An intelligent leakage warning flexible composite pipeline system and a warning method

Abstract

This application relates to the technical field of oil and gas transportation, and discloses an intelligent leakage warning flexible composite pipeline system and a warning method. The system includes a composite pipeline body, an optical signal processing device, and a data processing unit. The optical signal processing device is communicatively connected to the data processing unit to achieve data transmission. The warning method corresponds to the system. This application realizes intelligent leakage warning and monitoring of the flexible composite pipeline system; the distributed temperature sensing element can sense the temperature change of the pipeline; the optical signal processing device converts the laser signal into an electrical signal and transmits it to the data processing unit; the data processing unit calculates the temperature along the pipeline and the leakage position, and alarms for abnormal data; solves the problem that traditional flexible composite pipes lack sensing functions, effectively reduces environmental pollution and energy loss caused by oil and gas leakage during pipeline transportation, ensures the safety and stability of oil and gas transportation, and promotes the intelligent development of the composite pipeline industry.

Description

Technical Field

[0001] This application relates to the technical field of oil and gas transportation, and specifically to an intelligent leakage warning flexible composite pipeline system and a warning method. Background Art

[0002] As a new type of composite pipe, the flexible composite pipe is widely used in the field of oil and gas transportation. The flexible composite pipe usually consists of an inner lining layer, a reinforcing layer, and an outer protective layer. The inner lining layer and the outer protective layer usually use thermoplastic materials such as high-density polyethylene and cross-linked polyethylene, and are formed by an extrusion process; the reinforcing layer usually uses high-strength materials such as polyester industrial filaments, aramid ropes / yarns, glass fiber pre-impregnated tapes, steel cord pre-impregnated tapes, steel strips, and steel wires (ropes), and is symmetrically compounded on the surface of the inner lining layer in an even number of layers at a specific winding angle through a precision winding device. Its single root length can reach 150 - 2000m, and the weight is reduced by 40% - 60% compared with traditional steel pipes. Due to its advantages such as light weight, coiling ability, fast construction speed, corrosion resistance, and long service life, it has been applied in large-scale engineering in key fields such as oil and gas water transportation, onshore shale gas development, carbon dioxide flooding injection and production pipelines, and hydrogen energy storage and transportation systems, and has become an important part of the modern energy transportation system.

[0003] However, there are still limitations when the existing flexible composite pipe is used as a transportation carrier. The inventors found in the research on the application of the existing flexible composite pipe that: the existing flexible composite pipe lacks a sensing function. That is, when the pipeline is damaged by third-party construction or extreme stress, the medium leakage caused by the pipe body damage not only causes energy waste and ecological environmental pollution, but also when transporting sour associated gas or green hydrogen with a hydrogen purity > 99%, the pipeline failure will cause the escape of harmful gases and the leakage of combustible gases, and there are major safety accidents such as poisoning and explosion of personnel.

[0004] Based on this, the industry is vigorously promoting the intelligent technology iteration of flexible composite pipes, and building an intelligent pipeline system with real-time strain monitoring, precise leakage positioning and risk autonomous warning functions by integrating various sensors in the pipeline. For example, domestic patent application ZL201520095997.3 pre-buries optical fiber micro-tubes in the wall structure of flexible composite pipes to build an integrated optical fiber-tube composite system; this structure not only retains the mechanical properties of traditional flexible composite pipes, but also gives the pipeline distributed optical fiber sensing capabilities, which can realize real-time leakage monitoring of the entire pipeline; but in this solution, first, the wall thickness of the lining layer of the flexible composite pipe is greatly increased, which increases the production cost; second, the embedding of communication optical fiber in the lining layer inevitably causes local stress concentration, affecting the service life of the pipe; third, the non-standard design of pipes, joints, etc. restricts the large-scale market promotion and application, so there have been no related engineering application cases so far. US patent application US9658421B2 relates to a flexible composite pipe, including a multilayer structure of a metal skeleton layer, a polymer sealing layer, a Z-shaped steel belt compression armor layer, a spiral steel wire tensile armor layer and a polyethylene outer protective layer, and a communication optical fiber array is implanted in the interlayer space between the tensile armor layer and the outer protective layer, and a double protection mechanism is formed through the physical isolation of the armored steel wire, so that the optical fiber signal is transmitted stably; this type of pipe has a complex structure and high cost, and is only used for marine flexible risers, which is not conducive to promotion and application in onshore oil and gas fields. Traditional fiber optic early warning technology is to arrange sensing optical fibers outside the pipeline to monitor the stress and temperature field of the target pipeline and achieve the purpose of pipeline leakage early warning. For example, in patent application ZL201410158614.2, a protective sleeve with built-in sensing optical fibers is laid in parallel on the outside of the buried steel pipeline. Sensor holes are set at the bottom of the protective sleeve at regular intervals. The optical fiber sensor extends out of the protective sleeve through the sensor hole and is fixed to the outer wall of the monitoring pipeline to achieve real-time monitoring of the pipeline. This technology is cumbersome to operate and faces complex and harsh working conditions on site, making it difficult to construct. Therefore, it has not been promoted and applied so far.

