Corrosion-resistant and impact-resistant flexible composite pipe group for oil production wellhead

Abstract

A corrosion-resistant and impact-resistant flexible composite pipe set for an oil production wellhead is provided with a composite pipe, the composite pipe is provided with a polyethylene lining layer, a reinforcing layer and an outer sheath from inside to outside, and the polyethylene lining layer is made of crosslinked polyethylene or high-density polyethylene and adapts to high-temperature and low-temperature oil transportation environments; the reinforcing layers are formed by spirally winding polyester industrial filaments on the outer wall of the polyethylene lining layer, the number of the reinforcing layers is an even number larger than 0, and the polyester industrial filaments of the adjacent reinforcing layers are wound in the cross direction, so that the inner layers of the reinforcing layers are in a locked state; the outer sheath is made of polyethylene resin and is formed by wrapping the outer wall of the reinforcing layer, so that the reinforcing layer can be locked and fixed, and impact erosion of wind, sand and stones can be resisted; and an inlet and an outlet of the tee joint are respectively connected with an output port of the producing well and the composite pipe. Therefore, the corrosion resistance and the impact resistance of the flexible composite pipe group are improved, the oil transportation stability is improved, and the service life of the flexible composite pipe group is prolonged.

Description

Technical Field

[0001] The utility model relates to the field of oil pipelines for oil production wellheads, in particular to a corrosion-resistant and impact-resistant flexible composite pipe group for oil production wellheads. Background Art

[0002] In the oil extraction industry, oil is transported from the oil well to the ground output port through the extraction equipment, connected to the above-ground oil pipeline, and the oil pipeline transports the oil to the underground oil pipeline, and then to the oil storage equipment.

[0003] At present, there are two types of oil pipelines used in oil wellheads: one is steel seamless pipeline; the other is glass fiber reinforced plastic pipeline. The two pipelines have different defects during use. Since the medium transported contains corrosive substances such as sulfur and chloride ions, the corrosion resistance of steel pipelines is poor, which can easily cause pipeline corrosion and perforation, which not only wastes resources but also causes environmental pollution. Since the pipeline is installed on the ground, there are many wind-blown sand and gravel in the desert Gobi area, and the glass fiber reinforced plastic pipeline is brittle and has poor impact resistance, so it is easy to be damaged. Utility Model Content

[0004] 1. Technical issues to be solved

[0005] In view of the deficiencies of the prior art, the utility model provides a corrosion-resistant and impact-resistant flexible composite pipe group for an oil wellhead, which solves the problem that the existing oil pipelines used for oil wellheads have poor corrosion resistance or poor impact resistance.

[0006] (II) Technical solution

[0007] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] A corrosion-resistant and impact-resistant flexible composite pipe group for an oil wellhead is provided with a composite pipe, which is used to transport the oil output from the oil wellhead to an underground oil pipeline; the composite pipe is provided with a polyethylene lining layer, a reinforcement layer, and an outer sheath from the inside to the outside; the reinforcement layer is formed by spirally winding polyester industrial filaments on the outer wall of the polyethylene lining layer.

[0009] Preferably, the reinforcement layer is provided with N layers, and N is an even number greater than 0, and the polyester industrial filaments of adjacent reinforcement layers are in a state of being wound in cross directions.

[0010] Preferably, the outer sheath is made of polyethylene resin and is coated on the outer wall of the reinforcement layer.

[0011] Preferably, when the composite pipe is composed of multiple composite pipes connected in series, adjacent composite pipes are connected by joints, and both ends of the joints are connected to the inner walls of the composite pipes through the outer walls. The joints are lined with an anti-corrosion layer, and the anti-corrosion layer extends to both ends of the joint and is turned outward to the edges of the outer walls at both ends of the joints. The anti-corrosion layer is set to polytetrafluoroethylene or high-density polyethylene.

[0012] Preferably, the polyethylene liner is configured as high-density polyethylene or cross-linked polyethylene.

[0013] Preferably, a tee is also provided, the tee being provided with one inlet and two outlets, the inlet being connected to the output port of the oil production well via a composite pipe, one of the outlets being connected to a plug, and the other being connected to the composite pipe, and the composite pipe being connected to an underground oil pipeline; the tee being lined with polytetrafluoroethylene or high-density polyethylene.

