RU2773628C1 - Method for monitoring condition of pipelines for petroleum products and welded joints of pipelines for petroleum products by non-destructive testing radiographic method without termination of product transport - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: invention is intended to control the condition of pipelines and welded joints of pipelines for oil products by radiographic method for non-destructive testing without stopping the transport of the product. The substance of the invention lies in the fact that an X-ray source is placed on one side of the pipeline control section with the possibility of its movement relative to the pipeline, an X-ray receiver is placed on the other side of the pipeline control section with the possibility of movement relative to the control section, an image is obtained from the X-ray detector, formed during the passage of X-ray radiation from the X-ray source through the pipeline control section, at the same time, the control is carried out for several reinstallations of the x-ray machine and the x-ray receiver relative to the control area, a snapshot of the control area is formed in the initial position of the x-ray machine and the x-ray receiver, then the x-ray machine and the x-ray receiver are rearranged to the position, different from their previous position, at each reinstallation of the X-ray machine and the X-ray receiver, a snapshot of the control area is formed, as an X-ray receiver, a digital wireless flat-panel detector placed in a heat-shielding casing is used with a minimum signal-to-noise ratio of at least 70 units and the number of gray gradations from 5000 up to 65000 units, while the length of the flat panel detector is no more than 400 mm, each image formed during the passage of X-ray radiation from the X-ray source through the pipeline control section, at each reset, is obtained by multiple exposure with the accumulation of frames of the control section in the detector’s memory, while the exposure time is in the range from 5 to 180 seconds, the number of frames accumulated with multiple exposure to form one image of the control area is from 2 to 1000.

EFFECT: providing the possibility of radiographic inspection of pipes and welded joints of pipelines with oil and oil products without stopping the flow of the product, expanding the functionality by providing the possibility of monitoring and diagnosing pipes of large and small diameters with different wall thicknesses, increasing the accuracy of control and diagnostics by increasing the sensitivity of the control.

4 cl, 6 dwg, 14 tbl

Description

The invention relates to the field of diagnostics and assessment of the technical condition of welded joints and the base metal of pipelines of various nomenclature with large and small wall thicknesses by radiographic non-destructive testing, without decommissioning pipelines with oil products.

From the patent of the Russian Federation No. 2718514 for the invention, a method for testing welded joints is known, including placing an x-ray source control object on one side of the welded joint with the possibility of moving relative to the welded joint, placing an x-ray receiver on the other side of the welded joint of the test object with the possibility of moving relative to the welded joint connections, obtaining from the X-ray detector an image formed during the passage of X-ray radiation from the X-ray source through the welded joint of the test object, plotting the X-ray intensity distribution diagram on the image and determining the position of the X-ray intensity maximum on the image, subsequent adjustment of the position of the X-ray detector so that the maximum intensity of X-ray radiation in the image coincides with the center of the image receiver and x-ray radiation.

The disadvantages of this method include the unsuitability of the system for radiographic control through two pipeline walls and the provision of radiographic control without stopping the transportation of petroleum products.

From the patent of the Russian Federation No. 2685052 for the invention, a method is known for diagnosing welded joints, surfacings and the main body of a pipe of main gas pipelines by radiographic method, characterized in that the radiographic control is carried out under the pressure of the pumped medium (without stopping the transport of natural gas) using a combination of the following materials and equipment: radiographic cassette with a length of not more than 300 mm, consisting of an outer opaque cover and an internal opaque cover equipped with intensifying screens (metal fluorescent, blue-emitting, with an exposure reduction factor of 70 ÷ 150 times) and X-ray film (sensitized with an average gradient of 3.3; sensitivity (p-1) 800-1200; class according to EN 584-10), laid between the intensifying screens, X-ray apparatus of constant potential, with the possibility of adjusting the anode voltage from 250 to 300 kV, and the development of the obtained radiographic images is carried out at t temperature t≈5÷7°C.

The disadvantage of the diagnostic method according to patent No. 2685052 is that it does not provide radiographic control of pipelines with oil and refined products, due to:

- higher density in oil products than in gas, leading to greater attenuation of the primary x-ray radiation and insufficient sensitivity of the radiographic film;

- more scattered radiation on a moving denser oil, leading to a decrease in the signal-to-noise ratio and insufficient signal-to-noise ratios of existing radiographic films [ISO 11699-1, Non-destructive testing — Industrial radiographic film — Part 1: Classification of film systems for industrial radiography (Non-destructive control. Radiographic films for industrial radiography. Part 1. Classification of film systems for industrial radiography)].

- X-ray films are not suitable due to damage on the hot surfaces of pipelines with oil products at temperatures of 300-450°C and the surface of the insulation of pipelines with oil products at temperatures up to 100°C.

The method according to RF patent No. 2685052 is chosen as the closest analogue.