[0005] In summary, how to organically combine the sensing optical fiber early warning technology with the flexible composite pipe technology, develop a flexible composite pipe with intelligent early warning function, realize real-time monitoring of pipeline integrity, and analyze it through intelligent algorithms to establish an intelligent early warning system, which is of great significance to reducing oil and gas losses caused by pipeline failure, realizing green and environmental protection of oil fields, and promoting the intelligent development of the composite pipeline industry. Summary of the invention

[0006] The purpose of this application is to provide an intelligent leakage warning flexible composite pipeline system and a warning method to solve the technical problems raised in the above background technology.

[0007] To achieve the above objectives, this application discloses the following technical solutions:

[0008] In a first aspect, the present application discloses an intelligent leakage warning flexible composite pipeline system, including:

[0009] A composite pipeline body, including a lining layer, a reinforcing layer, an inner protection layer, at least one insulating layer arranged in sequence, and a distributed temperature sensing element integrated on the outer wall of the composite pipeline;

[0010] An optical signal processing device for transmitting an optical signal to the distributed temperature sensing element, receiving the reflected optical signal and converting it into temperature data;

[0011] A data processing unit for calculating the temperature distribution along the pipeline and the leakage position based on the temperature data and triggering an abnormal alarm;

[0012] Wherein, the distributed temperature sensing element senses temperature changes through optical properties, and the optical signal processing device is communicatively connected to the data processing unit to achieve data transmission.

[0013] Preferably, the temperature along the pipeline is determined based on the power ratio of Stokes light and anti-Stokes light in combination with a preset heat conduction model;

[0014] The leakage position is determined through the mapping relationship between the optical signal transmission time and the optical fiber path parameters.

[0015] Preferably, the temperature along the pipeline is calculated by the following formula:

[0016]

[0017] Wherein, is a preset initial reference temperature, used as a benchmark for temperature calculation; is a coefficient related to the heat conduction characteristics of the pipeline, used to reflect the heat conduction ability of the pipeline material; is the convective heat transfer coefficient, used to reflect the heat exchange efficiency between the pipeline and the surrounding environment or the internal fluid; is the change in the flow rate of the fluid inside the pipeline, used to reflect the influence of heat transfer and temperature distribution; is the optical power value of the anti-Stokes light at the temperature of ; is the optical power value of the Stokes light at the temperature of ; is the optical power value of the anti-Stokes light at the initial reference temperature ; is the optical power value of the Stokes light at the initial reference temperature ;

[0018] Preferably, the leakage position is calculated by the following formula:

[0019]

[0020] Among them, is the length of the sensing optical fiber from the starting point of the optical fiber connected to the device to the leakage point; is the pitch of the sensing optical fiber wound on the thermal insulation layer; is the outer diameter of the composite pipeline body; is the thickness of the outer protective layer; is the distance from the starting point of the optical fiber connected to the device to the end of the optical fiber entering the composite pipeline body; is the propagation speed of light in the distributed temperature sensing element; is the time interval from the emission of the optical signal to the reception of the reflected optical signal; is the refractive index of the optical fiber.

[0021] Preferably, the distributed temperature sensing element is of a multi-core structure, wound around the outside of the thermal insulation layer at a preset angle, and the signal continuity is achieved through optical coupling technology;

[0022] The reinforcing layer is made of a high-strength material and wound around the outside of the inner lining layer at a preset angle.

[0023] Preferably, the composite pipeline body is provided with a detachable joint, and the detachable joint includes an inner buckle type or threaded connection core sleeve and outer sleeve. The core sleeve and the outer sleeve seal the inner lining layer, the reinforcing layer and the protective layer through mechanical biting and seals.

[0024] Preferably, the composite pipeline body is provided with an optical fiber joint, and the optical fiber joint realizes continuous signal transmission through hot melt welding or an optical coupler. The outer layer of the optical fiber joint is an anti-corrosion coating.

[0025] Preferably, the data processing unit uses a dynamic data correction algorithm to filter abnormal temperature fluctuations, and the filtering of abnormal temperature fluctuations is specifically: reducing false alarms caused by environmental interference or sensor noise.

[0026] Preferably, the dynamic data correction algorithm is specifically:

[0027]

[0028] Among them, is the calculated abnormal data point is the replacement data of is the serial number of the abnormal data point, is the offset variable.

[0029] In a second aspect, the present application discloses an intelligent leakage warning method for a flexible composite pipeline, which is applied to the intelligent leakage warning flexible composite pipeline system as described above. The method includes the following steps:

[0030] S1: Configure a composite pipeline body, which includes a lining layer, a reinforcement layer, an inner protection layer, at least one insulation layer arranged in sequence, and a distributed temperature sensing element integrated on the outer wall of the composite pipeline;

[0031] S2: Transmit a laser signal to the distributed temperature sensing element through an optical signal processing device;

[0032] S3: Collect the reflected light through the optical signal processing device and convert it into temperature data;

[0033] S4: The data processing unit analyzes the temperature distribution based on the temperature data. If temperature anomalies are detected, calculate the temperature distribution along the pipeline and the leakage location, and issue an anomaly alarm.

