Method for judging suspended span and burying conditions of subsea pipeline
By establishing a digital twin model of the submarine pipeline and calculating the axial force distribution map, the problem of suspended and buried detection of submarine pipelines is solved, high-precision detection and early warning are achieved, and cost and manpower and material consumption are reduced.
Patent Information
- Application Number
- CN202411882939.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-19
- Publication Date
- 2025-05-13
AI Technical Summary
The prior art is difficult to effectively detect and early warning of the suspended span and burial of subsea pipelines, especially when the seabed topography changes are small and costly.
By establishing a digital twin model of the submarine pipeline, combining marine soil geological parameters and pipeline engineering parameters, the axial force distribution chart and strain conditions of the pipeline are calculated, and the theoretical pipe flow distribution data is derived, and the existence of the suspended and buried sections is judged by comparing the actual pipe flow and the theoretical pipe flow.
High-precision detection and early warning of the suspended span and buried conditions of subsea pipelines is achieved, which reduces costs and improves detection efficiency, and can promptly detect potential hazards caused by seabed geological changes.
Smart Images
Figure CN119989591A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of submarine pipeline detection, and in particular relates to a method for judging whether a submarine pipeline is suspended or buried. Background Art
[0002] Deep-sea oil development platforms are far from the shore, so deep-sea pipelines are generally long. In deep-sea conditions, the construction and maintenance costs of pipelines are very high. Once a pipeline accident occurs, it will not only affect the normal production of oil and gas fields, but also cause marine environmental pollution and affect the national economic life of pipeline users, causing economic, environmental and social impacts.
[0003] Under the influence of deep ocean currents, especially when the seabed is locally scoured and the water erodes the sediments around the pipeline, forming a suspended span, the pipeline, as a slender structure, is very easy to produce structural deformation based on vortex-induced vibration, and vortex-induced vibration is an important factor that causes damage to submarine pipelines. At present, the measurement of suspended spans mainly relies on acoustic imaging technology by measuring ships, and sonar detection of the entire pipeline from the sea surface to the seabed is carried out to find the suspended span section. When the suspended span section is small, it is difficult to observe it from the sea surface with sonar because it is blocked by the pipeline, which poses a safety hazard. In addition to the risk of suspended spans, the seabed where the pipeline is laid has ups and downs and the marine soil is soft. The seabed may also cause landslides, causing the pipeline to be buried. The buried pipeline cannot release the internal force generated by thermal expansion by free deformation, which causes the internal force to accumulate and cause danger. Large-scale landslides are often accompanied by some earthquake processes, which are easy to find, but due to the depth of water, smaller landslides are difficult to observe when they occur. In short, the current means of detecting smaller seabed terrain changes are limited and costly, while the safety of pipelines is closely related to the constraints of the seabed on the pipelines, so corresponding detection methods need to be developed. Summary of the invention
[0004] The present invention aims to provide a method for determining whether a submarine pipeline is overhanging or buried, so as to determine whether a certain section of the submarine pipeline is overhanging or buried, so as to provide timely warning to deal with potential hazards.
[0005] The occurrence of pipe running is mainly due to the friction between the axial pipe and the soil. The suspended span section of the pipeline is not constrained by the soil and has no axial pipe-soil friction, so the deformation will increase, which will lead to an increase in the amount of pipe running; while the buried section of the pipeline, the pipe-soil friction will increase significantly, making it difficult to deform freely, which will lead to a significant decrease in deformation. During the circulation process, the effective axial force on the pipeline is the constrained friction between the pipe and the soil, and its magnitude is closely related to the friction coefficient. Slight changes in the geological conditions of the marine soil will affect the friction coefficient between the pipe and the soil. Therefore, this method can be used to deal with the dangers caused by small changes that are difficult to observe, and it has high accuracy and can detect the small suspended span and buried sections of the pipeline in a timely manner.
[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:
[0007] A method for determining whether a submarine pipeline is suspended or buried comprises the following steps:
[0008] Step 1: For the target submarine pipeline to be inspected, a digital twin model of the submarine pipeline is established based on its known engineering parameters such as the pipeline size and material parameter database A, the marine soil geological parameter database B along the pipeline, the number, type and location database C of pipeline joints, and the pipeline working load database D;
[0009] Step 2: According to the data of database D, the load on and off time, load size and temperature are obtained, and the temperature distribution of the pipeline is calculated in combination with database A. Database B is called to obtain the axial force distribution diagram of the pipeline. Database C is called as the boundary condition of the pipeline to adjust the axial force distribution to obtain the final axial force distribution diagram EAF;
[0010] Step 3: Use the EAF diagram obtained in step 2 to calculate the strain of the pipeline, and then deduce the theoretical pipe flow distribution data of the entire pipeline;
[0011] Step 4: Measure the actual pipe flow at each measuring point on the submarine pipeline and compare it with the theoretical pipe flow data obtained in step 3. Analyze and determine whether there are suspended spans and / or buried sections on the submarine pipeline and find the specific locations of the suspended spans and / or buried sections based on the errors.
