Oil and gas transmission pipeline aging experiment device and method

Abstract

The invention discloses an oil and gas transmission pipeline aging experiment device and method.The oil and gas transmission pipeline aging experiment device comprises an aging cavity, an in-pipe experiment assembly and an out-pipe experiment assembly, the aging cavity extends in the first direction and is provided with a first end, a second end and a side wall, and the first end and the second end are opposite to each other; a supporting and stabilizing frame used for supporting and positioning the non-metal pipeline is arranged in the aging cavity, when the non-metal pipeline is installed in the aging cavity through the supporting and stabilizing frame, an annular out-pipe cavity can be formed between the outer wall of the non-metal pipeline and the inner wall of the aging cavity, and an in-pipe cavity is formed in the non-metal pipeline; one end of the first end and the second end is provided with an in-pipe flow inlet, and the other end of the first end and the second end is provided with an in-pipe flow outlet; and the side wall of the aging cavity is provided with an out-pipe flow inlet, an out-pipe flow outlet and the like. According to the invention, aging experiments in different environments inside and outside a nonmetal oil and gas transmission pipeline can be dynamically carried out at the same time.

Description

Technical Field

[0001] This invention relates to the field of aging test technology for non-metallic pipelines used in oil and gas transportation, and particularly to an aging test apparatus and method for oil and gas transportation pipelines. Background Technology

[0002] For a long time, the traditional oil and gas transportation industry has primarily relied on metal pipelines (including cast iron pipes, carbon steel pipes, and stainless steel pipes). With the deepening of extraction, to improve recovery rates, various displacement methods such as water flooding, carbon dioxide flooding, deoxygenated air flooding, deoxygenated air foam flooding, and polymer flooding have been applied to oil and gas fields to achieve stable or increased production. However, these extraction methods also make the extracted media in oil and gas fields more complex, such as increased concentrations of dissolved oxygen, carbon dioxide, hydrogen sulfide, bacteria, chloride ions, and scaling ions, posing a significant challenge to the safe transportation of traditional metal pipelines. Metal pipelines are typically in contact with soil on their outer walls and with other corrosive liquids internally, making them susceptible to corrosion from the chemical and electrochemical effects of the surrounding media. This leads to a reduction in the effective wall thickness and weakened mechanical strength, resulting in media leakage and explosions, ultimately causing pipeline failure and resulting in huge economic losses and social impacts.

[0003] To mitigate the corrosion of metal pipes by various media and reduce operating costs and environmental impact, oilfields have increased their investment in and use of non-metallic pipelines in recent years. Non-metallic pipelines possess excellent corrosion and wear resistance, low friction and water resistance, delayed scaling, ease of installation and maintenance, and long service life, making them a significant development direction for corrosion protection of surface gathering and transportation pipelines in oilfields. The use of non-metallic pipelines can significantly reduce the corrosion rate of pipelines, greatly saving on corrosion protection investment; simultaneously, it can reduce heat and pressure energy losses during transportation, enhancing the pipeline's transport capacity. Currently, research and application of non-metallic pipelines mainly focus on onshore or subsea oil and gas field gathering and transportation, as well as short-distance oil and gas transportation.

[0004] In practical applications, the use of non-metallic pipes still presents some problems: First, leaks are prone to occur at non-metallic pipe joints; second, as the service life of non-metallic pipes increases, a certain degree of aging and performance degradation occurs, failing to meet current service conditions; third, although non-metallic materials are corrosion resistant, they still interact with the transported medium, and with changes in the service environment, over time, non-metallic pipes are prone to failure phenomena such as cracking and delamination.

[0005] As non-metallic pipelines age during service, their failure rate gradually increases, primarily due to physical and chemical changes. These changes manifest macroscopically as alterations in physical properties such as physical state, elongation, tensile strength, and hardness, and microscopically as changes in morphology, functional group types, and component content. The combined result is that non-metallic pipelines gradually become unable to meet normal design requirements (temperature, pressure, service life) and performance requirements under special operating conditions; this process is known as the aging of non-metallic pipelines.

[0006] Failure of non-metallic pipelines can lead to leaks in the pipeline network. If exposed to an ignition source, this can cause significant economic losses, environmental pollution, and personal injury. Generally, non-metallic pipeline failures are primarily caused by aging. The microstructure of non-metallic pipelines mainly consists of glass fiber and resin. During long-term service, these materials are affected by heat, mechanical forces, and chemical factors, leading to aging. This causes delamination, inclusion, and debonding of the glass fiber and resin, resulting in a decline in non-metallic performance and ultimately, failure. To reduce the failure rate of non-metallic pipelines, it is necessary to study their aging mechanisms to predict their remaining lifespan and implement preventative protective measures to avoid severe losses caused by aging failure.

[0007] Currently, there is no aging test device for non-metallic oil and gas pipelines that can dynamically and realistically simulate the aging test of non-metallic oil and gas pipelines.

[0008] Therefore, it is necessary to propose an aging test device and method for oil and gas pipelines to address the aforementioned shortcomings. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides an aging test apparatus and method for oil and gas pipelines. This apparatus can simultaneously conduct dynamic aging tests on non-metallic oil and gas pipelines under different internal and external environments. This guides research on the aging patterns of non-metallic pipelines (including thermo-oxidative aging, hydrothermal aging, and oil-thermal aging) and the prediction of the remaining life of non-metallic pipelines. It effectively slows down the aging of non-metallic pipelines, reduces their failure rate, and provides technical support for ensuring the normal transportation of oil and gas.

[0010] The specific technical solution of the embodiments of the present invention is as follows:

[0011] An aging test apparatus for oil and gas pipelines, the apparatus comprising:

[0012] The aging test device for the oil and gas pipeline includes: an aging chamber, an internal test component, and an external test component.

[0013] The aging chamber has a hollow structure with an internal cavity for accommodating a non-metallic pipe. The aging chamber extends along a first direction and has a first end and a second end opposite to each other along the first direction, as well as a sidewall located between the first end and the second end. At least one of the first end and the second end is provided with a removable sealing cap. A support frame for supporting and positioning the non-metallic pipe is provided inside the aging chamber. When the non-metallic pipe is installed in the aging chamber through the support frame, an annular external cavity can be formed between the outer wall of the non-metallic pipe and the inner wall of the aging chamber, and an internal cavity is formed inside the non-metallic pipe. An internal inlet is provided at one of the first end and the second end, and an internal outlet is provided at the other end. Both the internal inlet and the internal outlet are connected to the internal cavity. An external inlet and an external outlet are provided on the sidewall of the aging chamber, and both the external inlet and the external outlet are connected to the external cavity.

