Risk Assessment of Urban Gas Pipeline Based on Different Unknown Measure Functions

Several risk factors threaten the safety of urban gas pipeline. How to effectively identify various risk factors affecting urban gas pipeline and put forward scientific risk assessment method is the focus in the field of urban safety research. To explore the uncertain factors in the process of gas pipeline risk assessment, and propose a practical assessment method, a three-layer index system for the risk assessment of urban gas pipeline was established using unascertained measure theory, which included 5 first-class evaluation factors and 34 second-class evaluation indexes. Four unascertained measure models (linear, parabolic, exponential and sinusoidal) were constructed, and the unascertained measure values of each evaluation index under four unknown measure function models were calculated. The weight of evaluation factors was determined by Analytic Hierarchy Process (AHP), and the confidence criterion was used for discriminant evaluation. Results demonstrate that the risk assessment models constructed with different measurement functions can effectively reduce the uncertainty of urban gas pipeline risk assessment, but for the same object, the risk level of the linear measurement model in 4# pipeline is lower than other measurement functions, and the risk level of sinusoidal measurement model in 8# pipeline is higher than other measurement functions. Therefore, considering the evaluation results under different measure functions and focusing on monitoring objects with different results is necessary when using unascertained measure theory for risk assessment. The conclusions obtained from this study clarify the application conditions of unascertained measure theory in urban gas pipeline risk assessment, which helps to reduce the uncertainty in the assessment process and improve the accuracy of the assessment results

Quantifying reputation loss of pipeline operator from various stakeholders perspectives, part 1: prioritization

Quantifying reputation loss (RL) due to pipeline damage is commonly generalized based on the owner's definition. This one-way perspective of portraying RL is unfair and unrealistic and consequently miscalculates the impact assessment of pipeline damage; hence, inaccurate risk prediction. It is crucial to develop a model to quantify qualitative RL to avoid unpredicted risk. Thus, this article provides a framework for a procedure to calculate RL by utilizing the factors identified in a previous study. In this paper (Part 1), the prioritization of factors based on the stakeholders' perspectives is presented. The factors were grouped into stakeholder-influenced categories and prioritized by a fuzzy analytic hierarchy process based on the feedback gained from the stakeholders, i.e., investors, customers, employees and the public. The result shows that factor D3, “Accident severity”, was ranked highest by all stakeholders. The priority vector for each factor obtained was assigned as a weight of the factor. The pipeline owner's reputation loss model (RLM) is developed by applying the obtained priority vectors in the subsequent paper (Part 2). The developed model was verified by experts as a comprehensive, clear, objective, practical and moderately reliable model. The model was applied to a case study and eventually produced a lower risk value when compared with the currently used model. It is proven that RL factors can be quantitatively measured and can simultaneously improve pipeline damage impact assessment. Thus, a risk-based inspection schedule can be managed comprehensively

Application and Development of Advanced Engineering Geographical Information Systems for Pipeline Design

This thesis proposes the use of an Advanced Engineering Geographical Information System (AEGIS) for the improved design of onshore pipelines, from concept to operation. The system is novel in that it is function rather than discipline or software specific. The thesis statement has been developed, and an aim and set of research objectives identified (along with the success criteria for the evaluation of the system), based on a review of current pipeline design methods. Drawing on a design science research methodology (DSRM), the thesis proposes the development of the system as an artefact in order to validate the proposed constructs, models, methods and implementations. The thesis discusses the underlying issues of data interoperability, the application of open data standards, and the integration of computer aided design (CAD) and geographical information systems (GIS). These challenges are addressed in the thesis and demonstrated through the implementation of the system. To support the development of the system, research was undertaken in the fields of pipeline engineering, environmental engineering and engineering design. As part of this research, a number of peer-reviewed journal papers were published, and conference papers presented in Kampala, Houston, London and Split. These papers covered the key fields contained in the thesis including, fluid mechanics, bio-systems engineering, environmental engineering,CAD/GIS integration (CGI), and the application and development of geospatial pipeline data models. The thesis concludes that the approach is valid, offering significant improvement across all fields compared to the current method of pipeline design. By taking a functional approach to the challenges of the design of pipelines, a system has been developed that addresses the requirements of the pipeline engineer, environmental engineer and engineering designer. The system enables the user to select the software of their choice, thereby reducing the problems associated with data interoperability, retraining and system integration. The sharing of data and outputs from analysis carried out within the system, provides an integrated approach, which can subsequently be used for the integrity management of the pipeline during the operational phase of the project. The scope for further development of this approach to pipeline design is also discussed. In addition to the inclusion of further engineering and environmental analysis, there is the potential for using the system for the design of subsea pipelines

