West-East Gas Pipeline Research Articles

Enhanced landslide susceptibility mapping in data-scarce regions via unsupervised few-shot learning

Given the critical need to assess landslide hazards, producing landslide susceptibility map (LSM) in regions with scarce historical landslide inventories poses significant challenges. This study introduces a novel landslide susceptibility assessment framework that combines unsupervised learning strategies with few-shot learning methods to increase the accuracy of LSM in these areas. The framework has been practically validated in a representative geological disaster-prone area along the West-East Gas Pipeline in Shaanxi Province, China. We employed three advanced few-shot learning models: a support vector machine, meta-learning, and transfer learning. These models implement feature representation learning for weakly correlated influencing factors through an unsupervised approach, thereby constructing an effective landslide susceptibility assessment model. We compared traditional learning methods and used the receiver operating characteristic (ROC) curve and SHAP values to quantify the effectiveness of the models. The results indicate that the meta-learning algorithm outperforms both the SVM and transfer learning in areas with limited landslide data. The integration of unsupervised strategies significantly improves performance, achieving area under the curve (AUC) values of 0.9385 and 0.9861, respectively. Compared with using meta-learning alone, incorporating unsupervised learning strategies increased the AUC by 4.76%, enhancing both the predictive power of the model and the interpretability of the features. Meta-learning under unsupervised conditions effectively mitigates the evaluation difficulties caused by insufficient landslide records, providing a viable path and empirical evidence for performance improvement in similar data- scarce regions worldwide.

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.

Model for the Failure Prediction Mechanism of In-Service Pipelines Based on IoT Technology

With the rapid increase in pipeline mileage in China, the accurate prediction of corrosion issues in in-service pipelines has become crucial for ensuring safe pipeline operation. Traditional pipeline leakage monitoring methods are significantly limited by human factors and equipment precision, making it challenging to predict and identify leakage points accurately. Therefore, aligned with the trend of intelligent pipeline development, this study aims to construct a failure pressure prediction mechanism model for corroded pipelines based on IoT technology. This model leverages intelligent sensing and prediction to assess the safety status of corroded pipeline sections. Ultrasonic phased array technology detects specific corrosion points and detailed defect parameters within pipeline sections. The parameters are then utilized in the Simdroid domestic finite element analysis model to simulate the ultimate burst pressure of the pipeline. A single-variable approach is employed to analyze the sensitivity of different parameters to the pipeline’s ultimate burst pressure, with the minimum burst pressure point of multi-point corroded sections selected as the overall segment failure pressure. Finite element simulation data are integrated into a neural network database to predict the pipeline failure pressure. The real-time operational data of the pipeline are monitored using negative-pressure wave sensing. The operational pressure of the corroded points is compared with the algorithm-predicted failure pressure; if the values approach a critical threshold, an alarm is triggered. Moreover, the remote control terminals evaluate the pipeline’s self-rescue time, providing a buffer for pipeline leakage self-rescue. The failure prediction mechanism model for in-service pipelines was applied to the Fujian–Guangdong branch of the West–East Gas Pipeline III to verify its accuracy and feasibility. The research results offer technical support for the maintenance and emergency repair of pipeline leakage scenarios, leveraging intelligent pipeline technology to reduce costs and increase the efficiency of pipeline operations, thereby supporting the sustainable development of China’s oil and gas pipelines with theoretical and technical backing.

Optimization research on energy consumption and carbon emissions in hydrogen-blended natural gas pipeline networks considering compressor performance - A case study of the west-east gas pipeline (line 1)

