An X-ray backscatter detection device for defect inspection in pipelines

Abstract

The present invention relates to an X-ray backscatter detection device for inspecting defects in pipelines. The device is positioned at the center of the pipeline and is scanned in a spiral manner inside the pipeline. The device includes an X-ray backscatter detection scanning head, a control and cooling device, a power supply and a driving device. The X-ray backscatter detection scanning head includes a main shaft. A ray source chamber is provided on the scanning head main shaft. The ray source chamber is used to place a radiation source. The ray source is used to generate radiation that can provide sufficient penetration for imaging. The ray backscatter detection scanning head also includes a beam collimator that can rotate around the scanning main shaft, which is used to modulate the radiation leaving the source chamber into a plurality of pencil-shaped beams. And multiple groups of detectors that can rotate around the scanning main shaft are used to detect X-rays backscattered by the pipe wall. The X-ray backscatter detection device for inspecting defects in pipelines of the present invention can realize comprehensive detection of various defects, and can be used in harsh environments and detection tasks where the source and the detector need to be arranged on one side.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear radiation backscatter imaging devices, and in particular to an X-ray backscatter detection device for defect inspection in a pipeline. Background Art

[0002] Problems faced by pipeline operators in managing the integrity of their production wells and pipeline assets are pipeline scaling, corrosion, sedimentation, and pipe and casing defects. These defects typically result in reduced production capacity of production wells, which is about 5% to 20%, as well as potential catastrophic failures that can cause serious injuries or even death. Therefore, expensive remediation (repair or replacement) of casing integrity issues is required.

[0003] Due to the technical limitations of pipeline maintenance operating conditions and existing detection technologies, the conventional mineral scale formation in wellbores and pipelines, microbial-induced corrosion, and material defect assessment and detection processes are very complex, time-consuming, and costly. The commonly used ultrasonic in-pipe detection method can detect layered corrosion and wall thickness, but has poor detection effects on pitting corrosion and requires liquid media and cleaning devices; the magnetic flux leakage detection method can detect pitting corrosion and deformation, but has poor detection effects on micro-sized corrosion damage. Moreover, the detection results of both detection methods are displayed in curves, which requires a high level of professional knowledge reserves from the detection technicians. In addition, the detection device uses a large number of detectors and has high maintenance costs.

[0004] The detection device based on Compton scatter imaging technology has the advantage that both the radiation source and the imaging device are placed on the same side of the target object, and the inspection results can be displayed in an intuitive image, which has advantages in application to defect inspection in pipelines. The Compton scatter image is formed by performing a flying spot scan on the object to be inspected by a pencil X-ray beam. At each position scanned by the pencil X-ray beam, the scattered X-rays are collected by a detector located on the same side of the system as the X-ray source. By tracking the instantaneous position of the pencil X-ray beam on the target object and measuring the overall intensity of the scattered X-rays incident on the detector, the scattered ray intensity can be associated with each pencil X-ray beam scanning position on the target detection object. Then, the target object can be moved in a direction perpendicular to the pencil beam scanning direction or the X-ray backscatter detector device can be moved. In this way, the target object can be scanned line by line to construct the entire two-dimensional image. Combined with relevant research on machine vision, automatic recognition of artificial intelligence images can be achieved.

[0005] X-ray backscatter imaging is currently used to detect and screen various objects, such as luggage, vehicles, and personnel. The working environment for conventional X-ray backscatter imaging devices to detect and screen these objects is relatively clean and at normal temperature and pressure. However, the environment inside the well casing is not very clean and is usually at high temperature and pressure, and conventional X-ray backscatter imaging devices cannot withstand such conditions. In addition, the geometry of the wellbore casing and pipeline is cylindrical and is not within the scope of conventional applications. In order to solve this problem, an X-ray backscatter imaging device that can be used for defect inspection in pipelines is required. Summary of the invention

