Rapid detection method for oil and gas pipeline and device applying method

Abstract

The invention provides a rapid detection method for an oil and gas transmission pipeline, and relates to the technical field of pipeline detection, and the method comprises the following steps: S1, adjusting the projection angle of a pipeline off-ray detection device, enabling at least one beam of ray to be tangent to the inner wall of the pipeline, and enabling the tangent point to be positioned near the lowest point or the highest point of the inner wall of the pipeline; an included angle between a connecting line of the tangent point and the center of the pipeline and the vertical direction is not more than 5 degrees; s2, acquiring a ray irradiation image of the pipeline by using the detection equipment; and S3, judging whether deposition occurs in the pipeline or not based on the ray irradiation image. According to the formation characteristics of the sediments, the rapid detection of the in-service oil and gas transmission pipeline is completed by adopting the transillumination angles as few as possible, the method is particularly suitable for identifying the sediments which are non-uniformly distributed in the circumferential direction of the pipeline, and the existence of the sediments can be rapidly detected in the initial stage of the formation of the sediments. By discovering the sediments in time, prevention and treatment measures can be taken to prevent the sediments from influencing the operation of the pipeline.

Description

Technical Field

[0001] This invention relates to the field of pipeline inspection technology, and in particular to a rapid inspection method for oil and gas pipelines and an apparatus for applying this method. Background Technology

[0002] Using X-rays for external inspection of oil and gas pipelines can provide intuitive information about the pipeline's internal structure. Compared with traditional external inspection equipment, X-ray external inspection technology can be used to inspect composite pipes and pipes with surface deposits. It can accurately detect defects in the inner and outer walls of double-layer insulated pipes, wall thickness reduction, and water ingress in the inner and outer annular spaces. It can also determine whether the internal filling material of the pipeline is different, such as hydrates, wax, or asphalt.

[0003] However, in the early stages of sediment formation, it is difficult to detect sediments in pipelines using external inspection equipment due to their thinness. Furthermore, once sediment forms on the pipe walls, the pipe narrows, flow velocity decreases, and the friction coefficient increases, further exacerbating sediment accumulation. Therefore, early detection and treatment of sediments in their initial stages can reduce emergency maintenance and cleaning costs caused by pipeline blockages, improving oil and gas transportation efficiency. Asphalt deposits also accelerate pipeline corrosion; timely treatment of asphalt deposits can extend pipeline lifespan.

[0004] The formation of deposits within oil and gas pipelines is a complex process, influenced by temperature, pressure, flow velocity, flow regime, and the medium. Numerous studies have disclosed the patterns of deposit formation within oil and gas pipelines. For cases of circumferentially uniform deposition, this application is identical to existing technologies and will not affect the sensitivity of the detection.

[0005] For circumferentially non-uniform deposition, such as in the cases of stratified smooth flow and stratified wavy flow, hydrate deposition is as follows: Figure 1 (As shown in MNLINGELEM et al., "Industrial Experience in Evaluation of Hydrate Formation, Inhibition, and Dissociation in Pipeline Design and Operation"), FLOW represents the flow direction, Water represents water, and Hydrate represents hydrates. Figure 1 The cross-section of the leftmost pipe shows the morphology of the downstream side of the sediment, which is consistent with the morphology of the early stage of hydrate deposition.

[0006] Figure 2This is a hydrate mass concentration distribution diagram for the bend in Ren Zhongbo's master's thesis, "Study on the Deposition Characteristics of Natural Gas Hydrates in Gathering and Transmission Pipelines." The transported medium flows from left to right. There is more hydrate deposition on the inner side of the bend before entering the bend (the area in the left box of the diagram) and on the outer side of the bend after exiting the bend (the area in the right box of the diagram).

[0007] For wax deposition (wax formation), as reported by Ararimeh Aiyejina et al. in "Wax formation in oilpipelines: A critical review", such as... Figure 3 . Figure 3 The images show cross-sections of pipes with wax deposition under different flow regimes, from left to right: stratified smooth flow, stratified wavy flow, intermittent flow, and annular flow. It can be seen that for stratified smooth flow, similar to hydrate deposition, wax buildup begins at the bottom of the pipe. For stratified wavy flow, in addition to wax buildup starting at the bottom like in stratified smooth flow, a thicker wax deposit forms near the gas-liquid interface. For intermittent flow, the wax buildup at the top of the pipe is even thicker.

