Lateral Buckling of Deepwater Pipelines in Operation

2012 ◽  
Author(s):  
Yetzirah Urthaler ◽  
Ryan Watson ◽  
Jonathan Davis
Keyword(s):  
Gulf Of Mexico ◽  
Lessons Learned ◽  
Design Solution ◽  
Pipeline System ◽  
Fe Model ◽  
Lateral Buckling ◽  
Operating Environments ◽  
Pipeline Systems ◽  
Fe Model Calibration

Deepwater pipeline systems are regularly designed to operate under high pressure and high temperature (HPHT) conditions. These operating environments typically mean that the systems are susceptible to Euler buckling, more commonly referred to as lateral buckling. An effective design solution, promoted by the SAFEBUCK JIP [1],[2] and now regularly adopted within the industry, is to accommodate the thermal expansion with planned buckle sites, thereby controlling the loads within the system. Traditionally, operators have spent a great deal of resources in designing, manufacturing and installing pipeline systems. However, it is equally important to demonstrate that the system is fit for service and that operational loads do not exceed the extreme design cases. In some instances, there have been a number of instances where lateral buckling has caused full bore rupture in offshore pipelines. In order to verify the long-term integrity of a pipeline system, it is essential to confirm the location, mode shape and amplitude of both the planned and rogue (unplanned) lateral buckles. This can be accomplished via pipeline surveys. Recent pipeline survey work was conducted on a pipeline system in the Gulf of Mexico. The data exhibited some areas of unexpected performance, which highlights the fact that operating uncertainty exists and that lateral buckling is an unstable phenomenon. The design Finite Element (FE) models were calibrated using the measured buckle shapes, and the fatigue life was estimated using recorded operational pressure and temperature data. The survey work performed has proven invaluable when assessing the long-term integrity of the pipeline system. This paper presents a review of the methods used for surveying a pipeline system in the Gulf of Mexico, a summary of the results obtained from the subsequent analysis and pipeline FE model calibration, as well as ‘lessons learned’ for future projects with similar design challenges.

On Pipeline Lateral Buckling: Lessons Learned and Current Design Challenges

2012 ◽  
Author(s):  
Emil A. Maschner ◽  
Basel Abdalla
Keyword(s):  
Cost Effective ◽  
Lessons Learned ◽  
Operating Conditions ◽  
Design Solution ◽  
Lateral Buckling ◽  
Diverse Range ◽  
Applied Loading ◽  
Direct Design ◽  
Safety Margins ◽  
Global Buckling

The subject of lateral buckling design in recent years has by necessity become increasingly more involved as pipeline projects have moved into more difficult environments where there is a need for optimized economic solutions with assured through-life reliability. The authors have had direct design responsibility and specialist involvement with a large number of projects covering a diverse range of environments, single or PIP systems, variable product characteristics and operating conditions, external applied loading type, and geographical installation limitations. These include shallow and deep water, large thin walled and small thick walled diameter pipes, flat to undulating hard to soft seabed, variable cohesive and non-cohesive surficial soil types and various other project considerations which have impacted on the chosen design solution. The purpose of this paper will be to highlight aspects of global buckling design associated with reliable in place systems and conversely those aspects associated with integrity risks to the as-laid operational pipelines. A review of past project challenges along with a commentary as to the state of the art at the time gives an opportunity to evaluate risks and challenges being faced on current projects. Particularly, as it seeks to develop ever more cost effective designs with proven robustness but optimized safety margins for the installation and operation of HT/HP pipelines in marginal fields.

LONG-TERM MONITORING OF SUBMERGED OIL IN THE GULF OF MEXICO FOLLOWING THE T/B DBL 152 INCIDENT

2008 ◽  
Vol 2008 (1) ◽  
pp. 275-278 ◽  
Author(s):  
Chris Pfeifer ◽  
Erik Brzozowski ◽  
Ralph Markarian ◽  
Ramsey Redman
Keyword(s):  
Gulf Of Mexico ◽  
Oil Recovery ◽  
Monitoring Program ◽  
Fate And Transport ◽  
Lessons Learned ◽  
Oil Field ◽  
Specific Information ◽  
Long Term Monitoring ◽  
Term Monitoring

