Using Pipeline Operating History for Integrity Management

2004 ◽  
Author(s):  
Robert Lazor ◽  
Stephanie Verbit
Keyword(s):  
Crack Growth ◽  
Initial Crack ◽  
Management Program ◽  
Operating Pressure ◽  
Buried Pipelines ◽  
Pressure History ◽  
Growth History ◽  
Integrity Management ◽  
Inspection And Maintenance ◽  
Rainflow Counting

There are several forms of material degradation that can affect the long-term integrity of buried pipelines, such as generalized corrosion, stress corrosion cracking, and fatigue crack growth. Pipeline operators must periodically assess the condition of their pipeline systems and address current repair priorities and then schedule the next inspection and maintenance programs. The analyses described in this paper have been used to determine the growth of typical cracks that could be found on buried pipelines using the pipeline operating pressure history and fracture mechanics techniques. The details that have been examined include the characterization of the pressure history using rainflow counting techniques and a review of typical pipeline defect types. Examples are provided to describe how the following variables affect the predicted crack growth history: • Pressure histogram ‘bin size’; • Initial crack dimensions. The general techniques and procedures can be used as an integral part of a pipeline integrity management program to establish failure risks and to schedule regular maintenance activities.

Effect of Pressure Loading on Integrity Management

2008 ◽  
Author(s):  
Sanjay Tiku ◽  
Aaron Dinovitzer ◽  
Scott Ironside
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Operating Pressure ◽  
Integrity Assessment ◽  
Pipeline Segment ◽  
Pressure Cycle ◽  
Integrity Management ◽  
Pump Compressor ◽  
Life Predictions

Integrity assessment or life predictions for in-service pipelines are sensitive to the assumptions they rely upon. One significant source of uncertainty is the pipeline operating pressure data often captured and archived using a Supervisory Control and Data Acquisition (SCADA) system. SCADA systems may be programmed to collect and archive data differently from one pipeline to another and the resulting pressure records can be significantly different on the basis of the sampling techniques, data processing and the distance from pump and compressor stations. This paper illustrates some of the issues involved in pressure load characterization and is based upon work sponsored by the Pipeline Research Council International (PRCI). A series of sensitivity studies using fatigue crack growth calculations have been carried out to evaluate several factors that can influence crack stability and growth predictions that are often employed in pipeline integrity planning and repair programs. The results presented will highlight the issues related to performing integrity management based upon pump/compressor discharge or suction SCADA data to characterize the potential severity of pressure fluctuation or peak pressure dependent defects, illustrate the differences in fatigue crack growth rates along a pipeline segment and demonstrate the complexity of pressure cycle severity characterization, based upon distance from discharge, elevation, hydraulic gradient, for different sites along the pipeline route.

Proof-Test-Based Life Prediction of High-Toughness Pressure Vessels

1996 ◽  
Vol 118 (1) ◽  
pp. 86-94 ◽  
Author(s):  
T. L. Panontin ◽  
M. R. Hill
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Life Prediction ◽  
Crack Size ◽  
Initial Crack ◽  
Pressure Vessels ◽  
Operating Pressure ◽  
High Toughness

The paper examines the problems associated with applying proof-test-based life prediction to vessels made of high-toughness metals. Two A106 Gr B pipe specimens containing long, through-wall, circumferential flaws were tested. One failed during hydrostatic testing and the other during tension-tension cycling following a hydrostatic test. Quantitative fractography was used to verify experimentally obtained fatigue crack growth rates and a variety of LEFM and EPFM techniques were used to analyze the experimental results. The results show that: plastic collapse analysis provides accurate predictions of screened (initial) crack size when the flow stress is determined experimentally; LEFM analysis underestimates the crack size screened by the proof test and overpredicts the subsequent fatigue life of the vessel when retardation effects are small (i.e., low proof levels); and, at a high proof-test level 2.4 × operating pressure), the large retardation effect on fatigue crack growth due to the overload overwhelmed the deleterious effect on fatigue life from stable tearing during the proof test and alleviated the problem of screening only long cracks due to the high toughness of the metal.