Risk Assessment and Management of Petroleum Transportation Systems Operations

Petroleum Transportation Systems (PTSs) have a significant impact on the flow of crude oil within a Petroleum Supply Chain (PSC), due to the great demand on this natural product. Such systems are used for safe movement of crude and/or refined products from starting points (i.e. production sites or storage tanks), to their final destinations, via land or sea transportation. PTSs are vulnerable to several risks because they often operate in a dynamic environment. Due to this environment, many potential risks and uncertainties are involved. Not only having a direct effect on the product flow within PSC, PTSs accidents could also have severe consequences for the humans, businesses, and the environment. Therefore, safe operations of the key systems such as port, ship and pipeline, are vital for the success of PTSs. This research introduces an advanced approach to ensure safety of PTSs. This research proposes multiple network analysis, risk assessment, uncertainties treatment and decision making techniques for dealing with potential hazards and operational issues that are happening within the marine ports, ships, or pipeline transportation segments within one complete system. The main phases of the developed framework are formulated in six steps. In the first phase of the research, the hazards in PTSs operations that can lead to a crude oil spill are identified through conducting an extensive review of literature and experts’ knowledge. In the second phase, a Fuzzy Rule-Based Bayesian Reasoning (FRBBR) and Hugin software are applied in the new context of PTSs to assess and prioritise the local PTSs failures as one complete system. The third phase uses Analytic Hierarchy Process (AHP) in order to determine the weight of PTSs local factors. In the fourth phase, network analysis approach is used to measure the importance of petroleum ports, ships and pipelines systems globally within Petroleum Transportation Networks (PTNs). This approach can help decision makers to measure and detect the critical nodes (ports and transportation routes) within PTNs. The fifth phase uses an Evidential Reasoning (ER) approach and Intelligence Decision System (IDS) software, to assess hazards influencing on PTSs as one complete system. This research developed an advance risk-based framework applied ER approach due to its ability to combine the local/internal and global/external risk analysis results of the PTSs. To complete the cycle of this study, the best mitigating strategies are introduced and evaluated by incorporating VIseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) and AHP to rank the risk control options. The novelty of this framework provides decision makers with realistic and flexible results to ensure efficient and safe operations for PTSs

Risk Quadruplet: Integrating Assessments of Threat, Vulnerability, Consequence, and Perception for Homeland Security and Homeland Defense

Risk for homeland security and homeland defense is often considered to be a function of threat, vulnerability, and consequence. But what is that function? And are we defining and measuring these terms consistently? Threat, vulnerability, and consequence assessments are conducted, often separately, and data from one assessment could be drastically different from that of another due to inconsistent definitions of terms and measurements, differing data collection methods, or varying data sources. It has also long been a challenge to integrate these three disparate assessments to establish an overall picture of risk to a given asset. Further, many agencies conduct these assessments and there is little to no sharing of data, methodologies, or results vertically (between federal, state, and local decision-makers) or horizontally (across the many different sectors), which results in duplication of efforts and conflicting risk assessment results. Obviously, risk is a function of our perceptions and those perceptions can influence our understanding of threat, vulnerability, and consequence. Some assessments rely on perceptions (elicited from subject matter experts) in order to qualify or quantify threat, vulnerability, and consequence. Others exclude perception altogether, relying on objective data, if available. Rather than fault the subjectivity of our perceptions, or muddle objective assessments with personal opinions, it makes sense to embrace our perceptions, but segregate them as a unique component of risk. A risk quadruplet is proposed to systematically collect and integrate assessments of threat, vulnerability, consequence, and perception, such that each dimension can be explored uniquely, and such that all four components can be aggregated into an overall risk assessment in a consistent, transparent, traceable, and reproducible manner. The risk quadruplet draws from the fields of homeland security, homeland defense, systems engineering, and even psychology to develop a model of risk that integrates all four assessments using multicriteria decision analysis. The model has undergone preliminary validation and has proven to be a viable solution for ranking assets based on the four proposed components of risk

