Gas Pipeline In China Research Articles

Reducing Carbon emissions through pipelines? Evidence from the West-East Gas Pipeline Project

ABSTRACT Transregional energy transmission can help balance resource allocation and serve long-term regional interests. The West–East Gas Pipeline Project (WEGPP), which is the longest natural gas pipeline in China, aims to address the serious imbalance between natural gas supply and demand in China’s eastern and western regions. Few studies have considered WEGPP’s effect on carbon emissions in terms of energy transmission. Using data for prefecture-level cities from 2000 to 2019, we consider WEGPP as a quasi-natural experiment and adopt a staggered difference-in-differences model to investigate the causal effect of energy transmission on carbon emissions. We find that WEGPP can reduce carbon emissions; various robustness tests confirm the reliability of the results. However, the emission-reduction effect is heterogeneous owing to factors such as operation batch, location, administrative level, population size, resource endowment, industrial level, and whether a city belongs to an old industrial base. We also reveal three important channels for WEGPP’s emission-reduction effect: environmental concern of the government, industrial agglomeration, and green technological innovation. This study provides a reference for assessing the feasibility and effectiveness of energy transmission in the context of emission reduction.

Precision and uncertainty in natural gas calorific value estimation: advanced combinatorial predictive models for complex pipeline systems

Abstract In recent years, natural gas pipelines have been characterized by multiple intake points, the mixing of different gas sources, and significant variations in gas quality. The existing volumetric measurement system is no longer suitable for the development and operation of natural gas pipelines in China. To ensure accurate and equitable implementation of natural gas measurement, there is a gradual shift towards energy measurement. However, due to numerous measurement interfaces, installing chromatographs at all measurement stations would lead to substantial investment costs. Therefore, predicting the calorific value of natural gas is a key technology for energy measurement. In view of the issues existing in the current methods of obtaining natural gas calorific value, different prediction models of natural gas calorific value are constructed. According to the influencing factors of natural gas calorific value, the uncertainty evaluation is carried out, and the accuracy of different calorific value prediction models is analyzed by case data. The maximum error of regression equation (RE), response surface analysis (RSA), BP neural network and genetic algorithm (GA) prediction model is 2.29%, 0.43%, 0.59% and 0.45% respectively. However, the combined calorific value (CCV)prediction model is 0.41%. The results indicate that the predicted value calculated by the CCV prediction model is closer to the actual value and has higher prediction performance, which provides a new method for the calorific value prediction and measurement management of natural gas.

Numerical Study on Explosion Risk and Building Structure Dynamics of Long-Distance Oil and Gas Tunnels

To comprehensively understand the explosion risk in underground energy transportation tunnels, this study employed computational fluid dynamics technology and finite element simulation to numerically analyze the potential impact of an accidental explosion for a specific oil and gas pipeline in China and the potential damage risk to nearby buildings. Furthermore, the study investigated the effects of tunnel inner diameter (d = 4.25 m, 6.5 m), tunnel length (L = 4 km, 8 km, 16 km), and soil depth (primarily Lsoil = 20 m, 30 m, 40 m) on explosion dynamics and on structural response characteristics. The findings indicated that as the tunnel length and inner diameter increased, the maximum explosion overpressure gradually rose and the peak arrival time was delayed, especially when d = 4.25 m; with the increase in L, the maximum explosion overpressure rapidly increased from 1.03 MPa to 2.12 MPa. However, when d = 6.5 m, the maximum explosion overpressure increased significantly by 72.8% from 1.25 MPa. Evidently, compared to the change in tunnel inner diameter, tunnel length has a more significant effect on the increase in explosion risk. According to the principle of maximum explosion risk, based on the peak explosion overpressure of 2.16 MPa under various conditions and the TNT equivalent calculation formula, the TNT explosion equivalent of a single section of the tunnel was determined to be 1.52 kg. This theoretical result is further supported by the AUTODYN 15.0 software simulation result of 2.39 MPa (error < 10%). As the soil depth increased, the distance between the building and the explosion source also increased. Consequently, the vibration peak acceleration and velocity gradually decreased, and the peak arrival time was delayed. In comparison to a soil depth of 10 m, the vibration acceleration at soil depths of 20 m and 30 m decreased by 81.3% and 91.7%, respectively. When the soil depth was 10 m, the building was at critical risk of vibration damage.

