Coilable pipe

Abstract

This invention relates to the field of composite pipe technology and discloses a coilable pipe. The pipe includes a core tube (20) with a uniform cross-section medium flow channel and a corrugated protective layer (10) sleeved on the outside of the core tube (20). The outer surface of the core tube (20) is fitted with the minimum inner diameter of the corrugated protective layer (10). The corrugated protective layer (10) includes at least a metal corrugated protective layer (11), an anti-corrosion layer (12), and a plastic outer protective layer (13) arranged from the inside out. Through the above technical solution, this invention improves the rigidity of the pipe by setting a corrugated protective layer on the outside of the core tube, increasing the pipe's axial tensile strength and resistance to external pressure, ensuring the roundness of the core tube, and preventing damage to the core tube during coiling, uncoiling, and laying. Furthermore, the corrugated protective layer in this invention provides a plastic outer protective layer on the outside of the metal corrugated protective layer and the anti-corrosion layer, further protecting the anti-corrosion layer and the metal corrugated outer protective layer.

Description

Technical Field

[0001] This invention relates to the field of composite pipe technology, and more specifically to a coilable pipe. Background Technology

[0002] Reinforced thermoplastic pipes (RTP) can be categorized based on their application scenarios, including wellhead pipes for oil extraction (used between oil wells and separation stations, gathering stations, and water injection stations), downhole pipes, marine transport pipes, and pipes for offshore oil platforms. The National Energy Administration has successively issued standards such as SY / T6662.1-2012, SY / T6794-2018, and SY / T6662.2-2020. These standards not only regulate the use of non-metallic composite pipes in industries such as oil and gas but also raise the performance requirements for RTP pipes.

[0003] In existing technologies, RTP pipes without a protective layer are prone to damage and failure of the reinforcing layer under the repeated impact of waves on offshore platforms or during marine transportation. In addition, downhole pipes are easily damaged by axial tensile forces such as their own vertical downward gravity during installation and use.

[0004] Therefore, there is a need to provide a pipe material that, while meeting the requirements of national standards, further improves the performance of the pipe material. Summary of the Invention

[0005] The purpose of this invention is to overcome the problem of poor pipe performance in the prior art and to provide a coilable pipe that has the advantage of improving the tensile and compressive strength of the pipe.

[0006] To achieve the above objectives, the present invention provides a coilable pipe, the pipe comprising a core tube having a medium flow channel of equal cross section and a corrugated protective layer sleeved on the outside of the core tube, the outer surface of the core tube being fitted with the minimum inner diameter of the corrugated protective layer, the corrugated protective layer comprising at least a metal corrugated protective layer, an anti-corrosion layer and a plastic outer protective layer arranged from the inside to the outside.

[0007] Optionally, the core tube is a pure plastic core tube.

[0008] Optionally, the corrugated protective layer includes a polyester film layer located between the anti-corrosion layer and the outer plastic protective layer, the polyester film layer being wrapped around the outside of the anti-corrosion layer.

[0009] Optionally, the core tube consists of an inner plastic layer, a reinforcing layer, and an outer plastic layer from the inside out, wherein the reinforcing layer is wound around the outside of the inner plastic layer.

[0010] Optionally, the core tube includes a wear-resistant layer located inside the inner plastic layer, and / or, both the inner plastic layer and the outer plastic layer are made of high-density polyethylene.

[0011] Optionally, the wear-resistant layer is made of nylon, and the wear-resistant layer is bonded to the inner surface of the plastic inner layer by an adhesive.

[0012] Optionally, the inner plastic layer consists of a first inner plastic layer, a barrier layer, and a second inner plastic layer from the inside out. The inner and outer sides of the barrier layer are respectively bonded to the first inner plastic layer and the second inner plastic layer by adhesives. The first inner plastic layer, the second inner plastic layer, and the outer plastic layer are all made of high-density polyethylene.

[0013] Optionally, a sliding layer is provided on the outer side of the plastic outer layer so that the corrugated protective layer can move axially relative to the core tube.

[0014] Optionally, the sliding layer is at least one of filament, strip, or film.

[0015] Optionally, the reinforcing layer is at least one of steel strip, steel wire, steel cord, steel cord or non-metallic reinforcing strip.

[0016] Optionally, the coilable tube includes an energy transmission device located between the core tube and the corrugated protective layer and arranged axially along the outer surface of the core tube.

[0017] Optionally, the energy transmission device is arranged as at least one of a single strand, a bundle, or a flat ribbon, and / or the energy transmission device is at least one of a communication cable, a detection cable, an optical fiber, or a heating wire.

[0018] Optionally, a heat insulation layer is provided between the anti-corrosion layer and the outer plastic protective layer, and / or, a heat insulation layer is provided between the core tube and the corrugated protective layer.