The technical problem solved by the invention is the lack of radiographic methods of non-destructive testing without stopping the flow of oil products of pipelines, without decommissioning pipelines with oil products, the complexity of existing methods.

The technical result achieved by the invention is the possibility of radiographic inspection of pipes and welded joints of pipelines with oil and oil products without stopping the flow of the product, simplifying the method and reducing the time of control by eliminating the need to stop the transportation of the product, remove the protective insulation from the pipes, decommission the pipeline when carrying out control, expanding functionality by providing the possibility of monitoring and diagnosing pipes of large and small diameters with different wall thicknesses, welded joints and the base metal of the pipe body for transporting various products - oil, oil products, liquefied gas, etc.; increasing the accuracy of control and diagnostics by increasing the sensitivity of control.

The claimed technical result is achieved due to the fact that in the claimed method of monitoring the condition of pipelines for oil products and welded joints of pipelines for oil products by radiographic method of non-destructive testing without stopping the transport of the product, which includes placing an X-ray source on one side of the control section of the pipeline with the possibility of its movement relative to the pipeline , placement on the other side of the control section of the pipeline of the x-ray receiver with the possibility of moving relative to the control section, obtaining from the x-ray receiver an image formed during the passage of x-rays from the x-ray source through the control section of the pipeline, according to the invention, control is carried out for several reinstallations of the x-ray machine and of the X-ray receiver relative to the control area, a snapshot of the control area is formed in the initial position x-ray machine and x-ray receiver, then the x-ray machine and x-ray receiver are rearranged to a position different from their previous position, at each reinstallation of the x-ray machine and x-ray receiver, a snapshot of the control area is formed, a digital wireless flat-panel detector with a minimum signal-to-noise ratio of at least 70 units and the number of gray gradations from 5000 to 65000 units, while the length of the flat-panel detector is not more than 400 mm, each image formed during the passage of x-ray radiation from the x-ray source through the pipeline control section at each reset, they are obtained by multiple exposure with the accumulation of frames of the control area in the detector’s memory, while the exposure time is in the range from 5 to 180 seconds, the number of frames c, accumulated during multiple exposure to form one image of the control area, ranges from 2 to 1000.

As an X-ray receiver, it is advisable to use a digital wireless flat-panel detector, made in the same housing with a battery.

It is advisable to choose the geometric parameters of each control area based on ensuring the quality of the image along the edges of the area corresponding to the specified image quality in its central part.

In the claimed method, the joint use of an X-ray machine and a digital wireless flat-panel detector is used, made in one housing with a battery, built-in memory, a wireless communication unit, a temperature sensor that provides a minimum signal-to-noise ratio (SNR) of at least 70 units and a maximum number of gradations at least 65,000 units of gray on a digital image, placed in a heat-shielding casing, with a total length of not more than 400 mm in order to allow the method of control and minimize the exposure time when conducting radiographic testing in the field or shop conditions, as well as software tools for improving the image quality of digital radiographic pictures.

If the signal-to-noise ratio (SNR) of the image is less than 70 units, then the detection of defects will be worse, the overall image quality will be worse. The minimum numerical value of 70 units is the requirement set by the invention for the quality level of the image and the digital detector used, which reliably and completely ensures the detection of defects.

The requirement for the achieved number of gray levels of 65,000 units is due to the fact that a large digitization bit depth (a larger number of gray levels) provides a larger dynamic range of signals simultaneously displayed on the image with the smallest and largest signal value. In practice, this makes it possible to control a wider range of thickness differences for objects of different thicknesses during one exposure. To achieve the result, it is noted that it is necessary to work with a detector with a 16-bit ADC, which provides 2 ¹⁶ = 65536 gray levels.

The requirement for the length of the wireless flat panel detector to be no more than 400 mm is due to the fact that if the length of the flat panel detector is more than 400 mm, then this will be an unjustified use of a more expensive detector and a more laborious process. Due to the geometrical parameters of the control of cylindrical objects (pipelines) at the edges of the image obtained with a flat rigid detector, the quality deteriorates. From practice on pipelines, the useful area of the detector is up to 400 mm.

The X-ray sensitivity of a flat panel digital wireless detector is higher than that of film systems [ISO 11699-1, Non-destructive testing - Industrial radiographic film - Part 1: Classification of film systems for industrial radiography. 1. Classification of film systems for industrial radiography)], which reduces the exposure time. The combination, which uses a powerful constant potential X-ray machine and a digital wireless flat panel detector, significantly reduces the exposure time, and, consequently, reduces the level of intrinsic and dynamic noise, and increases the sharpness of radiographic images. Reduction of noise from scattered radiation and moving oil products is achieved through the use of multiple exposures, accumulation of frames of the same section of the pipeline in the built-in memory of the detector, summation and averaging of their signal, which increases the signal-to-noise ratio of the final digital image. Exposure time may vary depending on the object of control in the range of 5 - 180 seconds. Increasing or decreasing the exposure time increases or decreases the level of grayscale produced by the specified shooting settings. The number of frames accumulated to create one digital image can vary depending on the object of control in the range from 2 to 1000. Increasing the number of frames taken to form one image does not affect the level of grayscale, but allows you to get a better image. At the same time, an increase in the number of frames increases the total control time and the time for switching on the radiation source.