[0014] The in-pipe experimental assembly includes: an in-pipe inlet control valve connected to the inlet of the pipe, an in-pipe outlet valve connected to the outlet of the pipe, a first pressure gauge for obtaining the pressure of the fluid flowing into the in-pipe cavity, a first thermometer for obtaining the temperature of the fluid flowing into the in-pipe cavity, and a first velocity meter for obtaining the flow rate of the fluid flowing into the in-pipe cavity.

[0015] The external experimental assembly includes: an external inlet valve connected to the external inlet, an external outlet valve connected to the external outlet, a second pressure gauge for obtaining the pressure of the fluid flowing into the external cavity, a second thermometer for obtaining the temperature of the fluid flowing into the external cavity, and a second velocity meter for obtaining the flow rate of the fluid flowing into the external cavity.

[0016] In a preferred embodiment, the aging chamber is a hollow cylindrical cavity, and the support frame includes multiple support columns. The multiple support columns are arranged circumferentially with the axial direction of the aging chamber as the center, and the inner contour formed by the multiple support columns is adapted to the outer contour of the non-metallic pipe.

[0017] In a preferred embodiment, the support column extends from the second end to the first end along the axial direction of the aging chamber, and the portion of the support column extending through the first end has a threaded section extending out of the aging chamber. The sealing cover is provided with a threaded hole that mates with the threaded section.

[0018] In a preferred embodiment, the support column is a bolt, the sealing cover is a flange, the bolt has a nut at its head end, the nut is snapped onto the outside of the aging chamber and contacts the second end, the threaded section passes through the first end and the flange, and is fastened to the flange on the side away from the first end by a nut.

[0019] In a preferred embodiment, the first end and the flange are further provided with sealing rings.

[0020] In a preferred embodiment, the upstream of the main control valve is provided with multiple branch pipes, which may include a first branch pipe, a second branch pipe, and a third branch pipe arranged in parallel.

[0021] In a preferred embodiment, a first valve is provided on the first branch pipe, a second valve is provided on the second branch pipe, and a third valve is provided on the third branch pipe. The first valve, the second valve, and the third valve are all valves with adjustable opening.

[0022] In a preferred embodiment, the first branch pipe, the second branch pipe, and the third branch pipe arranged in parallel have a confluence portion, and the pipe between the confluence portion and the inlet of the pipe is the main inlet pipe, and the first pressure gauge, the first thermometer, and the speedometer are disposed in the main inlet pipe.

[0023] In a preferred embodiment, the oil and gas pipeline aging test apparatus further includes: a heating device for heating the fluid, and / or a pressurizing device for pressurizing the fluid; the heating device is disposed within the aging chamber, or disposed on the aging chamber, or connected to the aging chamber; the pressurizing device is disposed within the aging chamber, or disposed on the aging chamber, or connected to the aging chamber.

[0024] An aging test method for oil and gas pipelines based on the aforementioned oil and gas pipeline aging test apparatus, the oil and gas pipeline aging test method comprising:

[0025] Open the main inlet control valve, and then open several valves among the first, second and third valves upstream of the main inlet control valve to introduce fluid at a predetermined temperature and pressure into the pipe cavity. Open the outlet valve to complete the medium flow in the pipe cavity.

[0026] The temperature signal of the inner cavity of the tube is obtained by the first thermometer and the pressure signal of the inner cavity of the tube is obtained by the first pressure gauge. Based on the temperature signal and the pressure signal of the inner cavity of the tube, the current temperature and pressure of the inner cavity of the tube are adjusted so that the temperature and pressure of the inner cavity of the tube meet the preset working condition requirements.

[0027] The flow velocity signal of the fluid flowing through the inner cavity of the pipe is obtained by the first velocity measuring instrument. Based on the flow velocity signal, the opening of the main inlet control valve and the outlet valve of the pipe are adjusted so that the flow velocity of the fluid flowing through the inner cavity of the pipe meets the preset working condition requirements.

[0028] Open the external inlet valve to introduce a heated and / or pressurized fluid into the external cavity of the pipe;

[0029] The temperature signal of the outer cavity of the tube is obtained by the second thermometer, and the pressure signal of the outer cavity of the tube is obtained by the second pressure gauge. Based on the temperature signal and the pressure signal of the outer cavity of the tube, the current temperature and pressure of the outer cavity of the tube are adjusted so that the temperature and pressure of the outer cavity of the tube meet the preset working condition requirements.

[0030] Open the outlet valve of the pipe to discharge all the gas in the outer cavity of the pipe and fill the outer cavity of the pipe with the medium;

[0031] The flow velocity of the fluid flowing through the outer cavity of the pipe is obtained by a second velocity measuring instrument. By controlling the opening of the inlet valve and the outlet valve of the pipe, the flow velocity of the fluid flowing through the outer cavity of the pipe is made to meet the preset working condition requirements.

[0032] In a preferred embodiment, the aging test method for oil and gas transmission pipelines further includes:

[0033] Accelerated aging experiments were conducted on three-phase media at different aging temperatures to obtain aging experiment data;

[0034] Tensile tests were conducted after the accelerated aging test to determine the strength retention rate under different aging temperatures and aging times.

[0035] Based on the aging test data and the strength retention rate, the relationship between the strength retention rate and the aging time is obtained as follows:

[0036] S=S0+η[1-exp(-λt)]-βln(1+αt)

[0037] In the above formula, S represents the residual strength retention rate of the non-metallic material after a certain number of days of aging, 100%;

[0038] S0 represents the initial strength retention rate of non-metallic materials, 100%;

[0039] η represents the degree of curing of non-metallic materials;

[0040] λ represents non-metallic materials and external environmental parameters;

[0041] t represents the remaining lifespan, in days;

[0042] β represents the ability of a nonmetallic material to resist crack propagation;

[0043] α represents the corrosivity coefficient of the external environment.

[0044] An aging test method for oil and gas pipelines based on the aforementioned oil and gas pipeline aging test apparatus, the oil and gas pipeline aging test method comprising:

[0045] Open the main inlet control valve, and then open several valves among the first, second and third valves upstream of the main inlet control valve to introduce fluid at a predetermined temperature and pressure into the pipe cavity. Open the outlet valve to complete the medium flow in the pipe cavity.

[0046] The temperature signal of the inner cavity of the tube is obtained by the first thermometer and the pressure signal of the inner cavity of the tube is obtained by the first pressure gauge. Based on the temperature signal and the pressure signal of the inner cavity of the tube, the current temperature and pressure of the inner cavity of the tube are adjusted so that the temperature and pressure of the inner cavity of the tube meet the preset working condition requirements.