[0014] Preferably, the number of the tees is two, the two tees are connected by a composite pipe, and the two ends of the composite pipe are respectively connected to one of the outlets of the two tees.

[0015] Preferably, each component is connected to a flange and is connected to each other through the flange. The connecting surface and the inner side of the flange are lined with polytetrafluoroethylene or high-density polyethylene, and the seal is configured as a flange blind plate.

[0016] (III) Beneficial effects

[0017] The utility model provides a corrosion-resistant and impact-resistant flexible composite pipe group for oil wellheads. It has the following beneficial effects:

[0018] By setting up a composite pipe, the composite pipe is respectively set as a polyethylene lining layer, a reinforcement layer, and an outer sheath from the inside to the outside, and the polyethylene lining layer is set as cross-linked polyethylene or high-density polyethylene, which can adapt to high-temperature and low-temperature oil transportation environments respectively; the reinforcement layer is made of polyester industrial filaments spirally wound on the outer wall of the polyethylene lining layer, and the number of reinforcement layers is set to an even number greater than 0, and the polyester industrial filaments of adjacent reinforcement layers are wound in a cross direction, so that the inner layer of the reinforcement layer is in a locked state; the outer sheath is made of polyethylene resin and coated on the outer wall of the reinforcement layer, which can not only lock the reinforcement layer, but also resist the impact erosion of wind, sand and stones; a tee is also set, and the inlet and outlet are respectively connected to the output port of the oil well and the composite pipe. Thereby improving the corrosion resistance and impact resistance of the above-mentioned flexible composite pipe group, improving the oil transportation stability, and extending the service life of the flexible composite pipe group. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the utility model;

[0020] Figure 2 This is a schematic diagram of the structure of the composite pipe of the utility model;

[0021] Figure 3 This is a schematic diagram of the connection state between one end of the connector of the utility model and the composite pipe.

[0022] In the figure, 1-composite pipe, 11-polyethylene lining layer, 12-reinforcement layer, 13-outer sheath, 2-joint, 3-anti-corrosion layer, 4-tee, 41-inlet, 42-outlet, 5-plugging, 6-flange. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] In the description of the embodiments of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present utility model can be understood according to specific circumstances.

[0025] In the description of the embodiments of the present invention, it should be noted that the terms "inside" and "outside" etc. indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present invention.

[0026] See also Figure 1-2The embodiment of the utility model provides a technical solution: a corrosion-resistant and impact-resistant flexible composite pipe group for oil wellhead, which is provided with a composite pipe 1, and the composite pipe 1 is used to transport the oil output from the oil wellhead to the buried oil pipeline; the composite pipe 1 is respectively provided with a polyethylene lining layer, a reinforcement layer and an outer sheath 13 from the inside to the outside; the reinforcement layer 12 is formed by spirally winding polyester industrial filaments on the outer wall of the polyethylene lining layer 11. It should be particularly noted that the polyethylene lining layer 11 is resistant to corrosion by corrosive substances such as sulfur and chloride ions in the oil; the polyester industrial filament has the characteristics of high fracture strength and strong impact resistance. For polyester industrial filaments, the standard GB / T 16604-2017 "Polyester Industrial Filament" can be referred to; the outer sheath 13 is mainly used to protect the composite pipe from the impact erosion of wind and sand and stones, because the oil pipeline is installed on the ground, and the oil wells are often faced with complex and harsh environments, such as the desert Gobi area where there are more wind and sand and stones.

[0027] See also Figure 2 In this embodiment, the reinforcement layer 12 is set to N layers, and N is an even number greater than 0, and the polyester industrial filaments of adjacent reinforcement layers 12 are in a cross-direction winding state. It should be particularly noted that: the number of reinforcement layers 12 is set to an even number greater than 0, and the adjacent reinforcement layers 12 are wound in a cross-direction, which can form a better locking effect for the inner layer.

[0028] See also Figure 2 In this embodiment, the outer sheath 13 is made of polyethylene resin and is coated on the outer wall of the reinforcement layer 12. It should be particularly noted that polyethylene resin has good plasticity and is suitable for coating on the reinforcement layer 12 of the composite pipe 1. It not only has a locking effect on the reinforcement layer 12, but also has good chemical stability and wear resistance, so that it can better adapt to the erosion of wind, sand and stones in the desert Gobi area, extend the service life of the composite pipe 1, and ensure the stability of oil transportation; polyethylene resin can refer to the standard GB / T 11115-2009 "Polyethylene (PE) Resin".