[0006] In view of the defects existing in the prior art, the purpose of the present invention is to provide an X-ray backscatter detection device for pipeline defect inspection, which can be used in harsh environments and complex pipeline structures. It can perform online detection of defects in the pipeline without affecting the pipeline transportation medium, and can practice fully automatic detection in combination with artificial intelligence defect recognition technology.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] An X-ray backscatter detection device for inspecting defects in a pipeline, the device is positioned at the center of the pipeline and scans the inside of the pipeline in a spiral manner;

[0009] The device comprises a ray backscatter detection scanning head, a control and cooling device, a power supply and a driving device;

[0010] The ray backscatter detection scanning head comprises a scanning spindle; a ray source chamber is arranged on the scanning spindle;

[0011] The radiation source room is used to place the radiation source;

[0012] The ray source is used to generate rays that can provide sufficient penetration for imaging;

[0013] The radiation backscatter detection scanning head further includes a plurality of radiation beam collimators rotatable around a scanning main axis, for modulating radiation leaving the source chamber into a pencil-shaped radiation beam; and

[0014] Multiple groups of detectors rotatable around the scanning axis are used to detect the rays backscattered by the tube wall;

[0015] Furthermore, the radiation backscatter detection scanning head also includes a rotating bracket for fixing and supporting the detector and the radiation beam collimator, and driving the radiation beam collimator and the detector to rotate.

[0016] Furthermore, the rotatable beam collimator is arranged circumferentially outside the source chamber to modulate the rays leaving the source chamber into a pencil beam; the pencil beam is emitted along the radial direction of the pipeline and is perpendicular to the pipeline wall. The rotatable detectors are arranged in pairs on both sides of the collimator along the axial direction of the pipeline; the pencil beam is located at the geometric center of the rotatable detector pair arrangement, and the number of detector pairs is consistent with the number of pencil beams;

[0017] Furthermore, the device also includes a centering limiting device in the pipeline, which is used to position the detection device at the center of the pipeline.

[0018] Furthermore, the scanning spindle also includes a fairing arranged at the front end thereof.

[0019] Furthermore, the ray backscatter detection scanning head, the control and cooling device, the power supply and the driving device are connected via an articulated device.

[0020] Furthermore, the rotating bracket is cylindrical and is covered on the outside of the main shaft; the rotating bracket is connected to the scanning main shaft through a bearing; a plurality of evenly distributed permanent magnets are fastened to the inner wall of the rotating bracket; a plurality of armature cores are distributed on the scanning main shaft, and the armature winding is wound on the armature cores.

[0021] Furthermore, the pipeline centering limiting device includes a hinge, a slider connector, a universal wheel and a telescopic rod. According to the inner diameter of the pipeline to be inspected, the telescopic rod can be adjusted to enable the inspection device to be suitable for the inspection of pipeline wall defects with different inner diameters.

[0022] Furthermore, the ray is an X-ray, and the X-ray tube adopts a circumferential machine to generate 360° circumferentially emitted X-rays, and forms a circumferentially distributed pencil-shaped X-ray beam through a rotatable collimator. The anode target of the X-ray tube is conical, and the X-ray tube is located in the center of the pipe.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The pipe wall defect detection device of the present invention is designed based on Compton scattering imaging technology. It has the advantage that the radiation source and the imaging device are placed on the same side of the detection object. It can display the inspection results given in an intuitive image, realize comprehensive detection of various defects, and can operate under extreme conditions such as wellbore casings and oil pipelines.

