Article Search
Oil & Gas Storage and Transportation2024 05
ZHANG Duihong1,LI Yuxing2
[Abstract](315)
[Objective] Amidst the ongoing pursuit of “dual carbon” goals, Carbon Capture, Utilization, and Storage (CCUS) has rapidly progressed as a foundational technology facilitating significant carbon emission reductions in China. Serving as a crucial link between upstream and downstream activities in the CCUS industry chain, the construction of CO2 pipelines is capitalizing on its golden development opportunities. To propel the construction and growth of CO2 pipelines in China, a relative latecomer in this realm, it is imperative to systematically address key challenges and core technologies associated with CO2 pipeline transmission while establishing a comprehensive technical standard system. [Methods] Literature research was undertaken to review and evaluate the current development status of CO2 pipeline transmission technologies. The significant advancements in CO2 pipeline transmission technologies were summarized through an in-depth analysis of various facets such as CO2 phase behaviors, the pipeline transmission process, pipeline safety, software simulations, and standards and specifications. Recommendations and future outlooks for planning CO2 pipelines and developing pipeline transmission technologies were delineated, considering the distinctive characteristics of carbon sources and sinks in China. [Results] In contrast to European nations and the United States, China faces a shortage in establishing long-distance supercritical CO2 pipelines. Currently, the only operational project is a dense phase CO2 pipeline linking the facilities of Sinopec Qilu Petrochemical Company (Qilu Petrochemical) with Shengli Oilfield. Additionally, the CO2 pipeline projects of PetroChina Daqing Petrochemical Company (Daqing Petrochemical) and Sinopec Jilin Oil Products Company (Jilin Petrochemical) remain in the preliminary design phase. As a result, it is foreseeable that the pace of CO2 pipeline construction in China will increase in the future. [Conclusion] China has developed a certain level of technical expertise for supercritical CO2 pipeline transmission. However, additional endeavors are required to address challenges in pilot testing and enhance theoretical models. Simultaneously, there is a need to advance engineering applications to demonstrate related technologies and enhance the standard system of CO2 pipeline transmission technologies. These steps are crucial to offer extensive and strong support for planning and building regional ten-million-ton CO2 pipeline transmission networks and interregional CO2 trunk pipelines in the future. (1 Figure, 1 Table, 49 References)
[PDF:1845KB](163)[Export Reference]
MIAO Qing
[Abstract](249)
[Objective] Carbon Capture, Utilization and Storage (CCUS) is a pivotal technology for reducing atmospheric carbon dioxide levels. The pipeline transportation of supercritical/dense-phase CO2 stands as the most cost-effective and practical means of conveying CO2 from capture sites to storage locations. In supercritical/dense-phase CO2 pipeline design, the key requirement is to mitigate long-range ductile fracture following the occurrence of cracks. At present, the most direct means for verifying the pipeline’s fracture resistance during a burst event is full-scale burst tests. [Methods] An investigative study revealed that a total of 11 full-scale burst tests have been carried out abroad. However, considering the disparities in pipe manufacturing processes and the different situations of actual CO2 transportation, in order to explore the crack arrest toughness of China’s supercritical CO2 pipelines, the first full-scale burst test of carbon dioxide pipelines in China was successfully carried out. The test employed welded pipes made of Grade X65 steel, featuring an outer diameter of 323.9 mm and a wall thickness ranging from 7.2 mm to 7.6 mm. The test gas was composed of 95%CO2, 4%N2 and 1%H2. The test pressure reached 11.85 MPa, and the temperature was maintained at 12.6 ℃. [Results] The test results indicated a successful execution of the full-scale burst test on the CO2 pipeline. The crack propagated along the pipeline from the crack initiating pipe. On the west side of the burst initiation location, the crack was arrested by ring-cutting at the circumferential weld of the two pipes. On the east side of the burst initiation location, the crack was arrested due to the toughness of the pipe base material, manifesting the typical characteristic of ductile shear fracture. Furthermore, crucial data regarding crack propagation speed, pressure and temperature were collected during the testing process. [Conclusion] This test yields crucial data for China to acquire expertise in the development, design and construction technology of million-ton carbon dioxide transportation pipelines, marking China’s important breakthrough in the field of CCUS technology research. (8 Figures, 2 Tables, 20 References)
