Natural Gas Transmission Research Articles

Comprehensive numerical analyses of the seismic performance of natural gas pipelines crossing earthquake faults

Coseismic fault displacement has been recognized as a critical hazard to natural gas transmission pipelines crossing earthquake faults. Prior studies on pipeline response to fault displacement were limited to specific types of pipes and faults, which were indeed constrained by the computational resources. As part of an effort to develop a Bayesian model to relate ground displacement in pipeline strain, we analyze more than 217,000 finite element models of gas pipeline fault crossings, which consider the pipe–soil interactions with both pipe and soil material nonlinearities. Such an enormous number of simulations are selected based on comprehensive sensitivity analyses and cover the most important parameters of gas pipelines in terms of combinations of the following: (1) pipe dimensions and materials, (2) soil properties, and (3) style of faulting and characteristics of fault movements. We devise an automated workflow for input generation–simulation submission–output extraction, by utilizing more than 10,000 cores high-performance super-computing facilities. Finally, we examine the pipeline response for every combination, by investigating the evolution of maximum compressive and tensile strains in the axial direction along the pipe over the fault displacement. These numerical analyses resulted in a comprehensive database of pipeline fragilities crossing earthquake fault for seismic risk analysis of natural gas infrastructure in an earthquake region.

Advancing in the decarbonized future of natural gas transmission networks through a CFD study

The injection of green hydrogen into the natural gas grid is a way to decarbonize the gas sector and build an economic transport route for the large-scale delivery of hydrogen. The suitability of the natural gas infrastructure for this purpose depends on the impact that hydrogen may have on the correct operation of its components and understanding the new flow conditions in the system is essential for this aim. Computational studies can anticipate the expected environment in the pipe system, assessing the readiness of the system. However, the experience on this topic is not extensive enough and deeper understanding is necessary. Here we show a CFD study to simulate the transport of H 2 /NG blends in a gas setup with the main characteristics of injection sites and gas pipelines representatives of the transmission gas network. This setup considers a blending station, the pumping and injection procedure, and different pipelines geometries to predict the behavior of various mixtures of H 2 /NG. It can be seen how (1) a good mixing is achieved in the blending station after a pipe length equivalent to 20–30 diameters is reached; (2) pumping gas by a piston type compressor shows pulsations in the flow regardless the composition of the blend that can be damped implementing mitigation measurements; and (3) asymmetries in the flow are found when the direction of the fluid changes after section reduction, but 20 diameters downstream of the reduction the flow is fully developed. • Modelling the injection of hydrogen in the natural gas transmission grid. • CFD studies to anticipate the behavior of the new fluid. • Mixing quality and possible segregation in blending stations considered. • Flow pattern when DN 80 pipes expands to a DN 150 or a DN 250 pipes. • Simulation of pumping of H 2 and CH 4 by a piston type compressor.

Study on Potential Role and Benefits of Liquified Natural Gas Import Terminal in Latvia

Abstract Natural gas is relatively clean energy source, which emits less greenhouse gases (hereinafter – GHG), compared to other fossil fuels, such as hard and brown coal, and therefore it may be the most feasible resource to ensure smooth energy transition towards Europe’s climate neutrality by 2050. Traditional natural gas can be easily transported and used in liquefied (hereinafter – LNG) or compressed form. As for biomethane, in future it also can be used in liquefied (hereinafter – bioLNG) and compressed form, as well as transported by means of the current natural gas infrastructure. It can also significantly enhance regional and national energy security and independence, which has been challenging for the European Union (hereinafter – EU) over at least several decades. Issue on energy independence, security of supply, alternative natural gas sources has been in a hotspot of the Baltic energy policy makers as well. Now, considering Russia’s invasion in Ukraine, since late February 2022, a problem of the EU natural gas dependency on the Russian Federation has escalated again and with force never before experienced. The European natural gas prices also hit records, as the natural gas prices in the Netherlands Title Transfer Facility reached 345 euros per megawatt-hour (hereinafter – EUR/MWh) in March 2022. Therefore, LNG import terminal is the only viable option to reduce national dependency of the so-called pipe gas which in some cases, due to the insufficient interconnections, may be delivered from very limited number of sources. The European policy makers and relevant institutions are currently working towards radical EU natural gas supply diversification, where LNG deliveries coming from outside of Russia will certainly take a central stage. In case of Latvia, the potential benefits of the LNG terminal development in Skulte were evaluated in order to reduce energy independence of the Russian natural gas deliveries in the Baltic region and to introduce new ways and sources of the natural gas flows to the Baltics. LNG terminal in Skulte could ensure significant capital investment cost reduction comparing to other projects proposed for Latvia in different periods, due to already existing natural gas transmission infrastructure and the relative closeness to the Incukalns underground gas storage (hereinafter – UGS). Various aspects, such as technical, political and economic ones, were analysed to assure that Skulte LNG terminal would be a real asset not only to customers of Latvia, but also to those of the whole Baltic region, where in future it would be possible to use biomethane for efficient utilisation of existing and developing natural gas infrastructure.