[0034] Beneficial effects: The intelligent leakage warning flexible composite pipeline system and warning method of the present application utilize the composite pipeline body, combined with an optical signal processing device and a data processing unit, to achieve intelligent leakage warning and monitoring of the flexible composite pipeline system; each layer of the composite pipeline body works together, and the distributed temperature sensing element senses the temperature change of the pipeline; the optical signal processing device converts the laser signal into an electrical signal and transmits it to the data processing unit; the data processing unit analyzes the electrical signal, calculates the temperature along the pipeline and the leakage location, and alarms for abnormal data; the entire system is organically combined, solving the problem that traditional flexible composite pipes lack sensing functions, effectively reducing environmental pollution and energy loss caused by oil and gas leakage in pipeline transportation, ensuring the safety and stability of oil and gas transportation, and promoting the intelligent development of the composite pipeline industry. Description of the Drawings

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0036] Figure 1 It is a schematic structural diagram of the intelligent leakage warning flexible composite pipeline system provided by the embodiment of the present application;

[0037] Figure 2 It is a structural diagram of the composite pipeline body provided by the embodiment of the present application;

[0038] Figure 3 It is a schematic diagram of the connection of the middle joint of the composite pipeline body provided by the embodiment of the present application;

[0039] Figure 4 It is a schematic diagram of the connection of the end joint of the composite pipeline body provided by the embodiment of the present application;

[0040] Reference numerals: 1, composite pipeline body; 11, inner lining layer; 12, reinforcing layer; 13, inner protective layer; 14, thermal insulation layer; 15, distributed temperature sensing element; 16, optical cable wrapping layer; 17, outer protective layer; 2, core sleeve; 21, core sleeve thread; 22, O-ring seal; 3, outer sleeve; 31, outer sleeve thread; 4, nut; 5, sensor connection point; 6, heat shrinkable sleeve; 7, flange; 8, optical signal processing device; 9, computer PC terminal. Specific embodiments

[0041] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0042] In this article, the term "including" is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, the elements defined by the statement "including..." do not exclude the existence of additional identical elements in the process, method, article or device including the said elements.

[0043] In the first aspect of this embodiment, an intelligent leakage warning flexible composite pipeline system is disclosed, including:

[0044] A composite pipeline body 1, including an inner lining layer 11, a reinforcing layer 12, an inner protective layer 13, at least one thermal insulation layer 14, a distributed temperature sensing element 15 integrated on the outer wall of the protective layer, an optical cable wrapping layer 16 and an outer protective layer 17 arranged in sequence; wherein, the reinforcing layer 12 is wound outside the inner lining layer 11, the thermal insulation layer 14 is arranged at least outside the reinforcing layer 12, the distributed temperature sensing element 15 is arranged outside the thermal insulation layer 14, the optical cable wrapping layer 16 wraps the distributed temperature sensing element 15, and the outer protective layer 17 is arranged outside the optical cable wrapping layer 16; the distributed temperature sensing element 15 senses temperature changes through optical characteristics (such as the power ratio of Stokes light and anti-Stokes light).

[0045] The optical signal processing device 8 is used to transmit an optical signal to the distributed temperature sensing element 15, receive reflected light and convert it into temperature data; the optical signal processing device 8 can be any one of the prior art, and is composed of electronic components such as a laser, a modulator, an amplifier, a signal receiver, a photoelectric converter, and an information transmitter, wherein the laser emits laser light, which is injected into the distributed temperature sensing element 15 after passing through the modulator and the amplifier, the signal receiver separates the Stokes light and the anti-Stokes light in the reflected light, and the photoelectric converter converts the optical signal into an electrical signal, which is transmitted to the data processing unit through the information transmitter;

[0046] The data processing unit is used to calculate the temperature distribution and leakage position along the pipeline based on the temperature data and trigger an abnormal alarm; the optical signal processing device 8 is connected to the data processing unit for communication to achieve data transmission. The carrier of the data processing unit is a computer PC terminal 9.

[0047] As a preferred implementation of this embodiment, the material of the inner lining layer 11 is usually preferably polyethylene, cross-linked polyethylene, polyvinylidene fluoride, nylon, polyphenylene sulfide, or other single-layer / multi-layer thermoplastic resins; the reinforcement layer 12 is selected from non-metallic or metal reinforcement materials, such as polyester industrial filament, aramid, fiber or steel cord prepreg tape, steel wire rope (wire), steel belt, etc.; the inner protective layer 13 is usually selected from thermoplastic resins such as polyethylene resin. Generally, the thickness of each layer of the inner lining layer 11, the reinforcement layer 12, and the inner protective layer 13 complies with the requirements of national standards and standards such as GB / T 38725.2-2020, SY / T 6662.2, and SY / T 6662.4. The insulation layer 14 can be made of high-performance insulation materials such as nano aerogel felt, rubber and plastic sponge, etc., and its thickness is set according to the pipeline laying process design results or the owner's requirements; the distributed temperature sensing element 15 uses two 2-core optical cables interlaced and wound on the outside of the insulation layer 14 (it can also be laid on the outside of the insulation layer 14 in a straight manner), and is fixed with PET tape, and the outer protective layer 17 is usually made of wear-resistant polyethylene.