[PDF:2647KB](148)[Export Reference]
ZHANG Junpeng1,MIAO Qing2,JING Shaodong1,WANG Yongsheng3,OUYANG Xin2,FAN Zhenning1,LIANG Haining1,ZHANG Jian1
[Abstract](214)
[Objective] CO2 pipeline transmission, a key link in the industrial chain of carbon capture, utilization, and storage (CCUS) technology, is exposed to risks of accidental leakage during operation. Compared with aboveground pipelines, buried high-pressure pipelines follow the leakage and diffusion mechanism subject to more intricate impacts from soil resistance. Unfortunately, existing researches center on reviewing the leakage and diffusion characteristics of aboveground CO2 pipelines, neglecting the specific challenges faced by buried ones. [Methods] This study focused on two common scenarios involving buried pipelines: small hole leakage and full-scale fracture. The experimental and simulation research progress on leakage and diffusion of buried pipelines was reviewed and evaluated through literature research. The influences of soil geological conditions, soil temperatures, ambient pressures, and wind velocities on the CO2 seepage and diffusion processes in the soil were also examined. Furthermore, the study summarized the currently prevalent modeling methods and physical models utilized for exploring leakage and diffusion of buried CO2 pipelines with full-scale fractures. [Results] The soil temperature changes near leakage openings and the growth patterns of dry ice layers and frozen soil layers were studied mainly through mini experiments, to reveal the characteristics of near-field leakage sources in the small hole leakage scenario of buried CO2 pipelines. The simulation study of far-field diffusion characteristics in the same scenario was mostly based on the assumption of constant soil porosity, neglecting the effects of phase transition of fluid and shock pressure on soil porosity. The gas jet diffusion of buried pipelines in the full-scale fracture scenario was studied mainly through simulations, and most models were directly derived from the physical prototype of formed pits, without considering the effects of pit formation on gas jet diffusion. [Conclusion] There remains considerable room for advancement in conducting field tests for full-scale fractures of buried CO2 pipelines and developing theoretical models for small hole leakage and diffusion scenarios. It is recommended to conduct specialized research on the diffusion mechanism of CO2 in soil, emphasizing geological conditions and ambient environmental factors. Furthermore, efforts should be intensified in conducting leakage and diffusion experiments for buried CO2 pipelines with large diameters or full-scale fractures, aiming to acquire more experimental data essential for constructing comprehensive and precise mathematical and physical models. (3 Figures, 2 Tables, 56 References)
[PDF:1854KB](163)[Export Reference]
LIU Guangyu1,ZHI Shujie2,LIU Xin3,CHAI Chong2,WANG Cailin1,YU Xinran1,HU Qihui1,RAO Shiduo1
[Abstract](231)
[Objective] Carbon Capture, Utilization and Storage (CCUS) is an effective approach for achieving “carbon peaking and carbon neutrality”, with promising application prospects. Long-distance CO2 pipeline transportation is a critical component of CCUS. Addressing internal corrosion in pipelines is a key safety concern that must be handled effectively to ensure the safe production and operation of these pipelines. [Methods] The study examined pipeline corrosion in supercritical CO2 environments, reviewed research outcomes on internal corrosion of supercritical/dense-phase CO2 pipelines, analyzed problems existing in the research outcomes, and outlined future development directions. [Results] The factors influencing CO2 pipeline corrosion in supercritical and dense-phase states were discussed, highlighting the impact of key parameters like temperature and pressure on water-CO2 solubility. Reasons for conflicting research outcomes were