[0025] 2. The device can be used in harsh environments such as wellbore casings and oil pipelines, and can also be used in other structures with similar geometric factors. For example, the device can be used in water pipelines and gas pipelines, commercial chimneys in power plants, and large storage containers to detect walls or linings. The device can also provide assistance for component inspections of dams, bridges, and buildings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall concept of the X-ray backscatter detection device used for defect inspection in pipelines in the present invention;

[0027] Figure 2 It is a schematic diagram of two detector arrangements of the backscatter detection scanning head in the present invention;

[0028] Figure 3 is a cross-sectional schematic diagram of an X-ray backscatter scanning head according to an embodiment of the present invention;

[0029] In the figure: 101-pipeline; 102-backscatter detection scanning head; 103-articulation device; 104-control and cooling device; 105-power supply and driving device; 201-pencil beam; 202-rotatable detector; 203-rotatable collimator; 204-rotating bracket; 205-ray source chamber; 301-scanning spindle; 302-fairing; 303-anode target; 304-cathode filament; 305-articulation; 306-slider connector; 307-universal wheel; 308-telescopic rod; 309-armature winding; 310-armature core; 311-permanent magnet; 312-bearing. DETAILED DESCRIPTION

[0030] In order to address the problems that existing pipeline defect inspection devices have incomplete defect detection types and non-intuitive detection results, this embodiment proposes a design scheme for a pipeline defect inspection device using X-ray backscatter imaging technology. The device using this scheme can perform online defect detection on pipelines with complex geometric structures under harsh environments such as high temperature and high pressure, and can detect various defects and display the detection structure in an intuitive image.

[0031] The following is an explanation of an X-ray backscatter detection device according to an embodiment of the present invention with reference to the accompanying drawings. However, it should be understood that the accompanying drawings and detailed description are not intended to limit the present disclosure to a specific form, but to cover all modifications, equivalent forms and alternative forms that fall within the spirit and scope of the present disclosure as defined by the accompanying claims. The drawings are not drawn to scale for illustration purposes.

[0032] Figure 1The overall conceptual diagram of the X-ray backscatter detection device used for pipeline defect inspection in the present invention is shown; the device uses a spiral forward method to scan inside the pipeline 101, obtains the internal pipeline scanning data, and transmits the scanning data to the display end for display in the form of an image. Artificial intelligence can be used to detect defects in the image to reduce the workload of the inspection personnel and improve the inspection efficiency. The device consists of an X-ray backscatter detection scanning head 102, a control and cooling device 104, a power supply and drive device 105 and a flexible articulation device 103. Among them, the X-ray backscatter detection scanning head 102 will be Figure 2 , 3 is given a detailed description. The flexible hinge device 103 connects the various components so that the device can move normally even at the bends or forks of the pipe, similar to a hinge. The control and cooling device 104 is equivalent to the brain of the entire device, controlling the data transmitted from the scanning head, transmitting the data to the host outside the pipe wirelessly or wiredly and displaying it; 104 is also responsible for receiving and processing user instructions, sending warnings and error messages, etc., controlling the operation of the entire machine, and providing cooling services for the entire device. The power supply and drive device 105 provides power and power drive for the entire device. Due to space limitations in the pipeline, a hinge structure is adopted, and each device can be arranged separately, which is not specifically limited to this example.

[0033] In order to produce a continuous image of the target, a continuous data stream needs to be obtained; the X-ray source must produce a continuous or high duty cycle fan beam. In order to obtain a reasonable coverage field of view, the opening angle of the fan beam should also be large. In order to enable pixel-by-pixel pencil beam scanning on the target, a rotatable collimator is located in front of the fan beam and has an opening designed to allow the required size of pencil beam to pass through. As the collimator rotates, the collimator selects different parts of the X-ray fan beam, thereby scanning the pencil beam in one dimension across the target. A rotating collimator is usually used instead of a reciprocating collimator to provide this function. The resolution of the system is determined by the chopper wheel aperture, the X-ray tube focal spot size, and the distance from the chopper wheel to the object to be detected. The detector designed to collect backscattered rays does not affect the image resolution.