[0048] Based on the above, this embodiment utilizes the composite pipe body 1, in combination with the optical signal processing device 8 and the data processing unit, to realize intelligent leakage warning and monitoring of the flexible composite pipe system. The various layers of the composite pipe body 1 work together, and the distributed temperature sensing element 15 senses the temperature change of the pipe; the optical signal processing device 8 converts the laser signal into an electrical signal and transmits it to the data processing unit; the data processing unit analyzes the electrical signal, calculates the temperature and leakage position along the pipe, and alarms for abnormal data. The entire system is organically combined to solve the problem of the lack of sensing function of traditional flexible composite pipes, which can effectively reduce environmental pollution and energy loss caused by pipeline oil and gas leakage, ensure the safety and stability of oil and gas transportation, and promote the development of the composite pipeline industry towards intelligence.

[0049] In this embodiment, the temperature along the pipeline is determined based on the power ratio of the Stokes light and the anti-Stokes light, in combination with a preset heat conduction model (such as the thermal characteristics of the pipeline material and the convective heat transfer coefficient of the fluid). Specifically, the temperature along the pipeline is calculated by the following formula:

[0050]

[0051] Wherein, is the real-time temperature value of a certain point along the pipeline calculated; is the preset initial reference temperature, which is used as the benchmark for temperature calculation; is the coefficient related to the heat conduction characteristics of the pipeline, which is used to reflect the heat conduction ability of the pipeline material; is the convective heat transfer coefficient, which is used to reflect the heat exchange efficiency between the pipeline and the surrounding environment or the internal fluid; is the change in the flow velocity of the fluid in the pipeline, which is used to reflect the influence of heat transfer and temperature distribution; At the temperature of is the optical power value of the anti-Stokes light; At the temperature of is the optical power value of the Stokes light; At the initial reference temperature is the optical power value of the anti-Stokes light; At the initial reference temperature is the optical power value of the Stokes light.

[0052] By the above, in this embodiment, using the temperature calculation formula and combining the various parameters under the actual working conditions of the pipeline, the accurate calculation of the temperature along the pipeline is realized. By determining parameters such as the initial reference temperature, the pipeline heat conduction coefficient, the convective heat transfer coefficient, the fluid flow velocity change amount, and the Stokes light and anti-Stokes light power values, and substituting them into the formula for operation. This enables the data processing unit to obtain the temperature information of each point along the pipeline in real time, providing a key basis for subsequent judgment of whether there is a leakage risk in the pipeline. The accurate temperature calculation improves the accuracy of leakage warning, avoids leakage accidents caused by temperature misjudgment, ensures the safety during the pipeline transportation process, and provides strong support for the stable operation of oil and gas transportation.

[0053] In this embodiment, the leakage location is determined by the mapping relationship between the optical signal transmission time and the optical fiber path parameters (such as the winding pitch and the pipeline diameter). Specifically, the leakage location is calculated by the following formula:

[0054]

[0055] Wherein, is the calculated length of the leakage site of the flexible composite pipe; is the length of the sensing optical fiber from the starting point of the optical fiber connected to the device to the leakage point; is the pitch of the sensing optical fiber wound on the thermal insulation layer; is the outer diameter of the composite pipeline body; is the thickness of the outer protective layer; is the distance from the starting point of the optical fiber connected to the device to the end of the optical fiber entering the composite pipeline body; is the propagation speed of light in the distributed temperature sensing element; is the time interval from the emission of the optical signal to the reception of the reflected optical signal; is the refractive index of the optical fiber.

[0056] Through the above, this embodiment utilizes the leakage position calculation formula that combines the parameters of the sensing optical fiber, the pipeline structure size, and the optical signal propagation characteristics to achieve precise positioning of the pipeline leakage position. By determining parameters such as the length of the sensing optical fiber from the starting point of the optical fiber connected to the device to the leakage point, the pitch of the sensing optical fiber winding, the pipeline outer diameter, the thickness of the outer protective layer 17, the optical signal propagation speed, the propagation time interval, and the refractive index of the optical fiber, formula operations are carried out. This enables the rapid determination of the leakage point position when the pipeline leaks, facilitating the staff to take timely measures for repair, reducing the losses caused by leakage, improving the emergency response ability of the pipeline system, and ensuring the efficiency and safety of oil and gas transportation.

[0057] In this embodiment, the principles of the temperature calculation formula and the leakage position calculation formula are as follows:

[0058] When the incident optical power is , the relationship between the Stokes optical power and temperature follows Equation 1, and the relationship between the anti-Stokes optical power and temperature follows Equation 3:

[0059] Equation 1

[0060] That is: Equation 2

[0061] Equation 3

[0062] Dividing Equation 1 by Equation 3 gives:

[0063] Equation 4

[0064] Calibrate the sensing optical fiber under the initial reference temperature condition:

[0065] Equation 5

[0066] Dividing Equation 2 by Equation 5 gives:

[0067] Equation 6

[0068] Solve for temperature The value is Equation 7, i.e., the temperature calculation formula:

[0069] Equation 7

[0070] Wherein, is the Stokes optical power; is the coefficient related to Stokes scattering; is the anti-Stokes optical power; is the coefficient related to anti-Stokes scattering; , , are the average propagation losses of the incident light, Stokes light, and anti-Stokes light, respectively; is the Boltzmann factor of the Stokes light; is the Boltzmann factor of the anti-Stokes light; is the length of the scattering point from the fiber optic inlet; is the propagation speed of light in the optical fiber.