[0047] The flow velocity signal of the fluid flowing through the inner cavity of the pipe is obtained by the first velocity measuring instrument. Based on the flow velocity signal, the opening of the main inlet control valve and the outlet valve of the pipe are adjusted so that the flow velocity of the fluid flowing through the inner cavity of the pipe meets the preset working condition requirements.

[0048] Open the external inlet valve to introduce a heated and / or pressurized fluid into the external cavity of the pipe;

[0049] The temperature signal of the outer cavity of the tube is obtained by a second thermometer, and the pressure signal of the outer cavity of the tube is obtained by a second pressure gauge. Based on the temperature signal and the pressure signal of the outer cavity of the tube, the current temperature and pressure of the outer cavity of the tube are adjusted so that the temperature and pressure of the outer cavity of the tube meet the preset working condition requirements.

[0050] An aging test method for oil and gas pipelines based on the aforementioned oil and gas pipeline aging test apparatus, the oil and gas pipeline aging test method comprising:

[0051] Open the external inlet valve to introduce a heated and / or pressurized fluid into the external cavity of the pipe;

[0052] The temperature signal of the outer cavity of the tube is obtained by the second thermometer, and the pressure signal of the outer cavity of the tube is obtained by the second pressure gauge. Based on the temperature signal and the pressure signal of the outer cavity of the tube, the current temperature and pressure of the outer cavity of the tube are adjusted so that the temperature and pressure of the outer cavity of the tube meet the preset working condition requirements.

[0053] Open the outlet valve of the pipe to discharge all the gas in the outer cavity of the pipe and fill the outer cavity of the pipe with the medium;

[0054] The flow velocity of the fluid flowing through the outer cavity of the pipe is obtained by a second velocity measuring instrument. By controlling the opening of the inlet valve and the outlet valve of the pipe, the flow velocity of the fluid flowing through the outer cavity of the pipe is made to meet the preset working condition requirements.

[0055] The technical solution of the present invention has the following significant beneficial effects:

[0056] This invention discloses an aging test apparatus and method for oil and gas transportation pipelines. By conducting aging experiments on the inner and outer walls of non-metallic pipelines at different temperatures and pressures, and simultaneously using flowing fluid to purge the medium inside the pipe, the influence of the medium inside the pipe on the concentration of the experimental fluid is avoided. This method can simulate the actual flow rate under real-world operating conditions, making it highly practical. Aging experiments conducted using this oil and gas transportation pipeline aging test apparatus can guide research on the aging patterns of non-metallic pipelines and the prediction of their remaining life, effectively slowing down the aging of non-metallic pipelines, reducing their failure rate, and providing technical support for ensuring the normal transportation of oil and gas.

[0057] Specific embodiments of the invention are disclosed in detail with reference to the following description and accompanying drawings, indicating how the principles of the invention can be employed. It should be understood that the embodiments of the invention are not therefore limited in scope. Within the spirit and scope of the appended claims, embodiments of the invention include many changes, modifications, and equivalents. Features described and / or shown for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments. Attached Figure Description

[0058] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can select various possible shapes and proportions to implement the invention according to specific circumstances.

[0059] Figure 1This is a schematic diagram of an aging test device for an oil and gas pipeline provided in the embodiments of this application.

[0060] Figure 2 This is a cross-sectional view of the aging chamber of an aging test apparatus for oil and gas pipelines provided in the embodiments of this application;

[0061] Figure 3 for Figure 2 A right view of the aging chamber of an aging test apparatus for oil and gas pipelines provided in the embodiments of this application;

[0062] Figure 4 for Figure 2 A left view of the aging chamber of an aging test apparatus for oil and gas pipelines provided in the embodiments of this application;

[0063] Figure 5 This is a flowchart illustrating the steps of a pipeline aging test method provided in the embodiments of this application.

[0064] Reference numerals in the figures of this application:

[0065] 1. Aging chamber;

[0066] 101. Support column;

[0067] 102. Nut;

[0068] 103. Sealing ring;

[0069] 104. Flange;

[0070] 105. Cavity;

[0071] 2. Inlet port inside the pipe;

[0072] 3. Inner outlet of the pipe;

[0073] 4. External inlet of the pipe;

[0074] 5. Outlet port of the pipe;

[0075] 6. Main inlet control valve for the pipeline;

[0076] 7. In-pipe outflow valve;

[0077] 8. External inlet valve;

[0078] 9. Outflow valve outside the pipe;

[0079] 10. First valve;

[0080] 11. Second valve;

[0081] 12. Third valve;

[0082] 13. First thermometer;

[0083] 14. First pressure gauge;

[0084] 15. Second thermometer;

[0085] 16. Second pressure gauge;

[0086] 17. First speed measuring instrument;

[0087] 18. Second speed measuring instrument. Detailed Implementation

[0088] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art fall within the scope defined by the appended claims.

[0089] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0090] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0091] Existing technology 1

[0092] Prior art 1 discloses a heating device for a hydrogen aging test tank in the field of optical fiber type testing equipment technology. This device includes a hydrogen aging test tank body, a heat-conducting copper pipe, an insulation layer, a drain valve, an electric heater, a water pump, an inlet valve, and pipes. The outer surface of the hydrogen aging test tank body is fitted with a heat-conducting copper pipe and an insulation layer. The top cover of the hydrogen aging test tank body is equipped with an inlet valve, a pressure gauge, a temperature detector, and an exhaust valve. An electric heater is installed on one side of the hydrogen aging test tank body, and the electric heater is connected to the outlet and inlet of the heat-conducting copper pipe through pipes. By installing a heating device on the outside of the hydrogen aging test tank, the ambient temperature of the hydrogen aging test tank is increased during the optical fiber hydrogen aging experiment, shortening the time required for the hydrogen aging experiment and providing timely experimental data for optical fiber production, thereby improving the production efficiency of optical fibers.

[0093] However, the existing technology is designed for fiber optic pipelines, and the internal and external media environments of the pipeline samples are the same (temperature and other conditions on the inner and outer walls of the pipeline are the same). Therefore, it cannot simultaneously conduct aging tests with different internal and external environments to realistically simulate the aging process of non-metallic oil and gas pipelines. Furthermore, since its application environment is not in the oil and gas transportation field, it does not require differentiated aging tests for the different internal and external environments of the pipe.