addressed, along with the influence mechanism of main impurity gases in the pipelines on CO2 corrosion. Additionally, an analysis was conducted on the effects of the structure, density and integrity of the corrosion product films (CPFs) on corrosion dynamics under varying CO2 phase states. Finally, the study identified suitable corrosion characterization techniques for supercritical CO2 environments and collated corrosion rate prediction models for thin liquid films in these environments. [Conclusion] To ensure the safe and stable operation of CO2 transportation pipelines, current corrosion research challenges for supercritical/dense-phase CO2 pipelines include: standardizing experimental procedures;studying the impact of impurity coupling on corrosion mechanisms and CPF structures; quantifying the protective effects of CPF characteristics on the substrate; measuring and analyzing electrochemical corrosion parameters in thin liquid film environments within water-saturated CO2 phase; and developing a prediction model for supercritical/dense-phase CO2 corrosion considering coupled multi-impurity interactions. (2 Figures, 2 Tables, 108 References)
[PDF:1289KB](157)[Export Reference]
CHEN Bing1,2,LI Leilei1,2,QI Wenjiao1,2
[Abstract](212)
[Objective] Carbon Capture, Utilization, and Storage (CCUS) technology has played a vital role in achieving the strategic goal of“carbon neutrality”. However, pipeline transmission, a critical component in the CCUS industry chain, is currently encountering challenges, particularly related to ductile crack arrest in dense-phase CO2 pipelines. [Methods] Drawing upon the crack arrest control mechanism, the research progress of the Battelle Two-Curve (BTC) method was thoroughly investigated to establish a foundation. A subsequent analysis was conducted to expose its technical standing and limitations in the application for controlling crack arrest in natural gas pipelines. Following this, the BTC correction method for crack arrest toughness was examined across three key factors: Charpy impact absorbed energy, drop weight absorbed energy, and crack tip opening angle. Taking into account the properties of dense-phase CO2, the feasibility of utilizing the BTC method to calculate the crack arrest toughness of CO2 pipelines was explored. [Results] Building on the BTC correction method for controlling crack arrest in natural gas pipelines, a new correction approach utilizing BTC was proposed for crack arrest control of CO2 pipelines. This method was developed from two perspectives: driving force and resistance, while incorporating the velocity criterion from the design criteria for crack arrest in dynamic ductile propagation. Through the examination of data from prior full-scale burst tests on CO2 pipelines, currently recognized as the most effective means for determining the crack arrest toughness of dense-phase CO2 pipelines, a correction coefficient range for the BTC method was established. This range serves as a benchmark for ensuring the safe operation of CO2 pipelines and promoting the broader adoption of CCUS technology. [Conclusion] The research on utilizing the BTC correction method to calculate the crack arrest toughness of dense-phase CO2 pipelines is still in its early stages of development. The correction coefficient for the BTC method derived from available full-scale burst test data of CO2 pipelines is inadequate, primarily due to the scarcity of experimental data and their limited application scope. Consequently, further research necessitates an integration with numerical simulation to develop more effective correction methods. (2 Figures, 2 Tables, 82 References)
[PDF:1392KB](138)[Export Reference]
CHEN Lei1,2,HU Yanwei1,YAN Xingqing1,YU Shuai1,LIU Zhenxi1,QIAO Fanfan1,YU Jianliang1,CHEN Shaoyun1,2
[Abstract](208)
