Shutdown Valves Research Articles

A probabilistic approach to optimal emergency shutdown valve configuration for pressurised CO2 pipelines

This study presents a multi-objective optimisation technique for determining the optimal number of in-line Emergency Shutdown Valves (ESDVs) for pressurised CO2 pipelines, aiming to balance risk associated with pipeline failure against the valve cost based on treating the risk as a probabilistic variable. Using standard Probability Density Functions (PDFs) to model the uncertainties inherent in pipeline characteristics and operating conditions, we perform a Monte Carlo simulation involving the random sampling from these PDFs to derive a probabilistic distribution of risk. This method contrasts with traditional deterministic methods that rely on assuming the worst-case failure scenario or pre-determining an averaged expected risk level — typically calculated by summing the products of failure frequencies and consequence magnitudes for various representative failure scenarios. The proposed approach integrates the risks of all possible failure scenarios directly into the optimisation process without such assumptions or pre-determinations, assessing them collectively based on their individual probabilities of occurrence. Our findings illustrate that the proposed technique allows for more reliable and effective ESDV configurations compared to the traditional methods. This approach not only facilitates safer CO2 transport within the context of Carbon Capture, Utilisation and Storage but also offers a framework for optimising pipeline ESDV configurations in general.

MAINTENANCE STRATEGY REVIEW (MSR) BASED ON ISO 14224:2016 IN INDONESIA OIL AND NATURAL GAS COMPANIES

<p>The oil and gas industry is vital for Indonesia, and the safety and effectiveness of work in processing and exploring the oil and gas that operate in Indonesia must comply with existing regulations. This safety and effectiveness are inseparable from how the company maintains the assets and instruments used at the oil and gas production and exploration site. Maintenance of pipes and instruments for production is one of the company's most vital assets. In addition to having appropriate productivity, pipes and instruments must be maintained optimally so that maintenance costs do not exceed the value of the oil and gas production. This study's research subject is a natural gas refinery from an oil and gas company operating in the Madura Strait, East Java, Indonesia. The object of research limited to the company's piping system (pipeline system). This study uses a quantitative assessment using the calculated Mean Time Before Failure (MTBF) method and a qualitative assessment using the asset maintenance standard to reveals how the maintenance cycle that has been implemented can be optimized. The author carried out a criticality assessment using Maintenance Strategy Review (MSR) to calculate the risk level of asset. This study found that 78 assets must be maintained in their maintenance cycle, two cash assets must be reduced in their maintenance cycle, and seven assets can be extended for their maintenance cycle. The two assets that need to be reduced in maintenance cycles are the shutdown valve asset that goes to the temporary pig receiver and the shutdown valve that goes to the HP flare header. An asset that can be extended its maintenance cycle is a transmitter for flow indicators.</p><div><div><p> </p></div></div>

Implementation of quantitative risk and cost–benefit analysis in an aging offshore facility

AbstractRiser shutdown valves (SDVs) are installed to isolate hydrocarbon through a subsea pipeline or to protect platforms and personnel from an unintended release of hydrocarbons. Unfortunately, the volume of gas leaking through the SDV is sometimes beyond the predetermined criteria. Therefore, a quantitative risk assessment is needed by conducting cost–benefit analysis (CBA). This is the methodology of this study. First, we carry out a frequency analysis to calculate the frequency of release from an isolatable section using an estimate of the release frequency, event tree analysis, and escalation from consequence modeling. Second, we study the consequences of modeling. Third, we carry out risk analysis and evaluation. Fourth, we do CBA calculation. Fifth, we consider the other perspectives. The results of this study can predict the possibility of riser SDV leakage in offshore facilities during the aging period and optimize operating and investment costs while maintaining safety to reduce the possibility of fire explosions. It poses a challenge because of the complexity of operational systems involving multiple potential contributors and multiple safety measures. The study results show that the probability of fire prediction at SDV with processing facilities increases from 8.10 × 10−09 to 7.93 × 10−05 for the worst case scenario. Case studies show that application of the CBA model can be used to optimize the allocation of safety investments.