[0094] Existing technology 2

[0095] Prior art 2 discloses a multifunctional integrated aging test chamber in the field of aging equipment, including a chamber body, an aging chamber located within the chamber body, and a sealed door located at the opening of the aging chamber. The chamber body is equipped with an ultraviolet light system, a heating system, a humidification system, an exhaust pressure reduction system, a pressurization system, and a control system. While this multifunctional integrated aging test chamber provides various aging functions, it cannot perform aging tests for scenarios with different environments inside and outside the pipe, thus failing to realistically simulate the aging process of non-metallic oil and gas pipelines. Furthermore, since its application environment is not in the oil and gas transportation field, it does not require differentiated aging tests for different environments inside and outside the pipe.

[0096] To address the problem that existing technologies cannot simultaneously and dynamically conduct aging tests on the inner and outer walls of non-metallic pipelines under different pressures and temperatures, this invention provides an aging test device and method for oil and gas transportation pipelines. This device can simultaneously and dynamically conduct aging tests on non-metallic oil and gas transportation pipelines under different internal and external environments. This provides guidance for research on the aging patterns of non-metallic pipelines (including thermo-oxidative aging, hydrothermal aging, and oil-thermal aging) and the prediction of non-metallic pipeline remaining life, effectively slowing down the aging of non-metallic pipelines, reducing their failure rate, and providing technical support for ensuring the normal transportation of oil and gas.

[0097] Please refer to the following for comprehensive information. Figures 1 to 2This application specification provides an aging test device for oil and gas pipelines. The device may include an aging chamber 1, an internal test component, and an external test component. The aging chamber 1 is hollow, with an internal cavity 105 for accommodating a non-metallic pipe. The aging chamber 1 extends along a first direction, having a first end and a second end opposite to each other, and a sidewall located between the first and second ends. At least one of the first and second ends is provided with a removable sealing cap. A support frame for supporting and positioning the non-metallic pipe is provided inside the aging chamber 1. When the non-metallic pipe is installed in the aging chamber 1 via the support frame, an annular external cavity is formed between the outer wall of the non-metallic pipe and the inner wall of the aging chamber 1, and an internal cavity is formed inside the non-metallic pipe. An internal inlet 2 is provided at one of the first and second ends, and an internal outlet 2 is provided at the other end. 3; The inlet 2 and the outlet 5 are both connected to the inner cavity of the pipe; the side wall of the aging chamber 1 is provided with an outlet 4 and an outlet 5, both of which are connected to the outer cavity of the pipe; the inner experimental assembly includes: an inner inlet control valve 6 connected to the inlet 2, an outlet valve 7 connected to the outlet 3, and a first pressure gauge 14 for obtaining the pressure of the fluid flowing into the inner cavity of the pipe. The first thermometer 13 measures the temperature of the fluid in the inner cavity of the pipe, and the first velocity meter 17 measures the flow rate of the fluid flowing into the inner cavity of the pipe. The external experimental assembly includes: an external inlet valve 8 connected to the external inlet 4, an external outlet valve 9 connected to the external outlet 5, a second pressure gauge 16 measures the pressure of the fluid flowing into the external cavity of the pipe, a second thermometer 15 measures the temperature of the fluid flowing into the external cavity of the pipe, and a second velocity meter 18 measures the flow rate of the fluid flowing into the external cavity of the pipe.

[0098] The oil and gas pipeline aging test apparatus provided in this application can conduct aging tests on the inner and outer walls of non-metallic pipes at different temperatures and pressures. Simultaneously, it uses flowing fluid to purge the medium inside the pipe, avoiding the influence of the internal medium on the concentration of the experimental fluid. This allows for the simulation of actual flow rates under real-world operating conditions, ensuring practicality. Experiments using this oil and gas pipeline aging apparatus can guide research on the aging patterns of non-metallic pipelines and the prediction of their remaining life, effectively slowing down the aging of non-metallic pipelines, reducing their failure rate, and providing technical support for ensuring the normal transportation of oil and gas.

[0099] The present application will now be described in detail with reference to the accompanying drawings and embodiments.

[0100] The aging test device for oil and gas pipelines can mainly include: aging chamber 1, internal test components and external test components.

[0101] The aging chamber 1 has a hollow structure, with an internal cavity 105 for accommodating non-metallic pipes. Generally, the aging chamber 1 can be a hollow cylindrical cavity; however, its specific construction can take other forms, which are not specifically limited herein. In the embodiments and accompanying drawings of this application, the hollow cylindrical shape of the aging chamber 1 is mainly used as an example for illustration.

[0102] The aging chamber 1 can extend along a first direction. When the aging chamber 1 is a hollow cylinder, the first direction is the axial direction of the aging chamber 1. For example, the axial direction of the aging chamber 1 is horizontal. Along the first direction, the aging chamber 1 has a first end and a second end opposite to each other, and a sidewall located between the first end and the second end. At least one of the first end and the second end may be provided with a removable sealing cap. During the experiment, the sealing cap can be opened, and the non-metallic pipe to be tested can be installed into the aging chamber 1. In the embodiments of this application, the example of the first end being provided with the sealing cap is mainly used for illustration.

[0103] In addition, the aging chamber 1 may also be equipped with a support and stabilizing frame for supporting and positioning the non-metallic pipe. The support and stabilizing frame can be any form that can support the non-metallic pipe and is fixed to the inner wall of the aging chamber 1.

[0104] like Figure 3 or Figure 4 As shown, in one embodiment, the support frame may include multiple support columns 101, which are arranged circumferentially around the axial direction of the aging chamber 1, and the inner contour formed by the multiple support columns 101 is adapted to the outer contour of the non-metallic pipe.

[0105] Specifically, the inner contour of the multiple support columns 101 can be a circular hole with a predetermined diameter, the diameter of which can be equal to or close to the outer diameter of the non-metallic pipe. To stably support the non-metallic pipe, the number of support columns 101 can be at least three. For example, there can be six, and the six support columns 101 can be evenly distributed circumferentially at 60° intervals. Of course, the number of support columns 101 is not limited to the above example; it can also be more or fewer.

[0106] Specifically, the support column 101 can be a threaded support column 101, which extends from the second end to the first end along the axial direction of the aging chamber 1. The portion of the support column 101 extending through the first end can have a threaded section extending outside the aging chamber 1, and the sealing cover is provided with a threaded hole that mates with the threaded section.

[0107] The threaded section can be used in conjunction with a sealing cap (such as flange 104) to achieve a sealing connection at the first end. To improve the service life of the support column 101, the material of the support column 101 can be selected from materials that are resistant to high temperature, high pressure, and corrosion, such as stainless steel. Of course, the material of the support column 101 can also be other materials with similar or even better properties than stainless steel; specifically, this application does not make a unique limitation.

