Whether used as an alternative fuel or a clean feedstock, renewable hydrogen (H2) could facilitate the deep decarbonization of hard-to-abate sectors, which is essential to meet China's carbon neutrality target. Nevertheless, the nationwide H2 backbone networks required have not yet been fully investigated. Employing a techno-economic analysis of solar photovoltaic and wind power on a scale of 1 km combined with source-sink matching among potential multisectoral H2 hubs, this study develops a decision support system (dubbed China Shared Hydrogen Infrastructure Network Enabler (SHINE)) to explore renewable H2 layouts commensurate with China's climate ambition, accounting for varying degrees of H2 demand and reuse of oil and gas pipeline corridors. Given total H2 demand scenarios of 54, 77, and 100 Mt/yr in 2060, the total length of the proposed trunkline networks will reach roughly 11,700, 18,300, and 29,900 km, with a levelized cost of production and transport of 1.55, 1.62, and 1.72 USD/kg, respectively. Additionally, by incorporating the spatial heterogeneities and sectoral disparities of H2 deployment expansion into the model, distinct policy instruments can be crafted for the shared nationwide H2 network.

Erosion poses a significant threat to gas transportation pipelines, particularly at pipe bends where sand particle impingement can lead to equipment malfunction and pipeline failure. In this work, we employ a one-way coupling simulation approach for flow–particle interactions across various bend geometries to understand sand dynamics in gas pipelines. First, Large-Eddy Simulations (LESs) are conducted to analyze flow patterns in 45°, 75°, 90°, and 180° pipe bend geometries with gas flow velocities of 8.5 m/s at the inlet. Our LES reveals that an energetic separation forms near the bend apex. Second, particle trajectory analysis indicates that particle impingement predominantly occurs downstream of the pipe bend across all geometries. Third, experimental studies utilizing the paint removal technique are also performed to correlate with the numerical prediction. Comparing the numerical results with the corresponding experimental observations, our results show that complex flow patterns control particle trajectories and potential erosion sites in bends. Finally, a detailed statistical analysis using probability density functions of particle velocity and rebound angle provides quantitative insights into particle behavior within each bend. Our study reveals distinct trends depending on the bend angle (α). This research develops a comprehensive engineering approach to predict particle trajectories and particle–wall interactions within pipe bends, ultimately informing erosion prediction.

Natural gas pipeline integrity management efficiency evaluation and prediction: A DEA-Malmquist-ML approach

A three-model integrated optimization framework for natural gas pipeline capacity operationally efficient and equitable allocation

Corrosion detection, localization, and severity estimation on gas pipeline surfaces using transfer learning and image processing

Blending hydrogen into natural gas pipelines is an effective and economical method for long-distance, large-scale hydrogen transportation. Current research on hydrogen-blended natural gas pipelines primarily focuses on hydraulic and thermal characteristics, while operational efficiency optimization has received less attention. Consequently, this study conducted the operational optimization of hydrogen-blended natural gas pipeline networks using the differential evolution algorithm. The optimization involved single-objective optimization aimed at minimizing compressor energy consumption, as well as multi-objective optimization that addresses both compressor energy consumption and throughput. For the single-objective optimization, the optimal operating scheme for the compressor can reduce energy consumption by around 40% across various hydrogen blending ratios. In the case of multi-objective optimization, maintaining the transportation task coefficients within the range of 0.55–0.6 ensures that the compressor operates within a safe and efficient region. Notably, when the transportation task coefficient is around 0.55, an inflection point emerges in the distribution of Pareto-optimal solutions. This point signifies an optimized design where both compressor power and throughput reach favorable conditions, marking a crucial operational sweet spot for efficient performance. This study provides valuable insights for optimizing hydrogen-blended natural gas pipelines.

