Pipeline hydrate flow monitoring method and system based on image gray level change

Abstract

The invention relates to a pipeline hydrate flow monitoring method and system based on image gray level change, and the method comprises the steps: obtaining and preprocessing a fluid image in a pipeline section, and obtaining a gray level value of the image; determining the size and the number of hydrate particles in the image by using scattered light intensity information reflected by a gray level numerical value; determining the growth and deposition dynamic state of the hydrate by using the gray level numerical value change of a plurality of continuous images in a set time period, and determining corresponding early warning and treatment measures; wherein the growth and deposition dynamic state of the hydrate is determined, specifically, the gray level numerical value is kept in a set range, and no hydrate is generated in the pipeline in the current time period; when the rising variation of the gray level numerical value exceeds a set value, hydrate nucleation begins in the pipeline in the current time period, and the volume of hydrate particles is gradually increased; the gray level value has a descending trend after the ascending trend, and the hydrate in the current time period in the pipeline begins to deposit on the wall surface of the pipeline.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline fluid safety assurance, and in particular to a pipeline hydrate flow monitoring method and system based on image grayscale changes. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Since deepwater long-distance pipelines are located in an extreme environment of high pressure and low temperature, hydrates are often easily generated in the pipelines during production and transportation. The accumulation of hydrates can easily lead to pipeline blockage, posing a serious threat to normal production and transportation.

[0004] For example, in a pipeline transporting liquid natural gas, natural gas hydrates gradually accumulate on the pipe wall, reducing the cross-sectional area of ​​the pipeline and eventually blocking the pipeline.

[0005] Since the inside of the pipeline is a closed environment, on-site personnel cannot directly monitor and judge the formation and growth of hydrates in the pipeline;

[0006] Secondly, once hydrates are generated, untimely treatment measures will lead to continuous hydrate deposition, eventually resulting in pipeline blockage. However, there is currently a lack of feedback methods that can provide real-time information on the hydrate deposition stage.

[0007] In addition, in the early stage of hydrate nucleation, a small amount of hydrate particles often does not bring about a large change in pressure drop. When the pressure drop changes significantly, it often means that the pipeline has been severely blocked by hydrates, resulting in the fact that monitoring hydrates in the pipeline by pressure changes cannot meet actual needs. Summary of the invention

[0008] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a pipeline hydrate flow monitoring method and system based on image grayscale changes, which can directly identify and monitor the hydrate generation and growth in the pipeline, especially for tiny hydrate particles in the early stage of hydrate nucleation. This method can effectively identify the growth of tiny hydrate particles. It can provide guidance and risk assessment for on-site hydrate prevention and control work.

[0009] In order to achieve the above object, the present invention adopts the following technical solution:

[0010] A first aspect of the present invention provides a pipeline hydrate flow monitoring method based on image grayscale changes, comprising the following steps:

[0011] Obtaining and preprocessing the fluid image in the pipe section to obtain the grayscale value of the image;

[0012] The scattered light intensity information reflected by the grayscale value is used to determine the size and number of hydrate particles in the image;

[0013] By using the grayscale value changes of multiple consecutive images within a set time period, the growth and deposition dynamics of hydrates can be determined, the changes in the size and quantity of hydrate particles can be obtained, and the corresponding early warning and control measures can be determined;

[0014] Among them, the growth and deposition dynamics of hydrates are determined by using the grayscale value changes of multiple consecutive images within a set time period, specifically:

[0015] The grayscale value remains within the set range, and no hydrate is generated in the pipeline during the current time period;

[0016] When the gray level value rises and changes more than the set value, hydrate nucleation begins in the pipeline in the current time period, and the volume of hydrate particles gradually increases;

[0017] The grayscale value shows a downward trend after an upward trend, and the hydrate in the pipeline in the current time period begins to deposit on the pipeline wall.