ABSTRACT In November 2005, approximately 1.9 million gallons of Group V slurry oil was released in the western Gulf of Mexico following the allision of the double-hulled tank barge DBL 152 with the submerged remains of a pipeline service platform that collapsed during Hurricane Rita. The released oil was denser than seawater and sank to the bottom. After approximately six weeks of intermittent cleanup using diver-direct pumping, submerged oil recovery operations were suspended by the Unified Command based on the high percentage (50%) of weather-related downtime, as well as indications that recoverable accumulations of oil were dispersing naturally, which further reduced the feasibility of cleanup. However, the responsible party was required to develop and implement a long-term monitoring program (LTMP) to track the fate and transport of the sunken oil and determine the potential need for resuming oil recovery operations once more favorable weather patterns returned in the spring. This paper will present an overview of the approach, methods and results of the long-term monitoring efforts performed over a 14-month period following the incident. Major objectives of the LTMP included tracking the movement and fate of non-recovered submerged oil to assess its extent and continued dispersion; providing advance warning of potential impacts to Gulf Coast shorelines and other sensitive areas; and documenting changes in the oil'S chemical composition and physical properties through time due to weathering processes. Major findings of the LTMP include the dissipation of the main submerged oil field over the course of several months and the discovery, differential behavior and eventual dissipation of a discrete high-concentration oil patch found several miles from the incident location. The importance of long-term monitoring data in the decision-making process to determine both the need for and feasibility of resuming submerged oil recovery operations will be emphasized. Information on the fate and transport characteristics of submerged oil and the adaptation of monitoring techniques to address evolving needs will also be addressed. Both the incident-specific information and the practical lessons-learned are intended to benefit those who may be faced with monitoring submerged oil spills in the future.

A COMPARISON OF METHODS FOR LOCATING, TRACKING AND QUANTIFYING SUBMERGED OIL USED DURING THE T/B DBL 152 INCIDENT

2008 ◽  
Vol 2008 (1) ◽  
pp. 255-259 ◽  
Author(s):  
Ramsey Redman ◽  
Chris Pfeifer ◽  
Erik Brzozowski ◽  
Ralph Markarian
Keyword(s):  
Gulf Of Mexico ◽  
Oil Recovery ◽  
Practical Experience ◽  
Lessons Learned ◽  
Comparison Of Methods ◽  
Underwater Video ◽  
Side Scan Sonar ◽  
Long Term Monitoring ◽  
Term Monitoring

ABSTRACT A variety of methods and equipment were employed during the response and long-term monitoring phases of the DBL 152 incident to locate, track and quantify the nearly 2 million gallons of low-API gravity oil that sank in the western Gulf of Mexico approximately 30 nautical miles off the coast of Cameron, Louisiana. Methods and equipment used to survey submerged oil included: divers; stationary snare sentinels; chain-weighted snare drags using devices known as vessel-submerged oil recovery systems or V-SORS; remotely operated vehicles (ROVs), underwater video drop camera, sled-mounted towed video, side-scan sonar and Rox-Ann sonar. This paper will describe each method and associated equipment and its specific application to submerged oil detection and assessment for this incident. It will also explore the evolution and refinement of approaches used throughout the course of the response and the underlying rationale for these changes. Guidelines and relevant considerations for selecting among these methods will be suggested. Finally, strengths and limitations of each approach will be discussed with the goal of capturing and communicating the lessons learned so that future submerged oil response efforts may benefit from the practical experience gained during the DBL 152 response.

scholarly journals The effect of the structural composition on the resilience of pipeline systems to node damage

Dependability ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 24-29
Author(s):  
I. A. Tararychkin
Keyword(s):  
Structural Optimization ◽  
Random Order ◽  
Source Node ◽  
Statistical Characteristics ◽  
Design Solution ◽  
Pipeline System ◽  
Emergency Situations ◽  
Pipeline Systems ◽  
Linear Elements ◽  
Individual Node

TheAimof this paper is to study the effect of the structural features of pipeline systems on the development of emergency situations by the mechanism of progressive blocking of transportation nodes. The blocking of an individual point element of a system is considered as the result of simultaneous failure of all the pipelines converging into the node. The process of progressive blocking of a certain set of nodes of a pipeline system in random order is called a progressive blocking. The development of progressive blocking is associated with the disconnection of the consumers from the source of end product and is a dangerous scenario of emergency development. The system’s resilience against progressive blocking is estimated by the resilience indicator F„, the average share of the system’s nodes whose blocking in a random order causes the disconnection of all consumers from the source of the end product.Methods of research.The values of 0 <F„< 1 were identified by means of computer simulation. After each fact of damage associated with a random blocking of an individual node, the connection between the source and consumers of the end product was established. The statistical characteristics of the process of progressive blocking were evaluated according to the results of repeated simulation of the procedure of damage of the analyzed network structure. In general, the structure of a pipeline system is characterized by a graph that describes the connections between point elements. The valence of an individual graph node is the number of edges that converge into it. Similarly, the valence of the respective network node is the number of converging linear elements (pipelines). Furthermore, an important characteristic of an individual node is the composition of the converging linear elements. Thus, the set of a system’s linear elements includes the following varieties that ensure the connection between: the source and the consumer (subset G1), two consumers (subset G2), a consumer and a hub (subset G3), two hubs (subset G4), the source and a hub (subset G5).Results.The author analyzed and examined the effect of the structural characteristics on the ability of pipeline systems to resist the development of emergency situations through the mechanism of progressive blocking of nodes. It was established that with regard to structural optimization the most pronounces positive effect associated with the increase of the values F^ is observed as the valence of the source node grows and additional linear elements of subset G1 are included in the system.Conclusions.The process of progressive blocking of pipeline transportation system nodes is a hazardous development scenario of an emergency situation. The most efficient method of improving pipeline system resilience against progressive blocking consists in increasing the valence of the source node and inclusion of additional linear elements of subset G1 in the system. Structural optimization of pipeline systems should be achieved by defining the values F^ for each of the alternatives with subsequent adoption of a substantiated design solution.

