layer 5 of the continuous tube is coated with a 50um~500um coating by spraying or brushing. S4: Measurement and inspection, including pipe diameter, welding quality, inner pipe deformation, coating thickness, to complete the processing of metal-armored coilable non-metallic cable-laying pipes.

[0025] The composite pipe of the metal-armored coilable non-metallic cable-laying pipe has a yield load range of 15~30 tons, a tensile load range of 20~50 tons, a continuous working internal pressure resistance range of 25~110Mpa, an outer diameter range of 25mm~90mm, and a single length range of 1000~7000m.

[0026] Example 3 The processing method for a metal-armored, coilable non-metallic cable-laying tube as described in Example 2 is used to process the metal-armored, coilable non-metallic cable-laying tube. Specifically, the inner tube 1 and the composite layer 6 are made of cross-linked polyethylene material, and 316 stainless steel capillary tubes 2 and 2.5mm thick are evenly spirally distributed inside the composite layer 6. 2 Cable 3 and multimode optical cable 4 are processed with armor layer 5 made of CT80 carbon steel with a wall thickness of 4mm. The outer coating 7 is epoxy phenolic resin with a thickness of 300um. The inner tube 1 forms an oil and gas transportation channel. The composite layer 6 provides power transmission, signal acquisition and transmission, and injection channels. The metal armor layer 5 provides strength and protection for the entire composite structure, solving the problems of cable collision, cable jamming, joint sealing, and insufficient strength that exist in different oil production methods in the traditional rodless lifting oil production process.

[0027] The inner tube 1 has a wall thickness of 5mm and the composite layer thickness of 5mm. It is formed into a continuous composite tube with equal wall thickness by extrusion coating. The continuous composite tube with equal wall thickness is inserted into the 4mm CT80 steel strip at a 30° angle through a four-roll mill. After forming, the longitudinal seam and the distance between the continuous composite tube with equal wall thickness are 2mm. After laser welding and 45° sizing holes, a metal armor layer 5 is formed, realizing a high-strength, wear-resistant composite tube with a single length of 1500m.

[0028] The armor layer 5 was sandblasted for surface degreasing and rust removal. A 300µm outer coating 7 was then formed using high-pressure airless spraying of epoxy phenolic resin, providing external corrosion protection for the pipe and ensuring safe operation. Internal pressure and yield strength tests were conducted on different specifications of the processed metal-armored coiled non-metallic cable-laying pipes. Specific results are shown in Table 1, and the corrosion resistance of the pipes is shown in Table 2.

[0029] Table 1. Test data on internal pressure resistance and yield strength of metal-armored coilable non-metallic cable conduits. Table 2. Corrosion Resistance Test Data of Metal-Armored Coilable Non-Metallic Cable Conduit As can be seen from Table 1, the composite pipe of the metal-armored coilable non-metallic cable-laying pipe of the present invention has an outer diameter range of 31.8mm to 88.9mm, a yield load range of 18.59 to 56.5 tons, and a continuous working internal pressure resistance range of 37.3 to 103.4 MPa. It has high tensile and compressive strength, and is not easily broken or crushed during downhole operations. It can meet the requirements of high tensile strength, high pressure resistance, electrical channels, signal acquisition and transmission channels for downhole oil production or water injection.

[0030] As can be seen from Table 2, the outer coating of the metal-armored coilable non-metallic cable-laying pipe of the present invention does not change under different acid, alkali and inorganic salt environments, and has excellent corrosion resistance, which can meet the requirements of use in complex downhole environments.

[0031] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for processing a metal-armored, coilable non-metallic cable conduit, characterized in that: The metal-armored coilable non-metallic cable conduit comprises, from the inside out, an inner tube (1), a composite layer (6), and an armor layer (5). Multiple capillary tubes (2), multiple cables (3), and multiple optical cables (4) are evenly distributed circumferentially within the composite layer (6). An outer coating layer (7) is provided on the outside of the armor layer (5). The inner tube (1) and the composite layer (6) are made of the same material, specifically one or more of modified polyethylene, polyvinylidene fluoride, polyketone, and polyimide. The capillary tubes (2) are metal or plastic tubes with a diameter ≤4mm. Specifically, the metal tube is a 316L metal tube, and the plastic tube is a PTFE plastic tube. The processing method includes the following steps: S1: A composite layer (6) is formed on the outside of the inner tube (1). The specific process is as follows: Using a cable winding machine, capillary tube (2), cable (3) and optical cable (4) are evenly distributed on the outer wall of inner tube (1) in a low-tension spiral or straight-line manner (0~3 kgf). Then, an extruder is used to fill the inner tube (1) with the same material as the inner tube (1). After hot melting, an integral adhesive structure is formed by a mold to form a composite continuous tube with equal wall thickness. S2: An armor layer (5) is formed on the outside of the composite layer (6), the specific process of which is as follows: S21: Metal armor layer forming: The carbon steel or unrepaired steel coil of the CT series is cut into a continuous length of longitudinal strip by a slitting machine according to the coiling direction. The longitudinal strip is then continuously formed along the width direction by a multi-roll forming machine using the UOE method to form a longitudinal butt joint. S22: Combination of metal armor layer and composite layer: The uniform wall thickness composite continuous tube obtained in S1 is inserted into the armor layer multi-roll forming machine at an angle of 0~45° through a transverse and longitudinal movable four-roll rounding machine to form a metal armor covering structure. The butt joint maintains a gap of 1mm~4mm with the outer wall of the uniform wall thickness composite continuous tube. The covering is completed by welding the butt joint with laser or argon arc welding. S23: Pipe sizing, the armor layer (5) continuous pipe is passed through a 10~60° tapered sizing hole to form a tight physical bonding layer between metal and non-metal, with an extrusion amount of 1.5mm~5mm, forming a seamless integrated mechanical pressing structure; S3: Coating: The armor layer of the continuous tube (5) is formed by spraying or brushing after shot blasting or sandblasting to form a 50um~500um coating. S4: Measurement and inspection, including pipe diameter, welding quality, inner pipe deformation, coating thickness, to complete the processing of metal-armored coilable non-metallic cable-laying pipes.

2. The processing method of a metal-armored, coilable non-metallic cable conduit according to claim 1, characterized in that: The capillary tube (2), cable (3), and optical cable (4) are laid on the outer wall of the inner tube (1) by winding or vertically adhering to it. The cross-section of the cable (3) is ≤4mm. 2 .

3. The processing method of a metal-armored, coilable non-metallic cable conduit according to claim 1, characterized in that: The armor layer (5) is made of carbon steel or stainless steel of the CT series, and the armor layer (5) has a wall thickness of ≥2.5mm.

4. The processing method of a metal-armored, coilable non-metallic cable conduit according to claim 1, characterized in that: The outer coating (7) is made of epoxy anti-corrosion coating, and the thickness of the outer coating (7) is 50um~500um.

5. The processing method of a metal-armored, coilable non-metallic cable conduit according to claim 1, characterized in that: The composite pipe of the metal-armored coilable non-metallic cable-laying pipe has a yield load range of 15~30 tons, a tensile load range of 20~50 tons, a continuous working internal pressure resistance range of 25~110Mpa, an outer diameter range of 25mm~90mm, and a single length range of 1000~7000m.

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