In-line Inspection Technology Research Articles

In-Line Inspection (ILI) Techniques for Subsea Pipelines: State-of-the-Art

Offshore oil and gas resources play a crucial role in supplementing the energy needs of human society. The crisscrossing subsea pipeline network, which serves as vital infrastructure for the storage and transportation of offshore oil and gas, requires regular inspection and maintenance to ensure safe operation and prevent ecological pollution. In-line inspection (ILI) techniques have been widely used in the detection and inspection of potential hazards within the pipeline network. This paper offers an overview of ILI techniques used in subsea pipelines, examining their advantages, limitations, applicable scenarios, and performance. It aims to provide valuable insights for the selection of ILI technologies in engineering and may be beneficial for those involved in pipeline integrity management and planning.

A Decade Review of the Art of Inspection and Monitoring Technologies for Long-Distance Oil and Gas Pipelines in Permafrost Areas

Long-distance oil and gas pipelines buried in permafrost areas will inevitably encounter typical geological disasters, such as frost heave and thaw settlement and sliding, which easily cause pipeline displacement, bending, or deformation. When there are certain defects in the pipeline, additional complex, external stress will further lead to the failure of the pipeline or weld and can even lead to serious accidents such as pipeline leakage, pipe burst, or fracture. This paper introduces in detail the typical defects and risks of buried pipelines in permafrost areas and summarizes the in-line inspection technologies, off-line inspection technologies, and integrated monitoring systems for pipelines in the pipeline industry. Regarding pipelines in permafrost areas, in-line inspection methods may be employed. These include magnetic flux leakage, electromagnetic eddy current, ultrasonic, IMU, and electromagnetic acoustic transducer inspections. Off-line inspection is also one of the important means of inspecting a pipeline in a permafrost area. Indirect inspection is combined with verification by direct inspection to check and evaluate the integrity of the anticorrosive coating and the effectiveness of the cathodic protection for the pipeline. Meanwhile, considering the external environment of a pipeline in a permafrost area, a monitoring system should be developed and established. This paper discusses and projects the future development of related technologies, which provides reference for the construction and operation of pipelines in permafrost areas.

A Comprehensive Analysis of In-Line Inspection Tools and Technologies for Steel Oil and Gas Pipelines

The transportation of oil and gas through pipelines is an integral aspect of the global energy infrastructure. It is crucial to ensure the safety and integrity of these pipelines, and one way to do so is by utilizing an inspection tool called a smart pig. This paper reviews various smart pigs used in steel oil and gas pipelines and classifies them according to pipeline structure, anomaly-detection capability, working principles, and application areas. The advantages and limitations of each sensor technology that can be used with the smart pig for in-line inspection (ILI) are discussed. In this context, ultrasonic testing (UT), electromagnetic acoustic transducer (EMAT), eddy current (EC), magnetic flux leakage (MFL), and mechanical contact (MC) sensors are investigated. This paper also provides a comprehensive analysis of the development chronology of these sensors in the literature. Additionally, combinations of relevant sensor technologies are compared for their accuracy in sizing anomaly depth, length, and width. In addition to their importance in maintaining the safety and reliability of pipelines, the use of ILI can also have environmental benefits. This study aims to further our understanding of the relationship between ILI and the environment.

In-line inspection technology of oil and gas long-distance pipeline based on alternating current field measurement

Abstract Alternating current field measurement (ACFM) has advantages of fast inspection speed, high efficiency, sensitive inspection, and easy quantification. In this study, a probe based on ACFM has been carried out, trying to inspect cracks on the inner wall of pipeline with high precision. An inspection tool which is working according to ACFM is developed in order to determine the stress corrosion cracking. The lift-off distance and excitation frequency parameters are optimized, and the influence of uneven magnetic permeability of the pipeline on the test results is analyzed. In addition, experiments are carried out to test the practicality of the tool. The minimum axial crack length that the probe can detect is 15 mm and the minimal depth is 1 mm. The research results show that the probe has the ability to quantitatively evaluate the axial cracks on the inner surface of the pipeline, which has certain guiding significance for the design and development of the AC electromagnetic field inspection probe.

Novel optical metrology for inspection of nanostructures fabricated by substrate conformal imprint lithography

Substrate conformal imprint lithography (SCIL) technology enables the fabrication of complex and non-trivial 3D nanostructures such a slanted gratings and metasurfaces with sub-10 nm resolution over large areas for industrial-scale production, which can be fabricated in a single lithography step. This technology utilizes novel composite silicone rubber stamps that provide versatility in addition to high precision. To inspect the quality and reproducibility of the nanostructures that are fabricated using SCIL, a novel optical characterization method using Fourier microscopy is proposed. In this method, nanostructures are illuminated under a microscope objective using a collimated light beam at different incident angles and the properties of the reflected and/or diffracted beams are analysed to extract the critical dimensions of the nanostructures. This fast and non-destructive method has the potential for being used as an in-line inspection technology to extract the critical dimensions of the nanostructures over large areas and improve the overall properties of nanostructured surfaces.