Emergency Shutdown Valve damage classification by machine learning using synthetic data

Emergency Shutdown Valves (EDSVs) are used in industrial applications to interrupt internal fluid flow in pipelines during hazardous events. During their operation, these valves can suffer cumulative damage on their reinforced polytetrafluoroethylene (RPTFE) seats that can put their operation and effectiveness at risk. One of the options for detecting the occurrence of damage is to analyse data acquired from fluid pressure and torque sensors during the closing and opening cycles of the valve. The resulting operational signatures are commonly evaluated through so-called Transition Points (TPs) that are manually marked in a subjective manner by a trained operator. In addition to being slow and laborious, this approach discards most of the acquired information. Alternatives to this method would be the use of Damage Indexes (DIs) that are extracted from the signatures, or even the evaluation of the complete pressure or torque signature. These methods, when associated with machine learning (ML) algorithms, could use the acquired information more efficiently and reliably, and would have the potential to completely automate the monitoring process. In this work, these three processing options were tested and compared using real and synthetic data that were generated with the Monte Carlo (MC) method. The results indicate that the evaluation of the complete signature with a Gradient Boosting Classifier (GBC) algorithm would be the most effective strategy, which correctly detects the damage in 99% of the cases considered.

An adaptable end-to-end maintenance performance diagnostic framework

PurposeThis paper proposes a progressive, multi-level framework for diagnosing maintenance performance: rapid performance health checks of key performance for different equipment groups and end-to-end process diagnostics to further locate potential performance issues. A question-based performance evaluation approach is introduced to support the selection and derivation of case-specific indicators based on diagnostic aspects.Design/methodology/approachThe case research method is used to develop the proposed framework. The generic parts of the framework are built on existing maintenance performance measurement theories through a literature review. In the case study, empirical maintenance data of 196 emergency shutdown valves (ESDVs) are collected over a two-year period to support the development and validation of the proposed approach.FindingsTo improve processes, companies need a separate performance measurement structure. This paper suggests a hierarchical model in four layers (objective, domain, aspect and performance measurement) to facilitate the selection and derivation of indicators, which could potentially reduce management complexity and help prioritize continuous performance improvement. Examples of new indicators are derived from a case study that includes 196 ESDVs at an offshore oil and gas production plant.Originality/valueMethodological approaches to deriving various performance indicators have rarely been addressed in the maintenance field. The proposed diagnostic framework provides a structured way to identify and locate process performance issues by creating indicators that can bridge generic evaluation aspects and maintenance data. The framework is highly adaptive as data availability functions are used as inputs to generate indicators instead of passively filtering out non-applicable existing indicators.

In-service performance of emergency shutdown valves and dependent operational relationships in the offshore oil and gas industry

Industrial process plants use emergency shutdown valves (ESDVs) as safety barriers to protect against hazardous events, bringing the plant to a safe state when potential danger is detected. These ESDVs are used extensively in offshore oil and gas processing plants and have been mandated in the design of such systems from national and international standards and legislation. This paper has used actual ESDV operating data from four mid/late life oil and gas production platforms in the North Sea to research operational relationships that are of interest to those responsible for the technical management and operation of ESDVs. The first of the two relationships is between the closure time (CT) of the ESDV and the time it remains in the open position, prior to the close command. It has been hypothesised that the CT of the ESDV is affected by the length of time that it has been open prior to being closed (Time since the last stroke). In addition to the general analysis of the data series, two sub-categories were created to further investigate this possible relationship for CT and these are “above mean” and “below mean”. The correlations (Pearson's based) resulting from this analysis are in the “weak” and “very weak” categories. The second relationship investigated was the effect of very frequent closures to assess if this improves the CT. ESDV operational records for six subjects were analysed to find closures that occurred within a 24 h period of each other. However, no discriminating trend was apparent where CT was impacted positively or negatively by the frequent closure group. It was concluded that the variance of ESDV closure time cannot be influenced by the technical management of the ESDV in terms of scheduling the operation of the ESDV.