Development of a sectionalizing method for simulation of large-scale complicated natural gas pipeline networks

By 2025, the total mileage of natural gas pipelines in China is expected to reach 163,000 km, placing urgent demands on the simulation technology for increasingly large-scale and more complicated pipeline networks. This paper describes the development of a new sectionalizing method, which is based on optimization strategy, for simulating large-scale and complicated natural gas pipeline networks. Based on analysis of the topological structures, the entire pipeline networks are decomposed into multiple sub-networks according to the connecting nodes between the adjoined pipelines. The sectionalizing method is then implemented by minimizing the residuals of conservation for continuity and momentum at the connecting nodes in isothermal mode. The hydraulic variables in each sub-network are obtained after the hydraulic variables at connecting nodes are updated. The calculation accuracy and efficiency of this sectionalizing method are demonstrated by comparison with a commercial software through three different test cases. It is shown that the maximum relative deviation of pressure of the method developed is within 2.5% of that calculated using the commercial software. In a 5 × 104 km test case with variable spatial step sizes, the computational efficiency is 2.1 to 3.2 times of that of the commercial software. The results of the three case studies suggest that this sectionalizing method is promising and suitable for application to large-scale complicate natural gas network simulation.

Gas Composition Tracking in a Transient Pipeline Using the Method of Characteristics

For a gas pipeline with multiple gas sources, the significance of tracking the composition of natural gas is increasing with the implementation of X+1+X system for the natural gas industry in China. Mathematically, the tracking problem is usually described by a system of partial differential equations (PDEs). The continuity equation on gas composition has been developed to track natural gas composition according to the law of mass conservation. The algorithm resulting from the method of characteristics (MOC) is proposed to solve the system of PDEs. Compared to the original MOC, numerical solutions of the continuity equation on gas composition are obtained after the hydraulic calculation and thermal calculation. Moreover, different combinations of boundary conditions for the MOC are derived, which could expand the range of application of the MOC and be applicable to various operating conditions. The heating values of diverse gas sources have been determined following the methods documented in ISO 6976:2016. The case study of a gas pipeline in China verified the validity of the algorithm via the commercial simulation software Pipeline Studio for Gas (TGNET). The heating value and gas composition obtained by the algorithm can be used in the custody transfer metering of natural gas pipelines for Class B and C metering stations described in GB/T 18603−2014.

Design and research of Sense, Know, Anticipate and Protect Integrated Intelligent Gas Pipeline Network Security System

Nowadays, China's gas pipeline network accidents are frequent, and gas accidents cause significant losses to people's lives and property safety, exposing many loopholes and shortcomings in urban safety management. Traditional social warning methods for gas safety accidents are insufficient and information dissemination is not in place, making it difficult for people in gas risk areas to obtain effective and timely warning information, often resulting in major gas explosion casualties. Home gas leaks are often more difficult to detect and dispose of, and coupled with the weak awareness of gas safety among users and their reluctance to purchase corresponding gas leak alarm devices, the safety problems faced by home gas are very serious. The paper focuses on gas safety hotspots, dovetails with national urban safety development strategies, and proposes 3 sets of system solutions through system innovation, technological innovation, and financial innovation for key and difficult issues such as gas safety monitoring, social surface warning, and user protection system construction. At the government management level, it realizes real-time and precise monitoring of gas pipeline networks. At the social early warning level, it realizes real-time systematic delivery of risk information. At the household protection level, it realizes household gas safety monitoring and the construction of a protection system. The 3 sets of solutions are hierarchical and logically progressive, forming a closed-loop working system of gas safety monitoring, early warning, management and guarantee for the whole field of government, society and family, providing a new system thinking, technology integration and operation system for the field of city gas safety.