[0108] Please combine Figure 2 , Figure 3 and Figure 4 In one specific embodiment, the support column 101 can be in the form of a bolt with threads at the end, with a nut at the first end. The nut is snapped onto the outside of the aging chamber 1 and contacts the second end. The threaded section passes through the first end and the flange 104, and a nut 102 is used to fasten the flange 104 on the side away from the first end. This achieves the construction of the support and stabilization frame inside the aging chamber 1, while also achieving a sealed connection at the first end. The overall structure is compact, and the sealing and connection are reliable.

[0109] To ensure the sealing of the connection between the flange 104 and the first end, a sealing ring 103 is provided between the flange 104 and the first end. When the nut 102 is connected to the threaded section of the support column 101, the sealing ring 103 can be pressed, thereby reliably sealing the detachable connection position of the aging chamber 1.

[0110] In this embodiment, the sealing cap at the first end of the aging chamber 1 can be formed by a flange 104. For example, a mounting hole with an outer diameter equal to or slightly larger than that of the non-metallic pipe can be provided at the first end of the aging chamber 1, and the flange 104 can be sealed with the first end of the mounting hole by a sealing ring 103.

[0111] In this embodiment, when the non-metallic pipe is installed in the aging chamber 1, an annular outer cavity is formed between the outer wall of the non-metallic pipe and the inner wall of the aging chamber 1. An inner cavity is formed inside the non-metallic pipe.

[0112] One of the first and second ends is provided with an inlet 2, and the other is provided with an outlet 3. Both the inlet 2 and the outlet 3 are connected to the inner cavity of the pipe.

[0113] Specifically, when the first end of the aging chamber 1 is provided with a flange 104, a first opening can be formed in the middle of the flange 104, which can be used as an inlet 2 inside the pipe. A second opening can be formed in the middle of the second end of the aging chamber 1, which can be used as an outlet 3 inside the pipe.

[0114] An external inlet 4 and an external outlet 5 are provided on the side wall of the aging chamber 1. Both the external inlet 4 and the external outlet 5 are connected to the external chamber.

[0115] The in-pipe experimental assembly may include: an in-pipe inlet control valve 6 connected to the in-pipe inlet 2, an in-pipe outlet valve 7 connected to the in-pipe outlet 3, a first pressure gauge 14 for obtaining the pressure of the fluid flowing into the in-pipe cavity, a first thermometer 13 for obtaining the temperature of the fluid flowing into the in-pipe cavity, and a first velocity meter 17 for obtaining the flow rate of the fluid flowing into the in-pipe cavity.

[0116] In the case of non-metallic oil and gas pipelines, the fluid medium transported may include a mixture of at least two different components, such as a gas-liquid two-phase flow. Of course, the embodiments of this application do not exclude the possibility that the fluid medium may be a single-phase gas or a single-phase liquid. To realistically simulate the fluid medium within the non-metallic pipeline, multiple branch pipelines can be installed upstream of the main control valve. These branch pipelines may include a first branch pipeline, a second branch pipeline, and a third branch pipeline connected in parallel. A first valve 10 may be installed on the first branch pipeline; a second valve 11 may be installed on the second branch pipeline; and a third valve 12 may be installed on the third branch pipeline. The first valve 10, second valve 11, and third valve 12 can all be adjustable valves, allowing adjustment of the proportions in the fluid medium according to actual simulation needs, thereby accurately simulating the actual fluid medium flowing through the non-metallic pipeline.

[0117] The first, second, and third branch pipes, which are arranged in parallel, have a confluence section. The pipe between this confluence section and the inlet 2 is the main inlet pipe. The first pressure gauge 14, the first thermometer 13, and the speedometer are installed in this main inlet pipe.

[0118] The external test assembly may include: an external inlet valve 8 connected to the external inlet 4, an external outlet valve 9 connected to the external outlet 5, a second pressure gauge 16 for obtaining the pressure of the fluid flowing into the external cavity, a second thermometer 15 for obtaining the temperature of the fluid flowing into the external cavity, and a second velocity meter 18 for obtaining the flow rate of the fluid flowing into the external cavity.

[0119] During the experiment, the fluid injected into the inner and outer cavities of the tube can be heated and / or pressurized. The device for heating and / or pressurizing the fluid can be located outside the aging chamber 1.

[0120] In addition, the aging test apparatus for oil and gas pipelines may also include a heating device for heating the fluid and / or a pressurizing device for pressurizing the fluid. The heating device and the pressurizing device may be installed inside the aging chamber 1, installed on the aging chamber 1, or connected to the aging chamber 1.

[0121] The oil and gas pipeline aging test apparatus provided in this application can conduct pipe wall aging tests on the inner and outer walls of non-metallic pipes at different temperatures and pressures, either separately or simultaneously. Simultaneously, it uses flowing fluid to purge the medium inside the pipe, avoiding the influence of the medium inside the pipe on the concentration of the experimental fluid. Through experiments conducted with this oil and gas pipeline aging test apparatus, research on the aging laws of non-metallic pipelines (including thermo-oxidative aging, hydrothermal aging, and oil-thermal aging) and the prediction of the remaining life of non-metallic pipelines can be guided. This effectively slows down the aging of non-metallic pipelines, reduces their failure rate, and provides technical support for ensuring the normal transportation of oil and gas.

[0122] Please refer to the appendix. Figure 5 Based on the oil and gas pipeline aging test apparatus provided in the above embodiments, an oil and gas pipeline aging test method is also provided. The oil and gas pipeline aging test method may include the following steps:

[0123] Step S10: Open the main inlet control valve of the pipe, and then open several valves among the first valve, second valve and third valve upstream of the main inlet control valve of the pipe to introduce fluid at a predetermined temperature and pressure into the pipe cavity, and open the outlet valve of the pipe to complete the medium flow in the pipe cavity;

[0124] Step S12: Obtain the temperature signal of the inner cavity of the tube through the first thermometer and the pressure signal of the inner cavity of the tube through the first pressure gauge. Based on the temperature signal and pressure signal of the inner cavity of the tube, adjust the current temperature and pressure of the inner cavity of the tube so that the temperature and pressure of the inner cavity of the tube meet the preset working condition requirements.

[0125] Step S14: Obtain the flow velocity signal of the fluid flowing through the inner cavity of the pipe using the first velocity measuring instrument. Based on the flow velocity signal, adjust the opening of the main inlet control valve and the outlet valve of the pipe so that the flow velocity of the fluid flowing through the inner cavity of the pipe meets the preset working condition requirements.