[0018] Furthermore, an image acquisition module is used to acquire the fluid image in the pipe section. The image acquisition module is arranged on the inner wall of the pipe and faces in a direction opposite to the fluid flow direction. The module is used to acquire the fluid image in the pipe section in the direction facing the fluid.

[0019] Furthermore, a backlight method is used to obtain the fluid image in the pipe cross section.

[0020] Furthermore, the grayscale value remains within the set range, and no hydrate is generated in the pipeline during the current time period, and no control measures are required.

[0021] Further, the setting range is 0%-0.5%.

[0022] Furthermore, when the rising change of the gray level value exceeds the set value, hydrate nucleation begins in the pipeline in the current time period, and the corresponding early warning and control measures are: issuing an early warning and adding a hydrate kinetic inhibitor or an anti-agglomeration agent to prevent further blockage of the pipeline.

[0023] Furthermore, the grayscale value shows a downward trend after an upward trend, and the hydrate in the pipeline in the current time period begins to deposit on the pipeline wall. The corresponding early warning and control measures are: issuing a warning and taking the pressure reduction method to remove the hydrate blockage.

[0024] A second aspect of the present invention provides a pipeline hydrate flow monitoring system based on image grayscale changes, comprising:

[0025] An image acquisition module is used to acquire and preprocess the fluid image in the pipe section to obtain the grayscale value of the image;

[0026] The image processing module is configured to: determine the size and quantity of hydrate particles in the image using scattered light intensity information reflected by grayscale values;

[0027] The fluid monitoring module is configured to: determine the growth and deposition dynamics of hydrates by using the grayscale value changes of multiple consecutive images within a set time period, obtain the changes in the size and number of hydrate particles, and determine corresponding early warning and control measures.

[0028] Furthermore, the image acquisition module is immersed in the fluid.

[0029] Furthermore, during the period when the image acquisition module acquires the fluid image, the light emitted by the light source passes through the fluid in the pipe and enters the image acquisition module, thereby acquiring the fluid image in the pipe cross section in a backlight manner.

[0030] Compared with the prior art, one or more of the above technical solutions have the following beneficial effects:

[0031] Grayscale processing is performed on the image information showing the fluid, and the hydrate formation and growth in the pipeline can be monitored and analyzed according to the grayscale change trend. Since the intensity of scattered light is related to the particle size and number during the hydrate formation period, the more particles there are and the larger the apparent volume, the stronger the scattered light will be, and the higher the image grayscale value will be. Conversely, if the number of particles decreases or the volume decreases, the scattered light intensity decreases, resulting in a decrease in the image grayscale value. By analyzing the intensity of scattered light with grayscale numerical values, information about the particle size and number can be obtained to determine the growth stage of the hydrate, and then the risk of pipeline blockage can be judged, realizing the monitoring and judgment of hydrate growth based on the law of image grayscale numerical changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0033] Figure 1 It is a schematic diagram of a pipeline hydrate flow monitoring process based on image grayscale changes provided by one or more embodiments of the present invention. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0035] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0036] It should be noted that the terms herein are only intended to describe specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0037] Terminology explanation:

[0038] Grayscale refers to the brightness information of each pixel in the image. In a grayscale image, the brightness value of a pixel is usually represented by an integer between 0 and 255, where 0 represents black, 255 represents white, and the values ​​in between represent different shades of gray.

[0039] Grayscale value refers to the number of possible gray levels in an image. For example, if the image is 8-bit, then the grayscale value is 256 (from 0 to 255). Grayscale value is actually a quantitative description of grayscale value. Grayscale value does not directly indicate the brightness of a pixel, but describes the fineness of the grayscale that can be distinguished in the image.

[0040] Grayscale values ​​are specific and describe the brightness of each pixel in the image. Grayscale values ​​are overall and describe the range or number of gray levels in the image. The two concepts are different but related in image processing. Grayscale values ​​determine the number of gray tones that can be distinguished in the image, while grayscale values ​​are the specific manifestations of these gray tones in the image.

