scholarly journals Comparison Between In-Line Crack Detection and Hydrostatic Testing in IPL’s Line 3

1998 ◽  
Author(s):  
Michael A. Gardiner ◽  
Clive R. Ward ◽  
Susan E. Miller
Keyword(s):  
Elastic Wave ◽  
Crack Detection ◽  
Rigorous Analysis ◽  
Shrinkage Crack ◽  
Seam Weld ◽  
Pipe Line ◽  
Remedial Work ◽  
Inspection Data ◽  
Line Crack

The BG Elastic Wave in-line crack detection vehicle was used to inspect 213.5 km (133 miles) of Interprovincial Pipe Line Inc’s (IPL’s) Line 3. Rigorous analysis of the inspection data, concentrated on the seam weld and surrounding region, identified 73 sites for excavation. Pressure retaining sleeves were fitted at 17 locations. Of these, the most severe defect noted was a 25 mm (1 inch), 40% through wall long seam shrinkage crack. This was the only feature exceeding a size predicted to possibly fail under hydrotest to 100% SMYS. Twelve other cracks were sleeved, all of which were measured to be between 20% and 35% through wall. Minor imperfections were found at the majority of those reported locations which were not sleeved. Following completion of remedial work, 198 km (124 miles) of Line 3 was hydrostatically tested at pressures up to 100% SMYS, including 156 km (98 miles) that had been inspected by the Elastic Wave vehicle. There were no leaks or ruptures under hydrotest, demonstrating the ability of the tool to reliably detect cracks in the seam weld and surrounding region that were smaller than would have been found by hydrostatic testing alone.

Enbridge Comparison of Crack Detection In-Line Inspection Tools

2002 ◽  
Author(s):  
Garrett H. Wilkie ◽  
Tanis J. Elm ◽  
Don L. Engen
Keyword(s):  
Power Systems ◽  
Elastic Wave ◽  
Crack Detection ◽  
Management Program ◽  
Metal Loss ◽  
Integrity Management ◽  
Magnetic Inspection ◽  
Extensive Program ◽  
Inspection Data ◽  
Geometry Inspection

Enbridge Pipelines Inc. operates the world’s longest and most complex liquids pipeline network. As part of Enbridge’s Integrity Management Program In-Line Inspections have been and will continue to be conducted on more than 15,000 km of pipeline. This extensive program is comprised of a mature metal loss and geometry inspection component as well as a crack inspection program utilizing the most sophisticated In-Line Inspection (ILI) tools available. Enbridge conducted its first ultrasonic crack inspection with the British Gas Elastic Wave Vehicle (Now GE Power Systems – Oil & Gas – PII Pipeline Solutions) in September 1993 on a Canadian portion of it’s 864–mm (34”) diameter line. The Elastic Wave Vehicle was also used for crack detection on additional segments of this same 864–mm (34”) diameter line during the following years, 1994, 1995 and 1996. Enbridge then conducted its first crack inspection with the Pipetronix UltraScan CD tool (Now also GE Power Systems – Oil & Gas – PII Pipeline Solutions) in November 1997 on a segment of this 864–mm (34”) diameter line that was previously inspected with the Elastic Wave Vehicle. The UltraScan CD tool was then utilized again in 1999, 2000 and 2001 completing crack inspection of the Canadian portion of this 864–mm (34”) diameter line. Enbridge conducted its first magnetic crack inspection with the PII TranScan (TFI) Circumferential Magnetic inspection tool in December 1998 on a United States portion of another 864–mm (34”) diameter line. This same section of line was subsequently inspected with the PII UltraScan CD tool in July 2001. This paper discusses the comparison of results from overlapping crack inspection data analysis from these three PII crack detection tools. Specifically, the overlap of the UltraScan CD and Elastic Wave Vehicle along with the overlap of the UltraScan CD and TranScan (TFI) tool. The relative performance of each crack detection tool will be explored and conclusions drawn.

A Review of Crack Detection In-Line Inspection Case Studies

2010 ◽  
Author(s):  
Neil Bates ◽  
David Lee ◽  
Clifford Maier
Keyword(s):  
Crack Growth ◽  
Case Studies ◽  
Crack Detection ◽  
Growth Parameters ◽  
Probability Distributions ◽  
Low Frequency ◽  
Probability Of Failure ◽  
Probability Of Detection ◽  
Inspection Data