Wear-optimized partial stroke test for all-electric actuation systems

Offshore production industry is continuously growing. Access to unexplored resources at the seabed represents a challenge for current technologies to fulfill the demanding standards to guarantee safe and pollution-free solutions. All-electric actuation systems arise as an alternative for the actuation of Emergency Shutdown valves in subsea x-mas trees. Partial Stroke Test (PST) corresponds to a diagnosis test that actuates all-electric actuation systems by partially opening/closing the valve. The novelty of this paper lies in a wear-optimized PST approach to diagnose all-electric actuation systems, evaluated through experimental tests. The PST software is designed and implemented in the actuators controller, keeping the system complexity level unaltered. Torque vs position graphs are live generated while varying parameters such as valve travel, operation modes, and process fluid. As conclusion, the PST approach implemented on all-electric actuation systems has a higher diagnostic coverage over the state of the art for a Normally Closed operation mode by detecting valve leakage through pressure estimation. For a Normally Open operation mode, the diagnostic coverage reaches the state of the art without additional hardware. The results are obtained with a PST that does not unseal the valve, avoiding the most critical moments that add wear to it.

Importance of “SMART valve positioners” in testing of final control elements in safety instrumented systems application

AbstractMany industrial facilities, especially those in the chemical and oil and gas industries, involve inherent risk in operations due to the processing of materials that may be hazardous in nature. It is therefore necessary to precisely identify and analyze these hazards, operability issues, associated risks, and consequences. Safety instrumented systems (SIS) are often used to reduce the risk associated with processes or plants to an acceptable or tolerable level. The reliability of safety function(s) implemented through SIS is dependent on how reliable the sub‐elements of the safety function, that is, sensors, logic solvers, and final elements, are. The final elements of such a SIS usually include the emergency shutdown valves, depressurizing valves, emergency isolation valves, and critical on–off valves. Since these final elements remain continuously open or are sometimes closed during the normal operation of the plant, it becomes a challenge to operate the final elements when there is a demand on the SIS. During an emergency, if these final elements fail to operate, this contributes to the dangerous failure of the plant, which may result in explosion, fire, or catastrophic damage to plant assets, environment, and personnel. Hence, it is essential to test these final elements frequently while in operation, without disturbing the operation of the running plant, to ensure that these final elements are available to perform their intended functions when needed. Smart valve positioners are one of the options among various methods available to test the final elements without disturbing the process. This paper evaluates the application, functionality, diagnostics, and advantages of SMART positioners in the testing of final control elements in a SIS application.

Consequence Analysis of Accidental LNG Release on the Collided Structure of 500 cbm LNG Bunkering Ship

The growing demand for liquefied natural gas (LNG)-fueled ships necessitates the establishment of an LNG bunkering facility. Ship-to-ship (STS) is one of the most practical forms of LNG bunkering systems. Although there are benefits to the LNG bunkering of ships, risk and safety issues are a concern due to the volatile cargo. Ship collision could result in accidental LNG release. The purpose of this study was to build LNG leakage scenarios, establish critical zones based on gas concentrations, and estimate the temperature reduction in a bunkering ship’s structure resulting from the use of cryogenic fluid. The condition of a target ship’s structure, both intact and when damaged due to collision, was considered. Leak size, leak direction, leak position, release rate, and reservoir pressure were included as leak parameters, and environmental parameters, such as the wind direction, wind speed, and ambient temperature, were also included. The release duration was set based on the shutdown duration of the emergency shutdown valve (ESD). A total of 72 leakage scenarios were generated for the main CFD analysis. Convergence tests were conducted to determine the appropriate grid and iteration numbers for a computational fluid dynamics (CFD) simulation. The gas dispersion characteristics and the cryogenic flow impact on the LNG bunkering ship’s structure are discussed through a parametric study.