[Objective] Pipelines serve as the primary transportation means for Carbon Capture, Utilization and Storage (CCUS) technology, so it is vital to study their dynamic fracture propagation laws. However, the prolonged preparation periods, technical complexities, substantial financial investments, and numerous uncertain factors associated with full-scale fracture experiments significantly impede progress in studying pipeline fracture and the internal decompression laws during CO2 transmission pipeline fracture propagation. [Methods] Leveraging bidirectional Fluid-Structure-Interaction (FSI) technology, a user-defined subprogram was developed with Frotran to delineate fluid decompression characteristics. A Gurson-Tvergarrd-Needleman (GTN) constitutive equation for pipes was established through an experiment focusing on material properties. Moreover, a fluid-structure interaction numerical model was constructed in ABAQUS/Explicit software to simulate supercritical dynamic crack propagation and internal decompression of CO2 transmission pipelines. This model was subsequently used for a collaborative analysis of pipeline crack propagation characteristics and internal medium decompression laws. The simulation results were further processed in batches through Python scripts. [Results] The pipeline fracture morphology from numerical simulation closely mirrored the experimental results. The crack propagation velocity showed an initial rapid increase after medium spillage, followed by gradual stabilization, and finally reaching approximately 225 m/s. The crack tip opening angles initially decreased, then increased before stabilizing at around 7.22°.CO2 remained under high pressure near the crack propagation tip, while saturated steam formed through decompressional expansion at the crack tip worked against crack arrest. [Conclusion] This study demonstrates the accurate replication of full-scale fracture experiments by simulation and showcases the advantages of simulation in revealing many parameters that can hardly be captured through experiments, such as crack tip opening angles, as well as pressure evolution at crack tips and fracture zones during pipeline fractures. The constructed numerical model of CO2 fluid-structure interactions facilitates an in-depth analysis of CO2 transmission pipeline fracture qualities. The simulation results can serve as references for safety control assessments of CO2 pipelines with varying dimensions and gas parameters. (12 Figures, 19 References)
[PDF:2776KB](125)[Export Reference]
XIE Naiya1,YAN Feng2,ZHU Jianlu1,CHEN Junwen3,CHENG Lei2,WANG Qihang1
[Abstract](205)
[Objective] The presence of impurities impacts the phase equilibrium of CO2, potentially compromising the safety of CO2 pipeline transmission. As efforts intensify towards advancing the application of Carbon Capture, Utilization and Storage (CCUS) technology, examining the phase equilibrium of impurity-containing CO2 systems is essential for the broader adoption of this technology. [Methods] An experimental setup was independently developed to measure the phase characteristics of impurity-containing CO2 systems, utilizing the compressibility difference between gas and liquid phases. This setup allows for the measurement and calculation of pressure at the bubbling and dew points for impurity-containing CO2 systems over the temperature range of -30 ℃ to 50 ℃. The experimental results were compared with simulations generated by the PR equation, GERG-2008 equation, BWRS equation, SRK equation, and PRSV equation to assess their predictive accuracy. [Results] For N2-CO2 binary systems with varying ratios, the predictive accuracy of all these state equations for pressure at the bubbling and dew points diminished as the N2 content increased. Additionally, the predictive accuracy varied across temperature intervals for these equations. Specifically, the PR equation demonstrated enhanced accuracy in pressure prediction at both the bubbling and dew points below 0 ℃, compared to predictions above 0 ℃. Conversely, the GERG-2008, SRK, and PRSV equations displayed an opposite trend. Furthermore, the BWRS equation consistently exhibited low predictive accuracy for this system across all ratios, without any identifiable pattern. [Conclusion] Taking into account the predictive accuracy trends of equations across different temperature intervals, excluding the BWRS equation which lacks any discernible pattern, optimization recommendations are suggested for these state equations. For pure CO2, it is advisable to utilize the PR equation below 0 °C and the PRSV equation above 0 °C. In the case of a mixture comprising 99.5% CO2 and 0.5% N2, the PR equation is recommended for use within the temperature range of -20 ℃ to 20 ℃. Similarly, for a mixture of 96% CO2 and 4% N2, both the PR equation and PRSV equation are recommended for use within the temperature range of -30 ℃ to 20 ℃. (10 Figures, 21 References)
[PDF:1694KB](150)[Export Reference]
HUANG Xiaohui1,2,BI Zongyue1,2,ZHAO Xiqi1,2,ZHANG Jingang1,2,WEI Feng1,2,WANG Boyu1,2,ZHAN Wenwen1,2
[Abstract](222)