[0029] See also Figure 2-3 In this embodiment, when the composite pipe 1 is composed of multiple composite pipes 1 connected in series, adjacent composite pipes 1 are connected by joints 2, and the two ends of the joints 2 are connected to the inner wall of the composite pipe 1 through the outer wall. The joints 2 are lined with an anti-corrosion layer 3, and the anti-corrosion layer 3 extends to the two ends of the joints 2 and turns outward to the outer wall edges of the two ends of the joints 2. The anti-corrosion layer 3 is set to polytetrafluoroethylene or high-density polyethylene. It should be noted that: when the oil pipeline is long and multiple sections of oil pipelines need to be connected in series, quick-connect joints are usually used, which are clamped and combined with the crimping sleeves preset at the pipe mouth of the oil pipeline, such as Figure 3As shown, however, in the present invention, the main emphasis is placed on the anti-corrosion effect of the joint 2, that is, by providing an anti-corrosion layer 3 inside the joint 2 and extending it to both ends of the joint 2 and turning it outward to the edges of the outer walls at both ends of the joint 2, so that the oil does not directly contact the outside and outer wall of the joint 2, thereby improving the corrosion resistance.

[0030] See also Figure 2 In this embodiment, the polyethylene liner 11 is set to high-density polyethylene or cross-linked polyethylene. It should be noted that high-density polyethylene and cross-linked polyethylene are both materials of the prior art. Cross-linked polyethylene is a polyethylene material that has been treated with a cross-linking reaction. During the preparation process, a cross-linking agent is added to form a cross-linked structure between the polyethylene molecular chains, thereby forming a 3D spatial structure; this cross-linked structure gives the material higher strength and heat resistance, is not easy to deform and age, and is suitable for high temperature environments. High-density polyethylene is a polyethylene material with a higher molecular weight and a higher density. High-density polyethylene is not treated with a cross-linking reaction, and its molecular chains are only closely arranged through intermolecular forces to form a physical cross-linked structure, thereby having a higher density and hardness. High-density polyethylene has excellent mechanical strength and chemical stability, has good wear resistance and corrosion resistance at normal temperature and pressure, and is suitable for low temperature environments.

[0031] See also Figure 1 In this embodiment, a tee 4 is also provided, the tee 4 is provided with one inlet and two outlets 42, the inlet 41 is connected to the output port of the oil production well through the composite pipe 1, one of the outlets 42 is connected to the plug 5, and the other outlet 42 is connected to the composite pipe 1, and the composite pipe 1 is connected to the buried oil pipeline; the tee 4 is lined with polytetrafluoroethylene or high-density polyethylene. It should be particularly noted that: the setting of the tee 4 facilitates the connection of the output port of the oil production well and the composite pipe 1 through the inlet 41 and the outlet 42 respectively.

[0032] See also Figure 1 In this embodiment, the number of the tees 4 is two, and the two tees 4 are connected by a composite pipe 1, and the two ends of the composite pipe 1 are respectively connected to one of the outlets 42 of the two tees 4. It should be noted that the number of the tees 4 is two, which can improve the oil transportation effect. In particular, the oil production well usually adopts a Christmas tree structure, and a Christmas tree usually has two output ends. The two output ends are respectively connected by the tees 4, which can improve the oil transportation efficiency.

[0033] See also Figure 1In this embodiment, each component is connected to a flange 6 and connected to each other through the flange 6. The connection surface and the inner side of the flange 6 are lined with polytetrafluoroethylene or high-density polyethylene, and the plug 5 is set as a flange blind plate. It should be particularly noted that the connection surface and the inner side of the flange 6 are lined with polytetrafluoroethylene or high-density polyethylene, that is, the part of the flange 6 that contacts the oil is lined with polytetrafluoroethylene or high-density polyethylene, so that the oil does not directly contact the flange 6, thereby improving the corrosion resistance of the flange 6.