Study on cooperative treatment of natural gas pipeline cleaning wastewater and membrane module

Membrane module and pigging wastewater are common pollutants in natural gas transmission process. The treatment of these pollutants is difficult. In this paper, ultrasonic (US), persulfate (PS) and ultrasonic coupled persulfate were used to degrade organic matter in natural gas cleaning wastewater. The effects of pH, initial PS concentration, ultrasonic power, PS dosing batch and other factors on chemical oxygen demand (COD) degradation efficiency of pigging wastewater were investigated. The experimental results show that the optimal treatment effect can be obtained when the dosage of sodium PS is 80g/L, pH=4, the dosing number is 5, and the ultrasonic power is 840 W. After 6 h of reaction, the removal rate of COD can reach 80.08 %. Considering the synergistic treatment of the ultrasonic coupling PS on the solid-liquid pollutant, we adjust the ultrasonic power to 55W (frequency is 40kHz), pH=4.5, dosing twice (total dosage 150mg/L), and the final COD concentration below 100mg/L. However, when pre-ultrasonic activated persulfate in clear water, COD removal rate can reach 95.35 %, which can meet the effluent requirements.

Black gold – the history of the energy sector

The history of oil production, processing and use is centuries old. Of course, the kerosene lamp, fractional distillation yielding kerosene of unprecedented purity, industrial extraction of oil, including from beneath the seabed, purification, and pipeline transmission of natural gas, led to the explosion (sic!) of the oil industry, transportation energy, chemistry, pharmaceuticals, and many other fields. Keywords: Crude oil, kerosene, bitumen, mine, natural gas, Ignacy Łukasiewicz

ON GOING COALBED METHANE (CBM) DEVELOPMENT IN THE SOUTH SUMATRA BASIN

Coalbed methane (CBM) is going to be an important facet of the nation’s energy mix. It is expected to contribute in importance energy back up for the future. CBM is natural gas, a clean-burning energy source that is reservoired in a coal seam. CBM is formed during the coal maturation process and may in a free or adsorbed state in coal seams in adjacent formations. CBM is dominantly methane but lesser concentrations of carbon dioxide and nitrogen, compare to conventional natural gas. However, in most cases, CBM is of sufficient quality for sale directly into natural gas transmission lines with a limited amount of moisture removal.CBM as natural gas has numerous benefits to include direct selling, well suited as city gas, electricity generation, boiler fuel, transportation fuel, and for many types of chemical industries feed. Beside CBM replaces coal to be greatly reduces the production of acid rain and other forms of air pollution, the development of CBM has benefitial for coal miners. It can contribute to improved mining safety as well as it can help reduce construction costs.CBM is probably one of the promising alternative fuel energy resources in Indonesia that its presence is actual and comparable with the existing coal resources in any potential basin. Unlike some well in developed countries where commercialization of methane production from coal seam has been developed, coals direct mined in Indonesia seem to be more attractive and preferable technique to supply the consumer demand of energy. This is because coal mines serve direct products, less complicated technology, low exploration risks, easy recovery, relatively low cost but quick yields and already have wide market. Consequently, people have overlooked the existence of consisting huge potential methane gas in coals.However, petroleum exploration data throughout Indonesia suggest that increasing coal rank occurs rapidly with depth in many basins and that gas kicks are almost common associated with some coal seams below 200 m depth. In addition, world CBM exploration now has shifted towards lower rank settings (i.e, vitrinite reflectance between 0.3% and 0.6% Ro). In Indonesia, thick coals generally are found at greater depth, higher in rank and therefore are expected to be more productive (Saghafi and Hadiyanto, 2000).LEMIGAS is currently conducting a drilling program to study the feasibility of CBM production in South Sumatra. The domain of the work is in the Muaraenim Formation (Upper – Middle Palembang). The coal sequences were deposited during Late Miocene. We believe that a big effort is extremely essential to establish the reserve and economic potential of CBM in South Sumatra to later extent to Indonesia.