A Method to Analyze the Impact of Inline Inspection Accuracy on Integrity Management Program Planning of Pipelines

2018 ◽  
Author(s):  
Mingjiang Xie ◽  
Zhigang Tian ◽  
Jeff Sutherland ◽  
Bingyan Fang ◽  
Bill Gu
Keyword(s):  
Program Planning ◽  
Initial Crack ◽  
Management Program ◽  
Multiple Cracks ◽  
Inspection Planning ◽  
Maintenance Costs ◽  
Integrity Assessment ◽  
Integrity Management ◽  
The Impact ◽  
Crack Growth Model

A pipeline integrity management program is greatly affected by integrity planning methods and inline inspection (ILI) tool performance. In integrity management program planning, inspection and maintenance activities are in common practice, determined from risk and integrity assessment practices with the objective to reduce risk and effectively exceed a reliability target for the safe operation of the pipeline. An efficient and effective integrity planning method can address the most significant risk and optimize the operational and maintenance costs. In this paper, a method is presented for analyzing the impact of ILI tool accuracy on integrity planning for pipelines for fatigue cracks. Crack inspection and threat of fatigue cracking was used as the working case for the analysis although the approach could potentially be used for any pipeline threat type. The proposed method is based on the use of a Monte Carlo simulation framework, where initial crack defect size and ILI measurement errors are considered as key random variables. The integrity (severity) assessment of the crack population scenarios used the CorLAS™ burst pressure model, and the Paris’ law crack growth model based on API 579. The subsequent pipeline reliability assessments also considered single and multiple cracks scenarios. Using a reliability / probability of failure (PoF) approach, the impact of ILI tool accuracy and initial crack size on when to set reinspection and reassessment intervals was investigated. Furthermore, integrity program cost scenarios for pipeline integrity programs with multiple cracks was also evaluated with respect to different (crack) populations, pipe conditions and ILI accuracies. A sensitivity analysis was performed considering different inspection costs, maintenance costs and relative crack severity for pipelines with financial metrics. Various scenarios were discussed regarding maintenance and inspection planning and a “total cost rate” for different situations. The proposed method can support integrity management program planning by linking risks with integrity plan costs associated with ILI accuracies, and optimal re-assessment intervals.

Effective Modeling of Fatigue Crack Growth in Pipelines

2012 ◽  
Author(s):  
Steven J. Polasik ◽  
Carl E. Jaske
Keyword(s):  
Fatigue Crack ◽  
Stress Intensity ◽  
Fatigue Crack Growth ◽  
Fracture Mechanics ◽  
Crack Growth ◽  
Growth Models ◽  
Critical Parameters ◽  
Operating Pressure ◽  
Mechanics Model ◽  
Key Variables

Pipeline operators must rely on fatigue crack growth models to evaluate the effects of operating pressure acting on flaws within the longitudinal seam to set re-assessment intervals. In most cases, many of the critical parameters in these models are unknown and must be assumed. As such, estimated remaining lives can be overly conservative, potentially leading to unrealistic and short reassessment intervals. This paper describes the fatigue crack growth methodology utilized by Det Norske Veritas (USA), Inc. (DNV), which is based on established fracture mechanics principles. DNV uses the fracture mechanics model in CorLAS™ to calculate stress intensity factors using the elastic portion of the J-integral for either an elliptically or rectangularly shaped surface crack profile. Various correction factors are used to account for key variables, such as strain hardening rate and bulging. The validity of the stress intensity factor calculations utilized and the effect of modifying some key parameters are discussed and demonstrated against available data from the published literature.

scholarly journals In-situ SEM and optical microscopy testing for investigation of fatigue crack growth mechanism under overload

2018 ◽  
Vol 165 ◽  
pp. 13013
Author(s):  
Wei Zhang ◽  
Liang Cai
Keyword(s):  
Growth Rate ◽  
Crack Growth Rate ◽  
Optical Microscopy ◽  
Crack Growth ◽  
Load Condition ◽  
Crack Tip ◽  
Initial Crack ◽  
Crack Growth Behavior ◽  
Single Overload