[0041] The inside of the pipeline is a closed environment, and on-site personnel cannot directly monitor and judge the formation and growth of hydrates in the pipeline. It takes a long time for hydrates to gradually develop from the initial nucleation stage to the state of blocking the pipeline. If the pressure change is monitored to identify the impact of hydrates on the flow of pipeline fluid, there will be a certain delay problem. In the early stage of hydrate nucleation, a small amount of hydrate particles often does not bring about a large pressure drop change, but when the pressure drop changes significantly, it often means that the pipeline has been severely blocked by hydrates.

[0042] In the field of image vision, the grayscale indicates the maximum number of different grayscale values ​​in the image. The larger the grayscale, the larger the brightness range of the image, which is the difference in pixel sensitivity and reflects the brightness level of the image. Therefore, the following embodiments provide a pipeline hydrate flow monitoring method and system based on image grayscale changes. The image acquisition module performs grayscale processing on the transmitted image information of the internal situation of the pipeline fluid. According to the grayscale change trend, the hydrate generation and growth in the pipeline are monitored and analyzed, the hydrate growth stage is determined, and the pipeline blockage risk is judged, and finally the monitoring and judgment method of hydrate growth based on the law of image grayscale value change is realized. It can directly identify and monitor the hydrate generation and growth in the pipeline, especially for tiny hydrate particles in the early stage of hydrate nucleation. This method can effectively identify the growth of tiny hydrate particles. It can provide guidance and risk assessment for on-site hydrate prevention and control work.

[0043] Embodiment 1:

[0044] like Figure 1 As shown, the pipeline hydrate flow monitoring method based on image grayscale change includes the following steps:

[0045] Obtaining and preprocessing the fluid image in the pipe section to obtain the grayscale value of the image;

[0046] The scattered light intensity information reflected by the grayscale value is used to determine the size and number of hydrate particles in the image;

[0047] By using the grayscale value changes of multiple consecutive images within a set time period, the growth and deposition dynamics of hydrates can be determined, the changes in the size and quantity of hydrate particles can be obtained, and the corresponding early warning and control measures can be determined;

[0048] Among them, the growth and deposition dynamics of hydrates are determined by using the grayscale value changes of multiple consecutive images within a set time period, specifically:

[0049] The grayscale value remains within the range of 0%-0.5%, and no hydrate is generated in the pipeline during the current period, and no control measures are required;

[0050] When the gray level value rises and changes more than the set value, hydrate nucleation begins in the pipeline in the current time period, and the volume of hydrate particles gradually increases;

[0051] The grayscale value shows a downward trend after an upward trend, and the hydrate in the pipeline in the current time period begins to deposit on the pipeline wall.

[0052] In step 1, the image acquisition module device is installed and arranged at the nodes along the pipeline. The device probe is inside the pipeline, and the optimal position of the probe is on the inner wall of the pipeline. The direction is opposite to the flow direction of the fluid, which is used to obtain the fluid image on the pipeline cross section in the direction of the fluid.

[0053] In this embodiment, the image acquisition module can be a camera or a video camera, and any normal shooting and recording device used under high or low pressure conditions can be selected, and embedded in the inner wall of the pipe or inserted from the outside by welding. And the image acquisition end needs to be completely immersed in the fluid to realize the monitoring of the inside of the fluid.

[0054] In step 2, the image is recorded in real time through the image acquisition module, where the light source adopts backlight shooting mode, because if direct light shooting is adopted, the light directly shines on the surface of the sample, which may cause strong reflected light, making the boundaries between particles unclear and difficult to distinguish individual particles, affecting the quality of the image and the accuracy of the analysis. The light of backlight shooting will pass through the back of the sample, which can clearly show the outline and size of the particles, provide a higher contrast, and help improve the accuracy of image edge detection, which is very important for identifying and judging the number and size of particles based on the grayscale of the image. Using backlight shooting facilitates grayscale recognition and subsequent data processing through image analysis software.