[0008] The situation is somewhat similar to that of asphalt deposits, but asphalt deposits begin to deposit at the interface between the liquid and oil phases; sand deposits, on the other hand, will only begin to deposit from the bottom of the pipe. Summary of the Invention

[0009] The main technical problem to be solved by the present invention is that when using external detection equipment to detect sediments in pipelines in the early stage of sediment formation, it is difficult to detect the sediments because the sediments are thin. In order to overcome the above-mentioned defects of the prior art, a rapid detection method for oil and gas pipelines and an apparatus for applying the method are provided.

[0010] The technical solution adopted by this invention to solve its technical problem is: A rapid inspection method for oil and gas transmission pipelines, comprising the following steps: S1. Adjust the projection angle of the pipeline X-ray external inspection equipment so that at least one beam of X-ray is tangent to the inner wall of the pipeline, and the tangent point is located near the lowest or highest point of the inner wall of the pipeline, and the angle between the line connecting the tangent point and the center of the pipeline and the vertical direction does not exceed 5°. S2. Obtain a radiation image of the pipeline using the detection equipment; S3. Determine whether deposition has occurred inside the pipe based on the X-ray irradiation image.

[0011] Furthermore, after acquiring the X-ray irradiation image, the method also includes: determining the position of the gas-liquid two-phase interface inside the pipeline through the image.

[0012] Furthermore, after determining the position of the gas-liquid interface, the process also includes: Based on the location of the gas-liquid two-phase interface, the projection angle of the pipeline X-ray external inspection equipment is adjusted to a predetermined angle; Adjust the projection angle of the pipeline X-ray external inspection equipment within a predetermined range to maximize the image contrast on both sides of the two-phase interface. At this point, the position of the horizontal ray is the actual position of the gas-liquid two-phase interface. The aforementioned predetermined range is -10° to 10°.

[0013] Furthermore, after determining the actual location of the gas-liquid interface, the process also includes: Adjust the projection angle of the pipeline X-ray external inspection equipment so that at least one beam of X-rays is tangent to the inner wall of the pipeline, and the tangent point is located at the intersection of the inner wall of the pipeline and the gas-liquid interface. Obtain the ray irradiation image at the corresponding location; Determine whether deposition has occurred at the intersection based on the image.

[0014] Furthermore, it also includes an oil-water interface detection step: Adjust the projection angle of the pipeline X-ray external inspection equipment so that at least one beam of X-ray coincides with the gas-liquid interface; Adjust the projection angle of the pipeline X-ray external inspection equipment so that at least one beam of X-ray is parallel to the gas-liquid interface, and the beam parallel to the gas-liquid interface gradually moves downward until the parallel beam reaches the lowest point of the inner wall of the pipeline under inspection, while acquiring the X-ray irradiation image. Determine whether the horizontal ray is located at the oil-water interface based on the acquired image.

[0015] Furthermore, after determining the location of the oil-water interface, the process also includes: Adjust the projection angle of the pipeline X-ray external inspection equipment so that at least one beam of X-rays is tangent to the inner wall of the pipeline, and the tangent point is located at the intersection of the inner wall of the pipeline and the oil-water interface. Obtain the ray irradiation image at the corresponding location, and determine whether deposition has occurred at the intersection based on the image.

[0016] Furthermore, when the object of inspection is a bent pipe, it also includes: Adjust the projection angle of the external X-ray inspection equipment for the pipeline so that at least one beam of X-rays is tangent to the inner wall of the pipeline and the beam is perpendicular to the turning plane of the bend. Acquire X-ray irradiation images and determine whether deposition has occurred based on the acquired images. The inner wall of the pipe is defined as: the pipe wall on the same side as the inner side of the bend before the bend enters the bend, and the pipe wall on the same side as the outer side of the bend after the bend exits the bend.

[0017] Furthermore, the method for determining whether deposition has occurred is at least one of the following: Compare the acquired X-ray irradiation image with the expected image, wherein the expected image is a historical detection image or an image obtained by theoretical calculation based on pipeline parameters and transport medium parameters; Compare X-ray images of different locations within the same pipe; Compare the data differences between sediments and adjacent transport medium regions in the same X-ray irradiation image.

[0018] A rapid detection device for oil and gas pipelines includes a controller, which controls the operation of the detection device and can automatically adjust the projection angle of the rapid detection device based on the pipeline weight, pipeline diameter, pipeline wall thickness and acquired images. The controller has a program that automatically identifies the interface positions of different substances, or the controller communicates with a computer that has the program.

[0019] Furthermore, it also includes a drive device for driving the detection device to travel axially along the pipeline.