[0019] Optionally, the outer contour shape of the corrugated protective layer is at least one of the following: annular corrugation, spiral corrugation, arc corrugation, arc corrugation with straight line segments at the trough, rectangular corrugation, trapezoidal corrugation, and zigzag corrugation without sharp corners.

[0020] Optionally, the material of the anti-corrosion layer is at least one of epoxy asphalt, asphalt cloth, or heavy-duty anti-corrosion paint; or, the anti-corrosion layer is one of single-layer or multi-layer anti-corrosion.

[0021] Through the above technical solution, this invention improves the rigidity of the pipe by setting a corrugated protective layer on the outside of the core tube, increases the pipe's axial tensile strength and resistance to external pressure, and ensures the roundness of the core tube, preventing damage to the core tube during coiling, unwinding, and laying. Furthermore, the corrugated protective layer in this invention is a plastic outer protective layer set outside the metal corrugated protective layer and the anti-corrosion layer. Utilizing the scratch-resistant and wear-resistant properties of plastic, it further protects the anti-corrosion layer and the metal corrugated outer protective layer. Attached Figure Description

[0022] Figure 1 This is a half-sectional view of one embodiment of the coilable pipe in this invention;

[0023] Figure 2 yes Figure 1 Enlarged view of point I in the middle;

[0024] Figure 3 yes Figure 1 A cross-sectional view at point AA of one embodiment of coiled pipe;

[0025] Figure 4 yes Figure 1 A cross-sectional view at point AA of another embodiment of the coiled pipe;

[0026] Figure 5 This is a half-sectional view of another embodiment of the coilable pipe in this invention;

[0027] Figure 6 yes Figure 5 Enlarged schematic diagram at point II;

[0028] Figure 7 This is a half-sectional view of another embodiment of the coilable pipe in this invention;

[0029] Figure 8 yes Figure 7 Enlarged schematic diagram at point III;

[0030] Figure 9 This is a half-sectional view of another embodiment of the coilable pipe in this invention;

[0031] Figure 10 yes Figure 9 Enlarged diagram of point IV in the middle;

[0032] Figure 11 This is a half-sectional view of another embodiment of the coilable pipe in this invention;

[0033] Figure 12 yes Figure 11 Enlarged view of point V in the middle;

[0034] Figure 13 yes Figure 11 Sectional view at point BB;

[0035] Figure 14 This is one embodiment of the outer contour shape of the corrugated protective layer in this invention;

[0036] Figure 15 This is another embodiment of the outer contour shape of the corrugated protective layer in this invention;

[0037] Figure 16 This is another embodiment of the outer contour shape of the corrugated protective layer in this invention;

[0038] Figure 17 This is another embodiment of the outer contour shape of the corrugated protective layer in this invention;

[0039] Figure 18 This is another embodiment of the outer contour shape of the corrugated protective layer in this invention.

[0040] Explanation of reference numerals in the attached figures

[0041] 10-Corrugated protective layer; 11-Metallic corrugated protective layer; 12-Anti-corrosion layer; 13-Plastic outer protective layer; 14-Polyester film layer; 20-Core tube; 21-Pure plastic core tube; 22-Plastic inner layer; 221-First plastic inner layer; 222-Barrier layer; 223-Second plastic inner layer; 224-Adhesive; 23-Reinforcing layer; 24-Plastic outer layer; 25-Wear-resistant layer; 26-Sliding layer; 30-Energy transmission device. Detailed Implementation

[0042] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. In the present invention, unless otherwise stated, directional terms such as "inner" and "outer" refer to the inner and outer contours of the respective components.

[0043] This invention provides a coilable pipe, comprising a core tube 20 having a media flow channel of equal cross-section and a corrugated protective layer 10 sleeved on the outside of the core tube 20. The outer surface of the core tube 20 is fitted with the minimum inner diameter of the corrugated protective layer 10. The corrugated protective layer 10 includes at least a metal corrugated protective layer 11, an anti-corrosion layer 12, and a plastic outer protective layer 13 arranged from the inside out. The anti-corrosion layer 12 can be made of at least one of epoxy asphalt, asphalt cloth, or heavy-duty anti-corrosion paint. Furthermore, the anti-corrosion layer 12 can be a single-layer or multi-layer anti-corrosion layer, wherein multi-layer anti-corrosion can be, for example, a combination of various anti-corrosion structures consisting of multiple layers of wound anti-corrosion cloth.

[0044] Through the above technical solution, the present invention improves the rigidity of the pipe by setting a corrugated protective layer 10 on the outside of the core tube 20, increases the axial tensile strength and external pressure resistance of the pipe, and ensures the roundness of the core tube 20, so that the core tube is not damaged during coiling, unwinding and laying. Furthermore, the corrugated protective layer 10 of the present invention sets a plastic outer protective layer 13 on the outside of the metal corrugated protective layer 11 and the anti-corrosion layer 12, utilizing the scratch-resistant and wear-resistant properties of the plastic material to further protect the anti-corrosion layer 12 and the metal corrugated outer protective layer 11.