[0034] Working principle and use process of the utility model: when in use, the oil is output from the oil wellhead, and the oil is transported to the inlet 41 of the tee 4 through the composite pipe 1, and output to the composite pipe 1 through the outlet 42 of the tee 4, and finally enters the buried oil pipeline; the composite pipe 1 is provided with a polyethylene lining layer 11 to prevent corrosion by corrosive substances such as sulfur and chloride ions in the oil, and a reinforcement layer 12 is provided, which is formed by spirally winding polyester industrial filaments on the outer wall of the polyethylene lining layer 11, and the number of layers of the reinforcement layer 12 is set to an even number greater than 0, and the polyester industrial filaments of adjacent reinforcement layers 12 are in a cross-direction winding state, so that the inner layer between adjacent layers is in a locked state, thereby improving the stability of the reinforcement layer; The outer sheath is set to be made of polyethylene resin material. Because of its good plasticity, it is suitable for coating on the reinforcement layer 12 of the composite pipe 1, which not only has a locking effect on the reinforcement layer 12, but also because of its good chemical stability and wear resistance, it can better adapt to the erosion of wind, sand and stones in the desert Gobi area, extend the service life of the composite pipe 1, and ensure the stability of oil transportation; the polyethylene lining layer 11 can be made of high-density polyethylene or cross-linked polyethylene, mainly considering the oil temperature conditions or seasons of the oil wells, and making adaptive choices by using cross-linked polyethylene and high-density polyethylene to adapt to high and low temperature environmental characteristics respectively, thereby improving oil transportation stability and extending the service life of the oil pipeline.

[0035] The above shows and describes the basic principles and main features of the utility model and the advantages of the utility model. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic features of the utility model. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the utility model is defined by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0036] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A corrosion-resistant and impact-resistant flexible composite pipe group for oil wellhead, characterized in that: A composite pipe (1) is provided, and the composite pipe (1) is used to transport oil output from an oil production wellhead to an underground oil pipeline; the composite pipe (1) is provided with a polyethylene lining layer (11), a reinforcement layer (12), and an outer sheath (13) from the inside to the outside; the reinforcement layer (12) is formed by spirally winding polyester industrial filaments on the outer wall of the polyethylene lining layer (11); When the composite pipe (1) is composed of a plurality of composite pipes (1) connected in series, adjacent composite pipes (1) are connected via joints (2), the two ends of the joints (2) are connected to the inner wall of the composite pipe (1) via the outer wall, the joints (2) are lined with an anti-corrosion layer (3), and the anti-corrosion layer (3) extends to the two ends of the joint (2) and is turned outward to the outer wall edges of the two ends of the joint (2), and the anti-corrosion layer (3) is set to polytetrafluoroethylene or high-density polyethylene.

2. The corrosion-resistant and impact-resistant flexible composite pipe assembly for oil wellhead according to claim 1, characterized in that: The reinforcement layer (12) is arranged to be N layers, where N is an even number greater than 0, and the polyester industrial filaments of adjacent reinforcement layers (12) are in a state of being wound in a cross direction.

3. The corrosion-resistant and impact-resistant flexible composite pipe assembly for oil wellhead according to claim 1, characterized in that: The outer sheath (13) is made of polyethylene resin and is formed by coating the outer wall of the reinforcement layer (12).

4. The corrosion-resistant and impact-resistant flexible composite pipe assembly for oil wellhead according to claim 1, characterized in that: The polyethylene liner layer (11) is configured as high-density polyethylene or cross-linked polyethylene.

5. A corrosion-resistant and impact-resistant flexible composite pipe assembly for oil wellhead according to any one of claims 1 to 4, characterized in that: A tee (4) is also provided, the tee (4) being provided with an inlet (41) and two outlets (42), the inlet (41) being connected to the output port of the oil production well via a composite pipe (1), one of the outlets (42) being connected to a plug (5), and the other of the outlets (42) being connected to the composite pipe (1), and the composite pipe (1) being connected to an underground oil pipeline; the tee (4) is lined with polytetrafluoroethylene or high-density polyethylene.

6. The corrosion-resistant and impact-resistant flexible composite pipe assembly for oil wellhead according to claim 5, characterized in that: The tees (4) are provided in two pieces, the two tees (4) are connected via a composite pipe (1), and the two ends of the composite pipe (1) are respectively connected to one of the outlets (42) of the two tees (4).

7. The corrosion-resistant and impact-resistant flexible composite pipe assembly for oil wellhead according to claim 5, characterized in that: Each component is connected to a flange (6) and is connected to each other through the flange (6). The connection surface and the inner side of the flange (6) are lined with polytetrafluoroethylene or high-density polyethylene, and the plug (5) is configured as a flange blind plate.

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