The blending of hydrogen into natural gas can utilize existing natural gas pipeline infrastructure to achieve long-distance, large-scale, and cost-effective hydrogen transportation. However, the introduction of hydrogen poses a series of new technical and safety challenges to the operation of natural gas pipelines. Addressing these issues, this paper focuses on minimizing compressor station energy consumption and carbon emissions as objective functions, conducting a comprehensive analysis of station operation modes. Incorporating the characteristics of the model, the soft frost search strategy, the hard frost penetration mechanism, and the positive greedy selection mechanism are introduced to propose the IRIME algorithm. Comparisons are made with well-performing optimization algorithms using classical test functions to evaluate algorithm performance. To further validate the algorithm's accuracy, the West-East Gas Pipeline (Line 1) is considered, comparing the convergence speed and precision of the IRIME algorithm, leading to its selection for solving the model. Furthermore, consider analyzing the impact of different hydrogen blending ratios on the performance curves and operating points of compressors. Results indicate that compared to conditions without hydrogen blending, the compressor outlet temperature and pressure drop increase for hydrogen blending ratios of 5%, 10%, 15%, and 20%; as the hydrogen blending ratio increases, the efficiency of fuel-driven compressors, efficiency of electrically driven compressors, and average efficiency of compressor units decrease; with an increase in hydrogen blending ratio, carbon emissions from fuel-driven compressors and electric-driven compressors both decrease. In conclusion, with an increasing hydrogen blending ratio, total energy consumption increases by 3.14%, 5.69%, 8.68%, and 10.90%, while total carbon emissions decrease by 2.99%, 5.36%, 8.32%, and 10.68%. These findings provide valuable insights for operational guidance in the field.

Joint Peak Shaving Mechanism of Pipeline Gas Storage: Case Study of West-East Gas Pipeline

Demand imbalance owing to gas supply is considered in the context of a surge in natural gas demand. Currently, a single method of storing gas at the end of a pipeline is commonly used to alleviate the peak shaving pressure. This method is economical, convenient, and able to respond quickly to fluctuations in user gas demand. However, because of its limited gas storage capacity, gas storage for peak shaving is still considered when the demand for peak shaving is high. With the increasing demand for natural gas inclined towards residential life, it is difficult to achieve a relative balance between the supply and demand of natural gas solely by relying on traditional pipeline-end storage and peak shaving. Based on this, a “pipeline gas storage integration” peak-shaving model is constructed. Furthermore, the model is combined with real-time analysis of the required peak-shaving amount of the pipeline to achieve synergistic effects of multiple peak-shaving methods. The established model is used to study the collaborative peak-shaving mechanism between pipelines and gas storage facilities under different supply and demand conditions. In addition, a quantitative relationship between the optimal economic benefits and different peak-shaving methods is constructed using the model. A peak-shaving mechanism of gas transmission considering different uniformity coefficients is also studied. Considering the case of the Jiangsu section of the West-East Gas Pipeline for simulation analysis, we reasonably plan the capacity and layout of gas storage facilities, optimize the peak shaving capacity of pipelines and gas storage facilities, and provide specific measures and guidance for actual engineering. Furthermore, we improve the efficiency and flexibility of the natural gas supply chain and achieve maximum economic benefits.

Addressing the inspection selection challenges of in-service pipeline girth weld using ensemble tree models

Natural gas transportation predominantly utilizes pipelines, and the safety of these systems largely hinges on the integrity of girth welds. However, once pipelines are buried post-construction, pinpointing weld inspection sites becomes complex. Presently, weld risk assessments rely on costly and specialized inspections. Hence, enhancing the accuracy in identifying defective welds and discovering superior inspection techniques is paramount. Our research employed machine learning, specifically an ensemble model of RandomForest and CatBoost, to prioritize weld inspections. After analyzing the West-East Gas Pipeline Girth Weld Dataset and addressing data imbalances using the SMOTE technique, we refined the model parameters. The culminating model yielded an F1-score of 0.815 and an average accuracy of 0.836, outperforming standalone models. Employing the SHAP method improved the model’s transparency, facilitating a more informed decision-making process regarding pipeline inspections. This study underscores the potential of machine learning in elevating oil and gas pipeline safety measures.