[0045] Specifically, in one embodiment of the present invention, the outer surface of the core tube 20 is fitted to the minimum inner diameter of the corrugated protective layer 10 but not bonded together, and the plastic outer protective layer 13 is fitted to the anti-corrosion layer 12 but not bonded together. Furthermore, the tubing in this application is flexible and coilable, with an outer diameter of 2 inches to 8 inches; coiling is commonly used internationally and domestically for diameters of 6 inches (inclusive) and below. To reduce the number of joints between tubing sections, a single coiled tube is longer than 200 meters.

[0046] like Figures 1 to 3 As shown, in one embodiment of the present invention, the core tube 20 can be a pure plastic core tube 21.

[0047] When the coilable pipe of this invention is used as a wellhead delivery pipe or downhole pipe in scenarios such as oil and offshore drilling platforms, it is sometimes necessary to heat the medium transmitted within the core pipe 20, or to lower communication and detection cables into the well or platform along with the pipe. Therefore, as Figure 4 As shown, in a preferred embodiment of the present invention, the coilable tubing includes an energy transmission device 30 located between the core tube 20 and the corrugated protective layer 10 and arranged axially along the outer surface of the core tube 20. Depending on the application, the energy transmission device 30 can be arranged as a single piece, in a bundle, or as a flat strip, at least one of these. Furthermore, depending on the signal or energy to be transmitted, the energy transmission device 30 can be at least one of a communication cable, a detection cable, an optical fiber, or a heating wire. It is understood that multiple energy transmission devices 30 extending axially along the outer surface of the core tube 20 can be arranged between the core tube 20 and the corrugated protective layer 10, and the types of energy transmission devices 30 can be one or more.

[0048] Furthermore, in order to keep the medium transported inside the core tube 20 warm, an insulation layer may be provided between the anti-corrosion layer 12 and the outer plastic protective layer 13. In addition, an insulation layer may also be provided between the core tube 20 and the corrugated protective layer 10.

[0049] As a preferred embodiment, refer to Figure 5 and Figure 6The core tube 20 consists of, from the inside out, an inner plastic layer 22, a reinforcing layer 23, and an outer plastic layer 24. The reinforcing layer 23 is wound around the outer side of the inner plastic layer 22. Both the inner plastic layer 22 and the outer plastic layer 24 are made of high-density polyethylene (HDPE). HDPE has advantages such as resistance to acids and alkalis, resistance to organic solvents, excellent electrical insulation, and the ability to maintain a certain degree of toughness at low temperatures. Furthermore, the reinforcing layer 23 is at least one of steel strip, steel wire, steel cord, steel cord tape, or non-metallic reinforcing tape. The non-metallic reinforcing tape can be made of glass fiber, polyester, or aramid fiber, etc.

[0050] like Figures 7 to 13 As shown, in another embodiment of the present invention, the corrugated protective layer 10 includes a polyester film layer 14 located between the anti-corrosion layer 12 and the plastic outer protective layer 13, the polyester film layer 14 being wound around the outside of the anti-corrosion layer 12. The polyester film layer 14 serves to wrap the anti-corrosion layer 12, thereby facilitating its bonding with the plastic outer protective layer 13.

[0051] like Figures 7 to 13 As shown, in a preferred embodiment of the present invention, a sliding layer 26 is provided on the outer side of the plastic outer layer 24 to allow the corrugated protective layer 10 to move axially relative to the core tube 20. The sliding layer 26 can be at least one of filament, strip, or film. The main function of the sliding layer 26 is to allow for a certain relative displacement between the core tube 20 and the corrugated outer protective layer 10, preventing stress or direct friction damage during tube coiling, unwinding, or flexible laying.

[0052] like Figure 9 and Figure 10 As shown, in one embodiment, the core tube 20 includes a wear-resistant layer 25 located inside the plastic inner layer 22. The wear-resistant layer 25 may be made of nylon, and it may be bonded to the inner surface of the plastic inner layer 22 using an adhesive.

[0053] like Figures 11 to 13 As shown, in a preferred embodiment of the present invention, the inner plastic layer 22 comprises, from the inside out, a first inner plastic layer 221, a barrier layer 222, and a second inner plastic layer 223. The barrier layer 222 is bonded to the first inner plastic layer 221 and the second inner plastic layer 223 on its inner and outer sides respectively by an adhesive 224. The first inner plastic layer 221, the second inner plastic layer 223, and the outer plastic layer 24 are preferably made of high-density polyethylene. The barrier layer 222 is a material capable of blocking, for example, hydrogen or other small molecules, preventing small molecules from penetrating the gaps between the high-density polyethylene molecules and corroding the outer structure.