In this paper, the in-situ scanning electron microscope (SEM) and optical microscopy experiments are performed to investigate the crack growth behavior under the single tensile overload. The objectives are to (i) examine the overload-induced crack growth micromechanisms, including the initial crack growth acceleration and the subsequent retardation period; (ii) investigate the effective region of single overload on crack growth rate. The specimen is a small thin Al2024-T3 plate with an edge-crack, which is loaded and observed in the SEM chamber. The very high resolution images of the crack tip are taken under the simple variable amplitude loading. Imaging analysis is performed to quantify the crack tip deformation at any time instant. Moreover, an identical specimen subjected to the same load condition is observed under optical microscope. In this testing, fine speckling is performed to promote the accuracy of digital imaging correlation (DIC). The images around the crack tip are taken at the peak loads before, during and after the single overload. After that, the evolution of local strain distribution is obtained through DIC technique. The results show that the rapid connection between the main crack and microcracks accounts for the initial crack growth acceleration. The crack closure level can be responsible for the crack growth rate during the steady growth period. Besides that, the size of retardation area is larger than the classical solution.

The Role of Offshore Monitoring in an Effective Deepwater Riser Integrity Management Program

2007 ◽  
Author(s):  
Brittany Goldsmith ◽  
Elizabeth Foyt ◽  
Madhu Hariharan
Keyword(s):  
Failure Modes ◽  
Human Life ◽  
Management Program ◽  
Measured Data ◽  
Operating Conditions ◽  
Environmental Damage ◽  
Positioning Systems ◽  
Integrity Management ◽  
Deepwater Riser

As offshore field developments move into deeper water, one of the greatest challenges is in designing riser systems capable of overcoming the added risks of more severe environments, complicated well requirements and uncertainty of operating conditions. The failure of a primary riser component could lead to unacceptable consequences, including environmental damage, lost production and possible injury or loss of human life. Identification of the risks facing riser systems and management of these risks are essential to ensure that riser systems operate without failure. Operators have recognized the importance of installing instrumentation such as global positioning systems (GPS), vessel motion measurement packages, wind and wave sensors and Acoustic Doppler Current Profiler (ADCP) units to monitor vessel motions and environmental conditions. Additionally, high precision monitoring equipment has been developed for capturing riser response. Measured data from these instruments allow an operator to determine when the limits of acceptable response, predicted by analysis or determined by physical limitations of the riser components, have been exceeded. Regular processing of measured data through automated routines ensures that integrity can be quickly assessed. This is particularly important following extreme events, such as a hurricane or loop current. High and medium alert levels are set for each parameter, based on design analysis and operating data. Measured data is compared with these alert levels, and when an alert level is reached, further response evaluation or inspection of the components in question is recommended. This paper will describe the role of offshore monitoring in an integrity management program and discuss the development of alert levels based on potential failure modes of the riser systems. The paper will further demonstrate how this process is key for an effective integrity management program for deepwater riser systems.

Integrity Management of Ground Movement Hazards

2016 ◽  
Author(s):  
Yong-Yi Wang ◽  
Don West ◽  
Douglas Dewar ◽  
Alex McKenzie-Johnson ◽  
Millan Sen
Keyword(s):  
Management Program ◽  
Ground Movement ◽  
Tensile Failure ◽  
Weld Strength ◽  
Factors Affecting ◽  
Ground Movements ◽  
Decision Points ◽  
Starting Point ◽  
Integrity Management ◽  
Girth Welds

Ground movements, such as landslides and subsidence/settlement, can pose serious threats to pipeline integrity. The consequence of these incidents can be severe. In the absence of systematic integrity management, preventing and predicting incidents related to ground movements can be difficult. A ground movement management program can reduce the potential of those incidents. Some basic concepts and terms relevant to the management of ground movement hazards are introduced first. A ground movement management program may involve a long segment of a pipeline that may have a threat of failure in unknown locations. Identifying such locations and understanding the potential magnitude of the ground movement is often the starting point of a management program. In other cases, management activities may start after an event is known to have occurred. A sample response process is shown to illustrate key considerations and decision points after the evidence of an event is discovered. Such a process can involve fitness-for-service (FFS) assessment when appropriate information is available. The framework and key elements of FFS assessment are explained, including safety factors on strain capacity. The use of FFS assessment is illustrated through the assessment of tensile failure mode. Assessment models are introduced, including key factors affecting the outcome of an assessment. The unique features of girth welds in vintage pipelines are highlighted because the management of such pipelines is a high priority in North America and perhaps in other parts of the worlds. Common practice and appropriate considerations in a pipeline replacement program in areas of potential ground movement are highlighted. It is advisable to replace pipes with pipes of similar strength and stiffness so the strains can be distributed as broadly as possible. The chemical composition of pipe steels and the mechanical properties of the pipes should be such that the possibility of HAZ softening and weld strength undermatching is minimized. In addition, the benefits and cost of using the workmanship flaw acceptance criteria of API 1104 or equivalent standards in making repair and cutout decisions of vintage pipelines should be evaluated against the possible use of FFS assessment procedures. FFS assessment provides a quantifiable performance target which is not available through the workmanship criteria. However, necessary inputs to perform FFS assessment may not be readily available. Ongoing work intended to address some of the gaps is briefly described.