[Objective] This study aims at fulfilling the steel requirements for supercritical CO2 transmission. [Methods] L450M (X65) hot rolled coils for pipes used in supercritical CO2 transmission were developed, with a microstructure mainly consisting of fine and flat polygonal ferrite + ferrite + a small amount of pearlite, boasting a Low-C medium-Mn micro-Ni alloying design, and leveraging the high-purification steelmaking and large-tonnage reduction rolling technologies. Numerous calculations were performed, focusing on OD219.1 mm×10 mm (pipe diameter×wall thickness) High Frequency Welding (HFW) pipes for supercritical transmission with a design pressure of 16 MPa, to ensure their resistance to cracking initiation and fracture propagation during operation, yielding the following results. The Charpy impact absorbed energy in the base metal at -45 ℃ was not less than 88 J for single values or not less than 117 J for averages. The Charpy impact absorbed energy in the welds and heat-affected zones at -45 ℃ was not less than 42 J for single values or not less than 56 J for averages. [Results] Based on the initial investigation into the forming, welding, and heat treatment processes, L450M HFW pipes for supercritical transmission with excellent cryogenic properties were developed under the following conditions: forming extrusion of 5.25 mm, welding rate at 17 m/min, and weld heat treatment at 930 ℃. The third-party testing validated the performance of the developed welded pipes in full compliance with the Line Pipe (API Spec 5L, 46th edition), and cryogenic toughness requirement. During the flattening experiment, the flattened pipes showcased no cracks within the base metal and welds. This observation underscored the robust plasticity and exceptional weld quality of both the base metal and welds. The yield strength of the base metal was 534 MPa, and the tensile strengths of the base metal and welds closely matched at 619 MPa and 620 MPa respectively, meeting the standard requirement of not less than 535 MPa and suggesting a sufficient strength margin. The hardness levels of the base metal, welds, and heat-affected zones did not surpass 220 HV10 and exhibited uniform profiles. At -45 ℃, the impact absorbed energy ranged from 177 J to 401 J for welds, from 200 J to 415 J for the heat-affected zones, and from 248 J to 416 J for the base metal. Furthermore, the ductile-brittle transition temperatures of the base metal, welds, and heat-affected zones remained below -60 ℃. [Conclusion] The developed HFW pipes demonstrate exceptional cryogenic toughness, high ductile crack arrest capabilities still under low temperatures, and impressive internal and external pressure-bearing capacities of 62.29 MPa and 38.9 MPa respectively. These properties are fully aligned with the operational requirements for HFW pipes utilized in supercritical CO2 transmission. (10 Figures, 3 Tables, 25 References)
[PDF:3138KB](149)[Export Reference]
YAN Bing1,SHI Bohui1,CHEN Junwen2,TANG Xiaoyong2,ZAN Linfeng2,WANG Yanjing1,LI Yupei1,GONG Jing1
[Abstract](207)
[Objective] Carbon capture, utilization and storage (CCUS) is essential for achieving carbon neutrality, in which the safety and efficiency of CO2 transmission plays a vital role. The pipeline transmission of CO2 in the supercritical phase has been widely applied internationally and China has basically mastered the rules to the process of supercritical CO2 pipelines steady-state transmission. However, further research is required to enhance understanding of the dynamic rules and safety risks associated with venting operations for supercritical CO2 pipelines with topographic relief. [Methods] Using OLGA, a physical model was developed for venting valve chambers at both ends of supercritical CO2 pipelines with topographic relief. A dynamic simulation analysis of pipeline venting was conducted, revealing the physical nature of the low-temperature phenomenon in the main pipeline during venting. Key issues in the venting process of the supercritical CO2 pipeline with topographic relief were discussed, focusing on the effects of topographic relief on phase transition, low-temperature risks, and dry ice formation. Finally, a safe venting scheme for backpressure control was suggested. [Results] The venting of supercritical CO2 pipelines with topographic relief should avoid high pressure and low temperatures as much as possible; appropriate venting pipe diameter and opening need to be designed to prevent risks such as low-temperature brittle fracture and dry ice formation; the suggested venting scheme was effective under specific terrain conditions, addressing extremely low temperatures in low-lying sections during main pipeline venting while minimizing harm at the venting outlet. [Conclusion] The research results offer theoretical backing for the safe venting process design and engineering construction of supercritical CO2 pipelines with topographic relief, holding practical value for engineering applications and contributing to ensuring the safe and efficient transmission of CO2 pipelines. (11 Figures, 5 Tables, 27 References)