The task of carrying out control at a high temperature of a pipeline with an oil product is solved by using a heat-shielding casing on the X-ray detector. To protect the digital detector and optimize inspection time without overheating, a temperature sensor is built into the digital wireless flat panel detector. The combination of the use of an insulating layer, a heat-shielding casing and a built-in temperature sensor allows for radiographic testing up to 100 degrees Celsius on the surface of the test object.

The heat shield is made of structural materials coated with a layer of material with low thermal conductivity.

Control is carried out for several reinstallations of the X-ray apparatus. The circumference of the controlled object is divided into several sections. In order to avoid the imposition of braid or wires from the insulating layer on the control area, a duplicate image is taken for each area with the equipment rearranged along the welded joint to a position that differs from the initial one, but does not correspond to the next one.

Each standard size of a pipeline with oil and oil products will have its own control scheme. The length of each section is selected taking into account the size of the pipeline in such a way that the quality at the edges of the image corresponds to the sensitivity of the control in order to maintain the detectability of defects along the entire length of the pipeline.

For example, for the size of a pipe with an oil product shown in Fig. 1 pipe is divided into sections with a length of not more than 260 mm. If the length of the section is more than 260 mm for a given pipeline size, then the quality at the edges of the image will not correspond to the sensitivity of the control and will not ensure the detection of defects.

To control sections of the perimeter of the welded joint or the base metal of the pipe body using a frontal radiographic transmission scheme, a digital wireless flat-panel detector is installed through two pipeline walls.

After installing the digital radiography complex and the X-ray apparatus on the pipe transporting the oil product, the X-ray apparatus is switched on for exposure, during which ionizing radiation is recorded on a digital wireless flat-panel detector.

Immediately after the end of the exposure, the image is processed - summarized and averaged, stored in the built-in memory of the digital wireless flat-panel detector, transmitted to the device for receiving and decoding information from the detector, where the quality criteria of the received image and its compliance with the requirements of regulatory and technical documentation are checked:

- GOST 7512-82. The control is non-destructive. Welded connections. radiographic method;

- GOST ISO 17636-2-2017. Non-destructive testing of welded joints. radiographic method. Methods of X-ray and gammagraphic control using digital detectors;

- RD-25.160.10-KTN-016-15 Guiding document “Main pipeline transportation of oil and oil products. Non-destructive testing of welded joints during the construction and repair of main pipelines, PJSC TRANSNEFT, 2021;

- STO Gazprom 2-2.4-083-2006. Instructions on non-destructive methods for quality control of welded joints during the construction and repair of field and main gas pipelines. Moscow: OAO Gazprom, 2006.

An indication that the equipment is not overloaded due to elevated temperatures is indicated on the device for receiving information from a digital detector. The absence of overloads due to elevated temperatures is indicated by the temperature indicator in the information receiving device, it comes from the temperature sensor built into the detector. If the temperature sensor registers an excess of the internal temperature of the detector ^over 60 ° C, then a conclusion is made about the presence of equipment overloads.

After the end of the first exposure, the digital radiography complex is installed in the next area, and an X-ray machine is installed opposite this area. Thus, by sequentially reinstalling the digital radiography complex and the X-ray machine, the clearance of the entire annular section of the pipeline is achieved.

The inventive method provides the possibility of monitoring and diagnosing the state of pipes and welded joints during the continuous transport of the product, in particular oil, and also without removing the insulation from the pipes, which greatly simplifies the control method.

The time of each exposure, taking into account the wall thickness of the pipeline with oil and oil products by the frontal method of transillumination through two pipeline walls under the above conditions, is no more than 3 minutes, with the sensitivity of radiographic images that meet the requirements established in:

- GOST 7512-82. The control is non-destructive. Welded connections. radiographic method;

- GOST ISO 17636-2-2017. Non-destructive testing of welded joints. radiographic method. Methods of X-ray and gammagraphic control using digital detectors.

Photo processing of images is not required - the acquisition, processing and archiving of images is done in digital format.