[0034] Figure 2The schematic diagram of two detector arrangement schemes of the backscatter detection scanning head in the present invention is shown. The detector module of the device is composed of a pencil collimated ray beam 201, a rotatable detector 202, a rotatable collimator 203 for forming a pencil collimated ray beam, a detector and collimator bracket 204, and a ray source chamber 205. The ray can be any ray that can provide sufficient penetration for imaging, and can be X-rays, gamma rays, neutrons, terahertz or electrons. This example is a special example, and an X-ray tube is considered to be used as a ray source. The X-ray tube is located in the ray source chamber. The X-ray tube uses a circumferential machine to generate 360° circumferentially emitted X-rays, and forms a circumferentially distributed pencil X-ray beam through a rotatable collimator 203; the X-ray beam interacts with the material of the pipeline 101 to generate Compton scattering, and the scattered rays are detected by the rotatable detector 202. The rotatable collimator and the rotatable detector are installed on the collimator bracket 204 and driven to perform rotational scanning on the inner wall of the tube, and the scanning data forms a scanning image. Since the pencil beam needs to rotate with the detector, the detector needs to be arranged in pairs with the beam; due to the limitation of the space in the tube and the economic cost of the device, the number of scanning beams and detectors cannot be too large. Figure 2 (a) and Figure 2 (b) The arrangement of the detection system in the scanning head when two pencil beams and three pencil beams are shown respectively. Figure 2 (a) Two pencil beams and two pairs of semi-cylindrical detectors are used. The detectors are arranged axially on both sides of the pencil beam, and the pencil beam is located at the geometric center of the detector pair. The detectors are separated by detector brackets to prevent backscattered rays from interfering between detectors. In addition, the energy threshold of the detector can be set to deduct low-energy particles that are scattered multiple times to improve the signal-to-noise ratio. Figure 2 (b) Three pencil beams and three pairs of flat panel detectors are used. The detectors are also arranged axially on both sides of the pencil beams, and the pencil beams are located at the geometric arrangement center of the detector pairs. Increasing the number of pencil beams and detectors is conducive to improving the scanning speed of the device; the shape and arrangement of the detectors are not limited to the form shown in the example.

[0035] Figure 3A cross-sectional schematic diagram of an X-ray backscatter scanning head of an embodiment of the present invention is shown, which shows in detail the specific details of the scanning head of the X-ray backscatter detection device. The main shaft 301 of the device includes a ray source chamber 205 and a fairing 302. The ray source chamber 205 has a built-in ray source. The X-ray tube used in this example is composed of an anode target 303 and a cathode filament 304; to form 360° circumferentially emitted X-rays, the anode target 303 needs to adopt a conical structure; since the device is applied in a pipeline, and the pipeline is often used to transport fluids, the fairing 301 can be used to reduce the resistance of the forward movement of the device. The X-ray backscatter detection device requires the device to be located in the center of the pipeline during operation, and a centering limiting device is required. The centering limiting device is composed of a hinge 305, a slider connector 306, a universal wheel 307 and a telescopic rod 308. The telescopic rod 308 uses a built-in hydraulic mechanism to drive extension and contraction, push the slider 306 to move, and then adjust the centering limiting device to be suitable for pipelines with different inner diameters. The rotatable collimator 203 and the rotatable detector 202 are both fixed on the detector and collimator bracket 204; the detector and collimator bracket 204 is connected to the device main shaft 301 through the bearing 312. A number of evenly distributed permanent magnets 311 are fastened to the inner wall of the rotating cylinder of the detector and collimator bracket 204. The permanent magnets 311, the armature core 310 and the armature winding 309 form a motor to drive the X-ray backscatter device to rotate and scan the pipeline. A number of armature cores 310 are evenly distributed on the main shaft 301; the armature winding 309 is wound on the armature core 310, and the device can be driven to rotate by passing an alternating current through the armature winding 310.

[0036] According to one embodiment of the present invention, an X-ray backscatter scanning head 102, a cooling and control device 104, and a power supply and driving device constitute an X-ray backscatter detection device. Without departing from the basic concept of this patent, a set of X-ray backscatter detection devices can be configured with multiple X-ray backscatter scanning heads 102 or multiple cooling and control devices, etc. The device is driven by battery power or driven forward in the pipeline by the pressure difference generated by the fluid in the pipeline before and after the device. The X-ray tube and high-voltage electronic equipment are cooled by a closed-loop water cooling system. The cooling system releases the heat generated by the device into the fluid transported by the pipeline. For gaseous fluids, a water-to-air radiator can be used; for liquids, a water-to-liquid radiator can be used.