[0012] In the above technical solution, step 4 is implemented according to the following steps:
[0013] Step 4.1: First, the entire submarine pipeline is preliminarily divided into several long sections to be tested, and the deformation of each section is measured to determine its actual pipeline running value;
[0014] Step 4.2: Compare the actual pipe running value of each pipe section obtained in step 4.1 with the corresponding theoretical pipe running value, and then preliminarily determine whether each pipe section has a suspended span or is buried;
[0015] If the actual pipe flow value of a pipe section is less than its theoretical pipe flow value, it is judged that there is a buried area on the pipe section; if the actual pipe flow value is greater than the theoretical pipe flow value, it is judged that there is a small suspended span section on the pipe section;
[0016] Step 4.3: For the pipe section with overhang or buried, further search for the specific location of the overhang or buried in the pipe section to determine the specific location of the overhang or buried.
[0017] In the above technical solution, for step 4.3, the following search method is adopted:
[0018] (a) First, the midpoint of the pipe section is selected, and the actual pipe flow values w1 and w2 of the two half sections from the beginning and end of the pipe section to the midpoint are measured respectively. Then, the actual pipe flow values w1′ and w2′ obtained by the established digital twin model are compared one by one to determine which half section of the pipe section has a difference.
[0019] (b) Then, for the half section with the difference, 48 measuring points are arranged on it to obtain 49 measuring sections, and 49 actual pipe flow values w3 are measured and obtained. Then, the actual pipe flow value w3 is compared with its corresponding theoretical pipe flow value w3′ to obtain a further difference section X;
[0020] (c) Based on the difference section X, a further detailed search is performed, and 8 detection points are arranged on it to obtain 9 pipe sections. The abnormal pipe section X' is finally determined through comparison.
[0021] In the above technical solution, for step 4.3, the following search method can also be used:
[0022] (a) A detection point is set every 500 meters on the pipe section, and the pipe flow values between adjacent detection points are measured and compared with the corresponding theoretical pipe flow values to obtain the difference section Y;
[0023] (b) 48 measuring points are arranged on the difference section Y to obtain 49 measuring sections, and 49 actual pipe flow values w4 are measured and obtained. The actual pipe flow values w4 are compared with the corresponding theoretical pipe flow values w4′ to obtain the difference section Y′;
[0024] (c) Based on the difference section Y', a detailed search is performed and 8 detection points are arranged on it to obtain 9 pipe sections. The abnormal pipe section Y" can be finally determined through comparison.
[0025] In the above technical solution, the theoretical pipe flow value is set to a range value, that is, the positive and negative deviations are set for the theoretical pipe flow value, and the actual pipe flow value is compared with the range value of the theoretical pipe flow value. If the actual pipe flow value is within the range, it indicates normal. If the actual pipe flow value is less than the lower limit value of the theoretical pipe flow range, it is judged that there is a buried area on the pipe section. If the actual pipe flow value is greater than the upper limit value of the theoretical pipe flow range, it is judged that there is an overhanging area on the pipe section.
[0026] The present invention has the following advantages and beneficial effects:
[0027] The present invention establishes a digital twin model of the pipeline, which can accurately calculate the pipeline axial force distribution diagram, use the pipeline axial force distribution diagram to calculate the strain occurring in the pipeline, and then deduce the theoretical pipe flow distribution data of the entire pipeline. In addition, the present invention arranges multiple detection points in the pipeline routing direction, measures the actual pipe flow of the pipeline, and compares it with the obtained theoretical pipe flow, and then analyzes and judges whether there are suspended spans and / or buried sections in the submarine pipeline based on the error. If the actual pipe flow value is less than the theoretical pipe flow value, it is judged that there is a buried area on the section of the pipeline; if the actual pipe flow value is greater than the theoretical pipe flow value, it is judged that there is a small suspended span section on the section of the pipeline. In addition, the present invention also designs a troubleshooting method that can find the specific location of the suspended span and / or buried section.