Influence of Pressurized Pipeline Leakage and Oil Pool Fires on Parallel Natural Gas Pipelines

Cooperative operation optimization of natural gas pipeline network and underground gas storage: economic scheduling and low-carbon control

A probabilistic-based numerical modeling of natural gas pipelines with random corrosion morphology

Impact Response Analysis of Buried Gas Pipelines under Continuous Excavation by Hydraulic Backhoe Excavators

Topology-aware hydrogen injection planning in natural gas pipeline networks: A case study for California

Liquid accumulation in low-lying and uphill sections of undulating shale gas pipelines significantly threatens transportation efficiency, pressure stability, and pipeline integrity due to corrosion. Accurate prediction of liquid holdup is therefore critical for flow assurance. This study investigates the liquid distribution in a shale gas pipeline through orthogonal testing, analyzing key operational factors including water and gas flow rates. The formation mechanisms and the relative significance of these factors on liquid accumulation are systematically elucidated. Subsequently, a predictive mathematical model correlating operational parameters with liquid accumulation volume is developed. The model's accuracy is rigorously validated against simulation results obtained from the industry-standard OLGA multiphase flow software. The findings of this study establish a theoretical foundation for optimizing pigging operations, thereby enhancing pipeline transport efficiency and reducing operational costs.

Application of real-time data lake technology in oil and gas pipeline SCADA system

During the operation of above-ground main oil and gas pipelines, their elastic bends occur due to the properties of the soils in which the pipeline bases are installed, climatic factors, and the intersection of geodynamic zones. Exceeding the stress values in the pipeline wall above their permissible values leads to a rupture of the wall metal and major accidents. Most methods for estimating the values of bending stresses in the pipeline wall cannot be implemented during their operation, when the pipeline already has a bend, and the installation of any additional equipment on the pipeline requires additional investments. At the same time, the most widely used method for estimating bending stresses based on data from in-pipe diagnostics does not allow for evaluation in areas with varying internal diameters of the pipeline, as well as right-angle turns. The most promising method for estimating bending stresses is aerial laser scanning of pipelines, which consists of obtaining a cloud of points on the pipeline surface, estimating its spatial position, and calculating stress values. However, this method requires the development of more accurate algorithms for processing laser scanning data, and the method is associated with a number of difficulties that can be eliminated by developing the correct sequence of actions during scanning. Within the framework of this article, an algorithm has been developed for analyzing the coordinates of a cloud of points on the pipeline surface, which makes it possible to estimate the values of bending stresses in the pipeline wall. The influence of the unevenness of the thermal insulation surface on the stress assessment results was also studied, taking into account the minimum angle of the scanned pipeline sector, which ensures the accuracy of determining stress values up to 5% using the developed method.

Clathrates have gained considerable attention due to their potential impact on various industries, including oil and gas production, and more recently in the fields ranging from energy storage and transportation to environmental protection and gas separation processes, opening up new technological possibilities. Overall, the attention is focused on their spontaneous and uncontrolled formation/nucleation in offshore oil and gas pipelines, which can lead to numerous and serious operational problems. Accordingly, significant research efforts have focused on understanding the mechanisms of clathrate formation and inhibition or dissociation. Different approaches are being explored; some are ambitious and innovative, whereas others seek further validation. Among these, particular interest has emerged in the coupling of Terahertz (THz) radiation with the collective low-energy and/or vibrational modes of water, and/or other molecules, as well as their clusters. In this review, we summarize recent advances and findings in this promising research field, highlighting the potential applications of THz radiation and spectroscopy, future applications in the field of clathrates, and the technological progress toward the implementation of THz-based solutions in transportation and industrial processes.

To ensure timely valve response in the event of leaks in marine oil and gas pipeline networks—thereby minimizing the impact of such leaks on the marine ecosystem—providing a continuous and stable power supply for pipeline networks in offshore environments remains a challenge. Integrating a runner into the valve cavity of a control valve to capture fluid energy flowing through the valve for power generation is a promising solution. However, current studies fail to emphasize the impact of valve body structure—and this research status of “prioritizing runners over valve bodies” while neglecting the coupling effect has become a major bottleneck for the further advancement of control valve-based hydroelectric technology. Based on the concept of shape-property collaboration, this study, through the bidirectional drive of shape optimization and performance improvement, fully considers the coupling characteristics of the runner and valve, modifies the geometric configuration of the valve cavity, and enhances the performance of the energy-harvesting valve. Based on an experimentally validated CFD model, the study reveals the influence laws of valve opening and the characteristic parameters of the new valve cavity configuration (flow-collecting deflection angle and surface grooves) on the valve’s fluid regulation performance and energy-harvesting characteristics. The results show that the flow-collecting structure and surface groove structure of the valve cavity have a significant effect on improving the performance of the energy-harvesting control valve.

