scholarly journals Progressive damage to structural elements of pipeline systems and efficiency assessment of protection measures

Dependability ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 34-39
Author(s):  
I. A. Tararychkin
Keyword(s):  
Network Structure ◽  
Random Order ◽  
Transportation System ◽  
Source Node ◽  
Pipeline System ◽  
Progressive Damage ◽  
Protection Measures ◽  
Individual Point ◽  
Pipeline Systems ◽  
Node Protection

The Aim of this paper is to evaluate the effect of transportation node protection on the resilience of pipeline systems to the development of damage by the mechanism of progressive blocking of nodes as well as the efficiency analysis of the employed protection measures. Damage to a point element of a system due to simultaneous transition into the down state of all the pipelines converging into it is called blocking. The process of progressive blocking of a transportation system’s nodes in a random order is considered to be progressive damage of a network structure. Progressive damage is a hazardous emergency development scenario that is associated with the disconnection of first some, then all end product consumers from the source. A system’s ability to resist progressive damage is estimated by the resilience indicator, the average share of the damaged nodes whose blocking in a random order causes the disconnection of all end product consumers from the source. Methods of research. A system’s indicator of resilience to progressive blocking of nodes was defined using computer simulation. The resilience indicator can only be used in comparative analysis of network structure properties if the analyzed systems are comparable. The condition of comparability of systems with protected point elements is the presence of equal numbers of disconnectable consumer nodes and damageable nodes. If the analyzed systems include protective peripheral clusters that represent interconnected sets of point elements, the following must be equal to enable the comparability of such systems: – number of peripheral clusters with two and more consumer nodes on condition of equal number of such nodes within each system; – most probable order of disconnection from the source of both individual consumers and peripheral clusters with equal numbers of end product consumers.Results. A system’s resilience to progressive blocking can be improved by means of managerial and technical measures of transportation node protection. It has been established that the highest efficiency of protection of individual point elements is achieved in case of protection of a consumer node located at the shortest possible distance from the source of the end product. It is demonstrated that the peripheral cluster for protection of a transportation system should be synthesized by including consumers situated at the minimal possible distance from the source node.Conclusions. The development of emergency situations by the mechanism of progressive blocking of nodes is a hazardous scenario of pipeline system damage. The resilience of a network structure to damage can be improved by means of measures of transportation system nodes protection. The highest efficiency of protection of individual point elements is achieved in case of protection of a consumer node located at the shortest possible distance from the source of the end product. The peripheral cluster for protection of a transportation system from progressive damage should be synthesized by including consumers situated at the minimal possible distance from the source node.

scholarly journals Progressive damage to structural elements of pipeline systems and efficiency assessment of protection measures

Dependability ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 34-39
Author(s):  
I. A. Tararychkin
Keyword(s):  
Network Structure ◽  
Random Order ◽  
Transportation System ◽  
Source Node ◽  
Pipeline System ◽  
Progressive Damage ◽  
Protection Measures ◽  
Individual Point ◽  
Pipeline Systems ◽  
Node Protection

The Aim of this paper is to evaluate the effect of transportation node protection on the resilience of pipeline systems to the development of damage by the mechanism of progressive blocking of nodes as well as the efficiency analysis of the employed protection measures. Damage to a point element of a system due to simultaneous transition into the down state of all the pipelines converging into it is called blocking. The process of progressive blocking of a transportation system’s nodes in a random order is considered to be progressive damage of a network structure. Progressive damage is a hazardous emergency development scenario that is associated with the disconnection of first some, then all end product consumers from the source. A system’s ability to resist progressive damage is estimated by the resilience indicator, the average share of the damaged nodes whose blocking in a random order causes the disconnection of all end product consumers from the source. Methods of research. A system’s indicator of resilience to progressive blocking of nodes was defined using computer simulation. The resilience indicator can only be used in comparative analysis of network structure properties if the analyzed systems are comparable. The condition of comparability of systems with protected point elements is the presence of equal numbers of disconnectable consumer nodes and damageable nodes. If the analyzed systems include protective peripheral clusters that represent interconnected sets of point elements, the following must be equal to enable the comparability of such systems: – number of peripheral clusters with two and more consumer nodes on condition of equal number of such nodes within each system; – most probable order of disconnection from the source of both individual consumers and peripheral clusters with equal numbers of end product consumers.Results. A system’s resilience to progressive blocking can be improved by means of managerial and technical measures of transportation node protection. It has been established that the highest efficiency of protection of individual point elements is achieved in case of protection of a consumer node located at the shortest possible distance from the source of the end product. It is demonstrated that the peripheral cluster for protection of a transportation system should be synthesized by including consumers situated at the minimal possible distance from the source node.Conclusions. The development of emergency situations by the mechanism of progressive blocking of nodes is a hazardous scenario of pipeline system damage. The resilience of a network structure to damage can be improved by means of measures of transportation system nodes protection. The highest efficiency of protection of individual point elements is achieved in case of protection of a consumer node located at the shortest possible distance from the source of the end product. The peripheral cluster for protection of a transportation system from progressive damage should be synthesized by including consumers situated at the minimal possible distance from the source node.