Application of optimal hardening for improving resilience of integrated power and natural gas system in case of earthquake

Growing penetration of natural gas-fired power units in power systems due to their superior characteristics has significantly increased the interaction between power system and natural gas system. In this paper, a robust optimization model is proposed to enhance the resilience of the integrated power and natural gas system (IPGS) against earthquakes. The proposed model is formulated as a tri-level mixed-integer linear program where optimal hardening of power transmission lines and natural gas transmission components (passive pipelines and compressors) is provided in the upper level as an effective preventive measure. A multi-regional uncertainty set is introduced in the middle level to determine the worst damages imposed to the IPGS by earthquake. A discrete uncertainty set is also considered in the middle level to take the intermittency of the wind generation into account. In the lower level that includes operational constraints of the IPGS, the recourse decisions are made to minimize power and natural gas load-loss cost and operation cost. Since there are binary variables in the lower level, the Nested Column and Constraint Generation algorithm is adopted to solve the proposed model. Numerical studies are tested on 6-bus-7-node and 24-bus-20-node IPGSs to validate the effectiveness of the proposed method.

Failure of a Natural Gas Transmission Pipeline—Material or Sabotage

Failure of a Natural Gas Transmission Pipeline—Material or Sabotage

Operation Optimization of Multiroute Cyclic Natural Gas Transmission Network under Different Objectives

Natural gas transmission networks (NGTNs) are the main facility connecting upstream gas sources and downstream consumers. For a cyclic NGTN with multiple gas transmission routes, different gas transportation schemes will affect not only the energy consumption of the system but also the pipeline transportation costs paid by consumers. In this paper, three operation optimization models are established to determine the optimal operating state of a multiroute cyclic NGTN under different scenarios. The three mathematical models correspond to three different objective functions: minimize the cost of compressor energy consumption, minimize the expense of pipeline transportation, and minimize the sum of the two expenses. The decision variables of the models include the pipeline flow rate, the number of operating compressors, and the outlet pressure of the compressors. In addition, a series of linear and nonlinear constraints of nodes, pipelines, and compressors is also proposed to guarantee the feasibility of solutions. The operation optimization problem is solved by the General Algebraic Modeling System (GAMS), and the effectiveness of this method is tested on a small double-route cyclic NGTN and a large three-route cyclic NGTN. The results show that the developed optimization model is able to find optimal solutions under different models. In the cyclic network, the difference in the flow distribution of gas transmission routes is the key factor affecting the optimization result. In addition, compared with the compressor energy consumption cost minimization objective, the pipeline transportation expense minimization objective can create greater economic benefits for consumers. In the two network cases, consumers can save 14.51 and 59.18×104 RMB. Finally, optimizing the two objectives at the same time makes it possible to achieve an effective balance between them.

Risk assessment for gas transmission station based on cloud model based multilevel Bayesian network from the perspective of multi-flow intersecting theory

Accidents occurred in the natural gas transmission stations may result in casualties, equipment damage, property loss and even political and ecological impact. It is necessary to propose an approach for the gas transmission stations risk assessment so as to identify risk factors and prevent accidents. However, insufficient attention has been paid to the complex interactions and coupling patterns of these factors with current risk assessment methods. Hence, a novel risk analysis strategy is needed for industrial site risk assessment. Given industrial site risk factors, the multi-flow intersecting theory (MIT) is first defined to consider material, information and behavior risk analysis. Then the multilevel Bayesian network is constructed to represent these factors from different flows. To handle issues of insufficient statistical data and subjectivity associated with expert judgement, cloud model and fuzzy Bayesian are incorporated. For the defuzzification, existing cloud model is improved by introducing the similarity degree of standard cloud and evaluation cloud. Then the prior and conditional probabilities obtained from cloud model are input into Bayesian network for further reasoning and accident probability prediction. To validate the utility of the proposed method, the gas transmission startup process was chosen for risk assessment.

Prospects of utilizing unloaded parts of natural gas transmission pipelines in technologies of carbon dioxide capture and storage

The gas transportation system (GTS) of Ukraine is one of the most complex systems of main gas pipelines in Eurasia. Prospects for the use of unloaded parts of transportation and storage of CO2 in carbon capture and storage (CCS) systems are considered. The mathematical model for estimating the main parameters of the process of filling the pipeline with carbon dioxide with their subsequent optimization is proposed. According to the simulation results, the regularities of the pipeline filling process are established.

Flexible object-oriented modelling for the control of large gas networks

In this work we develop an innovative framework for the dynamic modelling of natural gas transmission networks. Thanks to its flexibility, this tool may be used to support operation of the network while also giving the possibility to explore and test new optimized scenarios, introduce new elements in the grid itself (ranging from new branches to new machines) and test the use of new gas mixtures. We use as benchmark the Italian high pressure gas transportation network, executing simulations of past daily operation scenarios. Results are compared to real measurements so to prove the validity of the adopted approach.