Sistem Monitoring Instrument Air System Berbasis Internet Of Things di PT.Parna Raya

There is an operation process for facility & equipment support in the distribution process of the oil and gas company such as the Pressure Regulating System and Process Shutdown Valve. The supporting equipment uses pneumatic actuators as a driving force whose power source comes from air, as from the fact the compressor as an air producer is still manually used and the air pressure in the air receiver is not monitored from the control room. The purpose of this research is to develop the previous system by creating an integrated system that can be monitored remotely in real time by adding several electronic devices and utilizing Internet of Things technology. Based on the research that have been carried out, the pressure sensor has good accuracy with an average error of 0.06%, so it can be a reference in monitoring the pressure on the air receiver and a notification alarm will appear if the pressure on the air receiver reads 5.5 Bar as evidenced by testing 10 times the average pressure read on the blynk app of 5,460 Bar. Hardware and software function properly according to the design, air pressure at the air receiver and status of the compressor in stand-by or running state can be monitored through the blynk app, so that the gas distribution process does not stop again

Qualitative risk analysis of the overhead hydrogen piping at the conceptual process design stage

Namie, which is a town in Fukushima prefecture in Japan, has started a green innovation project using hydrogen to eliminate CO 2 release by 2050 and establish a zero-carbon city. One idea is to develop an overhead hydrogen piping, which is a low-pressure hydrogen supply system, in public spaces. To develop and implement the piping in Namie and other areas, it is important to both develop the process and perform the risk analysis during a preliminary process design stage. The purpose of this study was to qualitatively analyze and identify the critical risks and effective safety measures for the piping. A total of 183 accidental scenarios were identified by using a hazard identification study, and the preventive and mitigation safety measures were summarized. Hydrogen dispersion simulations revealed that low-pressure hydrogen dispersion leaking from small holes and fractured piping in public spaces could result in concerning risks depending on the leak size, direction, position, obstacles, and ignition source. In addition, a shutdown system of the piping was evaluated with a multiphysics modeling simulation, and its importance was discussed to proceed with detailed investigations. Finally, we suggested risk reduction measures based on the concept of inherent safety for the development of low-pressure hydrogen systems, and the findings can be applied to cases such as Namie. • The overhead hydrogen piping was developed. • Qualitative risk assessment using hazard identification study was carried out. • 183 accidental scenarios were identified, and safety measures were summarized. • The flammable concentration of hydrogen was predicted by dispersion simulations. • A piping shutdown valve was evaluated as a critical safety measure.

Optimal emergency shutdown valve configuration for pressurised pipelines

This paper presents the development and testing of a multi-objective optimisation technique for selecting the optimal in-line Emergency Shutdown Valve (ESDV) configurations for high-pressure transport pipelines. Using a real 150.2 km long, 1016 mm i.d. natural gas pipeline operating at 80 bar and 307.24 K as a case study, the optimisation technique is employed to strike the optimal balance between risk reduction, valve failure rate and capital cost expenditure. Starting with defining a set of six important valve and pipeline design characteristics as optimisation variables, Principal Component Analysis is employed to reduce the number of these parameters to three, reducing computational workload, whilst retaining accuracy. The results obtained using the multi-objective optimisation model are presented using scatter plots providing a geometrical visualisation of the set of optimal solutions in the space of objective functions. The findings demonstrate the efficacy of the proposed technique as an effective tool for the decision makers to select the optimal inline ESDV configurations, taking account of the valve type, pipeline overall dimensions, operating conditions, and the fluid composition being transported.

Prognostic model for reliability assessment of emergency shutdown valves used in oil & gas facility

Prognostic model for reliability assessment of emergency shutdown valves used in oil & gas facility

Prognostic model for reliability assessment of emergency shutdown valves used in oil & gas facility

Prognostic model for reliability assessment of emergency shutdown valves used in oil & gas facility

PFD analysis of LNG fuel gas supply system for improving combined-cycle power plant safety