Research on pipe in-line inspection technology based on the rotating electromagnetic field

A multidisciplinary non-destructive study based on the rotating electromagnetic field has been carried out in an attempt to inspect cracks in any direction on the inner wall of a pipeline with high precision. In this study, an approach is proposed to test and evaluate pipe integrity. An inspection tool that works according to the rotating electromagnetic field is developed in order to determine stress corrosion cracking. In addition, experiments are carried out to test the practicality of the tool. Firstly, the principle and function of the rotating electromagnetic field tool are revealed and the results show that the tool has an outstanding crack inspection capability on the pipe wall. It can also provide a technical reference for the early warning and long-term safe service of metal structures.

Simulation and experimental research on 316L liner of bimetal composite pipe with eddy current testing

Conventional magnetic flux leakage technology is unable to identify the stainless steel-lined defects of bimetallic composite pipe. In this paper, the in-line inspection technology of a 316L liner based on the eddy current flaw detection principle is studied with the aim of solving this problem. A printed circuit board (PCB) coil is designed and parameters such as the external diameter, the number of turns, the number of layers and the shape of the eddy current testing coil are determined. The impedance changes that occur under the influence of different factors of the coil are analysed according to finite element simulation. The contribution of each influencing factor during eddy current testing is investigated to optimise the coil parameters and excitation parameters. An eddy current flaw detection model for the stainless steel liner is finally established and numerical calculation is carried out on the impedance response of the defect, which is detected by parameterised scanning with the coil swept. The coil impedance is obtained under the ideal state and then verified by the experimental tests. The results show that the eddy current array testing coil has good applicability in the detection of surface defects on the stainless steel liner, which can provide references for the development of a bimetallic tube composite probe.

Research and Method for In-line Inspection Technology of Girth Weld in Long-Distance Oil and Gas Pipeline

With the increasing demand for energy, long-distance oil and gas pipeline has become the main mode of transportation of oil and gas resources. High pressure, inflammable and explosive medium, complex and changeable route environment and other factors make the safe transportation of pipeline concerned. The girth welds of oil and gas pipeline have always been the weak part of the pipeline due to the technical level during the construction, on-site welding practices and operation environment, and the girth weld cracking is one of the main failure forms of oil and gas pipeline. It is an effective way to ensure the safety of pipeline to adopt various advanced and targeted inspection to identify pipeline defects, judge the types of defects, and then carry out safety evaluation and maintenance. This paper analyzes the main failure factors of girth weld of oil and gas pipeline, and systematically summarizes the content and methods of various in-line inspection on girth weld in view of these failure factors, so as to provide reference for the development and application of in-line inspection technology on girth weld of oil and gas pipeline.

Improved methods for sizing metal loss in dents for ECA

Dents interacting with metal loss remain as a significant challenge to operators. Existing regulations require that dents with metal loss within high consequence areas be treated as immediate repairs or 60-day conditions, resulting in costly excavations for many operators. At the time when these regulations were written, it was not clear whether inline inspection technologies could discriminate the nature of the metal loss (i.e. corrosion or mechanical damage) or provide accurate sizing. Furthermore, advanced analysis techniques such as finite element analysis were limited, and fitness- forservice evaluations were not common. While the technological hurdles involved with evaluating interacting dent and metal loss features have been overcome, sensor lift-off remains a challenging issue for magnetic flux leakage (MFL) inspection tools, as sizing accuracy degrades at larger lift-off distances. Until recently, the sensor lift-off issue limited the ability to perform fitness- for- service evaluations because the metal loss in dent features could not be confidently sized. This study demonstrates how integrated lift-off sensors can be used to quantify the lift-off as the MFL sensors pass over a dent. This technology integration has allowed the confident application of sizing specifications for many dents with metal loss, thereby permitting robust fitness- for- service evaluations. Several case studies are examined in this paper, demonstrating how the integrated MFL and lift-off technology can serve to reduce excavations while still ensuring safe pipeline operations.

Compensation Method for Pipeline Centerline Measurement of in-Line Inspection during Odometer Slips Based on Multi-Sensor Fusion and LSTM Network.