[0126] Step S16: Open the external inlet valve to introduce warm and / or pressurized fluid into the external cavity of the pipe;

[0127] Step S18: Obtain the temperature signal of the outer cavity of the tube through the second thermometer and the pressure signal of the outer cavity of the tube through the second pressure gauge. Based on the temperature signal and the pressure signal of the outer cavity of the tube, adjust the current temperature and pressure of the outer cavity of the tube so that the temperature and pressure of the outer cavity of the tube meet the preset working condition requirements.

[0128] Step S20: Open the outflow valve outside the pipe to discharge all the gas in the outer cavity of the pipe and fill the outer cavity of the pipe with the medium;

[0129] Step S22: Obtain the flow velocity of the fluid flowing through the outer cavity of the pipe using the second velocity measuring instrument, and control the opening of the inlet valve and the outlet valve of the pipe to ensure that the flow velocity of the fluid flowing through the outer cavity of the pipe meets the preset operating conditions.

[0130] In step S10, the number of valves that can be opened depends on the composition of the fluid medium flowing into the non-metallic pipe. For example, the fluid medium can be a gas, a liquid, or a liquid-gas two-phase fluid.

[0131] During each aging test, the fluid medium flowing into the inner cavity of the device can be at different temperatures and pressures. The temperature range can be controlled within 1.5 times the design temperature, and the pressure range can be controlled within 2 times the design pressure.

[0132] In this embodiment, the material of the non-metallic pipeline can specifically be glass fiber. The experimental method provided in this application mainly uses glass fiber as an example for illustration. Of course, the material of the non-metallic pipeline can also be other materials, and this application does not make specific limitations here. Using the oil and gas pipeline aging test device provided in this application embodiment, during aging experiments, pipe wall aging experiments are simultaneously conducted on the inner and outer walls of the non-metallic pipe at different temperatures and pressures. Simultaneously, flowing fluid is used to empty the medium inside the pipe, avoiding the influence of the medium inside the pipe on the concentration of the experimental fluid. Through this device, experiments can guide research on the aging laws of non-metallic pipelines (including thermo-oxidative aging, hydrothermal aging, and oil thermal aging) and the prediction of the remaining life of non-metallic pipelines, effectively slowing down the aging of non-metallic pipelines, reducing the failure rate of non-metallic pipelines, and providing technical support to ensure the normal transportation of oil and gas.

[0133] During aging tests, various parameters can be measured, such as weight loss rate, Barcol hardness, resin content, mechanical properties, microstructure, and glass transition temperature.

[0134] In one embodiment, this aging test method for oil and gas pipelines can be used to predict the remaining life of non-metallic pipelines. Specifically, the aging test method for oil and gas pipelines may further include the following steps:

[0135] Accelerated aging experiments were conducted on three-phase media at different aging temperatures to obtain aging experiment data;

[0136] Tensile tests were conducted after the accelerated aging test to determine the strength retention rate under different aging temperatures and aging times.

[0137] Based on the aging test data and the strength retention rate, the relationship between the strength retention rate and the aging time is obtained as follows:

[0138] S=S0+η[1-exp(-λt)]-βln(1+αt)

[0139] In the above formula, S represents the residual strength retention rate of the non-metallic material after a certain number of days of aging, 100%;

[0140] S0 represents the initial strength retention rate of non-metallic materials, 100%;

[0141] η represents the degree of curing of non-metallic materials;

[0142] λ represents non-metallic materials and external environmental parameters;

[0143] t represents the remaining lifespan, in days;

[0144] β represents the ability of a nonmetallic material to resist crack propagation;

[0145] α represents the corrosivity coefficient of the external environment.

[0146] Specifically, based on the time-temperature equivalence principle, accelerated aging experiments in multi-factor laboratory environments can be designed, and at least three different control experimental temperatures can be selected to carry out aging experiments.

[0147] Aging test:

[0148] ① Multiple experimental fiberglass pipes underwent accelerated aging tests in a three-phase medium (water, oil, air) (water:

[0149] 95℃, 125℃, 155℃; oil 95℃, 125℃, 200℃; air 95℃, 125℃, 155℃), to obtain the aging test dataset, based on the aging test dataset and the actual life data set.

[0150] ② Tensile testing was conducted based on accelerated aging experiments. Following the circumferential tensile strength testing procedure of the disc method in ASTM D2990, circumferential sampling of the fiberglass pipes was performed, and tensile tests were conducted. The tensile strength retention rate under different aging temperatures and times was calculated.

[0151]

[0152] σ t σ0 represents the circumferential tensile strength value after aging time, while σ0 represents the initial circumferential tensile strength value. The threshold for failure determination is based on the strength retention rate decreasing to 75%.

[0153] Based on data obtained from accelerated aging experiments, the influence factor F of various aging environmental factors (temperature, pressure, medium - oil / water / gas) on the strength decay of FRP pipes was calculated.

[0154]

[0155] σ0 represents the initial strength of the glass fiber material, and t0 represents the initial time of the accelerated aging test (t0 = 0); σ i Let t be the remaining strength of the fiberglass pipe at time ti.

[0156] Based on the circumferential strength test data from accelerated aging experiments, a linear regression was performed on the strength retention rate Rs and aging time t under multiple temperature parameters under experimental conditions, using y = 100exp(-t / τ), to obtain the relationship between strength retention rate and aging time:

[0157] S=S0+η[1-exp(-λt)]-βln(1+αt)

[0158] In the above formula, S represents the residual strength retention rate of the non-metallic material after a certain number of days of aging, 100%;

[0159] S0 represents the initial strength retention rate of non-metallic materials, 100%;

[0160] η represents the degree of curing of non-metallic materials;

[0161] λ represents non-metallic materials and external environmental parameters;

[0162] t represents the remaining lifespan, in days;

[0163] β represents the ability of a nonmetallic material to resist crack propagation;

[0164] α represents the corrosivity coefficient of the external environment.

[0165] Among them, all parameters except for the remaining lifetime t and the remaining strength retention rate S are known parameters.

[0166] The oil and gas pipeline aging test apparatus provided in this application embodiment can also be used to study the accelerated aging test of the inner wall of non-metallic pipelines by fluid media. Specifically, the oil and gas pipeline aging test method may include the following steps:

[0167] Open the main inlet control valve, and then open several valves among the first, second and third valves upstream of the main inlet control valve to introduce fluid at a predetermined temperature and pressure into the pipe cavity. Open the outlet valve to complete the medium flow in the pipe cavity.

[0168] The temperature signal of the inner cavity of the tube is obtained by the first thermometer and the pressure signal of the inner cavity of the tube is obtained by the first pressure gauge. Based on the temperature signal and the pressure signal of the inner cavity of the tube, the current temperature and pressure of the inner cavity of the tube are adjusted so that the temperature and pressure of the inner cavity of the tube meet the preset working condition requirements.