[0071] When light is propagating forward, if the time for the scattered light to return to the incident end is , by calculating the time difference between the detected reflected light and the incident light, the position of the emitted light in the optical fiber can be located, and the calculation formula is as follows:

[0072] Equation 8

[0073] Wherein, is the distance between the scattering point in the optical fiber and the light source incident end face; is the speed of light; is the refractive index of the optical fiber.

[0074] When the sensing optical fiber is wound and laid outside the thermal insulation layer 14, the pipeline length is:

[0075] Equation 9.

[0076] Specifically, the reinforcing layer 12 is made of a high-strength material and is wound around the outside of the inner lining layer 11 at a preset angle. The reinforcing layer 12 can be, but is not limited to, high-performance fiber filaments, metal strips, or various fiber / metal wire prepregs. Among them, the preset angles in this embodiment are all empirical values well known to those skilled in the art.

[0077] With the above, this embodiment uses high-performance fiber filaments, metal tapes, or various fiber / metal wire prepregs as the reinforcing layer 12, and is wound around the outside of the inner liner layer 11 at a preset angle, achieving the effect of enhancing the structural strength and stability of the pipeline. Different reinforcing materials provide good mechanical properties, and the preset winding angle enables the reinforcing layer 12 to better withstand the internal pressure and external loads of the pipeline. This effectively improves the compressive and tensile capacities of the pipeline, reduces the risks of pipeline breakage and leakage caused by external forces, extends the service life of the pipeline, ensures the stable operation of the pipeline in complex oil and gas transportation environments, reduces the maintenance cost, and guarantees the reliability of energy transportation.

[0078] Specifically, the inner protective layer 13 is provided based on the design requirements of the composite pipeline body 1, and the design requirements include but are not limited to the working pressure of the pipeline, the type of transported medium, and the corrosiveness requirements.

[0079] With the above, this embodiment realizes the effective protection of the internal structure of the pipeline. By selecting appropriate materials and thicknesses of the inner protective layer 13 for different working pressures and medium corrosivities, it can prevent the transported medium from eroding the inner liner layer 11 and the reinforcing layer 12, and avoid pipeline leakage caused by medium corrosion. At the same time, the inner protective layer 13 can also play a certain buffering role, reducing the impact of internal pressure on the pipeline structure, improving the corrosion resistance and reliability of the pipeline, and guaranteeing the safe operation of the pipeline under different working conditions.

[0080] Specifically, the distributed temperature sensing element 15 has a multi-core structure and is wound around the outside of the thermal insulation layer 14 at a preset angle, and the signal continuity is achieved through optical coupling technology (such as forming an integrated structure by welding at the intermediate joint).

[0081] With the above, this embodiment realizes stable and reliable signal transmission and monitoring functions. The multi-core structure increases the redundancy of signal transmission and improves the accuracy of data acquisition; the preset angle winding can better cover the pipeline surface and improve the comprehensiveness of temperature monitoring; the welding of the intermediate joint forms an integrated structure, reducing the loss and interference of signal transmission. This enables the distributed temperature sensing element 15 to stably collect pipeline temperature information, provides reliable data support for leakage warning, and ensures the safe and stable operation of the pipeline system.

[0082] Specifically, the composite pipeline body 1 further includes a detachable joint. The detachable joint includes a core sleeve 2 and an outer sleeve 3 connected by internal buckling or threading. The core sleeve 2 and the outer sleeve 3 seal the inner liner layer 11, the reinforcing layer 12, and the protective layer through mechanical biting and a seal (such as an O-ring). It is feasible that the detachable joint includes a core sleeve 2 and an outer sleeve 3. Serrated tooth patterns and O-ring seal sites are provided on the inner and outer surfaces of the core sleeve 2. By expanding the inner part of the core sleeve 2 or buckling the inner part of the outer sleeve 3, the inner liner layer 11, the reinforcing layer 12, and the inner protective layer 13 of the composite pipeline body 1 are tightly buckled between the core sleeve 2 and the outer sleeve 3, and are sealed by an O-ring 22.

[0083] Through the above, the present embodiment realizes the tight connection and reliable sealing of each part of the composite pipeline body 1. By means of expanding the inner part of the core sleeve 2 or buckling the inner part of the outer sleeve 3, the pipeline inner liner layer 11, the reinforcing layer 12, and the inner protective layer 13 are tightly buckled between the core sleeve 2 and the outer sleeve 3, and then sealed by an O-ring 22, effectively preventing medium leakage. This connection method is simple to operate and firmly connected, ensuring the sealing and integrity of the pipeline system, improving the connection quality of the pipeline, ensuring that oil and gas do not leak during transportation, and guaranteeing the safety of energy transportation.