In FIG. 1 shows the layout of sections for the radiographic clearance of a steel pipeline with an oil product with a diameter of 325 mm, a wall thickness of 16 mm, with a protective insulating coating of the pipeline made of mineral wool and thin-sheet galvanized steel, with a total thickness of 80 mm, under the pressure of the transported oil product. The scheme shows the marking of sections for the radiographic lumen of a large-diameter pipeline for 6 x-ray machine installations and a digital radiography complex with duplicating rearrangement along the welded joint to a position that differs from the initial one, but does not correspond to the next one.

In FIG. 2 and in FIG. 3 shows a scheme of radiographic control of a pipeline (1) with a protective insulating coating (2) transporting oil or a refined product (3) with a gap through two pipeline walls with a permanent X-ray machine (4), with the ability to adjust the anode voltage up to 300 kV, and a digital wireless flat panel x-ray detector (5). Pipeline diameter 325 mm (including insulation 485 mm); the number of installations of the X-ray apparatus and the complex of digital radiography is 6. FIG. 2 - longitudinal section of the pipeline; fig. 3 - cross section of the pipeline.

In FIG. 4 shows an example of an X-ray detector heating/overheating indication.

In FIG. 5 shows a radiographic image of a section of a welded joint of a pipeline transporting a refined product, obtained by the proposed method.

In FIG. 6 shows a radiographic image of a section of the base metal of a pipeline transporting a refined product, obtained by the proposed method.

In FIG. 5 and 6 show defects in the welded joint and in the base metal of the pipe,

those. non-compliance of the welded joint and the main body of the pipe with the requirements is shown.

The claimed method is illustrated by examples of assessing the state of welded joints and the base metal of the pipeline body under pressure and without stopping the transport of oil and oil products, without removing the protective insulating coating of the pipeline, in the range of diameters performed by the radiographic method of non-destructive testing, using a digital flat panel detector, are presented in tables 1 -12.

For each example, a method was carried out for monitoring the condition of pipelines for oil products and welded joints of pipelines for oil products by a radiographic method of non-destructive testing without stopping the transport of the product, including placing an X-ray source on one side of the control section of the pipeline with the possibility of moving it relative to the pipeline, placing it on the other side of the section control of the pipeline of the x-ray receiver with the ability to move relative to the control section, receiving from the x-ray receiver an image formed during the passage of x-rays from the x-ray source through the control section of the pipeline. The control was carried out for several reinstallations of the X-ray apparatus and the X-ray receiver relative to the control area; a snapshot of the control area was formed in the initial position of the x-ray machine and the x-ray receiver, after which the x-ray machine and the x-ray receiver were rearranged to a position different from their previous position, but not corresponding to the subsequent position. At each reinstallation of the X-ray apparatus and the X-ray receiver, a snapshot of the control area was formed. As an X-ray receiver, we used a digital wireless flat-panel detector placed in a heat-shielding casing, made in one housing with a battery, with automatic averaging of frame signals accumulated in the detector’s memory during multiple exposure to reduce noise from oil and oil products, equipped with a detector temperature sensor, placed in a heat-shielding casing for inspection through the pipeline insulation with a surface temperature of up to 100 ° C (for example, the Tsifrakon 2532 digital radiography complex). During the operation of the flat panel detector, a minimum signal-to-noise ratio of at least 70 units was provided with a number of gray gradations of at least 5000 units and not more than 65000 units, while the length of the flat panel detector was up to 400 mm. Each image formed during the passage of X-ray radiation from the X-ray source through the pipeline control section at each reset was obtained by multiple exposure with the accumulation of frames of the control section in the detector’s memory, while the exposure time was in the range from 5 to 180 seconds, the number of frames accumulated with multiple exposure to form one image of the control area is from 2 to 1000,

For the pipeline shown in Fig. 1, the length of the sections was chosen no more than 260 mm. With such a length, the sensitivity of the control along the edges of the section met the requirements for the quality of the image in the evaluation area, including in its central part.

All examples are carried out on oil pipelines with insulation, the thickness of which in the range from 60 to 200 mm meets the requirements for the respective pipe diameter. In the course of the implementation of the examples, the pipelines were not removed, the flow of oil products did not stop, the pipelines were not decommissioned.

Example 1 "Assessment of the condition of pipelines without stopping the transportation of fuel oil."

Parameters under which example 1 was carried out:

- pipeline diameter: Ø 426 mm;

- signal-to-noise ratio: 100 units;

- section length: 280 mm;

- number of gradations of gray: 10000 units;

- length of the flat panel detector: 320 mm;

- exposure time: one frame 30 seconds;

- the number of accumulated frames for the formation of one image: 9.

Table 1 presents the results of the implementation of the proposed method according to example 1.