Coordination of long-term data management in the Gulf of Mexico: Lessons learned and recommendations from two years of cross-agency collaboration

Shore & Beach ◽  
2020 ◽  
pp. 17-22
Author(s):  
Kathryn Keating ◽  
Melissa Gloekler ◽  
Nancy Kinner ◽  
Sharon Mesick ◽  
Michael Peccini ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Data Management ◽  
Management Practices ◽  
Collaborative Work ◽  
Lessons Learned ◽  
The Many ◽  
Diverse Data ◽  
The University ◽  
Term Data

This paper presents a summary of collaborative work, lessons learned, and suggestions for next steps in coordinating long-term data management in the Gulf of Mexico in the years following the Deepwater Horizon oil spill (DWH). A decade of increased research and monitoring following the DWH has yielded a vast amount of diverse data collected from response and assessment efforts as well as ongoing restoration efforts. To maximize the benefits of this data through proper management and coordination, a cross-agency and organization Long-Term Data Management (LTDM) working group was established in 2017 with sponsorship from NOAA’s Office of Response and Restoration (OR&R) and NOAA’s National Marine Fisheries Service Restoration Center (NMFS RC) and facilitated by the University of New Hampshire’s Coastal Response Research Center. This paper will describe the LTDM working group’s efforts to foster collaboration, data sharing, and best data management practices among the many state, federal, academic and non-governmental entities working to restore and improve the coastal environment in the Gulf following the DWH. Through collaborative workshops and working groups, participants have helped to characterize region-specific challenges, identify areas for growth, leverage existing connections, and develop recommended actions for stakeholders at all organizational levels who share an interest in data coordination and management activities.

Lessons Learned From Operational Integrity of HP/HT Deepwater Pipelines

2019 ◽  
Author(s):  
Carlos O. Cardoso ◽  
Rafael F. Solano ◽  
Bruno R. Antunes
Keyword(s):  
Finite Element ◽  
High Pressures ◽  
Compressive Load ◽  
Lessons Learned ◽  
Fe Model ◽  
Special Device ◽  
Original Design ◽  
Element Analysis ◽  
Lateral Displacements

Abstract This paper addresses the results from a monitoring inspection as part of Petrobras regular plane of inspection of rigid pipelines (PIDR) and numerical Finite Element analysis (FEA) of two parallel HP/HT subsea pipelines operating in Brazilian deepwater subjected to lateral buckling and walking behaviors. The results obtained from inspection and numerical reanalysis furnishes important feedback for the integrity management of the two pipelines, reducing potential risks and lessons learned for future projects. Deepwater pipelines submitted to high pressures and temperatures (HP/HT) are susceptible to global buckling due to axial compressive load. To guarantee pipeline and equipment’s integrity frequently is necessary to relieve high stresses and strains at buckle apex as well as to mitigate end expansion. Thus, the two parallel HP/HT pipelines were designed with single and double sleepers to trigger buckles at pre-determined locations and an anchoring system to prevent pipeline walking. Another important design aspect was to avoid undesirable buckles at the several crossings along the pipeline route applying a special device with stoppers to lock lateral displacements. During a programmed inspection as part of regular Petrobras pipeline integrity program of rigid pipelines (PIDR), it has been verified that some double sleepers didn’t work as foreseen in design. Otherwise, some unplanned buckles on soil have been formed along the two pipelines changing the buckle apex stress levels and end expansions foreseen in detailed design. In order to understand buckle formation behavior and guarantee long-term integrity of the HP/HT pipelines a Multi-Beam Echosounder Survey (MBES) was conducted in 2016 to build a representative Finite Element (FE) model. The temperature and pressure gradients from steady state and transient conditions were obtained from flow assurance simulations based on monitored platform operational historic data. The FE model was calibrated with buckle shapes and end displacements to assess pipeline behavior and its long-term integrity for load scenarios different from original design.