Study on tide characteristics and mechanism of PSP in buried pipeline along the lake

The fluctuations of the Pipe-to-Soil Potential (PSP) in buried pipes are influenced by the geoelectric field induced by changes in the Earth's magnetic field, which can accelerate pipeline corrosion. Monitoring data of PSP along China's West–East Gas Pipeline near the lake indicates obvious tidal changes. This study proposes that the periodic movement of the conductivity boundary of the seepage area near the lake shore caused by tides is the fundamental cause of the tidal changes in PSP. The movement of the boundary changes the range of the H polarization of the geoelectric field, resulting in periodic changes in the PSP of the pipeline outside the seepage area. To investigate this mechanism, a dynamic boundary model of conductivity in the seepage area of Sailimu Lake in Xinjiang was established, and the characteristics of PSP at different distances from the boundary were analyzed using electromagnetic field finite element method and DSTL pipeline model. The study compared the simulation results of the model with the PSP data of the cathodic protection station and PSP monitoring station near Sailimu Lake, during a geomagnetic disturbance on September 23–24, 2016. The results of the study, as well as the corrosion of the test strips along the lake, verified the validity of the boundary change mechanism and model of the seepage zone. This study provides a theoretical basis for corrosion protection of pipelines near the lake’s edge.

Research on local buckling failure range of X80 buried steel pipeline under oblique-reverse fault

Permanent ground deformation induced by the earthquake will cause serious damage to long-distance buried oil and gas pipelines, resulting in buckling failure or even cracking damage to pipelines. Based on the ABAQUS program, a 3-D numerical model of X80 buried steel pipeline crossing oblique-reverse fault was established, and the failure characteristics and failure range of local buckling of buried pipeline were systematically analyzed. According to the engineering parameters of the Second West-East Gas Pipeline Project (China), the influence of fault dip angle, displacement, diameter-thickness ratio, burial depth, and internal pressure on the local buckling failure range of the pipeline was discussed in detail. Subsequently, regression analysis was carried out on the numerical results of 1800 sets of the finite element cases, and a semi-empirical prediction equation (“Risk Segment” regression formula) of the local buckling failure range of X80 steel pipeline subjected to oblique-reverse fault displacement was derived. The accuracy and applicability of the formula were verified by the numerical results of 120 practical examples. The results show that the “Risk Segment” regression formula has higher accuracy and is less time-consuming, which is suitable for failure range prediction and local safety design of X80 buried steel pipeline under oblique-reverse fault.

UAV Based on Communication Network to Obtain Oil Pipeline Data and 3D Modeling

With the advancement of science and technology and the development of industry, the demand for oil is increasing, and the measurement of oil is becoming more and more reliable and accurate. The communication network refers to the physical connection of various isolated devices to realize the link of information exchange between people, people and computers, and computers and computers, so as to achieve the purpose of resource sharing and communication. Oil and natural gas pipelines are an important strategic resource and the economic lifeline of a country. China’s long-distance oil and natural gas pipelines have developed rapidly in recent years, and the Beijing-Shijiazhuang Pipeline, the “West-East Gas Pipeline,” and the western crude oil and refined oil pipeline projects have been completed. The UAV can produce geometric data with high precision and build its 3D model. Therefore, this study proposed a UAV based on the communication network to obtain oil pipeline data and 3D modeling. The study mainly talked about the energy consumption in the era of communication. The energy acquisition was analyzed, the pipeline transportation measures for petroleum energy under UAV technology were focused on, the three-dimensional modeling of its terrain capture was carried out, and then the experimental data were analyzed after the equipment was debugged in the experimental part. The final experimental results showed that, under different frequencies, the data collected by the host computer were compared with the field measurement data, and the errors of the water and oil phases were calculated. It can be clearly seen from the data that the error was less than 5%, which also proved that this method was feasible.

Impacts of the West-East Gas Pipeline Project on energy conservation and emission reduction: empirical evidence from Hubei province in Central China.