[0084] It is feasible that the composite pipeline body 1 is provided with an optical fiber joint. The optical fiber joint realizes continuous signal transmission through hot melt welding or an optical coupler. The outer layer of the optical fiber joint is an anti-corrosion coating (such as 3PE cold wrap tape). The distributed temperature sensing element 15 is spirally wound around the joint connection part, and the two ends of the intelligent early warning flexible composite pipe and the joint are completely wrapped by a heat shrinkable sleeve 6 and strengthened by winding with 3PE cold wrap tape; the end part of the pipeline is connected to the inlet / outlet pipeline by a flange 7, and anti-corrosion protection is carried out in the same way as the intermediate joint.

[0085] Through the above, the present embodiment realizes the stability and good anti-corrosion performance of the pipeline connection part. The connection method in the middle ensures the firmness of the pipeline connection. The winding and welding of the distributed temperature sensing element 15 ensure the continuity of signal transmission; the heat shrinkable sleeve 6 and 3PE cold wrap tape effectively prevent corrosion of the connection part; the flange 7 connection and anti-corrosion measures at the end are unified with those in the middle, making the connection and anti-corrosion performance of the entire pipeline system consistent. This reduces the leakage risk at the pipeline connection, extends the service life of the pipeline, and guarantees the stability of oil and gas transportation.

[0086] In this embodiment, the data processing unit uses a dynamic data correction algorithm to filter abnormal temperature fluctuations. The filtering of abnormal temperature fluctuations specifically means: reducing false alarms caused by environmental interference or sensor noise. In a feasible implementation manner, the dynamic data correction algorithm is the ten-point data mean method. The ten-point data mean method specifically means:

[0087]

[0088] Among them, is the replacement data for the calculated abnormal data points , is the serial number of the abnormal data point, is the offset variable.

[0089] Through the above, this embodiment realizes the effective repair of temperature abnormal data and the improvement of data reliability. By taking the average value of the five data points before and after the abnormal data point (or taking the average value of the thirty data points before and after in case of continuous abnormality) to replace the abnormal data, the cause of the abnormality can be accurately judged, and the noise and interference in the data can be removed. This makes the data obtained by the data processing unit more accurate and reliable, provides more reliable data support for leakage warning, avoids misjudgment caused by data abnormality, improves the accuracy and stability of the leakage warning system, and ensures the safe and stable operation of the pipeline system.

[0090] In this embodiment, the ten-point data average formula is used to process the abnormal data. In a specific application, it is as follows:

[0091] First, by real-time monitoring the temperature data, based on the temperature range of the abnormal data, accurately judge whether the abnormality is caused by equipment failure, sensor error, environmental interference, etc., providing a basis for subsequent processing.

[0092] Secondly, for the abnormal data, the average value of the five data points before and after is used for repair. Then the repaired data T_repair can be calculated by the following formula:

[0093] Formula 10

[0094] When continuous abnormal situations occur, such as three consecutive data points being abnormal, this method will further expand the data affected range to ensure the accuracy of the repair. At this time, the average value of the thirty data points before and after will be calculated to replace this continuous abnormal data segment, as follows:

[0095] Formula 11

[0096] While improving the data reliability, this method can also restore the continuity and consistency of the data without introducing additional errors, providing strong support for the safe operation and precise regulation of the intelligent warning flexible composite pipe.

[0097] The second aspect of this embodiment discloses an intelligent leakage warning method for a flexible composite pipeline. This warning method is applied to the intelligent leakage warning flexible composite pipeline system as described above. This method includes the following steps:

[0098] S1: Configure the composite pipeline body 1, which includes a lining layer 11, a reinforcing layer 12, an inner protective layer 13, at least one insulating layer 14 arranged in sequence, and a distributed temperature sensing element 15 integrated on the outer wall of the composite pipeline;

[0099] S2: Transmit a laser signal to the distributed temperature sensing element 15 through the optical signal processing device 8;

[0100] S3: Collect the Stokes light and anti-Stokes light in the reflected light through the optical signal processing device 8 and convert them into temperature data;

[0101] S4: The data processing unit analyzes the temperature distribution based on the temperature data. If a temperature anomaly (such as exceeding the threshold or mutation) is detected, calculate the temperature distribution along the pipeline and the leakage location, and issue an anomaly alarm.

[0102] It should be noted that the intelligent leakage warning method for the flexible composite pipeline in this embodiment corresponds to the aforementioned intelligent leakage warning flexible composite pipeline system. Therefore, the content not specifically described in the intelligent leakage warning method for the flexible composite pipeline in this embodiment, which may but is not limited to function definition, working principle, technical effect, etc., can refer to the records in the aforementioned intelligent leakage warning flexible composite pipeline system and will not be elaborated herein.