The accurate measurement of pipeline centerline coordinates is of great significance to the management of oil and gas pipelines and energy transportation security. The main method for pipeline centerline measurement is in-line inspection technology based on multi-sensor data fusion, which combines the inertial measurement unit (IMU), above-ground marker, and odometer. However, the observation of velocity is not accurate because the odometer often slips in the actual inspection, which greatly affects the accuracy of centerline measurement. In this paper, we propose a new compensation method for oil and gas pipeline centerline measurement based on a long short-term memory (LSTM) network during the occurrence of odometer slip. The field test results indicated that the mean of absolute position errors reduced from 8.75 to 2.02 m. The proposed method could effectively reduce the errors and improve the accuracy of pipeline centerline measurement during odometer slips.

Development and application of new technologies and equipment for in-line pipeline inspection

In-line inspection is one of the most effective technical measures to ensure the safety of oil and gas pipelines. However, the extensive application of oil and gas pipelines of high-carbon steel, large diameter, high pressure and high flow rate in recent years brings about new challenges to in-line inspection. In this paper, we investigated the engineering application of new technologies and equipment, including the in-line inspection technology based on electromagnetic detector array, the extremely low frequency transient weak signal detection technology and new in-line inspection equipment. Then, the new technology and equipment of electromagnetic detector array were developed by applying the active emission and receiving of electromagnetic signal to inspect the metallic defects. Finally, noisy signals were inspected on the basis of Duffing chaotic oscillator, and thus the inspection of extremely low frequency signals in the noise was realized. In addition, the new method and equipment of extremely low frequency transient weak signal detection were developed and verified in actual inspection engineering. And the following research results were obtained. First, the in-line inspection technology based on electromagnetic detector array uses the synergetic effect between DC exciting magnetic field and high-frequency exciting magnetic field, so a perturbation response can be realized even by small signal excitation. Second, with the introduction of a novel compressive sampling of acquisition information composition, the speed bottleneck of in-line detector is broken through, and a new world record of the inspection speed of the electromagnetic detector array is set up, i.e., 8 m/s. Third, under the condition of high-speed movement, the received signals of in-line detector are weak and temporary while tracking and positioning outside the pipeline. And by virtue of the extremely low frequency transient weak signal detection method based on chaos, this technical bottleneck is broken through, and the signal-to-noise ratio (SNR) of transient weak signal in the process of real-time inspection is decreased below −10 dB. In conclusion, the superior performance of these new equipment has already been verified in the inspection engineering of in-service oil and gas pipelines. These research results will provide technical and equipment support for the safe operation of domestic main oil and gas pipelines.

Comparative Analysis of In-line Inspection Equipments and Technologies

Considering the global aging of pipelines and demand for new ones in more and more hostile environments, in-line inspection (ILI) based on the Non-Destructive Testing(NDT) was essential for pipeline operating company to protect their asset efficiently. This paper reviewed kinds of state of the art of ILI techniques and equipments, including geometry pig (GP), magnetic flux leakage pig (MFL PIG), ultrasonic pig (UT PIG), electromagnetic acoustic pig (EMAT PIG), eddy current pig (EC PIG), integrated function pig and specific function pig. Through the review of kinds of techniques, different approaches were compared, challenges and problems were highlighted and future research and direction was suggested.

An Integrated Prognostics Approach for Pipeline Fatigue Crack Growth Prediction Utilizing Inline Inspection Data

Fatigue cracking is a key type of defect for liquid pipelines, and managing fatigue cracks has been a top priority and a big challenge for liquid pipeline operators. The existing inline inspection (ILI) tools for pipeline defect evaluation have large fatigue crack measurement uncertainties. Furthermore, the current physics-based methods are mainly used for fatigue crack growth prediction, where the same or a small range of fixed model parameters is used for all pipes. They result in uncertainty that is managed through the use of conservative safety factors such as adding depth uncertainty to the measured depth in deciding integrity management and risk mitigation strategies. In this study, an integrated approach is proposed for pipeline fatigue crack growth prediction utilizing ILI data including consideration of crack depth measurement uncertainty. This approach is done by integrating the physical models, including the stress analysis models, the crack growth model governed by the Paris’ law, and the ILI data. With the proposed integrated approach, the finite element (FE) model of a cracked pipe is built and the stress analysis is performed. ILI data are utilized to update the uncertain physical parameters for the individual pipe being considered so that a more accurate fatigue crack growth prediction can be achieved. Time-varying loading conditions are considered in the proposed integrated method by using rainflow counting method. The proposed integrated prognostics approach is compared with the existing physics-based method using examples based on simulated data. Field data provided by a Canadian pipeline operator are also employed for the validation of the proposed method. The examples and case studies in this paper demonstrate the limitations of the existing physics-based method, and the promise of the proposed method for achieving accurate fatigue crack growth prediction as continuous improvement of ILI technologies further reduces ILI measurement uncertainty.

