Natural Gas Transmission Pipeline System Research Articles

Dynamic Simulation of Natural Gas Transmission Pipeline Systems through Autoregressive Neural Networks

Transmission of natural gas from its sources to end users in various geographical locations is carried out mostly by natural gas transmission pipeline networks (NGTNs). Effective design and operati...

Time-dependent economic risk analysis of the natural gas transmission pipeline system

A methodology to quantify the economic risk of a natural gas transmission pipeline system is developed in this study, and the effect of the line pack is considered. The methodology is based on the risk theory and hydraulic analysis of the transmission pipeline system. In the methodology, the failure probability of the key components in the transmission pipeline system are estimated firstly. Moreover, the transient compressible model for the pipeline system is employed to perform the consequence analysis, and the model is solved by the Semi-Implicit Method for Pressure-Linked Equation (SIMPLE) algorithm in the process of the consequence analysis. By combining the failure probability estimation with the consequence analysis, the economic risk when an accident happens can be evaluated. A detailed procedure for economic risk evaluation of a natural gas transmission pipeline system is presented, and its feasibility is confirmed with a real transmission pipeline system. Furthermore, impacts of the line pack on the economic risk are investigated, and suggestions to decrease the economy risk are proposed.

Gas supply reliability assessment of natural gas transmission pipeline systems

The uncertainty of market demand and dynamic behaviour of the pipeline system are usually ignored in previous gas supply reliability assessments. With the intent of overcoming these deficiencies, a novel methodology to assess the gas supply reliability of natural gas transmission pipeline systems is proposed in this paper. Considering both gas supply capacity and market demand uncertainties, calculations of these two items are integrated into a single Monte Carlo simulation. On each Monte Carlo trial, the hydraulic analysis of unsteady flow is combined with the state transition process simulation to calculate the gas supply capacity. In terms of market demand, the load duration curve technology is employed to predict the amount of demand. Then, the indicator proposed to quantify gas supply reliability is calculated on each trial. Finally, the average gas supply reliability is obtained based on N Monte Carlo trials. Applications of this methodology are demonstrated through a real transmission pipeline system. Thereafter, the method is compared with previous approaches and differences are discussed. Furthermore, the impacts of supply capacity and market demand uncertainties on the gas supply reliability are investigated and suggestions to improve the gas supply reliability are proposed.

A methodology to quantify the gas supply capacity of natural gas transmission pipeline system using reliability theory

A methodology to quantify the gas supply capacity of a natural gas transmission pipeline system is developed in this paper. The methodology is based on reliability theory and hydraulic analysis of unsteady flow. Considering the state transition process and change law of the flow rate, two reliability indicators, gas supply satisfaction (Sa) and gas supply supportability (Su), are proposed to quantify the gas supply capacity. The methodology is first able to simulate the state transition process and the duration of each operating state based on Monte Carlo approach, and then the hydraulic analysis of unsteady flow after the system transits to others states is applied to analyze the change law of the actual flow rate through the commercial software SPS (Stoner Pipeline Simulator). By combining the hydraulic analysis into the simulation of state transition process, the two reliability indicators are calculated. A detailed procedure for gas supply capacity evaluation of a natural gas transmission pipeline system is presented, and its feasibility is confirmed with two case studies including a hypothesis and a real transmission pipeline system. Furthermore, impacts of the line pack, availability of the components and the number of stand-by units on the gas supply capacity are investigated.

Gas pipeline preferential site selection occurrence for elemental sulphur & other particle matter formation & deposition

Field observations of “elemental sulphur” deposits within high-pressure natural gas transmission pipeline systems have prompted investigations into the study of preferential site selection process for the formation and deposition of these sulphur based contaminants. These deposits can cause complete blockage of the gas stream path. There have not been any known studies into why this preferential site selection process exists, and therefore it is the aim of this research to investigate plausible reasons by investigating affected pipeline systems.The results from the studies, which have been validated against known “elemental sulphur” affected transmission pipeline sites, confirm that the flow dynamics at the pipeline “T” junction could be a major contributing factor to the preferential site selection process. The paper discusses the results.

Particle deposition in natural gas pipelines using computational fluid dynamics modelling

ABSTRACTSolid particles within natural gas transmission and distribution pipeline systems are known to create varying operational constraints for pipeline operators—from temporary to complete stoppage of the gas flow. The solid particles can be extremely variable, both in composition and origin. The particles can consist of discrete elements or mechanically and chemically driven combinations of soils, iron oxides, iron sulfides, sulfur compounds, salts, metal oxides, hydrocarbons and other contaminants. These particles tend to get deposited along the walls of gas pipelines under different circumstances. The flow dynamics and the turbulence associated with the flow play an important role in the complex mechanism of particle deposition. In this work, we have shown how turbulence acts as a dominant mechanism in influencing particle deposition. A ball valve's downstream flow was simulated for various opening positions and varying inlet Reynolds numbers to understand turbulence and its effect on particle deposition. The percentage of number of particles getting deposited at the downstream increased on decreasing the valve opening, whereas it was not greatly affected by the change in the inlet Reynolds number. The particle deposition sites at downstream were governed indirectly by valve opening percentage. © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.

Natural Gas Production and Consumption and New Pipeline Developments in the Central and Northern Rocky Mountain Region

An extensive natural gas transmission pipeline system now exists on the North American continent and in the central and northern Rocky Mountain region embracing Wyoming, Montana, the Dakotas, Idaho, Utah, and Colorado. The regional interstate pipeline capacity is dominated by two major systems: Northwest Pipeline Corporation and Colorado Interstate Gas Company. In addition, there are over a dozen important area and intrastate systems. Not counting the lease, plant, and pipline fuel gas, the marketed produciton in the region totals nearly 1 tcf annually of 6% of the national total. Making some allowance for local import and export imbalances across state lines, approximately 45%, or 450 bcf, is consumed locally. Over 500 bcf (almost 1.5 bcf/day) are transported out of the region. Production and consumption in New Mexico, Arizone, and Nevada are not included in these figures. Regional natural gas enters the interstate and continental pipeline system at seven interconnecting points around the periphery of the mountain states. The regional gas must compete for capacity on the major pipelines. Several new projects are expanding pipeline capacity for transportation both within the region and to points outside the region.