Table 1:

Nominal wall thickness, mm Regulated control sensitivity according to GOST ISO 17636, class A, mm Achieved film sensitivity, mm Achieved sensitivity according to the claimed method, mm Up to 1.2 0.063 0.100 0.063 St. 1.2 to 2.0 0.080 0.200 0.063 St. 2.0 to 3.5 0.100 0.250 0.080 St. 3.5 to 5.0 0.125 0.5 0.100 St. 5.0 to 10.0 0.160 0.8 0.125 St. 10.0 to 15.0 0.200 Sensitivity not reached 0.200 St. 15.0 to 22.0 0.250 Sensitivity not reached 0.250

Sensitivity in radiographic methods of non-destructive testing characterizes the size of the minimum detectable defect, therefore, a lower value characterizes a higher sensitivity.

Example 2 "Assessment of the condition of pipelines without stopping the transportation of gasoline vapors."

Parameters under which example 2 was carried out:

- pipeline diameter: Ø 325 mm;

- signal-to-noise ratio: 80 units;

- section length: 270 mm;

- number of shades of gray: 15000 units;

- length of the flat panel detector: 320 mm;

- exposure time: one frame 20 seconds;

- the number of accumulated frames for the formation of one image: 8.

Table 2 presents the results of the implementation of the proposed method according to example 2.

Table 2:

Nominal wall thickness, mm Regulated control sensitivity according to GOST ISO 17636, class A, mm Achieved film sensitivity, mm Achieved sensitivity according to the claimed method, mm Up to 1.2 0.063 0.063 0.050 St. 1.2 to 2.0 0.080 0.080 0.063 St. 2.0 to 3.5 0.100 0.100 0.080 St. 3.5 to 5.0 0.125 0.125 0.100 St. 5.0 to 10.0 0.160 0.160 0.125 St. 10.0 to 15.0 0.200 0.200 0.160 St. 15.0 to 22.0 0.250 0.320 0.200

Example 3 "Assessment of the condition of pipelines without stopping the transportation of crude oil."

Parameters under which example 3 was carried out:

- pipeline diameter: Ø 426 mm;

- signal-to-noise ratio: 100 units;

- section length: 280 mm;

- number of gradations of gray: 20000 units;

- length of the flat panel detector: 320 mm;

- exposure time: one frame 20 seconds;

- the number of accumulated frames for the formation of one image: 8.

Table 3 presents the results of the implementation of the proposed method according to example 3.

Table 3:

Nominal wall thickness, mm Regulated control sensitivity according to GOST ISO 17636, class A, mm Achieved film sensitivity, mm Achieved sensitivity according to the claimed method, mm Up to 1.2 0.063 0.063 0.063 St. 1.2 to 2.0 0.080 0.080 0.063 St. 2.0 to 3.5 0.100 0.100 0.080 St. 3.5 to 5.0 0.125 0.125 0.100 St. 5.0 to 10.0 0.160 0.200 0.160 St. 10.0 to 15.0 0.200 0.4 0.160 St. 15.0 to 22.0 0.250 0.63 0.200

Example 4 "Assessment of the condition of pipelines without stopping the transportation of hydrogenated product."

Parameters under which example 4 was carried out:

- pipeline diameter: Ø 426 mm;

- signal-to-noise ratio: 120 units;

- section length: 280 mm;

- number of shades of gray: 15000 units;

- length of the flat panel detector: 320 mm;

- exposure time: one frame 15 seconds;

- the number of accumulated frames for the formation of one image: 6.

Table 4 presents the results of the implementation of the proposed method according to example 4.

Table 4:

Nominal wall thickness, mm Regulated control sensitivity according to GOST ISO 17636, class A, mm Achieved film sensitivity, mm Achieved sensitivity according to the claimed method, mm Up to 1.2 0.063 0.063 0.063 St. 1.2 to 2.0 0.080 0.080 0.063 St. 2.0 to 3.5 0.100 0.100 0.080 St. 3.5 to 5.0 0.125 0.125 0.100 St. 5.0 to 10.0 0.160 0.160 0.125 St. 10.0 to 15.0 0.200 0.32 0.160 St. 15.0 to 22.0 0.250 0.5 0.200

Example 5 "Assessment of the condition of pipelines without stopping the transportation of stabilized diesel fuel."

Parameters under which example 5 was carried out:

- pipeline diameter: 6 Ø 426 mm;

- signal-to-noise ratio: 100 units;

- section length: 280 mm;

- number of shades of gray: 30,000 units;

- length of the flat panel detector: 320 mm;

- exposure time: one frame 20 seconds;

- the number of accumulated frames for the formation of one image: 8.

Table 5 presents the results of the implementation of the proposed method according to example 5.