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.

scholarly journals Specificity of the development and characteristics of mixed damage to network structures of pipeline transportation systems

Dependability ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 4-11
Author(s):  
I. A. Tararychkin
Keyword(s):  
Emergency Situation ◽  
Random Order ◽  
Transportation Systems ◽  
Pipeline System ◽  
Progressive Damage ◽  
Network Structures ◽  
Pipeline Transportation ◽  
Pipeline Systems ◽  
Linear Elements ◽  
Correct Comparison

Pipeline transportation systems are used in various industries for the purpose of delivering various substances and materials to consumers. If, as the result of an accident development, a certain number of random linear elements (pipelines) consecutively fail, such scenario of events is called progressive damage. If several pipelines converging at a node fail simultaneously, such point element of the system is blocked. Progressive blocking of a certain set of nodes of a pipeline system in random order is called a progressive blocking. Simultaneous development within a system of progressive damage to linear elements and blocking of transportation nodes represents mixed damage. Mixed damage is a hazardous form of emergency, and its development causes fast degradation of a system’s transportation capabilities.The Aim of the paper is to study the characteristic properties and patterns of the progress of mixed damage affecting network structures of pipeline systems, as well as evaluating such systems’ capability to resist its development.Methods of research. The characteristics of network entities’ resilience to the development of mixed damage were identified by means of computer simulation. The nature of the effects to which a system is exposed was defined with a cyclogram, whose integer parameters indicate the alternation of the process of sequential damage of linear elements and nodes of a network structure.Results. It has been established that a correct comparison of the resilience of various network structures to mixed damage is only possible with regard to comparable facilities. For that purpose, the analyzed systems must have identical numbers of nodes, linear elements and end product consumers. Additionally, such systems must be exposed to effects with identical cyclograms. It is shown that the correlation of the resilience of comparable network structures does not depend on the specific type of mixed damage cyclogram, but is defined by the nature of the connections within a particular system.Conclusions. Mixed damage is a hazardous development scenario of an emergency situation that is associated with rapid degradation of the transportation capacity of pipeline systems. The ability of network structures of pipeline systems to resist mixed damage is evaluated based on indicators that are defined by means of simulation. A correct comparison of the resilience of various structures to mixed damage is only possible in case they are comparable. For that purpose, they must have identical numbers of nodes, linear elements and product consumers. Additionally, such systems must be exposed to damage procedures with identical cyclograms. The correlation of the resilience of network structures that comply with the comparability conditions does not depend on the adopted damage cyclogram, but is defined by the existing set of connections within a particular system.

Overpressure Protections in Liquid Pipeline Hydraulic Design

2016 ◽  
Author(s):  
Alan X. L. Zhou ◽  
David Yu ◽  
Victor Cabrejo
Keyword(s):  
New Technologies ◽  
Pressure Control ◽  
Petroleum Products ◽  
Integrated System ◽  
Operating Conditions ◽  
Design Stage ◽  
Pipeline System ◽  
Protection Measures ◽  
Pipeline Systems ◽  
Pipeline Design

