Vulnerability of Buried Pipelines to Landslides

2016 ◽  
Author(s):  
Gerald Ferris ◽  
Sarah Newton ◽  
Michael Porter
Keyword(s):  
Ground Movement ◽  
Buried Pipelines ◽  
Large Numbers ◽  
Vulnerability Model ◽  
Cause Of Failure ◽  
Integrity Management ◽  
Pipeline Failure ◽  
As Stress ◽  
Pipeline Failures ◽  
Landslide Movement

The movement of a mass of rock, debris or earth down a slope is a landslide, which in the pipeline industry is often referred to as ground movement. Landslides continue to cause pipeline failures throughout the industry, sometimes as the singular cause of failure and in others cases as a contributing factor to failures (such as stress corrosion cracking on slopes). Landslides can originate on slopes above a pipeline and cause impact loads; they can originate below a pipeline and cause unintended spans; and they can encompass the ground crossed by a pipeline, which can lead to high compressive (or tensile) strains and pipeline buckling. This paper focuses on the latter scenario. Similar to the approach recently outlined for watercourses [1], the term ‘vulnerability’ refers to the conditional probability of pipeline failure given that landslide movement spatially impacts a pipeline. This paper presents the development of a statistical and judgment-based vulnerability model for pipeline crossings of slopes that are subject to landslides that can be used to rank the relative importance of slopes at a screening level of assessment. The model is based on case histories where this type of landslide scenario caused pipeline failures (defined as holes, leaks and ruptures), or buckling of pipelines that resulted in the need for immediate repairs. Vulnerability has two main uses: on its own to help prioritize large numbers of slope crossings for further investigation; and, once combined with estimates of the probability of landslide movement, to provide a probability of pipeline failure estimate that can be used to guide integrity management programs.

Failures of Pipelines

2021 ◽  
pp. 531-556
Author(s):  
A. Hudgins ◽  
C. Roepke ◽  
B. James ◽  
B. Kondori ◽  
B. Whitley
Keyword(s):  
North America ◽  
Failure Analysis ◽  
Management Practices ◽  
Failure Modes ◽  
Degradation Mechanisms ◽  
Transmission Pipeline ◽  
Integrity Management ◽  
Pipeline Failure ◽  
Pipeline Failures

Abstract This article discusses the failure analysis of several steel transmission pipeline failures, describes the causes and characteristics of specific pipeline failure modes, and introduces pipeline failure prevention and integrity management practices and methodologies. In addition, it covers the use of transmission pipeline in North America, discusses the procedures in pipeline failure analysis investigation, and provides a brief background on the most commonly observed pipeline flaws and degradation mechanisms. A case study related to hydrogen cracking and a hard spot is also presented.

Updated Estimates of Frequencies of Pipeline Failures Caused by Geohazards

2016 ◽  
Author(s):  
Michael Porter ◽  
Gerald Ferris ◽  
Mark Leir ◽  
Miguel Leach ◽  
Mario Haderspock
Keyword(s):  
Western Europe ◽  
Management Practices ◽  
Western Canada ◽  
Failure Frequency ◽  
The Us ◽  
Integrity Management ◽  
Annual Frequency ◽  
Pipeline Failure ◽  
Pipeline Failures ◽  
Transmission Pipelines

This paper provides an updated compilation of geohazard-related pipeline failure frequencies for onshore hydrocarbon gathering and transmission pipelines, with a particular emphasis on the analysis of data from Western Europe, Western Canada, the US, and South America. The results will be of interest to owners, operators, regulators and insurers who wish to calibrate estimates of geohazard failure frequency and risk on planned and operating pipelines, particularly for pipelines traversing mountainous terrain. It concludes with an estimate of the global annual frequency of failures caused by geohazards on hydrocarbon gathering and transmission pipelines, and postulates that this failure frequency should continue to decline when measured on a per kilometer basis due to ongoing improvements in geohazard recognition, routing and design of new pipelines, and improvements to integrity management practices for operating pipelines.

Simulation of the Response of Buried Pipelines to Slope Movement Using 3D Continuum Modeling

2012 ◽  
Author(s):  
Abdelfettah Fredj ◽  
Aaron Dinovitzer
Keyword(s):  
Fluid Pressure ◽  
Slope Movement ◽  
Ground Movement ◽  
Ground Subsidence ◽  
Continuum Modeling ◽  
Buried Pipelines ◽  
Design Standards ◽  
Codes Of Practice ◽  
Modeling Process ◽  
Ongoing Work

