Establishing boundaries of safe shutdown process for supercritical CO2 pipeline of Xinjiang Oilfield Branch
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...
Saved in:
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | zho |
| Published: |
Editorial Office of Oil & Gas Storage and Transportation
2024-05-01
|
| Series: | You-qi chuyun |
| Subjects: | |
| Online Access: | http://yqcy.xml-journal.net/cn/article/doi/10.6047/j.issn.1000-8241.2024.05.011 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850186389536112640 |
|---|---|
| author | Xinze LI Chen SUN Xueqin ZHANG Weijie ZOU Liang YUAN Xiaoqin XIONG Xiaokai XING Ning XU |
| author_facet | Xinze LI Chen SUN Xueqin ZHANG Weijie ZOU Liang YUAN Xiaoqin XIONG Xiaokai XING Ning XU |
| author_sort | Xinze LI |
| collection | DOAJ |
| description | 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. |
| format | Article |
| id | doaj-art-36ffb04cad6641258856f65f34163277 |
| institution | OA Journals |
| issn | 1000-8241 |
| language | zho |
| publishDate | 2024-05-01 |
| publisher | Editorial Office of Oil & Gas Storage and Transportation |
| record_format | Article |
| series | You-qi chuyun |
| spelling | doaj-art-36ffb04cad6641258856f65f341632772025-08-20T02:16:22ZzhoEditorial Office of Oil & Gas Storage and TransportationYou-qi chuyun1000-82412024-05-0143557958910.6047/j.issn.1000-8241.2024.05.011yqcy-43-5-579Establishing boundaries of safe shutdown process for supercritical CO2 pipeline of Xinjiang Oilfield BranchXinze LI0Chen SUN1Xueqin ZHANG2Weijie ZOU3Liang YUAN4Xiaoqin XIONG5Xiaokai XING6Ning XU7Engineering School, China University of Petroleum-Beijing at Karamay//Xinjiang Key Laboratory for Transportation Safety of Multi-Medium PipelinesEngineering School, China University of Petroleum-Beijing at Karamay//Xinjiang Key Laboratory for Transportation Safety of Multi-Medium PipelinesPipeChina Institute of Science and TechnologyEngineering School, China University of Petroleum-Beijing at Karamay//Xinjiang Key Laboratory for Transportation Safety of Multi-Medium PipelinesDevelopment Company of PetroChina Xinjiang Oilfield BranchEngineering School, China University of Petroleum-Beijing at Karamay//Xinjiang Key Laboratory for Transportation Safety of Multi-Medium PipelinesEngineering School, China University of Petroleum-Beijing at Karamay//Xinjiang Key Laboratory for Transportation Safety of Multi-Medium PipelinesEngineering School, China University of Petroleum-Beijing at Karamay//Xinjiang Key Laboratory for Transportation Safety of Multi-Medium PipelinesObjective 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.http://yqcy.xml-journal.net/cn/article/doi/10.6047/j.issn.1000-8241.2024.05.011supercritical co2pipeline transportationshutdown processtransient characteristicsphase transitionsafe operational process boundary |
| spellingShingle | Xinze LI Chen SUN Xueqin ZHANG Weijie ZOU Liang YUAN Xiaoqin XIONG Xiaokai XING Ning XU Establishing boundaries of safe shutdown process for supercritical CO2 pipeline of Xinjiang Oilfield Branch You-qi chuyun supercritical co2 pipeline transportation shutdown process transient characteristics phase transition safe operational process boundary |
| title | Establishing boundaries of safe shutdown process for supercritical CO2 pipeline of Xinjiang Oilfield Branch |
| title_full | Establishing boundaries of safe shutdown process for supercritical CO2 pipeline of Xinjiang Oilfield Branch |
| title_fullStr | Establishing boundaries of safe shutdown process for supercritical CO2 pipeline of Xinjiang Oilfield Branch |
| title_full_unstemmed | Establishing boundaries of safe shutdown process for supercritical CO2 pipeline of Xinjiang Oilfield Branch |
| title_short | Establishing boundaries of safe shutdown process for supercritical CO2 pipeline of Xinjiang Oilfield Branch |
| title_sort | establishing boundaries of safe shutdown process for supercritical co2 pipeline of xinjiang oilfield branch |
| topic | supercritical co2 pipeline transportation shutdown process transient characteristics phase transition safe operational process boundary |
| url | http://yqcy.xml-journal.net/cn/article/doi/10.6047/j.issn.1000-8241.2024.05.011 |
| work_keys_str_mv | AT xinzeli establishingboundariesofsafeshutdownprocessforsupercriticalco2pipelineofxinjiangoilfieldbranch AT chensun establishingboundariesofsafeshutdownprocessforsupercriticalco2pipelineofxinjiangoilfieldbranch AT xueqinzhang establishingboundariesofsafeshutdownprocessforsupercriticalco2pipelineofxinjiangoilfieldbranch AT weijiezou establishingboundariesofsafeshutdownprocessforsupercriticalco2pipelineofxinjiangoilfieldbranch AT liangyuan establishingboundariesofsafeshutdownprocessforsupercriticalco2pipelineofxinjiangoilfieldbranch AT xiaoqinxiong establishingboundariesofsafeshutdownprocessforsupercriticalco2pipelineofxinjiangoilfieldbranch AT xiaokaixing establishingboundariesofsafeshutdownprocessforsupercriticalco2pipelineofxinjiangoilfieldbranch AT ningxu establishingboundariesofsafeshutdownprocessforsupercriticalco2pipelineofxinjiangoilfieldbranch |