Table 5:

Nominal wall thickness, mm Regulated control sensitivity according to GOST ISO 17636, class A, mm Achieved film sensitivity, mm Achieved sensitivity according to the claimed method, mm Up to 1.2 0.063 0.063 0.050 St. 1.2 to 2.0 0.080 0.080 0.063 St. 2.0 to 3.5 0.100 0.100 0.080 St. 3.5 to 5.0 0.125 0.125 0.100 St. 5.0 to 10.0 0.160 0.160 0.125 St. 10.0 to 15.0 0.200 0.250 0.160 St. 15.0 to 22.0 0.250 0.320 0.200

Example 6 "Assessment of the condition of pipelines without stopping the transportation of stripped oil."

Parameters under which example 6 was carried out:

- pipeline diameter: Ø 426 mm;

- signal-to-noise ratio: 100 units;

- section length: 280 mm;

- number of gradations of gray: 13000 units;

- length of the flat panel detector: 320 mm;

- exposure time: one frame 20 seconds;

- the number of accumulated frames for the formation of one image: 8.

Table 6 presents the results of the implementation of the proposed method according to example 6.

Table 6:

Nominal wall thickness, mm Regulated control sensitivity according to GOST ISO 17636, class A, mm Achieved film sensitivity, mm Achieved sensitivity according to the claimed method, mm Up to 1.2 0.063 0.063 0.063 St. 1.2 to 2.0 0.080 0.080 0.063 St. 2.0 to 3.5 0.100 0.100 0.080 St. 3.5 to 5.0 0.125 0.125 0.100 St. 5.0 to 10.0 0.160 0.160 0.125 St. 10.0 to 15.0 0.200 0.32 0.200 St. 15.0 to 22.0 0.250 0.5 0.250

Example 7 "Assessing the condition of pipelines without stopping the transport of light vacuum distillate."

Parameters under which example 7 was carried out:

- pipeline diameter: Ø 426 mm;

- signal-to-noise ratio: 100 units;

- section length: 280 mm;

- number of gradations of gray: 10000 units;

- length of the flat panel detector: 320 mm;

- exposure time: one frame 20 seconds;

- the number of accumulated frames for the formation of one image: 8.

Table 7 presents the results of the implementation of the proposed method according to example 7.

Table 7:

Nominal wall thickness, mm Regulated control sensitivity according to GOST ISO 17636, class A, mm Achieved film sensitivity, mm Achieved sensitivity according to the claimed method, mm Up to 1.2 0.063 0.063 0.050 St. 1.2 to 2.0 0.080 0.080 0.063 St. 2.0 to 3.5 0.100 0.100 0.080 St. 3.5 to 5.0 0.125 0.125 0.100 St. 5.0 to 10.0 0.160 0.200 0.160 St. 10.0 to 15.0 0.200 0.200 0.160 St. 15.0 to 22.0 0.250 0.320 0.200

Example 8 "Assessment of the condition of pipelines without stopping the transportation of the diesel fraction."

Parameters under which example 8 was carried out:

- pipeline diameter: Ø 325 mm;

- signal-to-noise ratio: 100 units;

- section length: 270 mm;

- number of gradations of gray: 10000 units;

- length of the flat panel detector: 320 mm;

- exposure time: one frame 23 seconds;

- the number of accumulated frames for the formation of one image: 10.

Table 8 presents the results of the implementation of the proposed method according to example 8.

Table 8:

Nominal wall thickness, mm Regulated control sensitivity according to GOST ISO 17636, class A, mm Achieved film sensitivity, mm Achieved sensitivity according to the claimed method, mm Up to 1.2 0.063 0.100 0.063 St. 1.2 to 2.0 0.080 0.100 0.080 St. 2.0 to 3.5 0.100 0.125 0.100 St. 3.5 to 5.0 0.125 0.125 0.125 St. 5.0 to 10.0 0.160 0.200 0.160 St. 10.0 to 15.0 0.200 0.4 0.160 St. 15.0 to 22.0 0.250 0.8 0.250

Example 9 "Assessment of the condition of pipelines without stopping the transportation of the cracked residue."

Parameters under which example 9 was carried out:

- pipeline diameter: 6 Ø 426 mm;

- signal-to-noise ratio: 80 units;

- section length: 280 mm;

- number of gradations of gray: 10000 units;

- length of the flat panel detector: 320 mm;

- exposure time: one frame 25 seconds;

- the number of accumulated frames for the formation of one image: 8.

Table 9 presents the results of the implementation of the proposed method according to example 9.

Table 9:

Nominal wall thickness, mm Regulated control sensitivity according to GOST ISO 17636, class A, mm Achieved film sensitivity, mm Achieved sensitivity according to the claimed method, mm Up to 1.2 0.063 0.125 0.063 St. 1.2 to 2.0 0.080 0.125 0.063 St. 2.0 to 3.5 0.100 0.160 0.080 St. 3.5 to 5.0 0.125 0.250 0.100 St. 5.0 to 10.0 0.160 0.5 0.125 St. 10.0 to 15.0 0.200 0.8 0.160 St. 15.0 to 22.0 0.250 1.25 0.250

Example 10 "Assessment of the condition of pipelines without stopping the transportation of kerosene."