The extensive use of natural gas provides a new approach to low carbonization of the structure of primary energy sources, as well as reduces the peak in carbon emissions before fossil fuels are completely replaced by clean energy. To explore the impact of the West-East Gas Pipeline Project (WEGPP) on energy conservation and emission reduction in Chinese inland areas, the effects of policy intervention on the socio-economic development in Hubei province are preliminary investigated in this paper. The causal inference of multi-bandwidth and multi-core analysis is carried out using regression discontinuity design (RDD), and the core conclusion of the counterfactual analysis is proven to be robust based on the synthetic control method. The results show that the transportation of natural gas from Western China to Hubei province can reduce the intensity of carbon emissions, demonstrating that it is an effective substitution to low-carbon energy. The WEGPP not only can meet the demands of a large number of energy shortages caused by the rise of the manufacturing industry, but also can solve the technique bottleneck of energy consumption in Central and Eastern China. The WEGPP has ensured the coordinated development in Western, Central, and Eastern China, achieving and maintaining a high and stable economic growth rate in China. These results have significant implications for making policies of energy conservation and emission reduction in a considerable number of gas-importing provinces in Central China.

Research on Abnormal Vibration and Vibration Reduction Measures of a Natural Gas Compressor Station: A Case Study of the JYG Compressor Station

As an important medium transmission element, the pipeline has a very important application in the chemical industry, electric power industry, and petroleum industry. However, the pipeline vibration problem has seriously restricted the large-scale development of equipment, reduced the reliability of equipment operation, and even caused serious accidents. Therefore, it is very important to analyze the dynamic characteristics of these vibrations and to reduce the impact of vibrations within pipelines. We focus on the problem of abnormal vibrations within the JYG compressor station pipeline and use a 3D calculation model of the launcher pipeline of west–east gas pipeline III to perform simulation analysis using Fluent to find the cause of the abnormal vibrations. Our results show that the fluid pressure fluctuation in the pipeline is the main factor for the abnormal vibration of the launcher pipeline in the JYG compressor station. The main causes of the vibrations are excessive fluid flow and high flow velocity. Also, by comparing and analyzing the natural frequency of the pipeline system and the pressure fluctuation frequency of the vortex core in the pipeline, we found that the pressure fluctuation frequency is close to the low-order natural frequency of the pipeline system, which is prone to resonance. In this paper, three vibration reduction schemes of the JYG compressor station are suggested and verified. The efficiency of vibration reduction is 68–94%, which can be effectively applied to the outgoing pipeline of the west–east gas pipeline III to solve the abnormal vibration problem of the pipeline.

Probabilistic-based geomechanical assessment of maximum operating pressure for an underground gas storage reservoir, NW China

One of the most cost-effective ways to increase deliverability and working gas capacity in underground gas storage (UGS) reservoirs is to operate the gas storage at higher pressure (increased delta pressure). Maximum operating pressure (MOP) for a gas storage reservoir depends on several geomechanical factors, including in-situ stresses, stresses induced by local and global pressure changes in the storage reservoir, and the stabilities of the caprock and faults. PetroChina’s Hutubi (HTB) gas storage site is located in the west gate of China’s west–east gas pipeline project. Multiple major faults intersect the gas storage reservoir and caprock, which pose safety concerns for increasing the gas storage pressure. The typical practice in an HTB storage site has been to operate gas storage pressures at levels equal to the original reservoir pressure because of concerns related to caprock integrity and fault stability. To investigate the possibilities of increasing the gas storage pressure, a comprehensive geomechanical study has been conducted. By utilizing the data from rock mechanics laboratory testing, in-situ stress measurements, 3D field-specific geomechanical models, and coupled reservoir-geomechanical simulations, this paper presents probabilistic risk assessment of fault slippage in response to injection-related increases in pore pressure. Uncertainties of relevant geomechanical parameters, such as the frictional strengths of faults, orientation, and magnitudes of in-situ stresses, have been incorporated through Monte Carlo simulations. The authors find that: (1) fault slippage is the controlling factor which determines the limit of MOP at a HTB gas storage site; (2) increasing the gas storage pressure by 12.5% above the initial reservoir pressure (34.5 MPa) leads to approximately 0.6% probability of fault instability that could provide a leakage pathway. Thus, from a geomechanical perspective, operating the storage pressure at initial reservoir pressure at a HTB gas storage field is an overly conservative approach that leads to under-utilization of the existing storage capability. This paper provides the first integrative geomechanical study for increasing MOP for large underground gas storage reservoir in China. The methodology as well as comprehensive data repository are potential sources for future geomechanical studies on similar underground gas storage projects.