Pipeline integrity is affected by the action of external soil loads in addition to internal fluid pressure. External soil loads can be generated by landslides or at sites subject to ground subsidence, heave or seismic effects. Under these varied conditions of ground movement potential pipeline safety involves constraints on design and operations. The design processes includes developing an understanding of strains that could be imposed on the pipe (strain demand) and strain limits that the pipe can withstand without failure. The ability to predict the pipeline load, stress or strains state in the presence of soil restraint and/or soil displacement induced loading is not well described in design standards or codes of practice. This paper describes the ongoing work involved in a study investigating the mechanical behavior of buried pipelines interacting with active landslides. Detailed pipe-soil interaction analyses were completed with a 3D continuum SPH method. This paper describes the LS-DYNA numerical modeling process, previously developed by the authors, which was refined and applied to site-specific conditions. To illustrate the performance of the modeling process to consider a translational slide, additional numerical model validation was completed and is described in this paper. These comparisons illustrate that good agreement was observed between the modeling results and experimental full scale trial results. Sample results of the application of the validated 3D continuum modeling process are presented. These results are being used to develop generalized trends in pipeline response to slope movements. The paper describes both the progress achieved to date and the future potential for simplified engineering design tools to assess the load or deformation capacity requirements of buried pipelines exposed to different types of slope movement.

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.

Pipeline Geohazard Assessment: Bridging the Gap Between Integrity Management and Construction Safety Contexts

2018 ◽  
Author(s):  
Rodney S. Read
Keyword(s):  
Construction Safety ◽  
Worker Safety ◽  
Ground Movement ◽  
Pipeline Construction ◽  
Probability Estimates ◽  
Subject Matter Expertise ◽  
Management Context ◽  
Integrity Management ◽  
Geohazard Assessment

Geohazards are threats of a geological, geotechnical, hydrological, or seismic/tectonic nature that may negatively affect people, infrastructure and/or the environment. In a pipeline integrity management context, geohazards are considered under the time-independent threat category of Weather-related and Outside Force in the American standard ASME B31.8S. Geotechnical failure of pipelines due to ground movement is addressed in Annex H and elsewhere in the Canadian standard CSA-Z662. Both of these standards allow flexibility in terms of geohazard assessment as part of pipeline integrity management. As a result of this flexibility, many systems for identifying, characterizing, analyzing and managing geohazards have been developed by operators and geotechnical engineering practitioners. The evolution of these systems, and general expectations regarding geohazard assessment, toward quantitative geohazard frequency assessment is a trend in recent pipeline hearings and regulatory filings in Canada. While this trend is intended to frame geohazard assessment in an objective and repeatable manner, partitioning the assessment into a series of conditional probability estimates, the reality is that there is always an element of subjectivity in assigning these conditional probabilities, requiring subject matter expertise and expert judgment to make informed and defensible decisions. Defining a specific risk context (typically loss of containment from a pipeline) and communicating uncertainty are important aspects of applying these types of systems. Adoption of these approaches for alternate risk contexts, such as worker safety during pipeline construction, is challenging in that the specific geohazards and threat scenarios considered for long-term pipeline integrity may or may not adequately represent all credible threats during pipeline construction. This paper explores the commonalities and differences in short- and long-term framing of geohazard assessment, and offers guidance for extending geohazard assessment for long-term pipeline integrity to other contexts such as construction safety.

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.

Estimating the Influence of Natural Hazards on Pipeline Risk and System Reliability

2004 ◽  
Author(s):  
Michael Porter ◽  
Clint Logue ◽  
K. Wayne Savigny ◽  
Fiona Esford ◽  
Iain Bruce
Keyword(s):  
Natural Hazards ◽  
System Reliability ◽  
Western Europe ◽  
Ground Movement ◽  
Injury Death ◽  
Ground Conditions ◽  
Service Disruption ◽  
Pipeline Failures ◽  
Pipeline Design ◽  
Design Construction

Natural hazards (also known as ground movement or geohazards) can cause pipeline failures, with consequences ranging from injury/death, environmental impact, and property damage, to lengthy service disruption and a failure to achieve delivery targets. In North America and western Europe, pipeline failure resulting from natural hazards are typically rare (but costly) events. However, where difficult ground conditions have not been properly accounted for in pipeline design, construction, and operation, natural hazards may have an overriding influence on pipeline risk and reliability. These issues are discussed, and a framework for estimating the influence of natural hazards on pipeline risk and system reliability is introduced.