Parameters under which example 10 was carried out:

- pipeline diameter: Ø 325 mm;

- signal-to-noise ratio: 100 units;

- section length: 270 mm;

- number of gradations of gray: 20000 units;

- length of the flat panel detector: 320 mm;

- exposure time: one frame 15 seconds;

- the number of accumulated frames for the formation of one image: 12.

Table 10 presents the results of the implementation of the proposed method according to example 10.

Table 10:

Nominal wall thickness, mm Regulated control sensitivity according to GOST ISO 17636, class A, mm Achieved film sensitivity, mm Achieved sensitivity according to the claimed method, mm Up to 1.2 0.063 0.063 0.050 St. 1.2 to 2.0 0.080 0.080 0.063 St. 2.0 to 3.5 0.100 0.100 0.080 St. 3.5 to 5.0 0.125 0.125 0.100 St. 5.0 to 10.0 0.160 0.160 0.125 St. 10.0 to 15.0 0.200 0.32 0.160 St. 15.0 to 22.0 0.250 0.63 0.200

Example 11 "Assessment of the condition of pipelines without stopping the transportation of liquefied hydrocarbon gases."

Parameters under which example 11 was carried out:

- pipeline diameter: Ø 426 mm;

- signal-to-noise ratio: 120 units;

- section length: 280 mm;

- number of gradations of gray: 10000 units;

- length of the flat panel detector: 320 mm;

- exposure time: one frame 20 seconds;

- the number of accumulated frames for the formation of one image: 8.

Table 11 presents the results of the implementation of the proposed method according to example 11.

Table 11:

Nominal wall thickness, mm Regulated control sensitivity according to GOST ISO 17636, class A, mm Achieved film sensitivity, mm Achieved sensitivity according to the claimed method, mm Up to 1.2 0.063 0.063 0.050 St. 1.2 to 2.0 0.080 0.080 0.063 St. 2.0 to 3.5 0.100 0.100 0.080 St. 3.5 to 5.0 0.125 0.125 0.100 St. 5.0 to 10.0 0.160 0.160 0.125 St. 10.0 to 15.0 0.200 0.200 0.125 St. 15.0 to 22.0 0.250 0.250 0.160

Example 12 "Assessment of the condition of pipelines without stopping the transportation of gasoline."

Parameters under which example 12 was carried out:

- pipeline diameter: Ø 426 mm;

- signal-to-noise ratio: 100 units;

- section length: 280 mm;

- number of gradations of gray: 10000 units;

- length of the flat panel detector: 320 mm;

- exposure time: one frame 20 seconds;

- the number of accumulated frames for the formation of one image: 8.

Table 12 presents the results of the implementation of the proposed method according to example 12.

Table 12:

Nominal wall thickness, mm Regulated control sensitivity according to GOST ISO 17636, class A, mm Achieved film sensitivity, mm Achieved sensitivity according to the claimed method, mm Up to 1.2 0.063 0.063 0.063 St. 1.2 to 2.0 0.080 0.080 0.063 St. 2.0 to 3.5 0.100 0.100 0.080 St. 3.5 to 5.0 0.125 0.125 0.100 St. 5.0 to 10.0 0.160 0.160 0.125 St. 10.0 to 15.0 0.200 0.4 0.160 St. 15.0 to 22.0 0.250 0.63 0.250

Example 13 "Assessment of the condition of pipelines without stopping the transportation of tar."

Parameters under which example 13 was carried out:

- pipeline diameter: Ø 426 mm;

- signal-to-noise ratio: 80 units;

- section length: 280 mm;

- number of gradations of gray: 10000 units;

- length of the flat panel detector: 320 mm;

- exposure time: one frame 35 seconds;

- the number of accumulated frames for the formation of one image: 10.

Table 13 presents the results of the implementation of the proposed method according to example 13.

Table 13:

Nominal wall thickness, mm Regulated control sensitivity according to GOST ISO 17636, class A, mm Achieved film sensitivity, mm Achieved sensitivity according to the claimed method, mm Up to 1.2 0.063 0.100 0.063 St. 1.2 to 2.0 0.080 0.160 0.063 St. 2.0 to 3.5 0.100 0.250 0.080 St. 3.5 to 5.0 0.125 0.4 0.100 St. 5.0 to 10.0 0.160 0.8 0.125 St. 10.0 to 15.0 0.200 1.25 0.160 St. 15.0 to 22.0 0.250 Sensitivity not reached 0.250

Example 14 "Assessment of the condition of pipelines without stopping the transportation of bitumen."