[0169] The flow velocity signal of the fluid flowing through the inner cavity of the pipe is obtained by the first velocity measuring instrument. Based on the flow velocity signal, the opening of the main inlet control valve and the outlet valve of the pipe are adjusted so that the flow velocity of the fluid flowing through the inner cavity of the pipe meets the preset working condition requirements.

[0170] Open the external inlet valve to introduce a heated and / or pressurized fluid into the external cavity of the pipe;

[0171] The temperature signal of the outer cavity of the tube is obtained by a second thermometer, and the pressure signal of the outer cavity of the tube is obtained by a second pressure gauge. Based on the temperature signal and the pressure signal of the outer cavity of the tube, the current temperature and pressure of the outer cavity of the tube are adjusted so that the temperature and pressure of the outer cavity of the tube meet the preset working condition requirements.

[0172] The oil and gas pipeline aging test apparatus provided in this application embodiment can also be used to study the accelerated aging test of non-metallic pipeline outer walls by fluid media. Specifically, the oil and gas pipeline aging test method includes:

[0173] Open the external inlet valve to introduce a heated and / or pressurized fluid into the external cavity of the pipe;

[0174] The temperature signal of the outer cavity of the tube is obtained by the second thermometer, and the pressure signal of the outer cavity of the tube is obtained by the second pressure gauge. Based on the temperature signal and the pressure signal of the outer cavity of the tube, the current temperature and pressure of the outer cavity of the tube are adjusted so that the temperature and pressure of the outer cavity of the tube meet the preset working condition requirements.

[0175] Open the outlet valve of the pipe to discharge all the gas in the outer cavity of the pipe and fill the outer cavity of the pipe with the medium;

[0176] The flow velocity of the fluid flowing through the outer cavity of the pipe is obtained by a second velocity measuring instrument. By controlling the opening of the inlet valve and the outlet valve of the pipe, the flow velocity of the fluid flowing through the outer cavity of the pipe is made to meet the preset working condition requirements.

[0177] This invention discloses an aging test apparatus and method for oil and gas transportation pipelines. By conducting aging experiments on the inner and outer walls of non-metallic pipelines at different temperatures and pressures, and simultaneously using flowing fluid to purge the medium inside the pipe, the influence of the medium inside the pipe on the concentration of the experimental fluid is avoided. This method can simulate the actual flow rate under real-world operating conditions, making it highly practical. Aging experiments conducted using this oil and gas transportation pipeline aging test apparatus can guide research on the aging patterns of non-metallic pipelines and the prediction of their remaining life, effectively slowing down the aging of non-metallic pipelines, reducing their failure rate, and providing technical support for ensuring the normal transportation of oil and gas.

[0178] It should be noted that in the description of this application, the terms "first," "second," etc., are used only for descriptive purposes and to distinguish similar objects; there is no order between them, nor should they be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more.

[0179] The various embodiments described in this specification are presented in a progressive manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0180] The above are merely a few embodiments of the present invention. Although the embodiments disclosed in the present invention are as described above, the content is only for the purpose of facilitating understanding of the present invention and is not intended to limit the present invention. Any person skilled in the art to which this invention pertains may make any modifications and changes in the form and details of the embodiments without departing from the spirit and scope disclosed in the present invention. However, the patent protection scope of the present invention shall still be determined by the scope defined in the appended claims.

Claims

1. An aging test apparatus for oil and gas pipelines, characterized in that, The aging test device for the oil and gas pipeline includes: an aging chamber, an internal test component, and an external test component. The aging chamber has a hollow structure with an internal cavity for accommodating a non-metallic pipe. The aging chamber extends along a first direction and has a first end and a second end opposite to each other along the first direction, as well as a sidewall located between the first end and the second end. At least one of the first end and the second end is provided with a removable sealing cap. A support frame for supporting and positioning the non-metallic pipe is provided inside the aging chamber. When the non-metallic pipe is installed in the aging chamber through the support frame, an annular external cavity can be formed between the outer wall of the non-metallic pipe and the inner wall of the aging chamber, and an internal cavity is formed inside the non-metallic pipe. An internal inlet is provided at one of the first end and the second end, and an internal outlet is provided at the other end. Both the internal inlet and the internal outlet are connected to the internal cavity. An external inlet and an external outlet are provided on the sidewall of the aging chamber, and both the external inlet and the external outlet are connected to the external cavity. The in-pipe experimental assembly includes: an in-pipe inlet control valve connected to the inlet of the pipe, an in-pipe outlet valve connected to the outlet of the pipe, a first pressure gauge for obtaining the pressure of the fluid flowing into the in-pipe cavity, a first thermometer for obtaining the temperature of the fluid flowing into the in-pipe cavity, and a first velocity meter for obtaining the flow rate of the fluid flowing into the in-pipe cavity. The external experimental assembly includes: an external inlet valve connected to the external inlet, an external outlet valve connected to the external outlet, a second pressure gauge for obtaining the pressure of the fluid flowing into the external cavity, a second thermometer for obtaining the temperature of the fluid flowing into the external cavity, and a second velocity meter for obtaining the flow rate of the fluid flowing into the external cavity.

2. The aging test apparatus for oil and gas pipelines as described in claim 1, characterized in that, The aging chamber is a hollow cylindrical cavity, and the support and stabilizing frame includes multiple support columns. The multiple support columns are arranged circumferentially with the axial direction of the aging chamber as the center, and the inner contour formed by the multiple support columns is adapted to the outer contour of the non-metallic pipe.

3. The aging test apparatus for oil and gas pipelines as described in claim 2, characterized in that, The support column extends from the second end to the first end along the axial direction of the aging chamber. The portion of the support column extending through the first end has a threaded section extending out of the aging chamber. The sealing cover is provided with a threaded hole that mates with the threaded section.

4. The aging test apparatus for oil and gas pipelines as described in claim 3, characterized in that, The support column is a bolt, the sealing cover is a flange, and the bolt has a nut at its head. The nut is snapped onto the outside of the aging chamber and contacts the second end. The threaded section passes through the first end and the flange, and is fastened to the flange on the side away from the first end by a nut.

5. The aging test apparatus for oil and gas pipelines as described in claim 4, characterized in that, The first end and the flange are also equipped with sealing rings.

6. The aging test apparatus for oil and gas pipelines as described in claim 1, characterized in that, The upstream of the main control valve is provided with multiple branch pipes, which may include a first branch pipe, a second branch pipe, and a third branch pipe arranged in parallel.