[0020] The beneficial effects of this invention are: This invention, based on the characteristics of sediment formation, enables rapid detection of in-service oil and gas pipelines using minimal illumination angles. It is particularly suitable for identifying sediments with uneven circumferential distribution within pipelines, and can quickly detect their presence in the early stages of formation. Timely detection of sediments allows for preventative and remedial measures to prevent them from impacting pipeline operation. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] Figure 1 This is a schematic diagram illustrating the formation of hydrates in this invention; Figure 2 This is a schematic diagram of the hydrate mass concentration distribution in the bent pipe of the present invention; Figure 3 This is a schematic diagram of wax deposition in this invention; Figure 4 This is a schematic diagram illustrating the tangential detection of the bottom of a pipe according to the present invention; Figure 5 This is a schematic diagram illustrating the tangential detection of the top of a pipe according to the present invention; Figure 6 This is a schematic diagram of the tangential detection results at the bottom of the pipe according to the present invention; Figure 7 This is a schematic diagram of the tangential detection of sediments at the interface between two phases according to the present invention; Figure 8 This is a diagram of the interface detection of two phases according to the present invention.

[0023] Explanation of the labels in the diagram: 1. Radiation source; 2. Detector; 3. Radiation; 4. Sediment; 5. Pipeline. Detailed Implementation

[0024] The present invention will be further described below with reference to specific embodiments. The illustrative embodiments and descriptions herein are used to explain the present invention, but are not intended to limit the present invention.

[0025] Reference Figures 4-8 As shown, this invention discloses a rapid detection method for oil and gas transmission pipelines. For sediments 4 uniformly distributed along the circumference of the pipeline 5, there is no difference in imaging from different projection angles. However, for sediments 4 unevenly distributed along the circumference of the pipeline 5, due to the density differences between different types of sediments 4 and the transport medium, tangential ray detection technology with a specific projection angle can more sensitively identify the presence of sediments 4.

[0026] like Figure 4 The diagram illustrates a tangential inspection of the bottom of pipeline 5 using a rapid inspection device for oil and gas pipelines. The radiation source 1 can be an X-ray machine, accelerator, or isotope source; the detector 2 can be an array detector, a flat panel detector, or film. If a single-row array detector is used, only a single-section projection image of pipeline 5 can be obtained from one side of the radiograph. To obtain a 2D projection image of pipeline 5, the device needs to be moved gradually to acquire projection images at different locations. Radiation 3 is a beam tangential to the inner wall of the inspected pipeline 5, with the tangent point located at the lowest point of the inner wall. This beam passes horizontally through the pipe wall. The portion of the beam passing through the pipe wall below this point will generate a projection image of the pipe wall on the detector, while the remaining portion not passing through the pipe wall will generate a projection image of the remaining portion. This remaining portion can be air or water, and its influence on radiation 3 remains constant or negligible during the inspection of the same section of pipeline 5. In some embodiments, the beam does not strictly pass horizontally through the lowest point of the inner wall of pipeline 5, allowing for a deviation of ±5°. That is, at this time, at least one ray is tangent to the inner wall of pipe 5, and the tangent point is located near the highest point of the inner wall of pipe 5. The line connecting the tangent point and the center of pipe 5 makes an angle of no more than 5° with the vertical direction.

[0027] Deposits 4 are formed at the bottom of pipe 5. Since there is a density difference between these deposits 4 and the transport medium, it can be determined whether they are deposits 4 by X-ray imaging 3. As can be seen from the figure, the horizontal transmission thickness of this part of the deposits 4 will be the greatest. That is, the difference between X-ray 3 passing through this part of the deposits 4 and passing through the transport medium will be the greatest. In other words, the detection sensitivity will be the highest, and the presence of deposits 4 can be detected in the early stage of their formation.

[0028] Theoretically, the detection sensitivity will be highest when ray 3 is parallel to the upper surface of sediment 4. However, in actual measurement, the projection angle needs to be repeatedly adjusted to find the upper surface of sediment 4, which is very disadvantageous for rapid detection. In addition, the method of this application can also detect thicker sediment 4, but for thinner sediment 4, the theoretical projection angle and the projection angle of this application will be very close. In actual detection, it is not very meaningful to distinguish between these two angles.

[0029] Therefore, this application will use a more definite and practically operable projection angle for imaging. Figure 4 The image shown is a cross-section of the pipe 5 being inspected. The detection device determines the presence of sediment 4 by comparing the acquired image with a predicted image, or by comparing images of different locations along a section of pipe 5, or by comparing the sediment 4 in the same image with data from adjacent transported media. This determination process can be performed by an operator or automatically by a program embedded in the detection device. The predicted image can be historical data or obtained through theoretical calculations based on pipe 5 data and transported media data.