[PDF:4792KB](127)[Export Reference]
YAN Feng1,YIN Buze2,OUYANG Xin1,HU Qihui2,ZHI Shujie1,LI Yuxing2,GONG Jiyu2
[Abstract](206)
[Objective] Supercritical/dense-phase CO2 pipelines serve as the primary mode for long-distance CO2 transportation. Given their high-pressure operation, it is crucial to calculate and evaluate the crack arrest toughness of pipe materials. Understanding the characteristics of decompression waves is vital for evaluating the crack arrest toughness of pipe materials. However, CO2 leakage involves a multi-phase decompression process that complicates the propagation behavior of decompression waves, posing challenges for accurate prediction of decompression wave and evaluation of crack arrest toughness. [Methods] To investigate the propagation behavior of decompression waves in CO2 pipeline leakage, an experimental setup was constructed specifically for this purpose. A numerical calculation model for decompression waves was then developed using the homogeneous flow model as the framework, integrating the state equation of gas, sound velocity model, and outflow velocity model. The accuracy of the model was verified through a comparison of calculated outcomes with experimental data. On this basis, numerical calculations were conducted at different initial temperatures and pressure levels. [Results] According to the experimental results, the wave velocities at the initial point of CO2 decompression wave plateau varied directly with pressure and inversely with temperature across different phase states. In contrast to gaseous CO2, the plateau height of decompression waves for dense-phase and supercritical CO2 decreased with rising pressure and increased with rising temperature. The effect of temperature and pressure on the decompression wave plateau is essentially the effect of initial entropy and density. The height of the decompression plateau depends on the initial entropy. Specifically, a lower initial entropy value in the gas phase results in a higher plateau, while higher initial entropy values lead to higher plateaus in dense-phase and supercritical states. Furthermore, higher initial density prolongs the plateau duration across all phase states. [Conclusion] In practical engineering, close attention should be paid to pipe crack arrest at the onset of high temperature and high pressure. The experimental method and calculation model for decompression waves can offer theoretical support for evaluating CO2 pipeline crack arrest toughness and informing pipeline design. (11 Figures, 1 Table, 21 References)
[PDF:2050KB](129)[Export Reference]
LI Xinze1,SUN Chen1,ZHANG Xueqin2,ZOU Weijie1,YUAN Liang3,XIONG Xiaoqin1,XING Xiaokai1,XU Ning1
[Abstract](217)
[Objective] Unlike crude oil and natural gas pipelines, supercritical CO2 pipelines encounter phase characteristic changes during the transient shutdown process. To ensure post-shutdown safety of a supercritical CO2 pipeline, it is crucial to establish the safe operational process (transport pressure and temperature) boundaries prior to shutdown. [Methods] A hydrothermodynamic calculation model was developed using OLGA to accurately depict the transient process of a post-shutdown pipeline, with the supercritical CO2 pipeline demonstration project of Xinjiang Oilfield Branch serving as a case study. At the same time, the accuracy of the commercial software model was validated through Matlab programming calculations utilizing the equation of flow continuity, equation of motion, energy equation, PR equation of state, and thermodynamic relations. Based on the observed fluctuation law from the coordinated variations of temperature, pressure, density, and phase state in the pipeline during shutdown, it was proposed that the safe shutdown time for the pipeline should be determined by the step change of CO2 density under the