Continuous economic development demands safe and efficient means of transporting large quantities of crude oil and other hydrocarbon products over vast extensions of land. Such transportation provides critical links between organizations and companies, permitting goods to flow between their facilities. Operation safety is paramount in transporting petroleum products in the pipeline industry. Safety can affect the performance and economics of pipeline system. Pipeline design codes also evolve as new technologies become available and management principles and practices improve. While effective operation safety requires well-trained operators, adequate operational procedures and compliance with regulatory requirements, the best way to ensure process safety is to implement safety systems during the design stage of pipeline system. Pressure controls and overpressure protection measures are important components of a modern pipeline system. This system is intended to provide reliable control and prevent catastrophic failure of the transport system due to overpressure conditions that can occur under abnormal operating conditions. This paper discusses common pressure surge events, options of overpressure protection strategies in pipeline design and ideas on transient hydraulic analyses for pipeline systems. Different overpressure protection techniques considered herein are based on pressure relief, pressure control systems, equipment operation characteristics, and integrated system wide approach outlining complete pressure control and overpressure protection architecture for pipeline systems. Although the analyses presented in this paper are applicable across a broad range of operating conditions and different pipeline system designs, it is not possible to cover all situations and different pipeline systems have their own unique solutions. As such, sound engineering judgment and engineering principles should always be applied in any engineering design.

scholarly journals Specificity of the development of the damage process to network structures of pipeline transportation systems

Dependability ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 9-16
Author(s):  
I. A. Tararychkin
Keyword(s):  
Network Structure ◽  
Limit State ◽  
Transportation Systems ◽  
Pipeline System ◽  
Progressive Damage ◽  
Network Structures ◽  
Pipeline Transportation ◽  
Linear Elements ◽  
System Resilience ◽  
Maintenance Activities

Introduction. Industrial pipeline transportation systems are complex, potentially hazardous engineering facilities that ensure the delivery of specified amounts of a target product to consumers. The development of emergencies associated with the transition to the down state of a certain number of pipelines may result in the disconnection of some or all the product consumers from the source. If the system’s linear elements transition to the down state in a random order, such a change of the network structure is called a progressive damage. A progressive damage is especially hazardous if, in the course of maintenance activities, a part of the system or a set of process pipelines is disconnected.The Aim of the work is to identify the change patterns of pipeline system resilience when affected by progressive damage and to develop practical recommendations for ensuring the resilience of such systems in operation and during maintenance operations.Methods of research. The resilience of systems as the capability to resist progressive damage was evaluated with an indicator that represents the average fraction of pipelines whose transition into the down state causes the disconnection of all consumers from the source of the product. The resilience values were defined by means of computer simulation. The network structure and the nature of the existing intersystem communications were defined using an adjacency matrix.Results. Damage to a transportation network structure is regarded as a result of a two-stage process. At the stage of target transformation, linear elements are purposefully excluded from a full graph-based structure, bringing the network to a certain initial state. At the second stage, the original structure is transformed according to the mechanism of progressive damage. Such approach allows correctly assessing the changes in the resilience of complex network structures and their ability to resist the development of the processes of damage. The paper sets forth calculated characteristics that allow predicting the behaviour of pipeline networks affected by emergencies. The existence of limit network structures is demonstrated that prove to be very vulnerable to the development of progressive damage.Conclusions. As the process of targeted transformation goes on, the ability of newly formed network structures to resist the development of progressive damage progressively diminishes. The lowest level of pipeline system resilience against the development of the process of progressive damage can be observed as the structure of the network nears the limit state. When preparing maintenance activities with scheduled exclusion of a number of linear elements from an active pipeline system, the proximity of the newly built network structure to the limit state should be assessed along with the resilience of the restored system to possible development of progressive damage.

scholarly journals Experimental and Numerical Vibration Analysis of Hydraulic Pipeline System under Multiexcitations

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Peixin Gao ◽  
Hongquan Qu ◽  
Yuanlin Zhang ◽  
Tao Yu ◽  
Jingyu Zhai
Keyword(s):  
Pressure Fluctuations ◽  
Fluid Motion ◽  
Fluid Pressure ◽  
Point Of View ◽  
Pipeline System ◽  
Base Excitation ◽  
Fem Method ◽  
Pipeline Systems ◽  
Pump Pressure ◽  
Improved Model

Pipeline systems in aircraft are subjected to both hydraulic pump pressure fluctuations and base excitation from the engine. This can cause fatigue failures due to excessive vibrations. Therefore, it is essential to investigate the vibration behavior of the pipeline system under multiexcitations. In this paper, experiments have been conducted to describe the hydraulic pipeline systems, in which fluid pressure excitation in pipeline is driven by the throttle valve, and the base excitation is produced by the shaker driven by a vibration controller. An improved model which includes fluid motion and base excitation is proposed. A numerical MOC-FEM approach which combined the coupling method of characteristics (MOC) and finite element method (FEM) is proposed to solve the equations. The results show that the current MOC-FEM method could predict the vibration characteristics of the pipeline with sufficient accuracy. Moreover, the pipeline under multiexcitations could produce an interesting beat phenomenon, and this dangerous phenomenon is investigated for its consequences from engineering point of view.