[0103] In a specific application of this embodiment, as shown in Figures 1 to 4 Take the DN100mm / PN6.4MPa intelligent leakage warning flexible composite pipeline system as an example. In the intelligent warning flexible composite pipe, the lining layer 11 is made of heat-resistant polyethylene, the reinforcing layer 12 is made of high-strength polyester industrial filament, the inner protective layer 13 is made of polyethylene, the insulating layer 14 is made of flexible insulating materials such as nano-aerogel felt or rubber sponge, the distributed temperature sensing element 15 uses 2 two-core optical cables, the optical cable wrapping layer 16 uses PET tape, and the outer protective layer 17 is made of wear-resistant polyethylene.

[0104] The single length of the composite pipeline body 1 is 200m, and the ends of each composite pipe are connected by crimping with a core sleeve 2 and an outer sleeve 3; during the joint crimping process, the core sleeve thread 21 and the outer sleeve thread 31 respectively bite the inside of the composite pipe lining layer 11 and the outside of the inner protective layer 13, and are tightly sealed by the O-ring 22 arranged on the core sleeve thread 21. The two sections of the composite pipe are connected by the joint thread and the nut 4. The distributed temperature sensing element 15 is welded by hot melting at the sensor connection 5, spirally wound on the outer wall of the pipeline, protected by a heat shrinkable sleeve 6, and strengthened by winding with 3PE cold wrap tape; the end uses a flange 7 to meet the incoming pipeline, the distributed temperature sensing element 15 is connected to the optical signal processing device 8, and the optical signal is converted into an electrical signal and then transmitted to the data processing unit for data analysis.

[0105] After the intelligent leakage warning flexible composite pipeline is put into operation, the laser in the optical signal processing device 8 emits laser light, which enters the distributed temperature sensing element 15 after passing through the modulator and amplifier. Then, the signal receiver collects the Stokes light and anti-Stokes light scattered at each position of the pipeline, converts them into electrical signals through the photoelectric converter, and transmits them to the data processing unit for analysis and denoising to achieve leakage warning of the pipeline.

[0106] If the composite pipeline body 1 transports oilfield sewage, the environmental temperature of the pipeline is 25 °C (298 K). When a leakage occurs, the local temperature rises, and the power changes of the Stokes light and anti-Stokes light are detected as follows:

[0107] When there is no leakage: ;

[0108] When there is a leakage: ;

[0109] Other parameter values: is 1.38×10-23 J / K, is 6.626×10-34 J·s, is 2.5×10-12 HZ. At this time .

[0110] Since it is known that the normal environmental temperature of the intelligent leakage warning flexible composite pipeline is 25 °C, and the calculated temperature at the detection point reaches 49 °C, it indicates that there may be a gas leakage phenomenon at this position. Therefore, a temperature threshold (such as 35 °C) can be set in this system, and once the monitored value exceeds the temperature threshold, a warning will be triggered.

[0111] If in the intelligent leakage warning flexible composite pipeline system, the data processing unit shows that the optical fiber at 1000 m has an abnormal temperature alarm, then the theoretical alarm time is:

[0112]

[0113] If the diameter of the composite pipeline body 1 is 127 mm, the thickness of the outer protective layer 17 is 3.5 mm, the diameter of the distributed temperature sensing element 15 is negligible compared to the diameter of the composite pipe, the fiber optic winding pitch is 10 cm, the length from the optical signal processing device 8 to the distributed temperature sensing element 15 entering the composite pipe is 50 m, and the length of the leakage warning optical fiber is 1000 m, then the length of the composite pipe at the leakage point .

[0114] In summary, for the intelligent leakage warning flexible composite pipeline system and warning method of this embodiment, by using the composite pipeline body 1 composed of the inner lining layer 11, the reinforcing layer 12, the inner protection layer 13, the thermal insulation layer 14, the distributed temperature sensing element 15, the optical cable wrapping layer 16, and the outer protection layer 17, in combination with the optical signal processing device 8 and the data processing unit, the intelligent leakage warning and monitoring of the flexible composite pipeline system are realized; each layer of the composite pipeline body 1 works together, and the distributed temperature sensing element 15 can sense the temperature change of the pipeline; the optical signal processing device 8 converts the laser signal into an electrical signal and transmits it to the data processing unit; the data processing unit analyzes the electrical signal, calculates the temperature along the pipeline and the leakage position, and alarms for abnormal data; the entire system is organically combined, solving the problem that traditional flexible composite pipes lack sensing functions, effectively reducing environmental pollution and energy loss caused by oil and gas leakage during pipeline transportation, ensuring the safety and stability of oil and gas transportation, and promoting the development of the composite pipeline industry towards the intelligent direction.

[0115] In the embodiments provided in this application, it should be understood that the embodiments described herein can be implemented in hardware, software, firmware, middleware, code, or any appropriate combination thereof. For hardware implementation, the processor can be implemented in one or more of the following units: application specific integrated circuit (ASIC), digital signal processor (DSP), digital signal processing device (DSPD), programmable logic device (PLD), field programmable gate array (FPGA), processor, controller, microcontroller, microprocessor, or other electronic units designed to implement the functions described herein, or a combination thereof. For software implementation, part or all of the processes of the embodiments can be completed by a computer program instructing the relevant hardware. When implemented, the above program can be stored in a computer-readable storage medium or transmitted as one or more instructions or codes on a computer-readable storage medium. The computer-readable storage medium includes computer storage media and communication media, where the communication media includes any medium that facilitates the transfer of a computer program from one place to another. The storage media can be any available medium that can be accessed by a computer. The computer-readable storage medium can include, but is not limited to, RAM, ROM, EEPROM, CD-ROM, or other optical disk storage, magnetic disk storage media, or other magnetic storage devices, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer.