synergic action of pressure and temperature. This approach reframes the concern of safe shutdown time to preventing the transition of supercritical CO2 into the gas phase in the transportation system. [Results] Based on the operating pressure and temperature parameters in this demonstration project, eight typical operational process boundaries were identified for summer and winter scenarios, including high-pressure & low-temperature, high-pressure & high-temperature, low-pressure & low-temperature, and low-pressure & high-temperature process boundaries. Furthermore, an analysis was conducted to compare and study the fluctuation characteristics of parameters in the pipeline, the coordinated variation between temperature and pressure, as well as the phase transition path and behavior during shutdown processes under various seasonal and boundary conditions. [Conclusion] The findings revealed that the high-pressure & low-temperature boundary is the safest, while the low-pressure & high-temperature boundary poses the highest risk. Additionally, the safe shutdown time for the pipeline in winter was significantly reduced compared to summer. To guide engineering practices, process boundary ranges and functional expressions for the safe shutdown of the demonstration project were provided for summer and winter scenarios. The research results can offer theoretical support and technical assurance for the safe operation of supercritical CO2 pipelines. (8 Figures, 4 Tables, 24 References)
[PDF:2572KB](135)[Export Reference]
MA Xinyuan1,OUYANG Xin2,ZHU Jianlu1,CHEN Junwen3,LIU Luoqian2,YANG Teng1,SONG Guangchun1
[Abstract](209)
[Objective] Transient processes like leakage and commissioning in CO2 pipeline operation pose simulation challenges due to the unique physical properties and phase behavior of CO2. Currently, there is a deficiency in adaptability evaluation of numerical simulation software for CO2 pipeline transient processes. [Methods] This study utilized two mainstream transient simulation software, OLGA and LedaFlow, to establish a numerical simulation model for transient CO2 leakage. Testing was conducted on a self-built experimental setup for DN200 high-pressure CO2 pipeline leakage across different phases, with software adaptability evaluated in terms of pressure, temperature and phase behavior. Furthermore, the adaptability of these software types was verified through a comparison of the simulation results with field data from transient commissioning of a long-distance CO2 pipeline in China. [Results] The comparison of the results from leakage test and software simulations revealed that under two specified leakage conditions, OLGA exhibited average pressure calculation errors of 15.3% and 14.7%, whereas LedaFlow exhibited errors of 16.7% and 18.0%. Consequently, the pressure calculation accuracy of OLGA closely aligns with that of LedaFlow. OLGA underestimated the lowest temperature in the pipe during leakage, with average relative errors of 21.2% and 24.5% at the two measuring points. In contrast, LedaFlow overestimated the lowest temperature with average relative errors of 13.1% and 11.1% at the two measuring points. During the commissioning of a CO2 pipeline, OLGA exhibited average relative errors of 1.2% for pressure and 6.1% for temperature, whereas LedaFlow exhibited errors of 1.3% and 5.2% for the same parameters. The simulation results from both software packages closely align with the field data. [Conclusion] In conclusion, in the process of CO2 pipeline leakage, OLGA underestimates the lowest temperature during the leakage process, which can enhance the low-temperature safety of the pipeline. OLGA is better suited for predicting pressure, temperature and phase behavior during CO2 leakage. Both OLGA and LedaFlow are suitable for simulation studies on pressure and temperature in CO2 pipelines during commissioning. (9 Figures, 4 Tables, 31 References)
[PDF:2419KB](144)[Export Reference]
About Journal
Governed by: PipeChina
Sponsored by: PipeChina North Pipeline Company
Published by: Editorial Office of Oil & Gas Storage and Transportation
Website: yqcy.paperonce.org
Address: Editorial Office of Oil & Gas Storage and Transportation, No.51, Jinguang  Rd., Langfang City, Hebei Province, 065000, P.R. China
Postal Code: 065000
Tel: +86(316)2176173
E-mail: yqcy@vip.163.com
ISSN 1000-8241 
CN 13-1093/TE
Frequency: Monthly
Book Size: 16-mo
Founded in: 1977

 

      

微信公众号

Official Account(Wechat)