scholarly journals Hydraulic Engineering at 100 BC-AD 300 Nabataean Petra (Jordan)

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3498
Author(s):  
Charles R. Ortloff
Keyword(s):  
Water Supply ◽  
Flow Rate ◽  
Distribution Systems ◽  
Maximum Flow ◽  
Hydraulic Engineering ◽  
World Heritage Site ◽  
Maximum Flow Rate ◽  
Pipeline System ◽  
Supply And Distribution ◽  
Pipeline Systems

The principal water supply and distribution systems of the World Heritage site of Petra in Jordan were analyzed to bring forward water engineering details not previously known in the archaeological literature. The three main water supply pipeline systems sourced by springs and reservoirs (the Siq, Ain Braq, and Wadi Mataha pipeline systems) were analyzed for their different pipeline design philosophies that reflect different geophysical landscape challenges to provide water supplies to different parts of urban Petra. The Siq pipeline system’s unique technical design reflects use of partial flow in consecutives sections of the main pipeline to support partial critical flow in each section that reduce pipeline leakage and produce the maximum flow rate the Siq pipeline can transport. An Ain Braq pipeline branch demonstrated a new hydraulic engineering discovery not previously reported in the literature in the form of an offshoot pipeline segment leading to a water collection basin adjacent to and connected to the main water supply line. This design eliminates upstream water surges arising from downstream flow instabilities in the two steep pipelines leading to a residential sector of Petra. The Wadi Mataha pipeline system is constructed at the critical angle to support the maximum flow rate from a reservoir. The analyses presented for these water supply and distribution systems brought forward aspects of the Petra urban water supply system not previously known, revising our understanding of Nabataean water engineers’ engineering knowledge.

Designing Offshore Pipeline Safety Systems Utilising Flow and Pressure in Multi Design Pressure Pipeline Systems

2008 ◽  
Author(s):  
Gjertrud Elisabeth Hausken ◽  
Jo̸rn-Yngve Stokke ◽  
Steinar Berland
Keyword(s):  
Pressure Drop ◽  
Flow Measurement ◽  
Large Diameter ◽  
Pressure Sensors ◽  
Safety System ◽  
Pipeline System ◽  
Outlet Pressure ◽  
Pipeline Systems ◽  
Pipeline Safety ◽  
Design Pressure

The Norwegian Continental Shelf (NCS) has been a main arena for development of subsea pipeline technology over the last 25 years. The pipeline infrastructure in the North Sea is well developed and new field developments are often tied in to existing pipeline systems, /3/. Codes traditionally require a pipeline system to be designed with a uniform design pressure. However, due to the pressure drop when transporting gas in a very long pipeline, it is possible to operate multi design pressure systems. The pipeline integrity is ensured by limiting the inventory and local maximum allowable pressure in the pipeline using inlet and outlet pressure measurements in a Safety Instrumented System (SIS). Any blockage in the pipeline could represent a demand on the safety system. This concept was planned to be used in the new Gjo̸a development when connecting the 130 km long rich gas pipeline to the existing 450 km long FLAGS pipeline system. However, a risk assessment detected a new risk parameter; the formation of a hydrate and subsequent blockage of the pipeline. In theory, the hydrate could form in any part of the pipeline. Therefore, the pipeline outlet pressure could not be used in a Safety Instrumented System to control pipeline inventory. The export pressure at Gjo̸a would therefore be limited to FLAGS pipeline code. Available pressure drop over the Gjo̸a pipeline was hence limited and a large diameter was necessary. Various alternatives were investigated; using signals from neighbour installations, subsea remote operated valves, subsea pressure sensors and even a riser platform. These solutions gave high risk, reduced availability, high operating and/or capital expenses. A new idea of introducing flow measurement in the SIS was proposed. Hydraulic simulations showed that when the parameters of flow, temperature and pressure, all located at the offshore installation, were used; a downstream blockage could be detected early. This enabled the topside export pressure to be increased, and thereby reduced the pipeline diameter required. Flow measurement in Safety Instrumented Systems has not been used previously on the NCS. This paper describes the principles of designing a pipeline safety system including flow measurement with focus on the hydraulic simulations and designing the safety system. Emphasis will be put on improvements in transportation efficiency, cost reductions and operational issues.