[0028] Different from the previous method of judging the seabed geology by only using engineering geophysical exploration and artificial submersible exploration, the present invention can observe the slight geological changes of the seabed along the pipeline, and can accurately find the changed seabed points, with a much higher degree of accuracy than the traditional method. At the same time, the present invention has a lower cost and less manpower and material consumption than the maintenance and use of traditional equipment. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Figure 1 It is a schematic diagram of the principle of the method for judging whether a submarine pipeline is suspended or buried according to the present invention.
[0030] For ordinary technicians in this field, other relevant drawings can be obtained based on the above drawings without any creative work. DETAILED DESCRIPTION
[0031] The technical solution of the present invention is further described below in conjunction with specific embodiments.
[0032] Embodiment 1
[0033] This embodiment provides a method for determining whether a submarine pipeline is suspended or buried, which specifically includes the following steps:
[0034] Step 1: For the target submarine pipeline to be inspected, a digital twin model of the submarine pipeline is established based on its known engineering parameters such as the pipeline size and material parameter database A, the marine soil geological parameter database B along the pipeline, the pipeline joint quantity, type and location database C, and the pipeline working load database D.
[0035] Step 2: Based on the data in database D, the load on and off time, load size and temperature can be obtained. The temperature distribution of the pipeline is calculated in combination with database A, and the axial force distribution diagram of the pipeline is obtained by calling database B. Database C is called as the boundary condition of the pipeline to adjust the axial force distribution to obtain the final axial force distribution diagram EAF (that is, the boundary conditions are used to calculate the force distribution along the pipeline using theoretical and numerical simulation methods to obtain the final axial force distribution diagram EAF).
[0036] Step 3: Use the EAF diagram obtained in step 2 to calculate the strain of the pipeline, and then deduce the theoretical pipe flow distribution data of the entire pipeline.
[0037] Step 4: Measure the actual pipe flow at each measuring point on the submarine pipeline and compare it with the theoretical pipe flow data obtained in step 3. Analyze and determine whether there are suspended spans and / or buried sections on the submarine pipeline and find the specific locations of the suspended spans and / or buried sections based on the errors.
[0038] Specifically, step 4 is implemented as follows:
[0039] Step 4.1: First, the entire submarine pipeline is preliminarily divided into several long sections to be tested. The sections can be divided into equal lengths or unequal lengths. For example, the sections can be divided into three sections, namely: near-shore section AB (preferably 1000 meters long), routing section BC and near-platform section CD (preferably 1000 meters long); then, the deformation of each divided section is measured to determine its actual pipe routing value.
[0040] Step 4.2: Compare the actual pipe flow value of each pipe section obtained in step 4.1 with the corresponding theoretical pipe flow value, and then preliminarily determine whether each pipe section has a cantilever span or is buried.
[0041] If the actual flow rate of a pipe section is less than its theoretical flow rate (see Appendix Figure 1 For a pipe section AB, point C1 in the figure is the theoretical pipe flow of measuring point C. If point C2 is the actual pipe flow of measuring point C, it can be seen that C2 is less than C1), which means that the actual pipe flow of the pipe section is small and the restrained friction force is large, indicating that a small landslide has occurred, that is, it is judged that there is a buried area on the pipe section; if the actual pipe flow value is greater than the theoretical pipe flow value (see Appendix Figure 1In the figure, point C1 is the theoretical pipe flow of measuring point C. If point C3 is the actual pipe flow of measuring point C, it can be seen that C3 is greater than C1), which means that the actual pipe flow of this pipe section is large and the constrained friction force is small. It is judged that there is a small cantilever section on this pipe section.
[0042] It should be noted that, in actual implementation, the theoretical pipe routing value can be set to a range value, that is, the positive and negative deviations are set for the theoretical pipe routing value, and the actual pipe routing value is compared with the range value of the theoretical pipe routing value. If the actual pipe routing value is within the range, it indicates normal (that is, there is no overhanging section or burial). If the actual pipe routing value is less than the lower limit value of the theoretical pipe routing range, it is judged that there is a buried area on the pipe section. If the actual pipe routing value is greater than the upper limit value of the theoretical pipe routing range, it is judged that there is an overhanging area on the pipe section.
[0043] Step 4.3: For the pipe section with overhang or buried, further search for the specific location of the overhang or buried in the pipe section to determine the specific location of the overhang or buried.
[0044] For this step, this embodiment designs the following two search methods:
[0045] The first search method is:
[0046] (a) First, the midpoint of the pipe section is selected, and the actual pipe flow values w1 and w2 of the two half sections from the head and tail ends of the pipe section to the midpoint are measured respectively. Then, they are compared one by one with the corresponding theoretical pipe flow values w1′ and w2′ obtained by the established digital twin model to determine which half section of the pipe section has a difference.