The Contribution of In-Line IMU Inspection to Geohazard and Crack Management Strategies

2021 ◽  
Author(s):  
Andy Young ◽  
Andrew Wilde ◽  
Ivan Grosmann
Keyword(s):  
Management Practices ◽  
Load Capacity ◽  
Management Strategies ◽  
High Strength ◽  
Ground Movement ◽  
Ground Subsidence ◽  
Measurement Unit ◽  
External Loading ◽  
Integrity Management ◽  
The Right

Abstract Geohazards and external loads are a significant threat to the integrity of pipelines in hilly terrain, at river crossings and where ground subsidence is taking place. Well designed pipelines can tolerate strains that exceed the nominal strain of 0.5% that corresponds specified minimum yield strengths, however the presence of weld defects and stress corrosion cracking can reduce the load capacity dramatically. Welds that are to specification but are under-matched on actual strength to the adjacent parent pipe have also been recognised as potentially vulnerable to low strain failures in high strength pipes. Modern pipelines in terrain susceptible to geohazards normally include design studies to identify and avoid or mitigate the threats. Surveillance of the right-of-way is also routinely carried out for pipelines with good integrity management practices, and particularly for major strategic lines. In-line inspection using an inertial measurement unit (IMU) is a well-known method to detect ground movement loads and contributes to the integrity management of pipelines. In this paper we illustrate : 1. How IMU inspection is an important tool in the management of geohazards and how it compliments other methods of geohazard assessment. 2. How locations of elevated pipe strain are identified and evaluated for external loading threats, and can be aligned with other data sets that indicate the pipeline load capacity. 3. How the locations of bending strain can be prioritised for further action. 4. How the loading profile in the pipeline can be incorporated into crack management strategies in order prioritise locations for further investigation or assessment.

Challenges Related to Pipeline Free Spans in Watercourse Crossings

2021 ◽  
Author(s):  
Mario Caruso ◽  
Gerry Ferris ◽  
Hans Olav Heggen ◽  
Burke Delanty
Keyword(s):  
Management Practice ◽  
Economic Loss ◽  
The Past ◽  
Repair Costs ◽  
Vortex Induced Vibrations ◽  
River Erosion ◽  
Liquid Products ◽  
Integrity Management ◽  
Erosion Mechanisms ◽  
Pipeline Failures

Abstract Free span assessment in watercourse crossings for the on-shore pipeline industry has become a more and more important part of pipeline integrity practice. One reason is that it has become increasingly well known that the dominant cause of pipeline failures in watercourse crossings is fatigue failure due to vortex induced vibrations at pipeline free spans. Recognition of this is now being identified in industry recommended practices and owners are incorporating this type of assessment into their pipeline integrity management practice. On shore pipelines are not designed with an allowable free span as is the practice with off-shore pipelines, but are buried. Design codes specify minimum depths of cover when constructed and indicate that pipelines should be maintained so that no excessive loads occur. In the past the no excessive loads requirement has been interpreted that the pipeline must remained buried. As experience from the off-shore environment and increasingly from experience on-shore has shown that most exposed and/or free spans do not fail. Due to various river erosion mechanisms; scour, bank erosion or avulsion, previously buried pipelines do develop free spans. Some of the free spans fail and release products directly into the watercourse. Failures, particularly for liquid products, are very expensive due to the economic loss, repair costs and environment clean-up of the watercourse and its banks. Similarly, costs associated with pipeline replacement for free spanning pipelines or repair of pipelines that might develop free spans are relatively high. It is important to develop an understanding of the probability of the pipeline failing due to a free span, or put another way, determine which free span is a threat to integrity. This paper discusses some of the challenges with assessing free spans in watercourse crossings as part of integrity programs and highlights experiences in assessing this threat to integrity. The objective of this paper is to discuss some of the key uncertainties related to the management of the threat due to free spans. These uncertainties are due to the reliability of information about the free span, water velocity and condition of the pipelines.

Risk Based Inspection for Prioritizing Repair and Inspections of Large Numbers of Platforms in Gulf of Suez

2006 ◽  
Author(s):  
Mohamed A. El-Reedy
Keyword(s):  
Main Part ◽  
Pushover Analysis ◽  
Gulf Of Suez ◽  
Severe Damage ◽  
Rule Based ◽  
Structure Condition ◽  
Large Numbers ◽  
Key Characteristics ◽  
Integrity Management ◽  
Main Factor

GUPCO has more than hundred platforms located in Gulf of Suez that require topsides and underwater inspections on a regular basis as a part of integrity management system. Because of the high cost of underwater inspections and repair, GUPCO has developed a risk-based process to more effectively implement inspection resources. The process is based upon the critical key characteristics of each platform (year designed, number of legs, framing configuration, manning level, etc.) as well as results from previous inspections (date of last inspection, amount of inspection, flooded members, cut member, excessive marine growth, anode status, etc.). Using this information, the overall “risk” of the platform is determined using a rule-based scoring estimation of the likelihood and consequence of failure. In parallel, the severe damage platform structure is assessment by performing pushover analysis. The platforms are then ranked from highest to lowest risk, with the highest risk platforms receiving priority for repair and inspections. By calculating the likelihood of failure which is the main part of the assessment it is found that the age is the main factor affecting the structure condition. So from this paper one can calculate approximate value for failure likelihood occurring to the structure by knowing its age.

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