ABSTRACT Non-destructive testing of pipeline structures is crucial for ensuring industrial safety. To address the challenges of insufficient separation of multi-modal frequency signals and difficulty in feature extraction under noise interference in acoustic resonance technology, this study establishes a mathematical model of resonance frequencies for pipeline defects based on acoustic resonance mechanisms. Additionally, an improved singular spectrum decomposition (ISSD) method with a frequency-domain concentration characteristic (FDCC) indicator. ISSD adaptively optimises the fixed embedding dimension using a spectral kurtosis-to-spectral entropy ratio factor, effectively suppressing mode mixing. The FDCC indicator quantitatively evaluates resonant energy concentration, enabling precise component selection and accurate defect characterisation. Simulation and experimental results demonstrate that, compared to other methods, ISSD exhibits superior purity and noise robustness, clearly distinguishing between pipe wall and defect resonance frequencies. Using FDCC, two-dimensional defect localisation and contour quantification are achieved, while depth is determined via the resonance-thickness relationship. Tests on four defects show depth errors under 0.2 mm and in-plane errors within 4 mm.This study provides an effective means for the identification and quantitative assessment of pipeline defects.

Empirical approaches alone have significant limitations for accurate estimation of the fracture toughness of welds in gas line pipes being considered for repurposing to hydrogen service. These problems arise because most samples machined from ex-service welds contain a range of microstructures. The different microstructural zones have different properties and even when compact tension samples with side grooves are utilized, it is unlikely that plane strain conditions are achieved during laboratory testing. Thus, the measured toughness may not be directly relevant to assessing in-service performance. The present research has been undertaken as part of an integrated series of projects seeking to define a robust protocol for assessing the damage tolerance of piping used for the transmission of hydrogen, especially when considering repurposing existing infrastructure. The key work described in this paper involved establishing heat treatments which produced microstructures relevant to the constituents found in ex-service welds of X46 type steel. Following comprehensive microstructural characterization, these heat treatments were applied to steel sections which allowed for the fabrication of standard compact tension specimens, which were subsequently tested in hydrogen to measure fracture toughness. The results obtained showed that the fracture behavior varied for different microstructures. To identify the influence that hydrogen gas has on the performance of pipeline steels, it is important to assess microstructures relevant to the welds present, as testing only on base metal may not provide conservative information. However, the results from well-planned and carefully executed programs can be used to identify the relative performance in hydrogen. The data can also be used as critical input to models which form part of an integrated approach to structural integrity assessment.

Pipeline transportation is currently the main method for large-scale, long-distance transport of oil and natural gas. As the service life increases, the risk of pipeline leaks also gradually rises. Oil and gas pipeline inspection, as a key link in pipeline integrity, can provide a scientific basis for the prevention and maintenance of pipeline accidents. Pipeline robots play an important role in pipeline inspection, as they can enter complex pipeline environments to carry out tasks such as inspection, cleaning, and maintenance. At the same time, with the development of artificial intelligence, machine vision technology is widely applied in pipeline inspection. This paper provides a comprehensive review of pipeline inspection robots based on machine vision, including mechanical structures and visual inspection methods, and analyzes and compares their performance characteristics. It summarizes the factors limiting their development and proposes solutions, providing a reference for the further development of machine vision-based oil and gas pipeline inspection robots.

Pipeline infrastructure constitutes the primary transportation system within the oil and gas industry, where operational safety is critically dependent on advanced in-line inspection technologies. This study presents a comprehensive analysis of eddy current testing (ECT) applications for pipeline integrity assessment. The fundamental principles of ECT are first elucidated, followed by a systematic comparative evaluation of five key ECT methodologies: conventional, multi-frequency, remote field, pulsed, and array eddy current techniques. The analysis examines their detection mechanisms, technical specifications, comparative advantages, and current developmental trajectories, with particular emphasis on future technological evolution. Subsequently, integrating global pipeline infrastructure development trends and market requirements, representative designs of pipeline inspection tools are detailed and we review relevant industry applications. Finally, persistent challenges in ECT applications are identified, particularly regarding adaptability to complex operational environments, quantification accuracy for micro-scale defects, and predictive capability for defect progression. This study proposes that future ECT equipment development should prioritize multi-modal integration, miniaturization, and intelligent analysis to enable comprehensive pipeline safety management throughout the entire asset lifecycle.