Application of Deterministic and Probabilistic Methods in Pipeline Lateral Buckling Design

2012 ◽  
Author(s):  
Hammam Zeitoun ◽  
Maša Branković ◽  
Edwin Shim ◽  
EuJeen Chin ◽  
Benjamin Anderson
Keyword(s):  
Structural Reliability ◽  
Design Guidelines ◽  
Probabilistic Methods ◽  
Design Solution ◽  
Design Parameters ◽  
Pipeline System ◽  
Limit States ◽  
Lateral Buckling ◽  
Current Design ◽  
Subsea Pipelines

Subsea pipelines lateral buckling design has significantly evolved over the last years as more pipeline projects have moved into more challenging environments and into high temperature / high pressure (HT/HP) design application. Knowledge and understanding of pipeline lateral buckling has improved with design application resulting in refined and enhanced design approaches. Using current design approaches, it is now quite acceptable to control lateral buckle formation along the pipeline by using buckle triggers or to allow uncontrolled lateral buckles, provided that the various design limit states are satisfied. A number of design methodologies can be used to check the acceptability of uncontrolled buckling or to design for controlled buckling including deterministic, probabilistic buckle formation and full Structural Reliability Assessment (SRA) methods. Using SRA or probabilistic methods is usually an attractive design option as lateral buckling design involves dealing with a large number of uncertainties and variation in design parameters. These methods help to ensure the reliability of the proposed buckle initiation scheme. However, the use of these methods is also associated with a number of challenges such as the need to identify key parameters influencing the design and quantifying their uncertainties. Deterministic design approaches on the other hand are simpler to apply. However, they do not provide means to quantify the reliability of the proposed buckling scheme or the design risks. The choice of input parameters in a deterministic design is also relatively subjective which can possibly result in an overly conservative or unconservative design solution depending on the adopted design approach, selected design parameters and pipeline system being considered. Design guidelines and recommended practices such as SAFEBUCK (20) offer comprehensive guidelines to design for lateral buckling. However when faced with a range of complex variables, the designer needs to be aware of the effect of these parameters on the overall design. This paper describes the application of Deterministic and Probabilistic design approaches in lateral buckling design. The paper starts by describing these approaches, their advantages and limitations. The paper then explores a number of key uncertainties and variation in design parameters that the designer is faced with and its effect on the pipeline response.

Maximizing Outcomes in Group Treatment of Aphasia: Lessons Learned From a Community-Based Center

2014 ◽  
Vol 24 (3) ◽  
pp. 100-105 ◽  
Author(s):  
Darlene Williamson
Keyword(s):  
Group Treatment ◽  
Treatment Protocol ◽  
Lessons Learned ◽  
Group Program ◽  
Community Based ◽  
Multiple Treatment ◽  
Use Of Technology ◽  
Communication Impairments ◽  
Treatment Settings

Given the potential of long term intervention to positively influence speech/language and psychosocial domains, a treatment protocol was developed at the Stroke Comeback Center which addresses communication impairments arising from chronic aphasia. This article presents the details of this program including the group purposes and principles, the use of technology in groups, and the applicability of a group program across multiple treatment settings.

Periodic monitoring of vampire bats and rabies: a new framework for animal restoration projects in the Neotropics

2020 ◽  
Author(s):  
Fernando Gonçalves ◽  
Daniel G. Streicker ◽  
Mauro Galetti
Keyword(s):  
Disease Transmission ◽  
Lessons Learned ◽  
Multidisciplinary Teams ◽  
Risk Area ◽  
Food Web Structure ◽  
Land Bridge ◽  
High Risk Area ◽  
Restoration Project ◽  
Vampire Bats

Nowadays, restoration project might lead to increased public engagement and enthusiasm for biodiversity and is receiving increased media attention in major newspapers, TED talks and the scientific literature. However, empirical research on restoration project is rare, fragmented, and geographically biased and long-term studies that monitor indirect and unexpected effects are needed to support future management decisions especially in the Neotropical area. Changes in animal population dynamics and community composition following species (re)introduction may have unanticipated consequences for a variety of downstream ecosystem processes, including food web structure, predator-prey systems and infectious disease transmission. Recently, an unprecedented study in Brazil showed changes in vampire bat feeding following a rewilding project and further transformed the land-bridge island into a high-risk area for rabies transmission. Due the lessons learned from ongoing project, we present a novel approach on how to anticipate, monitor, and mitigate the vampire bats and rabies in rewilding projects. We pinpoint a series of precautions and the need for long-term monitoring of vampire bats and rabies responses to rewilding projects and highlighted the importance of multidisciplinary teams of scientist and managers focusing on prevention educational program of rabies risk transmitted by bats. In addition, monitoring the relative abundance of vampire bats, considering reproductive control by sterilization and oral vaccines that autonomously transfer among bats would reduce the probability, size and duration of rabies outbreaks. The rewilding assessment framework presented here responds to calls to better integrate the science and practice of rewilding and also could be used for long-term studying of bat-transmitted pathogen in the Neotropical area as the region is considered a geographic hotspots of “missing bat zoonoses”.

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