[0047] (b) Then, for the half section with the difference, 48 measuring points are arranged on it to obtain 49 measuring sections, and 49 actual pipe flow values w3 are measured to obtain. The actual pipe flow value w3 is then compared with its corresponding theoretical pipe flow value w3′ to obtain a further difference section X.
[0048] (c) Based on the difference segment X, a further detailed search is performed, and 8 detection points are arranged on it to obtain 9 pipe segments. The abnormal pipe segment is finally determined by comparison and recorded as X'.
[0049] The second search method is:
[0050] (a) A detection point is set every 500 meters on the pipe section, and the pipe flow values between adjacent detection points are measured and compared with the corresponding theoretical pipe flow values to obtain the difference section Y.
[0051] (b) 48 measuring points are arranged on the difference section Y to obtain 49 measuring sections, and 49 actual pipe flow values w4 are measured and obtained. The actual pipe flow values w4 are compared with the corresponding theoretical pipe flow values w4′ to obtain the difference section Y′.
[0052] (c) Based on the difference section Y', a detailed search is performed and 8 detection points are arranged on it to obtain 9 pipe sections. The abnormal pipe section Y" can be finally determined through comparison.
[0053] Embodiment 2
[0054] This embodiment provides a pipe flow measurement system, which is used to implement step 4 of the above-mentioned embodiment 1, to measure the actual pipe flow value of the pipeline in real time, and can measure the distance change between specific detection points.
[0055] Parallel to the pipeline routing direction, multi-beam and side-scan sonar survey lines (Zi) are laid out. Perpendicular to the pipeline routing direction, a transverse survey line (SBPi) is laid out. Inspection points are arranged where the two survey lines intersect on the pipeline. The distances between the inspection points are measured in real time to obtain the pipe flow values between the inspection points.
[0056] Embodiment 3
[0057] This embodiment also provides a pipe flow measurement system, which is used to implement step 4 of the above embodiment 1 to measure the actual pipe flow value of the pipeline in real time, and can measure the distance change between specific detection points.
[0058] This embodiment adopts the sliding rheostat measurement principle, regards the pipeline as a large resistor, selects a point on the marine soil as the location of the slider, and when the pipeline breaks, the resistance of the detection circuit will change, and the pipeline breaking value is calculated by judging the size of the connected resistance.
[0059] According to the above principle, multiple cut-off points are set on the submarine pipeline to form multiple sliding rheostats. A slider is set on each sliding rheostat as a detection point. Each sliding rheostat is connected to the detection circuit. When the pipeline breaks, the resistance of the detection circuit will change. The value of the pipeline breaking at each detection point is calculated by judging the size of the resistance.
[0060] Embodiment 4
[0061] This embodiment also provides a pipe flow measurement system, which is used to implement step 4 of the above embodiment 1 to measure the actual pipe flow value of the pipeline in real time, and can measure the distance change between specific detection points.
[0062] In this embodiment, a fixed measuring point is set on the seabed to keep the position of the fixed measuring point relative to the earth unchanged. A hammering device is set at the fixed measuring point to hammer the pipeline so that the pipeline generates vibration waves that propagate along the pipeline; and a plurality of detection sensors are installed on the pipe wall of the pipeline at intervals along the length direction of the pipeline, each detection sensor serves as a detection point, and the detection sensor is used to detect the vibration wave signal generated after hammering the pipeline and has a timing function; the hammering device and all the detection sensors are connected to a control and information processing system through a signal transmission line, and the control and information processing system is used to control the operation of the hammering device and each detection sensor, as well as to receive data from each detection sensor and analyze and process the data.
[0063] During measurement, the control and information processing system sends a start measurement command to the hammer device at the fixed measuring point and all the detection sensors through the signal transmission line; the hammer device starts after receiving the start measurement command and hammers the pipeline; the detection sensor starts timing after receiving the start measurement command; then, the vibration wave signal generated after hammering the pipeline is detected in real time by each detection sensor. When the detection sensor detects the vibration wave signal, it stops its own timing. At this time, the time recorded by it represents the transmission time of the vibration wave from the fixed measuring point to the current detection sensor detection point, and the timing time data is fed back to the control and information processing system through the signal transmission line; the control and information processing system calculates the distance value between each detection point of the pipeline and the fixed measuring point in this measurement according to the timing time data fed back by each detection sensor and the known propagation speed of the vibration wave in the submarine pipeline, and then calculates the distance change between the detection points, that is, the pipe running value.