[0037] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. An X-ray backscatter detection device for pipeline defect inspection, characterized in that: The detection device is used for detecting defects on the wall of pipelines with different inner diameters. The detection device is positioned at the center of the pipeline and scans the inside of the pipeline in a spiral manner; The detection device comprises a ray backscatter detection scanning head, a control and cooling device, a power supply and a driving device, and the control and cooling device cools the detection device through a closed-loop water cooling system; The ray backscatter detection scanning head comprises a scanning spindle; a ray source chamber is arranged on the scanning spindle, and the scanning spindle also comprises a fairing arranged at the front end thereof, and the fairing is used to reduce the resistance of the forward movement of the detection device; The ray source chamber is used to place a ray source. The ray source is built into the ray source chamber, and the ray source includes an anode target and a cathode filament. The ray source is used to generate rays that can provide sufficient penetration for imaging; The ray is an X-ray, and the X-ray tube adopts a circumferential machine to generate X-rays emitted in a 360° circumferential direction, and forms a circumferentially distributed pencil-shaped X-ray beam through a beam collimator; the anode target of the X-ray tube is conical to form X-rays emitted in a 360° circumferential direction, and the X-ray tube is located at the center of the pipeline; The radiation backscatter detection scanning head also includes a radiation beam collimator which can rotate around a scanning main axis and is used to modulate the radiation leaving the radiation source chamber into a pencil-shaped radiation beam; as well as A plurality of detectors rotatable around a scanning axis are used to detect rays backscattered by the tube wall, wherein the detectors are separated by detector brackets; The radiation backscatter detection scanning head also includes a rotating bracket, which is used to fix and support the detector and the radiation beam collimator, and drive the radiation beam collimator and the detector to rotate; The detection device further comprises a pipeline centering limiting device, which is used to position the detection device at the center of the pipeline. The pipeline centering limiting device comprises a hinge, a slider connector, a universal wheel and a telescopic rod. One end of the hinge and the telescopic rod are both fixed to the rotating bracket. The telescopic rod is connected to the hinge through the slider connector. The universal wheel is arranged at one end of the portion connected to the hinge. The telescopic rod is driven to extend and shorten by a built-in hydraulic mechanism to push the slider connector to move. According to the inner diameter of the pipeline to be detected, the telescopic rod is adjusted so that the detection device can be applied to the detection of pipe wall defects of pipelines with different inner diameters. The rotating bracket is cylindrical and is covered on the outside of the scanning spindle; the rotating bracket is connected to the scanning spindle through a bearing; a plurality of evenly distributed permanent magnets are fastened to the inner wall of the rotating bracket; a plurality of armature cores are distributed on the scanning spindle, and armature windings are wound on the armature cores, and an alternating current is passed through the armature windings to drive the detection device to rotate, and the centering limiting device in the pipeline is arranged on the rotating bracket.

2. An X-ray backscatter detection device for pipeline defect inspection according to claim 1, characterized in that: The ray beam collimator is arranged circumferentially outside the ray source room to modulate the rays leaving the ray source room into a pencil ray beam; the pencil ray beam is emitted radially along the pipeline and perpendicular to the pipeline wall; the detectors are arranged in pairs on both sides of the ray beam collimator along the pipeline axis; the pencil ray beam is located at the geometric center of the detector pair arrangement, and the number of detector pairs is consistent with the number of pencil ray beams.

3. An X-ray backscatter detection device for pipeline defect inspection according to any one of claims 1 to 2, characterized in that: The ray backscatter detection scanning head, the control and cooling device and the power supply and the driving device are connected through a hinge device.

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