[0055] In step 3, the image file transmitted by the image acquisition module is analyzed in real time in grayscale. Since the light signal received by the image acquisition module is the result of the superposition of multiple scattered or reflected photons, the intensity of the scattered light is related to the size and number of the particles under backlight shooting. The more particles there are and the larger the apparent volume, the stronger the scattered light, so the grayscale value of the image will be higher. Conversely, if the number of particles in the fluid decreases or the volume decreases, the intensity of the scattered light decreases, resulting in a decrease in the grayscale value of the image. By analyzing the intensity of the scattered light by grayscale numerical value, information about the size and number of particles can be obtained.

[0056] In this embodiment, there is no clear relationship equation between the grayscale value and the size and number of hydrate particles, but the grayscale of the image reflects the overall situation of the hydrate particles, that is, the total volume of the hydrate particles reflected by the size and number of the hydrate particles. In other words, the change in grayscale is a manifestation of the overall change in the size and number of the hydrate particles.

[0057] Therefore, this embodiment only needs to analyze the changing trend of the overall situation of hydrates through grayscale changes, and does not need to separately process specific parameters such as particle size and quantity. Here, the main consideration is to judge the overall generation of hydrates through grayscale changes.

[0058] In step 4, the hydrate growth and deposition dynamics in the pipeline are analyzed through the grayscale changes of the image file.

[0059] When there is no hydrate formation in the pipeline, the gray level of the image will fluctuate around 0-0.5%. The reason for the fluctuation is that the bubbles in the fluid will also generate scattered light, which in turn causes the gray level to change, but the impact of this value is extremely small and can be ignored;

[0060] When hydrate particles appear in the fluid, the grayscale value will increase significantly (for example, the grayscale no longer fluctuates between 0-0.5%, but significantly exceeds 0.5%), and will continue to increase as the number of hydrate particles in the pipeline increases;

[0061] When the hydrate concentration in the pipeline is large enough and there is a tendency for wall deposition, the grayscale value will show a downward trend.

[0062] In step 5, different hydrate early warning and control measures need to be taken according to the gray level change stage in step 4.

[0063] In the gray level rising stage, the change trend indicates the rapid nucleation and growth of hydrate particles in the fluid. At this time, it is necessary to add a hydrate kinetic inhibitor or an anti-agglomeration agent to ensure good fluidity of the fluid and prevent further blockage of the pipeline. In this embodiment, the dosage of the kinetic inhibitor and the anti-agglomeration agent is generally between 0% and 1%.

[0064] When the gray level shows a downward trend, it indicates that the fluidity of the fluid is weakened, and the hydrate slurry will further form sedimentation and blockage. At this time, it is necessary to reduce the pressure to remove the hydrate blockage.

[0065] In this embodiment, "taking the approach of reducing pressure" specifically means: reducing the pressure to below the hydrate phase equilibrium pressure under the current pipeline ambient temperature conditions. The hydrate phase equilibrium calculation formula here can adopt any equation that can calculate phase equilibrium, such as the Chen-Guo equation, etc. The main purpose is to reduce the pipeline pressure to below the phase equilibrium pressure to ensure the decomposition of hydrates. Therefore, the pressure reduction range can be below the phase equilibrium pressure.

[0066] Embodiment 2:

[0067] like Figure 1 As shown, the pipeline hydrate flow monitoring system based on image grayscale change includes:

[0068] An image acquisition module is used to acquire and preprocess the fluid image in the pipe section to obtain the grayscale value of the image;

[0069] The image processing module is configured to: determine the size and quantity of hydrate particles in the image using scattered light intensity information reflected by grayscale values;

[0070] The fluid monitoring module is configured to: determine the growth and deposition dynamics of hydrates by using the grayscale value changes of multiple consecutive images within a set time period, obtain the changes in the size and number of hydrate particles, and determine corresponding early warning and control measures.