Design an Optimum Highway Route using Remote Sensing Data and GIS-Based Least Cost Path Model, Case of Minya-Ras Ghareb and Minya-Wahat-Bawiti Highway Routes, Egypt

The traditional method of aligning highways is a tedious, time-consuming process, and needs a lot of manual work, expensive consuming and complicated process, where numerous environmental issues need to be addressed. The problem is exacerbated where the alignment is influenced by the location of services, existing roads, and buildings. Therefore, there is a great need to adopt new technologies that save time and money in designing and assessment of highway paths. Remote Sensing and GIS make the highway alignment most appropriate avoiding vulnerable high-risk zones such as sand dunes, stream crossing, fault zones, etc….in addition to considering environmental protection constraints and cost savings. It needs less manpower, less time consuming and less cost. In this context, a survey was conducted to determine the factors that affect the process of choosing the path of roads through the previous literature and a panel of experts. Minya Ras-Gharib road in the Eastern Desert of Egypt and Minya Wahat Bawiti road in the Western Desert of Egypt as a case study. Remotely sensing techniques, Landsat 8 and digital elevation models were used to produce land use maps, sand dunes, existing roads, slopes, and flood sites. In addition, thematic maps such as rock type, faults, protectorates. Cost factors were determined and cost surface for each factor was established, standardized, weighed and aggregated based on previous literature. A pairwise comparison is used to determine the weight of factors. These weighted factors /criteria maps were combined to create the least cost surface map. Four visions were modeled: an economic vision, an environmental vision, an equal vision, and economy only vision. A comparison was made between the four-route using the DEFINITE software.The equal-weights route was the best route. A comparison was made between the equal-weight route and the existing route.The results of the comparison show that the recommended route save about 48% for the road of Minya Ras Gharib and save about 33 % for the road of Minya Wahat Bawiti compared to the existing road, in addition to saving the time, effort and cost

Reliability analysis of aged natural gas pipelines based on utility theory

Pipelines are of major importance for transport of natural gas, but a lot of the current in-service pipelines are in wear-out phase. Safe and reliable operations of these pipelines are related to economic development and social stability. It is of great importance and practical significance to study when the corroded pipelines will be retired and how to guarantee that these pipelines will be operating under safe and reliable conditions. The paper proposes a model for assessing risk in natural gas pipelines, and for classifying sections of pipeline into risk categories with utility theory. It aims to help transmission and distribution companies when engaged in risk integrated assessment and decision making consider multiple dimensions of risk from pipeline leakage accidents. Firstly, we analyze the corrosion leakage probability of pipeline remaining life using the exponential distribution; secondly, we evaluate the economic loss, loss of life and damage to the environment in terms of the utility function to get the corresponding risk value of external loss. Finally, we calculate the internal economic loss when in-service pipelines are replaced ahead of scheduled time and then schedule a most optimal date to exchange the aging pipelines containing corrosion. To verify the effectiveness of the proposed methods, a numerical application based on a real case study is presented

Стан та перспективи технологій оцінювання ризиків експлуатації магістральних трубопроводів

The linear part of main oil and gas pipelines, which are potentially the most dangerous type of pipeline networks, selected as the object of investigation. The paper presents the method for risk assessment of pipelines using GIS-technologies for predictive modeling. Describes the basic principles of risk assessment and mapping of pipeline risk prediction using geoinformation systems

Bottom-up formulations for the multi-criteria decision analysis of oil and gas pipeline decommissioning in the North Sea : Brent field case study

Peer reviewe