In order to determine an unavailability of each safety function subsystem that influences on an overall unavailability of entire protection system for safety analysis and enhancement, a modeling is required. This article presents a safety system modeling to evaluate the detected–undetected failures and repairable behaviors of each safety function subsystem in the studied fuel gas supply system (FGSS), which is utilized in a combined-cycle power plant. The proposed modeling deals with probability of failure on demand (PFD) analysis for calculation of the unavailability of three safety function subsystems, which are gas analytical subsystem (GAS), fuel gas controller subsystem (FGC), and shutdown valve subsystem (SDV). The interested GAS includes two different groups of gas analyzers in 2-out-of-2 (2oo2) voting scheme, when using three gas analyzers in each group in 2-out-of-3 and diagnosis (2oo3D) voting scheme. The interested FGC consists of two controllers in 2oo2 voting scheme, when the structure of each controller is in 1-out-of-1 and diagnosis (1oo1D) voting scheme. The interested SDV consists of two shutdown valves, which are installed in 1-out-of-2 (1oo2) voting scheme. The reliability block diagram is utilized for representative of combination of all three safety function subsystems, and the fault tree is utilized for calculation of PFD unavailability of each safety function subsystem. As the results obtained from the proposed safety function modeling, the influence of three safety function subsystems on the total unavailability of the FGSS is described. In addition, an example of the proposed modeling application to provide two guidelines for effective engineering design and operation is also presented. The first is a guideline to implement an effective human machine interface (HMI) at an operator workstation for real-time monitoring of the studied FGSS in the presence of failures that can be automatically detected by device diagnosis. The latter is a guideline to maintain and troubleshoot the failures that can be revealed by proof test. Based on diagnostic information and proof test results, operation and maintenance savings can be achieved.

Diagnostic Protocol for Thermal Performance of District Heating Pipes in Operation. Part 2: Estimation of Present Thermal Conductivity in Aged Pipe Insulation

Buried and operating district heating (DH) pipes are exposed to thermal degradation of their polyurethane (PUR) insulation over time, and their status is hard to assess without excavation. By using DH pipe valves in manholes as measurement points during a shutdown with an ensuing cooling period, non-destructive assessments can be performed. This study compares new improved field measurements with numerical simulations of the temperature decline in drainage valves and shutdown valves. The drainage valve measurements were used to thermally assess part of a buried DH network. Results indicate that by using the drainage valves as measurement points in a cooling method, the thermal conductivity of the buried DH network could be predicted with an accuracy of >95%. In addition, a general diagnostic protocol has been established for assessing the thermal status of a DH network, ready for network owners to use.

Diagnostic Protocol for Thermal Performance of District Heating Pipes in Operation. Part 1: Estimation of Supply Pipe Temperature by Measuring Temperature at Valves after Shutdown

This study evaluates temperatures measured at district heating (DH) valves in manholes and their usability for non-destructively assessing the thermal performance of buried DH pipes. The study was conducted as a field test in which part of a DH network was shut down and the temperature decline in the valves was analysed in terms of absolute temperature and thermal response time from the DH pipe to the top of the valve. The calculated and measured supply pipe temperatures by the drainage valves were in good agreement, with 1% deviation. The valve measurement analysis from this study shows that the drainage valve has good potential to serve as a measurement point for assessing the thermal status of a DH network. However, the shutdown valve measurements were greatly affected by the manhole environment.

Technical Language Processing for Efficient Classification of Failure Events for Safety Critical Equipment

Previous research has investigated how automated annotation and technical language processing of maintenance work orders can support maintenance decisions for different types of equipment, e.g., Sexton et al. (2018) and Brundage et al. (2021). The objective of this paper is to investigate how technical language processing can be utilized for efficient and automated classification of failure events for safety critical equipment on petroleum facilities (e.g., gas detectors and shutdown valves). For such equipment, maintenance decisions are heavily influenced by the consequence of a failure, e.g., if the failure is classified as critical or degraded, or dangerous or safe.
 To explore the possibilities for automated classification of failure events, the paper will first present the fundamental concept hierarchy needed during annotation of safety critical equipment on petroleum facilities. This hierarchy is based on previous work where taxonomies from the ISO 14224:2016 standard (ISO 14224, (2016)) have been operationalised and detailed for safety critical equipment. The concept hierarchy is tested by a group of experts on a set of notifications to ensure that it is fit for purpose. The results from the test group are then used to refine the concept hierarchy before a larger group of persons, having different roles in the petroleum industry, is engaged in the entity typing of notifications. This entity typing will then provide the basis for mapping informal technical language to a computable format. By combining this knowledge with available structured information, such as failure mode and detection method, it is expected that an automated, standardised, and more efficient classification of failure events will be possible. Our database of several thousand manually classified notifications collected during the last decade, will finally enable us to evaluate the performance of the automated classification.