7. The aging test apparatus for oil and gas transmission pipelines as described in claim 6, characterized in that, A first valve is installed on the first branch pipe, a second valve is installed on the second branch pipe, and a third valve is installed on the third branch pipe. All three valves, including the first valve, the second valve, and the third valve, are adjustable valves.

8. The aging test apparatus for oil and gas transmission pipelines as described in claim 6, characterized in that, The first branch pipe, the second branch pipe, and the third branch pipe, which are arranged in parallel, have a confluence section. The pipe between the confluence section and the inlet of the pipe is the main inlet pipe. The first pressure gauge, the first thermometer, and the speedometer are installed in the main inlet pipe.

9. The aging test apparatus for oil and gas transmission pipelines as described in claim 7, characterized in that, The aging test apparatus for oil and gas pipelines further includes: a heating device for heating the fluid, and / or a pressurizing device for pressurizing the fluid. The heating device is disposed within the aging chamber, or disposed on the aging chamber, or connected to the aging chamber; the pressurizing device is disposed within the aging chamber, or disposed on the aging chamber, or connected to the aging chamber.

10. An aging test method for oil and gas transmission pipelines based on the oil and gas transmission pipeline aging test apparatus according to claim 9, characterized in that, The aging test method for the oil and gas transmission pipeline includes: Open the main inlet control valve, and then open several valves among the first, second and third valves upstream of the main inlet control valve to introduce fluid at a predetermined temperature and pressure into the pipe cavity. Open the outlet valve to complete the medium flow in the pipe cavity. The temperature signal of the inner cavity of the tube is obtained by the first thermometer and the pressure signal of the inner cavity of the tube is obtained by the first pressure gauge. Based on the temperature signal and the pressure signal of the inner cavity of the tube, the current temperature and pressure of the inner cavity of the tube are adjusted so that the temperature and pressure of the inner cavity of the tube meet the preset working condition requirements. The flow velocity signal of the fluid flowing through the inner cavity of the pipe is obtained by the first velocity measuring instrument. Based on the flow velocity signal, the opening of the main inlet control valve and the outlet valve of the pipe are adjusted so that the flow velocity of the fluid flowing through the inner cavity of the pipe meets the preset working condition requirements. Open the external inlet valve to introduce a heated and / or pressurized fluid into the external cavity of the pipe; The temperature signal of the outer cavity of the tube is obtained by the second thermometer, and the pressure signal of the outer cavity of the tube is obtained by the second pressure gauge. Based on the temperature signal and the pressure signal of the outer cavity of the tube, the current temperature and pressure of the outer cavity of the tube are adjusted so that the temperature and pressure of the outer cavity of the tube meet the preset working condition requirements. Open the outlet valve of the pipe to discharge all the gas in the outer cavity of the pipe and fill the outer cavity of the pipe with the medium; The flow velocity of the fluid flowing through the outer cavity of the pipe is obtained by a second velocity measuring instrument. By controlling the opening of the inlet valve and the outlet valve of the pipe, the flow velocity of the fluid flowing through the outer cavity of the pipe is made to meet the preset working condition requirements.

11. The aging test method for oil and gas transmission pipelines as described in claim 10, characterized in that, The aging test method for oil and gas transmission pipelines also includes: Accelerated aging experiments were conducted on three-phase media at different aging temperatures to obtain aging experiment data; Tensile tests were conducted after the accelerated aging test to determine the strength retention rate under different aging temperatures and aging times. Based on the aging test data and the strength retention rate, the relationship between the strength retention rate and the aging time is obtained as follows: S=S0+η[1-exp(-λt)]-βln(1+αt) In the above formula, S represents the residual strength retention rate of the non-metallic material after a certain number of days of aging, 100%; S0 represents the initial strength retention rate of non-metallic materials, 100%; η represents the degree of curing of non-metallic materials; λ represents non-metallic materials and external environmental parameters; t represents the remaining lifespan, in days; β represents the ability of a nonmetallic material to resist crack propagation; α represents the corrosivity coefficient of the external environment.

12. An aging test method for oil and gas transmission pipelines based on the oil and gas transmission pipeline aging test apparatus according to claim 9, characterized in that, The aging test method for the oil and gas transmission pipeline includes: Open the main inlet control valve, and then open several valves among the first, second and third valves upstream of the main inlet control valve to introduce fluid at a predetermined temperature and pressure into the pipe cavity. Open the outlet valve to complete the medium flow in the pipe cavity. The temperature signal of the inner cavity of the tube is obtained by the first thermometer and the pressure signal of the inner cavity of the tube is obtained by the first pressure gauge. Based on the temperature signal and the pressure signal of the inner cavity of the tube, the current temperature and pressure of the inner cavity of the tube are adjusted so that the temperature and pressure of the inner cavity of the tube meet the preset working condition requirements. The flow velocity signal of the fluid flowing through the inner cavity of the pipe is obtained by the first velocity measuring instrument. Based on the flow velocity signal, the opening of the main inlet control valve and the outlet valve of the pipe are adjusted so that the flow velocity of the fluid flowing through the inner cavity of the pipe meets the preset working condition requirements. Open the external inlet valve to introduce a heated and / or pressurized fluid into the external cavity of the pipe; The temperature signal of the outer cavity of the tube is obtained by a second thermometer, and the pressure signal of the outer cavity of the tube is obtained by a second pressure gauge. Based on the temperature signal and the pressure signal of the outer cavity of the tube, the current temperature and pressure of the outer cavity of the tube are adjusted so that the temperature and pressure of the outer cavity of the tube meet the preset working condition requirements.

13. An aging test method for oil and gas pipelines based on the oil and gas pipeline aging test apparatus of claim 9, characterized in that, The aging test method for the oil and gas transmission pipeline includes: Open the external inlet valve to introduce a heated and / or pressurized fluid into the external cavity of the pipe; The temperature signal of the outer cavity of the tube is obtained by the second thermometer, and the pressure signal of the outer cavity of the tube is obtained by the second pressure gauge. Based on the temperature signal and the pressure signal of the outer cavity of the tube, the current temperature and pressure of the outer cavity of the tube are adjusted so that the temperature and pressure of the outer cavity of the tube meet the preset working condition requirements. Open the outlet valve of the pipe to discharge all the gas in the outer cavity of the pipe and fill the outer cavity of the pipe with the medium; The flow velocity of the fluid flowing through the outer cavity of the pipe is obtained by a second velocity measuring instrument. By controlling the opening of the inlet valve and the outlet valve of the pipe, the flow velocity of the fluid flowing through the outer cavity of the pipe is made to meet the preset working condition requirements.

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