Safety inspection system and comprehensive evaluation method for concrete structure of gas pipeline tunnel based on fuzzy mathematics

Regular safety inspections are an important guarantee to ensure the high-quality operation of concrete structures of tunnels. The Chinese West-east Gas Pipeline Project is large in scale and complex in construction environment. These tunnels are equipped with gas pipelines, and the concrete structural defects of the tunnels are continuously exacerbated during the long-term operation. There are few studies on the safety evaluation methods of concrete structures of gas tunnels. Based on the characteristics of the operation of the gas tunnels, this paper proposes the establishment of a structural safety comprehensive inspection system from the following seven aspects, that is, the void between the concrete lining and surrounding rock, the strength of the concrete lining, the thickness of the protective layer of the reinforced concrete lining, the carbonization depth of the concrete lining, the deformation of the tunnel section, the cracks in the concrete lining, and the auxiliary concrete structure of the tunnel. In addition, a corresponding quantitative determination method and safety level classification standard are established. Based on the fuzzy mathematics theory and a structural safety comprehensive inspection system, a five-level safety evaluation method for tunnel concrete structures is proposed. Finally, a comprehensive inspection and evaluation were carried out for a tunnel running across the mountain.

Study on the maintenance scheduling model for compressor units of long-distance natural gas networks considering actual maintenance demands

Most maintenance strategies serving for the practical applications are formulated based on the single maintenance objective and do not consider the physical layout of compressor units in the complex pipeline networks and the actual maintenance demands, resulting in the over-maintenance or under-maintenance. The effective maintenance strategies for compressor units improve the unit reliability, economy, and maintenance efficiency. This work establishes a multi-level maintenance scheduling model composing of unit life prediction, unit-level maintenance decision, and system-level maintenance scheduling to guide the maintenance planning with cost and availability as the evaluation objectives. The maintenance strategies are developed by considering the series-parallel layout of compressor units, actual maintenance demands, and maintenance capability. The effectiveness of the proposed model is verified through 31 compressor unit networks in the Chinese west-east gas pipeline under the strategies of separating maintenance, combining maintenance, single maintenance team, and multiple maintenance teams, and compared it with the traditional methods. Compared with the traditional individual and simultaneous maintenance modes, the proposed method based on the optimal time window can reduce the maintenance cost by at least 27.7% and 25.1%, respectively. The weight factors and reliability have a great influence on the cost increase rate and unit availability. The multi-objective maintenance scheduling can improve the unit availability by 1.6% compared with the single availability optimization objective, and the corresponding maintenance cost rate is only increased by 0.68%. For the complex compressor unit networks, it is a better choice to consider the multi-objective maintenance planning under the single maintenance team. The model can improve the anti-risk ability of compressor units in long-distance natural gas networks and put forward maintenance suggestions from the perspective of safety, economy, and reliability.

Stresses measurement and failure prevention of on-line natural gas transmission pipelines for compressor station on collapsible loess area in northwest China

There are many collapsible loess foundations in the first-line project of West-East gas pipeline of China. The collapsible loess has a great influence of the structure integrity of pipeline, especially the stress distribution. In this paper, the stresses of natural gas transmission pipelines for compressor station on collapsible loess area were measured by indentation strain method. The key position for every typical cases to occur strength failure is analyzed. A failure prevention method was also proposed. The results show that the axial stress may exceed the tensile strength induced by download bend deformation of pipelines, and becomes a potential zone to occur strength failure. An improving stresses distribution method was proposed by using added support pier below the ball valve. The axial stresses can be reduced by proposed improving method which will enhance the strength of pipelines very well. The stresses of gas pipelines in the collapsible loess should be measured regularly to avoid strength failure.