Seismic Vulnerability Assessment and Retrofit of a Major Natural Gas Pipeline System: A Case History

2005 ◽  
Vol 21 (2) ◽  
pp. 539-567 ◽  
Author(s):  
Dharma Wijewickreme ◽  
Douglas Honegger ◽  
Allen Mitchell ◽  
Trevor Fitzell
Keyword(s):  
Natural Gas ◽  
Vulnerability Assessment ◽  
Seismic Vulnerability ◽  
Ground Improvement ◽  
Lateral Spreading ◽  
Gas Pipeline ◽  
Pipeline System ◽  
Seismic Vulnerability Assessment ◽  
Natural Gas Pipeline ◽  
Pipeline Systems

The performance of pipeline systems during earthquakes is a critical consideration in seismically active areas. Unique approaches to quantitative estimation of regional seismic vulnerability were developed for a seismic vulnerability assessment and upgrading program of a 500-km-long natural gas pipeline system in British Columbia, Canada. Liquefaction-induced lateral spreading was characterized in a probabilistic manner and generic pipeline configurations were modeled using finite elements. These approaches, developed during the early part of this 10-year program, are more robust than typical approaches currently used to assess energy pipeline systems. The methodology deployed within a GIS environment provided rational means of distinguishing between seismically vulnerable sites, and facilitated the prioritization of remedial works. While ground improvement or pipeline retrofit measures were appropriate for upgrading most of the vulnerable sites, replacement of pipeline segments using horizontal directional drilling to avoid liquefiable zones were required for others.

Designing Offshore Pipeline Systems Divided Into Sections of Different Design Pressures

2004 ◽  
Author(s):  
Gunnar Staurland ◽  
Morten Aamodt
Keyword(s):  
Uniform Design ◽  
External Pressure ◽  
Transportation Systems ◽  
Point Of View ◽  
Pipeline System ◽  
Operating Pressure ◽  
Pipeline Systems ◽  
Upstream Pressure ◽  
Transmission Pipeline ◽  
Design Pressure

Norwegian waters have been a main arena for development of subsea pipeline technology over the last 25 year. The gas transportation systems from Norway to continental Europe comprise the largest and longest sub sea pipelines in the world. Codes traditionally require a pipeline to be designed with a uniform design pressure between stations with overpressure protection capabilities. However, the downstream part of a very long gas transmission pipeline may, after commissioning, rarely, if ever, see pressures near the pressure at the upstream end. There is, therefore, a potential for cost reduction and capacity improvement if two, or several, sections of different design pressure could be used without having to implement sub sea pressure regulation and overpressure protection facilities at the point of transition between the different sections of design pressure. In determining the lower design pressure the shutdown of the pipeline outlet facilities, at any point in time allowing for a practicable, achievable delay for closure of the upstream inlet valve has to be taken into account. The settle out pressure in a “normal” shut-in situation shall then not exceed the lower design pressure. In addition, deep water pipelines are often designed to withstand buckling due to bending and external pressure during installation, and may therefore locally tolerate a much higher internal pressure than the pipeline was designed for. Transmission pipelines crossing deepwater areas may therefore be designed for two or more operating pressures along the pipeline, thereby optimizing the cost. Even more important, for already existing pipelines, the capacity may be significantly increased by utilizing the upstream heavy wall sections. The operating pressure range for a long offshore gas transmission pipeline is very wide compared to an onshore line, typically between an upstream pressure of 150–250 bar, and a downstream pressure of 60 to 80 bar over a distance of several hundred kilometers. It may take hours to notice the closure of a downstream valve on the upstream pressure. Unless the pipeline is extensively packed, it is obvious that the pressure drop along the pipeline may be taken into account by allowing a lower design pressure for downstream part than for the upstream part. Thereby, the investment cost can be reduced. This paper describes the principles of designing a pipeline system divided into sections of different design pressures from a hydraulic point of view. The basis is the offshore standard for designing submarine pipeline systems, DNV OS-F101. The focusing will be on improvements in transportation efficiency, cost reductions and operational issues.

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