This paper describes case studies involving crack detection in-line inspections and fitness for service assessments that were performed based on the inspection data. The assessments were used to evaluate the immediate integrity of the pipeline based on the reported features and the long-term integrity of the pipeline based on excavation data and probabilistic SCC and fatigue crack growth simulations. Two different case studies are analyzed, which illustrate how the data from an ultrasonic crack tool inspection was used to assess threats such as low frequency electrical resistance weld seam defects and stress corrosion cracking. Specific issues, such as probability of detection/identification and the length/depth accuracy of the tool, were evaluated to determine the suitability of the tool to accurately classify and size different types of defects. The long term assessment is based on the Monte Carlo method [1], where the material properties, pipeline details, crack growth parameters, and feature dimensions are randomly selected from certain specified probability distributions to determine the probability of failure versus time for the pipeline segment. The distributions of unreported crack-related features from the excavation program are used to distribute unreported features along the pipeline. Simulated crack growth by fatigue, SCC, or a combination of the two is performed until failure by either leak or rupture is predicted. The probability of failure calculation is performed through a number of crack growth simulations for each of the reported and unreported features and tallying their respective remaining lives. The results of the probabilistic analysis were used to determine the most effective and economical means of remediation by identifying areas or crack mechanisms that contribute most to the probability of failure.

Methodology to Develop Fitness-for-Service Assessments for Crack Detection In-Line Inspection Data

2006 ◽  
Author(s):  
David Shanks ◽  
Rob Leeson ◽  
Corina Blaga ◽  
Rafael G. Mora
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Crack Detection ◽  
Corrosion Cracking ◽  
Life Extension ◽  
Remaining Life ◽  
Service Monitoring ◽  
Criticality Assessment ◽  
Inspection Data

Implementation of Integrity Management Programs (IMP) for pipelines has motivated the design of Fitness-For-Service methodologies to assess Stress Corrosion Cracking (SCC) and fatigue-dependent features reported by Ultrasonic Crack Detection (UTCD) In-Line Inspections. The philosophical approach defined by the API 579 [1] “Fitness-For-Service” from the petrochemical industry in conjunction with Risk-based standards and regulations (i.e. CSA-Z662-2003 [2] and US DOT 49 Parts 192 [3] and 195 [4]) and in-line inspection validation (i.e. API 1163 [5]) approaches from the pipeline industry have provided the engineering basis for ensuring the safety, reliability and continued service of the in-line inspected pipelines. This paper provides a methodology to develop short and long-term excavation and re-inspection programs through a four (4) phase-process: Pre-Assessment, Integrity Criticality Assessment, Remediation and Repair, Remaining Life Extension and In-Service Monitoring. In the first phase, Pre-assessment, areas susceptible to Stress Corrosion Cracking (SCC) and fatigue-dependent features are correlated to in-line inspection data, soil modeling, pipeline and operating conditions, and associated consequences in order to provide a risk-based prioritization of pipeline segments and technical understanding for performing the assessment. The second phase, Integrity Criticality Assessment, will develop a short-term maintenance program based on the remaining strength of the in-line inspection reported features previously correlated, overlaid and risk-ranked. In addition, sites may be identified in Phase 1 for further investigation. In the third phase, a Remediation and Repair program will undertake the field investigation in order to repair and mitigate the potential threats as well as validating the in-line inspection results and characterization made during the Pre-assessment and Integrity Criticality Assessment (Phases 1 & 2). With the acquired knowledge from the previous three (3) phases, a Remaining Life Extension and In-Service Monitoring program will be developed to outline the long-term excavation and re-inspection program through the use of SCC and Fatigue crack growth probabilistic modeling and cost benefit analysis. The support of multiple Canadian and US pipeline operating companies in the development, validation and implementation of this methodology made this contribution possible.

Continuous Depth Sizing of ILI Ultrasonic Crack Detection

2016 ◽  
Author(s):  
Abdullahi Atto ◽  
Marius Grigat ◽  
Jens Voss
Keyword(s):  
Crack Detection ◽  
Performance Test ◽  
Crack Depth ◽  
Integrity Assessment ◽  
Depth Profiles ◽  
Field Verification ◽  
Large Populations ◽  
Continuous Crack ◽  
General Improvement ◽  
Inspection Data