[0030] Similarly, for intermittent flow, the projection angle of ray source 1 needs to be adjusted to... Figure 5 As shown, the X-ray beam is tangent to the inner wall of the inspected pipe 5, with the tangent point located at the highest point of the inner wall of the pipe 5. This is beneficial for detecting the upper deposits 4.

[0031] For stratified wavy flow, the gas-liquid interface within pipe 5 is fluctuating; an intermediate value can be taken as the interface used in this application. During tangential detection of the top and bottom of pipe 5, the complete projection of pipe 5 at the detected location is simultaneously obtained. The position of the gas-liquid interface can be calculated using these detection image data. Figure 6 As shown, taking bottom tangential detection as an example, the left side is a schematic diagram of bottom tangential detection, and the right side shows the detector output data. Three obvious inflection points or extreme values ​​can be seen: A is the bottom pipe wall, B is the gas-liquid interface, and C is the projection of the pipe wall tangential to the X-ray beam at the upper right of pipe 5. The left pipe wall intersects with the gas-liquid interface; the angle between the line connecting the intersection point and the X-ray source focal point and the horizontal direction is β. The pipe inner diameter is r, and the distance from the X-ray source focal point to the pipe center is d. These parameters uniquely determine the height h of the gas-liquid interface, calculated using the following formula: h =( + ) Similarly, this method can also be used to determine the height of the interface between the other two phases, and then... Figure 7As shown, the sediment 4 at the interface between the two phases is detected tangentially. At this time, at least one beam of light is tangential to the inner wall of the pipe 5, and the tangent point is located at the intersection of the inner wall of the pipe 5 and the above-mentioned oil-liquid two-phase interface.

[0032] If accurate measurement of the interface between two phases is required, the projection angle of the detection device can be gradually adjusted near the possible interface height, for example, within the range of -10° to 10°. When at least one beam of light coincides with the interface between the two phases, such as... Figure 8 As shown, the lower part is water and the upper part is air. The detector can detect a very steep edge at this point. By differentiating this set of data, compared to other projection angles, this projection angle will produce a peak with the largest amplitude and narrowest width at this location. For the image, the contrast is greatest near both sides of this edge. If the density difference between the two phases is relatively small, such as crude oil and water, a peak with the largest amplitude and narrowest width can also be obtained.

[0033] For oil-gas-water mixed transport pipelines, the gas-liquid interface can be detected first. Then, the projection angle of the pipeline X-ray external inspection equipment is adjusted to ensure that at least one beam of light is parallel to the gas-liquid interface. The beam parallel to the gas-liquid interface is gradually moved downward until the parallel beam reaches the lowest point of the inner wall of the pipeline being inspected. At the same time, an image is acquired, and the horizontal beam is determined based on the acquired image to determine whether it is located at the oil-water interface.

[0034] In the case of bends, deposits tend to form on the pipe wall on the same side as the inner side of the bend before entering the bend, and on the pipe wall on the same side as the outer side of the bend after exiting the bend. Therefore, it is necessary to inspect the pipe wall. The inspection method is similar to that used for inspecting the pipe wall at the two-phase interface. When adjusting the projection angle of the inspection device, ensure that at least one beam of light is tangent to the inner wall of the pipe, and that this beam is perpendicular to the turning plane of the bend. In some embodiments, a deviation of + / - 5° is also permissible. In some embodiments, the length of the pipe wall inspected on the in-bend and out-of-bend sides does not exceed 20 times the pipe diameter.

[0035] In the above embodiments, after completing the projection angle adjustment and acquiring image data, it is necessary to determine whether deposition has occurred based on the acquired image.

[0036] This invention also proposes a rapid detection device for oil and gas pipelines, including a controller. The controller controls the operation of the detection device and has a resident processing program that can automatically determine the interface positions of different substances, including gas-liquid two-phase interfaces, oil-liquid two-phase interfaces, and the interface between sediment 4 and the transport medium. The controller can also communicate with a computer and complete the automatic determination of different substance interfaces through the corresponding program resident in the computer. Simultaneously, the controller can automatically adjust the projection angle of the rapid pipeline detection device based on the pipeline weight, pipeline diameter, pipeline wall thickness, and acquired images. In some embodiments, the detection device can also be equipped with a drive device to drive the detection device along the pipeline axis, thus achieving automatic and rapid detection.