[0054] Furthermore, the outer contour shape of the corrugated protective layer 10 in this invention can be annular corrugations or spiral corrugations, such as... Figures 14 to 18 In the embodiment of the outer contour shape of the corrugated protective layer 10 shown, the outer contour shape of the corrugated protective layer 10 can be a corrugation with arc-shaped crests and troughs connected by straight line segments (see...). Figure 14 The inflection point is a circular arc-shaped zigzag pattern (see...). Figure 15 ), Waves with semi-circular crests and troughs connected by vertical straight segments (see...) Figure 16 The inflection point is a rectangular wavy line in the shape of an arc (see...). Figure 17 The inflection point is a trapezoidal ripple with an arc shape, or the crest is an arc shape and the trough is a straight line segment. The crest and trough are connected by a straight line segment, and the connection between the trough and the straight line segment is an arc shape (see...). Figure 18 ).

[0055] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A coilable pipe, characterized in that, The pipe includes a core tube (20) with a medium flow channel of equal cross section and a corrugated protective layer (10) sleeved on the outside of the core tube (20). The outer surface of the core tube (20) is attached to the minimum inner diameter of the corrugated protective layer (10). The corrugated protective layer (10) includes at least a metal corrugated protective layer (11), an anti-corrosion layer (12), and a plastic outer protective layer (13) arranged from the inside to the outside. The core tube (20) consists of an inner plastic layer (22), a reinforcing layer (23), and an outer plastic layer (24) from the inside to the outside. The reinforcing layer (23) is wrapped around the outer side of the inner plastic layer (22), and a sliding layer (26) is provided on the outer side of the outer plastic layer (24) so ​​that the corrugated protective layer (10) can move axially relative to the core tube (20). The material of the anti-corrosion layer (12) is at least one of epoxy asphalt, asphalt cloth or heavy-duty anti-corrosion paint; The corrugated protective layer (10) includes a polyester film layer (14) located between the anti-corrosion layer (12) and the plastic outer protective layer (13), the polyester film layer (14) being wrapped around the outside of the anti-corrosion layer (12), and the plastic outer protective layer (13) being bonded to the polyester film layer (14).

2. The coilable pipe according to claim 1, characterized in that, The core tube (20) is a pure plastic core tube (21).

3. The coilable pipe according to claim 1, characterized in that, The core tube (20) includes a wear-resistant layer (25) located inside the inner plastic layer (22), and / or, the inner plastic layer (22) and the outer plastic layer (24) are both made of high-density polyethylene.

4. The coilable pipe according to claim 3, characterized in that, The wear-resistant layer (25) is made of nylon, and the wear-resistant layer (25) is bonded to the inner surface of the plastic inner layer (22) by an adhesive.

5. The coilable pipe according to claim 1, characterized in that, The inner plastic layer (22) consists of a first inner plastic layer (221), a barrier layer (222), and a second inner plastic layer (223) from the inside to the outside. The barrier layer (222) is bonded to the first inner plastic layer (221) and the second inner plastic layer (223) on its inner and outer sides respectively by an adhesive (224). The first inner plastic layer (221), the second inner plastic layer (223), and the outer plastic layer (24) are all made of high-density polyethylene.

6. The coilable pipe according to claim 1, characterized in that, The sliding layer (26) is at least one of filament, strip or film.

7. The coilable pipe according to claim 1, characterized in that, The reinforcing layer (23) is at least one of steel strip, steel wire, steel cord, steel cord or non-metallic reinforcing strip.

8. The coilable pipe according to claim 1, characterized in that, The coilable tube includes an energy transmission device (30) located between the core tube (20) and the corrugated protective layer (10) and arranged axially along the outer surface of the core tube (20).

9. The pipe according to claim 8, characterized in that, The energy transmission device (30) is arranged as at least one of a single strand, a bundle, or a flat ribbon, and / or the energy transmission device (30) is at least one of a communication cable, a detection cable, an optical fiber, or a heating wire.

10. The coilable pipe according to claim 1, characterized in that, A heat insulation layer is provided between the anti-corrosion layer (12) and the outer plastic protective layer (13), and / or, a heat insulation layer is provided between the core tube (20) and the corrugated protective layer (10).

11. The coilable pipe according to claim 1, characterized in that, The outer contour shape of the corrugated protective layer (10) is at least one of the following: annular corrugation, spiral corrugation, arc corrugation, arc corrugation with straight line segments at the trough, rectangular corrugation, trapezoidal corrugation, and zigzag corrugation without sharp corners.

12. The coilable pipe according to claim 1, characterized in that, The anti-corrosion layer (12) is either a single-layer anti-corrosion layer or a multi-layer anti-corrosion layer.

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