Risk assessment of oil and gas pipelines hot work based on AHP-FCE

A new quantitative risk assessment method for hot work is proposed based on the Analytic Hierarchy Process (AHP) and Fuzzy Comprehensive Evaluation (FCE). It can help pipeline companies realize the risk management of hot work and further ensure the safe operation of oil and gas pipelines. Taking one natural gas pipeline in China as an example, this paper evaluates the risk of a single hot work in the spring of one natural gas pipeline in a high consequence region. First of all, the risk factors are determined with reference to the job safety analysis (JSA), and then experts were invited to fill out a questionnaire to collect their opinions. According to the results of the questionnaire, AHP is used to calculate the weight coefficients of the evaluation indicators, and FCE is used to evaluate the risk level of hot work. After calculation, the comprehensive risk score of hot work is 40.888. It belongs to a "General risk". This method can not only quantitatively evaluate the risk levels of hot work, but also reasonably sort the importance of various risk factors. It is helpful for the effective management of hot work and provides suggestions for implementing control measures.

Key Techniques for Rapid Jacking and Laying of Pipelines: A Case Study on ‘Jingshihan’ Gas Pipelines in China

With the rapid growth of the oil and gas storage, transportation, and pipeline industries, it is necessary to improve the construction process of oil and gas pipelines. By combining the technical advantages of horizontal directional drilling and pipe jacking construction, the direct pipe laying method is suitable for pipeline crossing in different strata in the oil and gas, water conservancy and hydropower, and municipal industries due to its advantages of less construction land, high speed, and reversibility. Using the rapid jacking and laying of pipelines crossing Nanjuma River in the ‘Jingshihan’ gas pipeline double line project as a case study, this paper investigates the application status of the direct pipe laying method, summarizes the project, and introduces the construction of the working well, equipment selection, guiding control technology, supporting equipment installation, and drag reduction measures, as well as analyzes the influencing factors of thrust force and trajectory deviation combined with formation information.

Experimental Study on Thermal Insulation Effect of the Buried Oil-Gas Pipelines in Permafrost Regions

In permafrost regions, long distance buried pipelines are widely used to transport oil and natural gas resources. However, pipeline problems occur frequently due to the complicated surrounding environment and transportation requirement of positive temperature. In this study, a thermal insulation layer was applied to mitigate permafrost degeneration around the buried oil-gas pipelines. Based on engineering background of the Sebei-Xining-Lanzhou natural gas pipeline in China, an indoor model test was designed and carried out in which many key indices, such as the temperature regime, vertical displacement, pipeline wall stress, and water content, were closely monitored. The test results indicate that the large heat loss of the buried pipeline produces a rapid increase in ground temperatures which seriously reduces the bearing capacity of the permafrost foundation. The buried oil-gas pipelines with a thermal insulation layer can effectively reduce the thawing range and vertical displacement of the permafrost foundation around the buried pipelines, so as to control the stress of the pipeline wall in the normal range and protect the safe and stable operation of the buried oil-gas pipelines. The experimental results can serve as a reference for the construction, operation, and maintenance of buried oil-gas pipelines in permafrost regions.

Industrial Development of Hydrogen Blending in Natural Gas Pipelines in China

Industrial Development of Hydrogen Blending in Natural Gas Pipelines in China

Research on Emergency Treatment Measures for Oil and Gas Pipeline Passing Though Mining Subsidence Area

With the continuous increase in the mileage of long-distance oil and gas pipelines in China, more and more pipelines need to pass through prospecting areas, mining areas and mined-out areas. In these areas, underground subsidence and surface cracking may occur due to over-exploitation of underground minerals, which may cause damage to buried oil and gas pipelines. In order to ensure the safety of the pipelines in these areas, it is necessary to put forward appropriate measures for the management of different mined-out areas. This is a new topic that needs further study for the mined-out area pipelines. This paper takes the geological disasters of the collapsible subsidence suffered by the Puxian-Hejin gas pipeline as an example, through the establishment of a settlement monitoring system for mined-out area and the analysis and verification of pipeline stress status, comprehensive physical survey, on-site monitoring data analysis, expert experience, calculation and analysis of pipeline stress, evaluation of geological safety in mined-out area, and emergency measures such as trench excavation, interception and drainage, weld protection, timely pipe lift, decompression and gas transmission, and monitoring and early warning measures to effectively reduce the risk of pipeline damage and ensure the safe operation of pipelines. The treatment measures have reference and reference significance for the treatment of oil and gas pipelines in mined-out areas.