[0037] This invention, based on the characteristics of sediment formation, enables rapid detection of in-service oil and gas pipelines using minimal illumination angles. It is particularly suitable for identifying sediments with uneven circumferential distribution within pipelines, and can quickly detect their presence in the early stages of formation. Timely detection of sediments allows for preventative and remedial measures to prevent them from impacting pipeline operation.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A rapid detection method for oil and gas transmission pipelines, characterized in that, Includes the following steps: S1. Adjust the projection angle of the pipeline X-ray external inspection equipment so that at least one beam of X-ray is tangent to the inner wall of the pipeline, and the tangent point is located near the lowest or highest point of the inner wall of the pipeline, and the angle between the line connecting the tangent point and the center of the pipeline and the vertical direction does not exceed 5°. S2. Obtain a radiation image of the pipeline using the detection equipment; S3. Determine whether deposition has occurred inside the pipe based on the X-ray irradiation image.

2. The rapid detection method for oil and gas transmission pipelines according to claim 1, characterized in that, After acquiring the X-ray irradiation image, the method further includes: determining the position of the gas-liquid interface within the pipeline based on the image.

3. The rapid detection method for oil and gas transmission pipelines according to claim 2, characterized in that, After determining the location of the gas-liquid interface, the process also includes: Based on the location of the gas-liquid two-phase interface, the projection angle of the pipeline X-ray external inspection equipment is adjusted to a predetermined angle; Adjust the projection angle of the pipeline X-ray external inspection equipment within a predetermined range to maximize the image contrast on both sides of the two-phase interface. At this point, the position of the horizontal ray is the actual position of the gas-liquid two-phase interface. The aforementioned predetermined range is -10° to 10°.

4. The rapid detection method for oil and gas transmission pipelines according to claim 3, characterized in that, After determining the actual location of the gas-liquid interface, the following steps are also included: Adjust the projection angle of the pipeline X-ray external inspection equipment so that at least one beam of X-rays is tangent to the inner wall of the pipeline, and the tangent point is located at the intersection of the inner wall of the pipeline and the gas-liquid interface. Obtain the ray irradiation image at the corresponding location; Determine whether deposition has occurred at the intersection based on the image.

5. The rapid detection method for oil and gas transmission pipelines according to claim 1, characterized in that, It also includes the oil-water interface detection step: Adjust the projection angle of the pipeline X-ray external inspection equipment so that at least one beam of X-ray coincides with the gas-liquid interface; Adjust the projection angle of the pipeline X-ray external inspection equipment so that at least one beam of X-ray is parallel to the gas-liquid interface, and the beam parallel to the gas-liquid interface gradually moves downward until the parallel beam reaches the lowest point of the inner wall of the pipeline under inspection, while acquiring the X-ray irradiation image. Determine whether the horizontal ray is located at the oil-water interface based on the acquired image.

6. The rapid detection method for oil and gas transmission pipelines according to claim 5, characterized in that, After determining the location of the oil-water interface, the following steps are also included: Adjust the projection angle of the pipeline X-ray external inspection equipment so that at least one beam of X-rays is tangent to the inner wall of the pipeline, and the tangent point is located at the intersection of the inner wall of the pipeline and the oil-water interface. Obtain the ray irradiation image at the corresponding location, and determine whether deposition has occurred at the intersection based on the image.

7. The rapid detection method for oil and gas transmission pipelines according to claim 1, characterized in that, When the object of inspection is a bent pipe, it also includes: Adjust the projection angle of the external X-ray inspection equipment for the pipeline so that at least one beam of X-rays is tangential to the inner wall of the pipeline and perpendicular to the turning plane of the bend. Acquire an X-ray irradiation image and determine whether deposition has occurred based on the acquired image. The inner wall of the pipe is defined as: the pipe wall on the same side as the inner side of the bend before the bend enters the bend, and the pipe wall on the same side as the outer side of the bend after the bend exits the bend.

8. A rapid detection method for oil and gas transmission pipelines according to any one of claims 1-7, characterized in that, The method for determining whether deposition has occurred is at least one of the following: Compare the acquired X-ray irradiation image with the expected image, wherein the expected image is a historical detection image or an image obtained by theoretical calculation based on pipeline parameters and transport medium parameters; Compare X-ray images of different locations within the same pipe; Compare the data differences between sediments and adjacent transport medium regions in the same X-ray irradiation image.

9. A rapid testing device for oil and gas pipelines, employing the rapid testing method for oil and gas pipelines as described in claim 8, characterized in that... Includes a controller for controlling the operation of the detection device. The controller can automatically adjust the projection angle of the rapid pipeline detection device based on the pipeline weight, pipeline diameter, pipeline wall thickness, and the acquired images. The controller has a program that automatically identifies the interface positions of different substances, or the controller communicates with a computer that has the program.

10. A rapid detection device for oil and gas pipelines according to claim 9, characterized in that, It also includes a drive unit for driving the detection device to travel axially along the pipe.

Images