Business Readiness for Implementation of AI Prevention of Potential Risks in Natural Gas Transmission and Storage

Despite the high pace at which AI navigates in various areas of the business, there are still aspects to provoke restraints and limitations. Such restrains could be regarded to the concerns in experts that they would be literally substituted by the machines. In the same time, the dynamycal of the surrounding environment apply the necessity of accelerated optimisations of processes and namely by the abilities offered by of the AI. This article aims to identify how AI can improve risk management processes which are the pros and cons and how it relates to experts in the field. In order to determine the possibilities to integrate AI by the risk prevention during working with natural gas, the following are analyzed here: the importance and place of natural gas in the economy; the main risks by the transmission and storage of natural gas; the place of AI in risk prevention. An empirical study is conducted in this material, which reveals the opinion of experts in the field and their attitudes regarding AI. All this is aimed at achieving the goal of reducing the risk and negative consequences of its manifestation in the transmission and storage of natural gas.

Analysis of Natural Gas Consumption Interdependence for Polish Industrial Consumers on the Basis of an Econometric Model

The transmission of natural gas is a key element of the Polish energy system. The published data of the Polish distribution system operators and the transmission system operator on the volume of gaseous fuel transmitted indicate a growing trend in the consumption of energy produced from natural gas. In connection with the energy transformation, switching energy generation sources from hard coal to natural gas in Poland, it is important for transmission operators to know the future demand for gaseous fuel. The aim of the article is to attempt to develop an econometric model related to the consumption of gaseous fuel by Polish entrepreneurs. The knowledge therein may be useful for making business decisions related to the possible expansion of the transmission system, and thus investing financial resources for this purpose. This knowledge will also provide quantitative information related to the interest in gaseous fuel among industrial consumers and the analysis of the trend of natural gas consumption in Poland in the aspect of energy transition. The intention of the publication was to determine the macroeconomic indicators that strongly affect natural gas consumption by the Polish industry and the quantitative growth of consumption depending on changes in these indicators. The results showed that the highest correlation of the growth of natural gas consumption is related to the production of chemistry, the chemical industry, and the power industry.

Experimental investigation of axial compression behavior after low velocity impact of glass fiber reinforced filament wound pipes with different diameter

The GRP (Glass Reinforced Polymer) composite pipes produced by filament winding (FW) technique are used in many applications such as the transmission of pressurized gases, liquids, oil, and natural gas transmission. These composite pipes may be subjected to low velocity impacts during production and/or service for various reasons. The impact on the composite pipes may lead to invisible damages such as matrix crack, fiber damage, and inter-layer separation. In this study, pipes with three different diameters (Ø54, Ø72, and Ø96 mm) were produced to investigate the damage caused by low velocity impact and to determine the effect of these damages on the strength losses of the composite pipe. The pipes were subjected to low velocity impact test according to ASTM D 7136 with 1.5, 2, 2.5, and 3 m/s impact velocities. In order to examine the effects of impact damages on the strength of pipes, Compression after impact (CAI) tests were performed on pre-damaged pipes according to ASTM D 7137 and Force-Displacement and Stress-Strain relations were obtained. The results of impacted samples were compared with the behavior of undamaged samples. After the experiments, macro/micro damage analyses of GRP pipes were performed by optical microscope and SEM imaging.

Urban residential energy switching in China between 1980 and 2014 prevents 2.2 million premature deaths

Urban residential energy switching in China between 1980 and 2014 prevents 2.2 million premature deaths

Comparative Study of Superconducting DC Energy Pipelines With Different Bipolar Structural Layouts

Superconducting DC energy pipeline combines long-distance electricity and liquified natural gas transmission, which could improve the overall efficiency of the pipeline system and save construction space. The characteristics of superconducting DC energy pipelines with bipolar coaxial, double-core and partitioned structural layouts are analyzed and compared in this paper, which are significant for the selection of pipeline structure. The voltage levels are set as ±10 kV/±100 kV for electricity distribution and transmission applications, and the rated current is set as 1 kA. The simulation models of energy pipelines with each structural layout are established in order to evaluate the respective operation characteristics. The operation conditions of the steady state, the quench transient process under a short-circuited fault and the quench recovery transient process afterwards are analyzed in order to evaluate the stability and safety of the pipeline system. The comparison results illustrate the distinguishing features of each structural layout from various aspects. It is found that the double-core structure and the partitioned structure are the most suitable options at the voltage levels of ±10 kV and ±100 kV respectively.