Parameters under which example 14 was carried out:

- pipeline diameter: Ø 426 mm;

- signal-to-noise ratio: 90 units;

- section length: 280 mm;

- number of gradations of gray: 32000 units;

- length of the flat panel detector: 320 mm;

- exposure time: one frame 30 seconds;

- the number of accumulated frames for the formation of one image: 10.

Table 14 presents the results of the implementation of the proposed method according to example 14.

Table 14:

Nominal wall thickness, mm Regulated control sensitivity according to GOST ISO 17636, class A, mm Achieved film sensitivity, mm Achieved sensitivity according to the claimed method, mm Up to 1.2 0.063 0.100 0.063 St. 1.2 to 2.0 0.080 0.160 0.063 St. 2.0 to 3.5 0.100 0.250 0.080 St. 3.5 to 5.0 0.125 0.4 0.100 St. 5.0 to 10.0 0.160 0.8 0.125 St. 10.0 to 15.0 0.200 1.25 0.160 St. 15.0 to 22.0 0.250 Sensitivity not reached 0.250

Sensitivity requirements are set out in:

- GOST 7512-82. The control is non-destructive. Welded connections. radiographic method.

- GOST ISO 17636-2-2017. Non-destructive testing of welded joints. radiographic method. Methods of X-ray and gammagraphic control using digital detectors.

- RD-25.160.10-KTN-016-15 GUIDING DOCUMENT Main pipeline transportation of oil and oil products. Non-destructive testing of welded joints in the construction and repair of main pipelines. PJSC "TRANSNEFT", 2021. - 222 p.

- STO Gazprom 2-2.4-083-2006. Instructions on non-destructive methods of quality control of welded joints during the construction and repair of field and main gas pipelines. Moscow: OAO Gazprom, 2006.

The claimed method allows to expand the possibilities of using X-ray flaw detection of welded joints and the base metal of the pipeline body under pressure, without removing the pipeline insulation, without stopping the transport of oil and oil products. The application of the proposed method allows to reduce the total downtime of main and technological pipelines during diagnostic work, and also allows, in addition to existing control methods, to most accurately determine the condition of the diagnosed objects.

The inventive method is simpler than the known ones, because does not require removal of insulation from the pipeline, which significantly reduces the time of inspection and

The claimed method allows to expand its functionality in comparison with known methods by providing the possibility of monitoring and diagnosing pipes of large and small diameters with different wall thicknesses, welded joints and the base metal of the pipe body, and also allows for monitoring during the transportation of various products - oil, oil products , gas, etc.

The inventive method improves the accuracy of control and diagnostics by increasing its control sensitivity - the ability of the non-destructive testing method to detect discontinuities (GOST 7512-82).

Claims (4)

1. A method for monitoring the condition of pipelines for petroleum products and welded joints of pipelines for petroleum products by radiographic method of non-destructive testing without stopping the transport of the product, including placing an X-ray source on one side of the pipeline control section with the possibility of its movement relative to the pipeline, placing it on the other side of the pipeline control section an x-ray receiver with the ability to move relative to the control area, obtaining from the x-ray receiver an image formed during the passage of x-ray radiation from the x-ray source through the control section of the pipeline, characterized in that the control is carried out by several reinstallations of the x-ray machine and the x-ray receiver relative to the control area, a snapshot of the control area is formed in the initial position of the x-ray machine and the x-ray receiver, then the x-ray machine and the x-ray receiver are rearranged to a position that differs from their previous position, at each reinstallation of the x-ray machine and the x-ray receiver, a snapshot of the control area is formed, a digital wireless flat-panel detector placed in a heat-shielding casing is used as an x-ray receiver with a minimum signal-to-noise ratio at least 70 units and the number of gray gradations from 5000 to 65000 units, while the length of the flat-panel detector is not more than 400 mm, each image formed during the passage of X-ray radiation from the X-ray source through the pipeline control section, at each reinstallation, is obtained by multiple exposure with accumulation of frames of the control area in the memory of the detector, while the exposure time is in the range from 5 to 180 seconds, the number of frames accumulated during multiple exposure to form one image fermentation of the control area ranges from 2 to 1000. 2. The method according to claim 1, characterized in that a digital wireless flat-panel detector is used as an X-ray receiver, made in the same housing with a battery. 3. The method according to claim 2, characterized in that a digital wireless flat-panel detector is used as an X-ray receiver with automatic averaging of frame signals accumulated in the detector’s memory during multiple exposure to reduce noise from oil and refined products, equipped with a detector temperature sensor, placed into a heat-shielding casing for testing through the pipeline insulation with a surface temperature of up to 100 °C. 4. The method according to claim 1, characterized in that the geometric parameters of each control area are selected based on ensuring the image quality at the edges of the area corresponding to the specified image quality in its central part.

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