Fatigue failure analysis of dented pipeline and simulation calculation

Natural gas pipeline leaks may cause considerable damage to people, properties, and the surrounding environment. This study investigates a dent leak in a gas pipeline in China that has operated for six years. The failure pipe section meets American Petroleum Institute (API) specification 5L-2012 standard for carbon steel pipelines. The cause of leakage is evaluated not only through visual examination, micromorphology observation, structural deformation analysis, and residual stress measure of the dented region near the leak point of the pipe body, but also through finite element analysis on the deformation and stress of the pipe under different loads. The dent formation is related to rocks during pipeline laying. Under the combined effect of external load and internal pressure, the maximum equivalent stresses of the dented edge at the outer wall, bulge top of the inner wall, and dented edge of the inner wall are greater than the yield stress of the material. Moreover, micro-crack formation occurs due to the maximum deformation at the bottom of the dent and the maximum equivalent stress on top of the inner surface bulge. Under alternating stress, microcracks gradually expand until they penetrate the wall thickness, and thereby cause pipeline leakages.

Supply adequacy assessment of the gas pipeline system based on the Latin hypercube sampling method under random demand

The aim of this paper is to develop a common methodology to assess the supply adequacy of the gas pipeline system under random demand. To reduce the computational burden, Latin hypercube sampling with the Cholesky decomposition is applied to generate various demand scenarios. For each scenario, the gas supply adequacy is calculated through hydraulic-thermal simulations of the gas pipeline considering all the physical and legal constraints. Under the condition that the customers' demands cannot be fully satisfied, four methods are proposed to adjust the flow rate of each customer to meet the contract pressure requirement for the customers and satisfy the demand of the global pipeline system to the greatest extent. The adequacy cumulative probability distribution function is used to assess the gas supply adequacy, and the assessment results are compared and analyzed. The proposed methodology is applied in the case study based on a real gas pipeline in China.

Integrating Effort across Institutional Borders: A Case Study of Turkmenistan – China Gas Pipeline

In this study we investigate the role of organizational structure in integrating effort across institutionally underdeveloped environment. We ground our study in the case of the Turkmenistan – China Gas Pipeline Project, one of the first infrastructure developments of China´s Belt and Road Initiative. We reveal the impacts of distinct institutional environment on the integration of effort via the form of organizing projects. We analyze how the capital-intensive project organization was decomposed into three legally independent entities by geographical zones despite the limited decomposability of the pipeline system itself. Specifically, we identify a new type of institutional voids for cross-border project development that originates from plural, often contending, institutional arrangements. We then trace the choice to create a nearly decomposable project organizational system (as opposed to using hierarchical or market governance) to a search for an organizational structure that was flexible enough to navigate the institutional voids in the environment and thus facilitate the integration of effort. We find that by creating an array of overlapping joint ventures with key local partners at the planning and implementation stages, the system architect was able to mitigate cooperation hazards, whilst facilitating coordination through complementary coordination structure once entering the operation phase. We discuss implications for theory and practice of organization design in institutionally underdeveloped environment.

Fracture Control of the 2nd West to East Gas Pipeline in China

The 2nd West to East Gas Pipeline ( WEGP) is the first major pipeline project in China importing abroad natural gas and also the longest and largest gas transmission pipeline in the world with gas supply of Middle Asian natural gas and adjusting gas supply of domestic gas from Tarim Basin and Ordos Basin. Its total length is 9 000 kilometers, in which the total length of artery from Khorgos to Guangzhou is 4 900 kilometers. Its design throughput is 30 billion cubic meters per year. Designed maximum operation pressure is 12 MPa, largest diameter of pipe is 1219mm and highest steel grade is X80. To ensure the long-term safety and reliability in operation, fracture control program has been proposed through systematic research, including crack initiation control, brittle fracture control and ductile long-running fracture control. The requirement of arrest toughness of the 2nd WEGP had been studied on the basis of pipe full-scale burst test data base in the world, Battelle Two Curve (BTC) method and GasDecom software. Full-scale burst tests of X80 high-pressure gas pipeline had been successfully performed based on previous research results. The fracture control program was set up based on different fracture criteria and the principle of both safety and economy. The crack arrest ability of X80 spiral submerged arc welded (SSAW) steel pipe was firstly verified and a new correct factor of arrest toughness prediction was obtained. Results presented that the crack arrest ability of SSAW pipe is better than longitudinal submerged arc welded (LSAW) pipe. It lays a solid foundation for the safe operation of the X80 pipeline after construction and completion.