[0064] The above description is only used to illustrate the present invention, and is not intended to limit the present invention to the structure and scope of use shown and described. Therefore, all corresponding modifications and equivalents made within the spirit and principle of the present invention belong to the patent scope applied for by the present invention.
Claims
1. A method for determining whether a submarine pipeline is suspended or buried, characterized in that: The following steps are involved: Step 1: For the target submarine pipeline to be inspected, a digital twin model of the submarine pipeline is established based on its known engineering parameters such as the pipeline size and material parameter database A, the marine soil geological parameter database B along the pipeline, the number, type and location database C of pipeline joints, and the pipeline working load database D; Step 2: According to the data of database D, the load on and off time, load size and temperature are obtained, and the temperature distribution of the pipeline is calculated in combination with database A. Database B is called to obtain the axial force distribution diagram of the pipeline. Database C is called as the boundary condition of the pipeline to adjust the axial force distribution to obtain the final axial force distribution diagram EAF; Step 3: Use the EAF diagram obtained in step 2 to calculate the strain of the pipeline, and then deduce the theoretical pipe flow distribution data of the entire pipeline; Step 4: Measure the actual pipe flow at each measuring point on the submarine pipeline and compare it with the theoretical pipe flow data obtained in step 3. Analyze and determine whether there are suspended spans and / or buried sections on the submarine pipeline and find the specific locations of the suspended spans and / or buried sections based on the errors.
2. The method for determining whether a submarine pipeline is suspended or buried according to claim 1 is characterized in that: Step 4 is implemented as follows: Step 4.1: First, the entire submarine pipeline is preliminarily divided into several long sections to be tested, and the deformation of each section is measured to determine its actual pipeline running value; Step 4.2: Compare the actual pipe running value of each pipe section obtained in step 4.1 with the corresponding theoretical pipe running value, and then preliminarily determine whether each pipe section has a suspended span or is buried; If the actual pipe flow value of a pipe section is less than its theoretical pipe flow value, it is determined that there is a buried area on the pipe section; If the actual pipe running value is greater than the theoretical pipe running value, it is judged that there is a small suspended span section on the pipe section; Step 4.3: For the pipe section with overhang or buried, further search for the specific location of the overhang or buried in the pipe section to determine the specific location of the overhang or buried.
3. The method for determining whether a submarine pipeline is suspended or buried according to claim 2 is characterized in that: For step 4.3, use the following search method: (a) First, the midpoint of the pipe section is selected, and the actual pipe flow values w1 and w2 of the two half sections from the beginning and end of the pipe section to the midpoint are measured respectively. Then, the actual pipe flow values w1′ and w2′ obtained by the established digital twin model are compared one by one to determine which half section of the pipe section has a difference. (b) Then, for the half section with the difference, 48 measuring points are arranged on it to obtain 49 measuring sections, and 49 actual pipe flow values w3 are measured and obtained. Then, the actual pipe flow value w3 is compared with its corresponding theoretical pipe flow value w3′ to obtain a further difference section X; (c) Based on the difference section X, a further detailed search is performed, and 8 detection points are arranged on it to obtain 9 pipe sections. The abnormal pipe section X' is finally determined through comparison.
4. The method for determining whether a submarine pipeline is suspended or buried according to claim 2 is characterized in that: For step 4.3, use the following search method: (a) A detection point is set every 500 meters on the pipe section, and the pipe flow values between adjacent detection points are measured and compared with the corresponding theoretical pipe flow values to obtain the difference section Y; (b) 48 measuring points are arranged on the difference section Y to obtain 49 measuring sections, and 49 actual pipe flow values w4 are measured and obtained. The actual pipe flow values w4 are compared with the corresponding theoretical pipe flow values w4′ to obtain the difference section Y′; (c) Based on the difference section Y', a detailed search is performed and 8 detection points are arranged on it to obtain 9 pipe sections. The abnormal pipe section Y" can be finally determined through comparison.
5. The method for determining whether a submarine pipeline is suspended or buried according to claim 1 is characterized in that: The theoretical pipe flow value is set to a range value, that is, the positive and negative deviations are set for the theoretical pipe flow value, and the actual pipe flow value is compared with the range value of the theoretical pipe flow value. If the actual pipe flow value is within the range, it indicates normal. If the actual pipe flow value is less than the lower limit value of the theoretical pipe flow range, it is judged that there is a buried area on the pipe section. If the actual pipe flow value is greater than the upper limit value of the theoretical pipe flow range, it is judged that there is a suspended span area on the pipe section.