[0071] Furthermore, the image acquisition module is immersed in the fluid.

[0072] Furthermore, during the period when the image acquisition module acquires the fluid image, the light emitted by the light source passes through the fluid in the pipe and enters the image acquisition module, thereby acquiring the fluid image in the pipe cross section in a backlight manner.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A pipeline hydrate flow monitoring method based on image grayscale changes, characterized in that: The following steps are involved: Obtaining and preprocessing the fluid image in the pipe section to obtain the grayscale value of the image; The scattered light intensity information reflected by the grayscale value is used to determine the size and number of hydrate particles in the image; By using the grayscale value changes of multiple consecutive images within a set time period, the growth and deposition dynamics of hydrates can be determined, the changes in the size and quantity of hydrate particles can be obtained, and the corresponding early warning and control measures can be determined; Among them, the growth and deposition dynamics of hydrates are determined by using the grayscale value changes of multiple consecutive images within a set time period, specifically: The grayscale value remains within the set range, and no hydrate is generated in the pipeline during the current time period; When the gray level value rises and changes more than the set value, hydrate nucleation begins in the pipeline in the current time period, and the volume of hydrate particles gradually increases; The grayscale value shows a downward trend after an upward trend, and the hydrate in the pipeline in the current time period begins to deposit on the pipeline wall.

2. The pipeline hydrate flow monitoring method based on image grayscale change according to claim 1, characterized in that: The image acquisition module is used to acquire the fluid image in the pipe section. The image acquisition module is arranged on the inner wall of the pipe and faces in the opposite direction of the fluid flow direction. It is used to acquire the fluid image in the pipe section in the direction facing the fluid.

3. The pipeline hydrate flow monitoring method based on image grayscale change according to claim 1, characterized in that: The backlight method is used to obtain the fluid image in the pipe section.

4. The pipeline hydrate flow monitoring method based on image grayscale change according to claim 1, characterized in that: The grayscale value remains within the set range, and no hydrate is generated in the pipeline during the current period, so no control measures are required.

5. The pipeline hydrate flow monitoring method based on image grayscale change according to claim 1, characterized in that: The setting range is 0%-0.5%.

6. The pipeline hydrate flow monitoring method based on image grayscale change according to claim 1, characterized in that: When the rising change of the gray level value exceeds the set value, hydrate nucleation begins in the pipeline in the current time period. The corresponding early warning and control measures are: issuing an early warning and adding a hydrate kinetic inhibitor or an anti-agglomeration agent to prevent further blockage of the pipeline.

7. The pipeline hydrate flow monitoring method based on image grayscale change according to claim 1, characterized in that: The grayscale value shows a downward trend after an upward trend. The hydrate in the pipeline in the current time period begins to deposit on the pipeline wall. The corresponding early warning and control measures are: issue a warning and take the pressure reduction method to remove the hydrate blockage.

8. A pipeline hydrate flow monitoring system based on image grayscale changes, used to implement the method described in any one of claims 1 to 7, characterized in that: include: An image acquisition module is used to acquire and preprocess the fluid image in the pipe section to obtain the grayscale value of the image; The image processing module is configured to: determine the size and quantity of hydrate particles in the image using scattered light intensity information reflected by grayscale values; The fluid monitoring module is configured to: determine the growth and deposition dynamics of hydrates by using the grayscale value changes of multiple consecutive images within a set time period, obtain the changes in the size and number of hydrate particles, and determine corresponding early warning and control measures.

9. The pipeline hydrate flow monitoring system based on image grayscale change according to claim 1, characterized in that: The image acquisition module is immersed in the fluid.

10. The pipeline hydrate flow monitoring system based on image grayscale change according to claim 1, characterized in that: When the image acquisition module acquires the fluid image, the light emitted by the light source passes through the fluid in the pipe and enters the image acquisition module, thereby acquiring the fluid image in the pipe cross section in a backlight manner.

Images