Fast-Tracking an FLNG Relocation in Malaysia

This article, written by JPT Technology Editor Judy Feder, contains highlights of paper OTC 30440, “Floating LNG 1 Relocation: Another World’s First,” by Muhammad Fakhruddin Jais, Wan Mahsuri Wan Hashim, and Ariff Azhari Ayadali, Petronas, et al., prepared for the 2020 Offshore Technology Conference Asia, originally scheduled to be held in Kuala Lumpur, Malaysia, 17–19 August. The paper has not been peer reviewed. Copyright 2020 Offshore Technology Conference. Reproduced by permission. Floating liquefied natural gas (FLNG) allows LNG to be processed hundreds of kilometers away from land to unlock gas reserves in remote and stranded fields previously uneconomical to monetize. The complete paper describes the operator’s fast-tracking of a 450-km FLNG unit relocation from Sarawak to Sabah offshore Malaysia. The time from selecting the new field to unloading LNG at the new location was 13 months. The complete paper discusses pre-execution and engineering studies, relocation preparation and execution, and challenges encountered, including timeline, cost minimization, and manning. Introduction Since 2016, Petronas has operated its first floating LNG production, storage, and offloading facility offshore Sarawak. During the tenure of operation, cargo was delivered successfully to customers worldwide. An opportunity to help a different gas supplier monetize another stranded field offshore Sabah, approximately 450 km away from the unit’s original location, presented itself. The new opportunity was deemed feasible for several reasons. - The identified location is still within Malaysian waters and thus is subject to similar authority and regulations. - Operation within the same country ensures common support from vendor and contractors to some extent. - The two fields have similar gas profiles and water depth. The project team determined that these factors would result in minimal modification at both FLNG and up-stream facilities to meet minimum shut-down from project sanction until first LNG cargo was produced. Pre-Execution and Engineering Studies To fast-track the project, an evaluation was conducted of the new feed-gas composition and modification of both up-stream and FLNG facilities. Long-lead items (LLIs) were identified, and studies were conducted to secure the items. One of the identified LLIs was the flexible pipeline from the upstream facilities to the FLNG. A flow-assurance study covered the steady-state and transient operation for the flexible line. This study confirmed the size of the pipeline and defined the functional requirement for the flexible pipeline procurement. Among the key parameters identified were the pipeline’s thermal conductivity and design pressure. During the feasibility stage, a steady-state study was conducted to determine the length of the flexible line in order to meet the landing pressure and temperature at the FLNG. Instead of requiring additional cooler, the flexible line was extended 2 km to take advantage of the Joule-Thomson cooling effect resulting from the pressure drop across the pipeline. In addition to defining the LLI properties, the flow-assurance study also examined the transient operation for both upstream and FLNG upon the closure of the riser shutdown valve. The study assessed flow-assurance issues, such as hydrates and adequacy of the slug receiver during the transient operation, that might arise, and defined the start-up and commissioning sequence for the facilities.

Determining Constructions Phase Risk Mitigation of Shutdown Valve Control Panel Replacement Project West Madura Offshore

PHA is an oil and gas Cooperation Contract Contractor (KKKS) in Indonesia, playing an important role in achieving the national oil and gas production target. To maintain operational and production continuity, a replacements shutdown valve control panel project performs at the production facility of West Madura offshore field. It was the first control panel replacement project carried out at the live production facility. Project team identify some high risk activity through process and occupational safety. Research needs in order to determine construction phase project risk mitigation, by hazard identification, risk analysis, classification and proposed preventive actions as necessary. Proposed analysis and risk management determined by Focus Group Discussion and House of Risk modeling methods, research identified 23 risk events, 23 risk agents, risk mitigation defined by aggregate risk potential and its prioritie. Aiming on reducing risk occurrence and improving positive impact for sustainability and objectives of the project. 24 preventive actions are selected with 5 top priority preventive action proposed.