周辺視目視検査を模擬したインライン外観検査技術に関する研究

周辺視目視検査を模擬したインライン外観検査技術に関する研究

Three-axis magnetic flux leakage in-line inspection simulation based on finite-element analysis

With the increase of pipelines, corrosion leakage accidents happen frequently. Therefore, nondestructive testing technology is important for ensuring the safe operation of the pipelines and energy mining. In this paper, the structure and principle of magnetic flux leakage (MFL) in-line inspection system is introduced first. Besides, a mathematic model of the system according to the ampere circuit rule, flux continuity theorem, and column coordinate transform is built, and the magnetic flux density in every point of space is calculated based on the theory of finite element analysis. Then we analyze and design the disposition of measurement section probes and sensors combining both three-axis MFL in-line inspection and multi-sensor fusion technology. Its advantage is that the three-axis changes of magnetic flux leakage field are measured by the multi-probes at the same time, so we can determine various defects accurately. Finally, the theory of finite element analysis is used to build a finite element simulation model, and the relationship between defects and MFL inspection signals is studied. Simulation and experiment results verify that the method not only enhances the detection ability to different types of defects but also improves the precision and reliability of the inspection system.

New technology for inspecting critical in‐plant piping systems

AbstractInspection and fitness‐for‐service (FFS) of critical in‐plant piping systems remains an ongoing concern for the chemical industry. Recent failures in the US indicate that there is a present and severe risk in piping systems. Historically, unpiggable in‐plant piping can now be inspected with advanced smart pigging technology for complete ultrasonic inspection. High‐resolution inspection data is analyzed to identify the locations and degree of corrosion and piping deformations. This article discusses current industry experience with the inspection and assessment of in‐plant piping systems using advanced smart pigging technology.Utilizing more advanced inline inspection and assessment technology helps operators reduce inspection costs associated with difficult‐to‐inspect pipelines and piping systems; reduce maintenance costs by more accurately pinpointing anomalies and assessing FFS conditions; and accurately determine the actual conditions for lines previously deemed unpiggable. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2011

13nm gate Intentional Defect Array (IDA) wafer patterning by e-beam lithography for defect metrology evaluation

Fabricating and inspecting wafers with defects intentionally created at known locations enables a quantitative and repeatable methodology to assess the performance of in-line defect metrology tools with regard to ITRS requirements. With each successive design node, in-line defect inspection technology becomes more challenging and there are significant concerns about the capability to support 2× and 1× technology nodes. In this paper we report progress at the College of Nanoscale Science and Engineering (CNSE) in Albany, New York, to print and process advanced defect metrology test structures intended to represent a 13nm gate length. The ISMI 13nm gate Intentional Defect Array (IDA) has lithographic defects in known locations with sizes varying from 25% to 400% of the corresponding 32nm node, resulting in defect sizes ranging from 8 to 128nm. The film stack consists of 30nm TEOS hard mask, 60nm polysilicon, 35nm TiN and 2nm HfO2 on top of silicon. The patterns are first printed (at 1×) on a 300mm wafer using a Vistec VB300 electron beam lithography tool with a high resolution HSQ resist (commercially known as Dow Corning XR-1541). The features are subsequently etched to transfer the pat- tern from the resist onto the wafer stack. The resulting IDA wafers are intended to help ISMI engineers investigate next generation metrology techniques and identify solutions for future technology nodes.

Research on in-line glass defect inspection technology based on Dual CCFL

The automatic in-line glass defect inspection technology based on Dual CCFL(Cold Cathode Fluorescent Lamp) was studied. We take the Dual CCFL as illuminant and placed them with a certain interval. The data processor received and processed the light intensity signals, which was transmitted from the glass ribbon and collected by linear CCD array. According to the characteristics of glass defect, high threshold and low threshold, defect signal was processed by ternaruzation data processing method. The data without defect was discarded, and only defect data was stored. Through the judgment of defect data's connectivity and number of defect data, the defect area was computed and type was recognized.

Breakthrough of In-Line Inspection Technology in Volume Production for 65 nm Node and Beyond

We have developed the electron beam inspection system utlizing the projection electron microcope (EBI-PEM) to improve the productivity of electron beam system for next generation semiconductor volume production use. In this paper, we will present the advantagous inpection throughput of EBI-PEM as compared with the conventional electron beam system.

Breakthrough of in-line Inspection Technology for Beyond 65nm Device Volume Production

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