Analysis and Research on Pipeline Vibration of a Natural Gas Compressor Station and Vibration Reduction Measures

The abnormal vibration of natural gas station pipelines seriously threatens the safety of pipeline transportation, and improper handling will cause huge economic losses. For the abnormal vibration of the pipeline, reasonable treatment must be carried out. The Yongchang gas station belongs to the west–east gas pipeline system in China. Since its production, abnormal vibration has often occurred in the west-third outbound pipeline of the Yongchang gas station, and the vibration changes according to the different gas transport volumes. In this paper, the outbound pipeline of the Yongchang pressure station is taken as the research object, and the vibration analysis of the station yard pipeline is carried out. The numerical model of the station yard pipeline is established, and the correctness of the model is verified by the field vibration test. The fluid–solid coupling method is used to analyze pipeline vibration under different working conditions. Then, three kinds of vibration reduction schemes are proposed and verified by simulation. The main conclusions are as follows: (1) The fluid pressure fluctuation in the pipeline is the root cause of abnormal vibration in the station. (2) When the gas transmission volume is large, the vibration of the pipeline system will become more severe. (3) The scheme of increasing pipe diameter and adding appropriate constraints has the best vibration reduction effect.

Research on the impact of mega-projects on carrying capacity of cities taking the first-line project of the West-East gas pipeline as an example

With the acceleration of China’s urbanization, the functions and benefits of mega-projects are required higher. With the deepening of “the Silk Road Economic Belt and the 21st-Century Maritime Silk Road”, the quantitative evaluation of multinational investment projects will help strengthen cross-border communication among government, society and enterprises, which provide a basis for mutual trust. This study empirically analyzes and evaluates the impact of mega-projects on carrying capacity of cities, by using the DID method based on the panel data of 15 cities in China from 2000 to 2013. The results show that the construction and operation of the first-line project of the West-East gas pipeline has a significant positive impact on the improvement of carrying capacity of cities along the line. However, the degree of impact on three dimensions is slightly different. The impact on the social carrying capacity is the greatest, then the ecological and economic carrying capacity. Therefore, the decisions of domestic mega-projects should be unified with urban planning to promote the sustainable development of China’s economy and social. The investment of mega-projects abroad should also be coordinated with the carrying capacity of host cities, in order to enhance the competitiveness and creativity of Chinese multinational mega-projects investment.

Vibration monitoring for the West-East Gas Pipeline Project of China by phase optical time domain reflectometry (phase-OTDR)

Optical fiber phase optical time domain reflectometry (phase-OTDR) has been applied on the West-East Gas Pipeline Project (WEPP) of China for vibration monitoring. In order to improve the accuracy of the threat identification, a machine learning algorithm from the voice recognition is introduced. The feature extraction and pre-emphasis processes were modified to characterize the vibrations in the soil. The threat identification accuracy increased from 83% in 2017 to 90.6% in 2018 by continuously training the algorithm. Massive vibration measurements were recorded during the past two years and interesting results have been obtained from the data analysis. These results are expected to assist engineers to have a better understanding of how the threatening incidents occur near pipelines.

Risk Assessment of Pipeline Failure Based on Fuzzy Analytic Hierarchy Process

Pipeline failure is a serious economic, environmental and safety issue. Risk assessment is an effective method to determine the risk of pipeline failure. This paper proposes an evaluation system. In the evaluation process, the fuzzy concept and method are used to transform the qualitative effect into quantitative fuzzy numbers based on linguistic variables. The weights are calculated by MATLAB software. Calculate the weight result and classify each indicator risk, and finally determine the pipeline failure risk level. Taking a section of the third-line pipeline of the West-East Gas Pipeline as an example, the fuzzy analytic hierarchy process is used for analysis. The two indicators of external corrosion and management system are medium risk grades, and the overall pipeline failure risk level is II (lower). The evaluation results show that the proposed evaluation system and method are effective and objective for evaluating pipeline failure risk. The pipeline failure assessment based on fuzzy analytic hierarchy process can not only objectively assess the risk status of pipelines, but also have a positive effect on improving pipeline risk management.

West-East Gas Pipeline Project

West-East Gas Pipeline Project