Corrosion Behavior Studies of Al and Zn Based Alloys for Internal Corrosion Protection in Natural Gas Transmission Pipelines

Internal coatings and liners can be used to minimize CO2 corrosion inside steel pipelines transporting natural gas. Many factors such as climate, gas velocity and properties of the gas traveling through the pipeline contribute to the complexity of designing an efficient metallic coating to mitigate internal corrosion. The objective of this study was to investigate the corrosion behavior of aluminum and zinc-based alloys as sacrificial coating candidates for protection of pipeline steel in a CO2-saturated aqueous electrolyte under natural gas conditions.To determine the corrosion resistance of the Al and Zn alloys, electrochemical studies using potentiodynamic polarization, linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) were performed in simulated natural gas environments. These environments included variable CO2 pressures simulating the partial pressures that are found in gas transmission over a solution of 3 ½ wt.% NaCl heated to 40 ºC. The effect of electrolyte flow and CO2 partial pressure on corrosion rate of Al and Zn were determined from weight loss data and electrochemical measurements. Also, the corrosion behavior of API 5L X65 pipeline steel coupled to Zn and Al immersed in CO2-statured 3.5 wt.% NaCl under flow and stagnant conditions was evaluated. Post-corrosion surface characterization was performed by scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS).The results show that the corrosion rates for Al or Zn alloys increase with increasing CO2 partial pressure due to the increase of the cathodic reaction kinetics. Aluminum oxide and zinc carbonate-containing compounds as corrosion product layers were formed on API 5L X65 steel coupled to aluminum and zinc, respectively. The obtained data show that an Al and Zn based alloy can be used as sacrificial anodic materials to protect the interior of the steel pipeline against CO2 corrosion in a natural gas transmission environment.Keywords : CO2 corrosion, natural gas pipelines, aluminum alloy, zinc alloy, sacrificial coatings, electrochemical reaction autoclave

A steady-state energy flow analysis method for integrated natural gas and power systems based on topology decoupling

The existing analyses of integrated natural gas and power systems generally ignore gas temperature variations, which may misjudge gas pressure and jeopardize natural gas transmission. Furthermore, the conventional Newton-Raphson based natural gas flow analysis methods may cause non-convergence or unnecessary computational burden. Based on topology decoupling, an efficient energy flow analysis method is proposed in the paper for integrated natural gas and power systems with the consideration of temperature distribution in natural gas systems. A lumped parameter model of natural gas flow in pipelines considering temperature is developed based on the Weymouth and Shukhov formulas. A natural gas flow model considering temperature is then established. According to the topological characteristics of natural gas systems, a topology decoupling based natural gas flow analysis method is proposed to improve computational efficiency and to lower the requirement of initialization. An energy flow analysis method for integrated natural gas and power systems is presented based on a Newton-Raphson method. The correctness and adaptability of the proposed method are verified using three widely-used test systems. The obtained simulation results show that the temperature distribution and natural gas pressures of a natural gas network can be accurately described and estimated to ensure the secure operation of integrated natural gas and power systems, and the computational efficiency and convergence performance are largely improved.

A unified benchmark for security and reliability assessment of the integrated chemical plant, natural gas and power transmission networks

This work presents a simulation framework to investigate the rigorous transient behavior of integrated systems comprising natural gas and power transmission networks, and a chemical plant whose feedstock is natural gas. This framework entails dynamic models for the gas transmission network and the SynGas plant, and a continuous-time AC-power flow formulation with dispatchable loads. It addresses the following key challenges: (i) analyzing energy and chemical system interdependencies, and their impacts on each other's supply reliability and security; (ii) providing an environment conducive to settling a critical question of how to prioritize the natural gas consumption as fuels of power plants or feedstocks of chemical plants based on sustainability and resiliency criteria. The framework provides an integrated benchmark enabling users to realistically study various planning, scheduling, and operation problems of these integrated systems such as process control, fault diagnosis, optimization, and environmental damage analyses. Effectively coordinating natural gas, power, and chemical industries, the benchmark outclasses conventional energy test problems in analyzing presented reliability and security scenarios since such traditional works solely focused on integrated gas and power systems. Results evidence the effects of nonlinear behavior of chemical plants on reliability and security of both natural gas and power transmission networks, in an integrated manner. Moreover, scenarios on power demand variations, compressor failure occurrences, and gas storage utilizations are enacted; according to the results, the unified benchmark lends insight into crucial information such as spatiotemporal characteristics of disturbances and their propagation throughout the integrated systems and the required period and strategy to damp such disturbances. Such information facilitates reliability and security analyses of the integrated systems and enables the coordination of chemical plants with traditional gas and power networks, particularly in multiple load shedding events which requires supply prioritization of natural gas to power and chemical plants.