Since the market launch of Ultrasonic crack detection tools, the conventional crack depth sizing is based on four depth classes or buckets. A more differentiated, continuous depth sizing is becoming increasingly relevant for the pipeline operators and especially for pipelines with large populations of planar anomalies (SCC colonies, lack-of-fusion in ERW seam-welds, etc.). The ILI industry is introducing a continuous crack depth sizing. Next to the better differentiation and the linearity of the depth reporting, the main advantage of the continuous depth sizing is the direct comparability to the results of the field verifications. The continuous depth sizing improves the ability to assess the performance validation of the depth sizing and thus, contributes to a general improvement of the crack depth sizing. This paper describes the development and implementation of a continuous crack depth sizing approach and shows its advantages in comparison to the conventional depth classes. A sizing model is introduced, making use of an empirically derived function, that relates the amplitude measurement to the defect depth. The continuous depth sizing applies to crack-like defects with depths ranging from 1mm to 4mm. The parameters of the model are derived from performance tests based on artificial flaws. In addition, the model is validated by means of field verification results. The depth sizing accuracy and confidence levels are obtained from the performance test data in accordance to API 1163 [1] and POF 2009 [2]. In addition, the paper discusses the extraction of the crack depth profiles from inspection data, making use of the newly developed continuous depth sizing model. In comparison to standard reporting of maximum depth and length, crack depth profiles deliver more accurate and more valuable input to the integrity assessment for pipeline operators. Examples of a direct comparison of these crack depth profiles to field verification data are included.

SCC Detection and Mitigation Based on In-Line Inspection Tools

2004 ◽  
Author(s):  
Walter Kresic ◽  
Scott Ironside
Keyword(s):  
High Resolution ◽  
Management System ◽  
Crack Detection ◽  
Fitness For Purpose ◽  
Preventative Maintenance ◽  
Precise Method ◽  
Field Inspection ◽  
Integrity Management ◽  
Inspection Data ◽  
Ongoing Monitoring

The focus of the Enbridge Integrity Management System is to prevent leaks or ruptures caused by all duty-related pipe deterioration including SCC. As with all pipe defect types, ongoing monitoring programs are employed to determine whether SCC has occurred. Where it has, preventative maintenance programs are employed to mitigate the SCC. Where required, Enbridge employs high-resolution crack in-line inspection (ILI) as the most precise method for managing SCC. As a member of the Canadian Energy Pipeline Association (CEPA), Enbridge participated in the development of a basic framework for SCC management programs and has adopted this framework as the basis for the Enbridge program. Ultrasonic crack detection ILI, capable of detecting SCC, has been employed on over 3000 km of Enbridge pipe and several hundred investigative excavations have been conducted in relation to the ILI data. The results gathered from these investigations have been trended to define the effectiveness of crack detection ILI to detect, size, and discriminate SCC defects. This paper and presentation describes Enbridge’s experience utilizing ultrasonic crack detection ILI for SCC management. The Enbridge trends have shown that ILI can be reliably utilized to detect SCC but, additional innovation is required for defect sizing. While ILI sizing is limited, trends developed from field inspection data have provided the ability to categorize ILI signals into general classifications that ensure all relevant SCC features are highlighted. The categorization is accurate but added precision would reduce the number of investigative excavations, which currently, are also conducted on many sub-relevant features. Coincident with SCC activities driven by ILI data, trends were also developed for peripheral aspects such as field NDT technology, fitness-for-purpose equations, and SCC initiation and growth causes. Observations and trends related to these activities are also described herein.

Development and Experiences of a Circumferential Stress Corrosion Crack Management Program

2018 ◽  
Author(s):  
Neil Bates ◽  
Mark Brimacombe ◽  
Steven Polasik
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Crack Detection ◽  
Circumferential Stress ◽  
Management Program ◽  
Corrosion Cracking ◽  
Pipeline System ◽  
Average Growth ◽  
Proactive Management ◽  
Inspection Data

A pipeline operator set out to assess the risk of circumferential stress corrosion cracking and to develop a proactive management program, which included an in-line inspection and repair program. The first step was to screen the total pipeline inventory based on pipe properties and environmental factors to develop a susceptibility assessment. When a pipeline was found to be susceptible, an inspection plan was developed which often included ultrasonic circumferential crack detection in-line inspection and geotechnical analysis of slopes. Next, a methodology was developed to prioritize the anomalies for investigation based on the likelihood of failure using the provided in-line inspection sizing data, crack severity analysis, and correlation to potential causes of axial or bending stress, combined with a consequence assessment. Excavation programs were then developed to target the anomalies that posed the greatest threat to the pipeline system or environment. This paper summarizes the experiences to date from the operator’s circumferential stress corrosion cracking program and describes how the pipeline properties, geotechnical program, and/or in-line inspection programs were combined to determine the susceptibility of each pipeline and develop excavation programs. In-line inspection reported crack types and sizes compared to field inspection data will be summarized, as well as how the population and severity of circumferential stress corrosion cracking found compares to the susceptible slopes found in the geotechnical program completed. Finally, how the circumferential SCC time-average growth rate distributions were calculated and were used to set future geohazard inspections, in-line inspections, or repair dates will be discussed.

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