[0116] Finally, it should be noted that the above are only the preferred embodiments of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An intelligent leakage warning flexible composite pipeline system, characterized in that, Comprising: A composite pipeline body, including a lining layer, a reinforcing layer, an inner protective layer, at least one insulating layer, a distributed temperature sensing element integrated on the outer wall of the protective layer, an optical cable wrapping layer, and an outer protective layer arranged in sequence; An optical signal processing device for emitting an optical signal to the distributed temperature sensing element, receiving the reflected light, and converting it into temperature data; A data processing unit for calculating the temperature distribution along the pipeline and the leakage position based on the temperature data, and triggering an abnormal alarm; Wherein, the distributed temperature sensing element senses temperature changes through optical characteristics, and the optical signal processing device is communicatively connected to the data processing unit to achieve data transmission; The temperature along the pipeline is determined based on the power ratio of Stokes light and anti-Stokes light, combined with a preset heat conduction model; The leakage position is determined through the mapping relationship between the optical signal transmission time and the optical fiber path parameters; The leakage position is calculated by the following formula: Among them, is the length of the sensing optical fiber from the starting point of the optical fiber connected to the device to the leakage point; is the pitch of the sensing optical fiber wound on the insulation layer; is the outer diameter of the composite pipeline body; is the thickness of the outer protective layer; is the distance from the starting point of the optical fiber connected to the device to the end of the optical fiber entering the composite pipeline body; is the propagation speed of light in the distributed temperature sensing element; is the time interval from the emission of the optical signal to the reception of the reflected optical signal; is the refractive index of the optical fiber; The distributed temperature sensing element is of a multi-core structure, wound around the outside of the insulating layer at a preset angle, and signal continuity is achieved through optical coupling technology; the reinforcing layer is composed of high-strength materials and wound around the outside of the lining layer at a preset angle.

2. The intelligent leakage warning flexible composite pipeline system according to claim 1, characterized in that, The temperature along the pipeline is calculated by the following formula: Among them, is the preset initial reference temperature, which is used as the benchmark for temperature calculation; is the coefficient related to the heat conduction characteristics of the pipeline, which is used to reflect the heat conduction ability of the pipeline material; is the convective heat transfer coefficient, which is used to reflect the heat exchange efficiency between the pipeline and the surrounding environment or the internal fluid; is the change in the flow velocity of the fluid in the pipeline, which is used to reflect the influence of heat transfer and temperature distribution; At the temperature of is the optical power value of the anti-Stokes light; At the temperature of is the optical power value of the Stokes light; At the initial reference temperature is the optical power value of the anti-Stokes light; At the initial reference temperature is the optical power value of the Stokes light.

3. The intelligent leakage warning flexible composite pipeline system according to claim 1, characterized in that The composite pipeline body is provided with a detachable joint, and the detachable joint includes an inner snap-in or threaded core sleeve and an outer sleeve. The core sleeve and the outer sleeve seal the lining layer, the reinforcing layer, and the protective layer through mechanical engagement and seals.

4. The intelligent leakage warning flexible composite pipeline system according to claim 1, wherein, The composite pipeline body is provided with an optical fiber joint, and the optical fiber joint realizes continuous signal transmission through hot melt welding or an optical coupler. The outer layer of the optical fiber joint is an anti-corrosion coating.

5. The intelligent leakage warning flexible composite pipeline system according to claim 1, characterized in that, The data processing unit uses a dynamic data correction algorithm to filter abnormal temperature fluctuations. The filtering of abnormal temperature fluctuations specifically means: reducing false alarms caused by environmental interference or sensor noise.

6. The intelligent leakage warning flexible composite pipeline system according to claim 5, characterized in that The dynamic data correction algorithm specifically is: Among them, is the replacement data for the calculated abnormal data point , is the serial number of the abnormal data point is the offset variable.

7. A leakage warning method for an intelligent leakage warning flexible composite pipeline, which is applied to the intelligent leakage warning flexible composite pipeline system according to any one of claims 1-6, and is characterized in that, This method includes the following steps: S1: Configure a composite pipeline body, which includes a lining layer, a reinforcing layer, an inner protective layer, at least one insulating layer, and a distributed temperature sensing element integrated on the outer wall of the composite pipeline arranged in sequence; S2: Emitting a laser signal to the distributed temperature sensing element through an optical signal processing device; S3: Collecting Stokes light and anti-Stokes light in the reflected light through an optical signal processing device and converting them into temperature data; S4: The data processing unit analyzes the temperature distribution based on the temperature data. If an abnormal temperature is detected, calculate the temperature distribution along the pipeline and the leakage position, and issue an abnormal alarm.

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