Testing of Acoustic Emission Technology to Detect Cracks and Corrosion in the Marine Environment

2010 ◽  
Vol 26 (02) ◽  
pp. 106-110
Author(s):  
Ge Wang ◽  
Michael Lee ◽  
Chris Serratella ◽  
Stanley Botten ◽  
Sam Ternowchek ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Structural Integrity ◽  
Pilot Project ◽  
Development Project ◽  
Management Program ◽  
Pipeline System ◽  
Inspection Planning ◽  
Structural Degradation ◽  
Integrity Management ◽  
Acoustic Emission Technology

Real-time monitoring and detection of structural degradation helps in capturing the structural conditions of ships. The latest nondestructive testing (NDT) and sensor technologies will potentially be integrated into future generations of the structural integrity management program. This paper reports on a joint development project between Alaska Tanker Company, American Bureau of Shipping (ABS), and MISTRAS. The pilot project examined the viability of acoustic emission technology as a screening tool for surveys and inspection planning. Specifically, testing took place on a 32-year-old double-hull Trans Alaska Pipeline System (TAPS) trade tanker. The test demonstrated the possibility of adapting this technology in the identification of critical spots on a tanker in order to target inspections. This targeting will focus surveys and inspections on suspected areas, thus increasing efficiency of detecting structural degradation. The test has the potential to introduce new inspection procedures as the project undertakes the first commercial testing of the latest acoustic emission technology during a tanker's voyage.

Implementing a Geohazard Integrity Management Program: Statistics and Lessons Learned Over 15 Years

2014 ◽  
Author(s):  
Alex J. Baumgard ◽  
Tara L. Coultish ◽  
Gerry W. Ferris
Keyword(s):  
Management System ◽  
Management Program ◽  
Lessons Learned ◽  
Proactive Approach ◽  
Oil Pipelines ◽  
Pipeline Networks ◽  
The Usa ◽  
Integrity Management ◽  
Pipeline Failures ◽  
Program Challenges

Over the last 15 years, BGC Engineering Inc. has developed and implemented a geohazards Integrity Management Program (IMP) with 12 major pipeline operators (consisting of gas and oil pipelines and of both gathering and transmission systems). Over this time, the program has been applied to the assessment of approximately 13,500 individual hydrotechnical and geotechnical geohazard sites spanning approximately 63,000 km of operating pipelines in Canada and the USA. Hydrotechnical (watercourse) and geotechnical (slope) hazards are the primary types of geohazards that have directly contributed to pipeline failures in Canada. As with all IMPs, the core objectives of a geohazard management system are to ensure a proactive approach that is repeatable and defensible. In order to meet these objectives, the program allows for varying levels of intensity of inspection and a recommended timescale for completion of actions to manage the identified geohazards in accordance with the degree of hazard that the site poses to the pipeline. In this way, the sites are managed in a proactive manner while remaining flexible to accommodate the most current conditions at each site. This paper will provide a background to the key components of the program related specifically to existing operating pipeline systems, present pertinent statistics on the occurrence of various types of geohazards based on the large dataset of inspections, and discuss some of the lessons learned in the form of program results and program challenges from implementing a geohazard integrity management system for a dozen operators with different ages of systems, complexity of pipeline networks, and in varied geographic settings.

A Spatio-Temporal Water Mains Integrity Management Program for California

2017 ◽  
Author(s):  
Sathya Geetha Ganesan ◽  
Diego Martínez García ◽  
Juneseok Lee ◽  
Jonathan Keck ◽  
Paul Yang
Keyword(s):  
Management Program ◽  
Water Mains ◽  
Integrity Management ◽  
Spatio Temporal
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