Application of 0.8 Design Factor in China Gas Pipeline

The paper reviews current situation of high design factor application abroad, and analyzes development of high-strength pipeline in China. It shows that related technology has greatly improved in China, such as manufacture of high strength pipe, inspection, quality control, pipeline construction and pipeline integrity management. So it is available to use 0.8 design factor for the class one location in China. And the paper also introduces trial section experiences in the third West-East pipeline on safety pre-assessment, design check, pipe specification, construction technology and integrity management plan. With relative specifications further perfected, it is promising to put the 0.8 design factor into a wide use in Chinese pipeline project.

基于FR和WOE评价模型的西南某管道敷设沿线地质灾害危险性分区研究

基于FR和WOE评价模型的西南某管道敷设沿线地质灾害危险性分区研究

The impact of new natural gas pipelines on emissions and fuel consumption in China

We examine the impact of constructing a new, large scale natural gas pipeline on environmental outcomes and fuel consumption patterns in China. We use the construction of three natural gas pipelines in China, constructed at different times but operated by the same state-owned enterprise, as a quasi-experiment to estimate the impact of pipeline projects as a driver of changes in air quality. We then estimate the impact of the pipeline on firm and household energy choices providing a mechanism to explain the reductions in air pollution we find. The difference-in-differences estimates indicate that placing the pipeline into operation significantly reduced emission intensity and led to an increase in natural gas intensity and decrease in coal intensity in industrial sectors with more limited impacts on residential energy consumption.

Synthetic Evaluation of Natural Gas Pipeline Operation Schemes Based on the Multi-level Grey Cluster Decision Method

In this paper, a multi-level grey cluster decision method is proposed for the synthetic evaluation of operation schemes of natural gas pipelines with inexact data and insufficient information. A four-level index system is built as the synthetic evaluation criterion, aiming in balancing transmission volume, economic profit, and safety of the pipeline. The analytic hierarchy process (AHP) method is applied to calculate the weights of indexes. In order to assess the pipeline’s operation schemes with multi-level index, the principle of AHP method and the conventional grey cluster decision method are incorporated into a new multi-level grey evaluation method. The essential procedures of the method are illustrated in details, including computations of the grey class, whitenization weight function, decision coefficient matrix, weighted normalized decision coefficient matrix and synthetic evaluation score. Finally, this method is applied to seven operation schemes of Se–Ning–Lan gas pipeline in China. The results demonstrate that synthetic prior order of each scheme is not dependent on any one evaluation index, but on the comprehensive performance of the transmission volume, economic profit and pipeline safety. The application proves that the pipeline’s operation schemes can be reasonably evaluated even if insufficient data are used. The achievement of this paper provides a new analytical method as well as a powerful tool for the synthetic evaluation of operation schemes for natural gas pipelines.

A Reliability Assessment of the Hydrostatic Test of Pipeline with 0.8 Design Factor in the West–East China Natural Gas Pipeline III

The use of 0.8 design factor in Chinese pipeline industry is a breakthrough with the success of the test pipe section in the west–east China gas pipeline III. For such a design factor, the traditional P-V (Pressure-Volume) curve based pressure test control cannot describe the details of the process, and the 0/1 type failure is not an efficient index to show the safety level of the pipeline. In this paper, a reliability based assessment method is proposed to monitor the real-time failure probability of the pipeline during the hydrostatic test process. The reliability index can be used as the degree of risk. Following the actual hydrostatic testing of a test pipe section with 0.8 design factor in the west–east China gas pipeline III, reliability analysis was performed using Monte Carlo technique. The basic values of input parameters of the limit state equations are based on the data collected from either the tested section or the recommended value in the codes. The analysis of limit states, i.e., the yielding deformation and the excessive plastic deformation of pipeline, proceeded based on these distributions. Finally, it is found that the gradually increased water pressure makes the failure probability increase accordingly. A reliability assessment method was proposed and illustrated with the practical pressure test process.