Due to the high potential risk and many influencing factors of subsea horizontal X-tree installation,to guarantee the successful completion of sea trials of domestic subsea horizontal X-trees,this paper established a ...Due to the high potential risk and many influencing factors of subsea horizontal X-tree installation,to guarantee the successful completion of sea trials of domestic subsea horizontal X-trees,this paper established a modular risk evaluation model based on a fuzzy fault tree.First,through the analysis of the main process oftree down and combining the Offshore&Onshore Reliability Data(OREDA)failure statistics and the operation procedure and the data provided by the job,the fault tree model of risk analysis of the tree down installation was established.Then,by introducing the natural language of expert comprehensive evaluation and combining fuzzy principles,quantitative analysis was carried out,and the fuzzy number was used to calculate the failure probability of a basic event and the occurrence probability of a top event.Finally,through a sensitivity analysis of basic events,the basic events of top events significantly affected were determined,and risk control and prevention measures for the corresponding high-risk factors were proposed for subsea horizontal X-tree down installation.展开更多
Temperature drop is commonly observed in subsea vertical X-mas trees during shutdown.The presence of a huge temperature difference between internal crude oil and external seawater can cause severe equipment degradatio...Temperature drop is commonly observed in subsea vertical X-mas trees during shutdown.The presence of a huge temperature difference between internal crude oil and external seawater can cause severe equipment degradation of the oil flow channel(e.g.,hydrate precipitation),which can block the oil flow channel and interrupt the production process.The most vulnerable parts of a subsea vertical X-mas tree tend to be components with high convective heat transfer rates,such as production modules and short joints.We proposed an innovative approach for the insulation design of underwater equipment under a shutdown condition.First,we obtained a heat transfer analysis of the tree under working conditions through computational fluid dynamics to ascertain the initial temperature condition for an unsteadystate analysis.Second,we investigated the unsteady heat transfer characteristics of the tree with an insulation layer in the shutdown state and derived the relationships between insulation duration and thickness by data analysis.We used data analysis to identify the relationship between insulation duration and thickness.Finally,we derived the empirical formula of insulation thickness for underwater equipment given the effect of environmental factors on the heat preservation effect.We performed the experiment with an oil pipeline,and the results showed that the internal oil of the equipment did not hydrate within 8 h under the shutdown condition with insulation layers.展开更多
基金financially supported by the National Ministry of Industry and Information Technology Innovation Special Project-Engineering Demonstration Application of Subsea Production System,Topic 4:Research on Subsea X-Tree and Wellhead Offshore Testing Technology(Grant No.MC-201901-S01-04)the Key Research and Development Program of Shandong Province(Major Innovation Project)(Grant Nos.2022CXGC020405,2023CXGC010415)。
文摘Due to the high potential risk and many influencing factors of subsea horizontal X-tree installation,to guarantee the successful completion of sea trials of domestic subsea horizontal X-trees,this paper established a modular risk evaluation model based on a fuzzy fault tree.First,through the analysis of the main process oftree down and combining the Offshore&Onshore Reliability Data(OREDA)failure statistics and the operation procedure and the data provided by the job,the fault tree model of risk analysis of the tree down installation was established.Then,by introducing the natural language of expert comprehensive evaluation and combining fuzzy principles,quantitative analysis was carried out,and the fuzzy number was used to calculate the failure probability of a basic event and the occurrence probability of a top event.Finally,through a sensitivity analysis of basic events,the basic events of top events significantly affected were determined,and risk control and prevention measures for the corresponding high-risk factors were proposed for subsea horizontal X-tree down installation.
基金financed by the Scientific Research Project of Ocean Engineering Equipment,Ministry of Industry and Information Technology of China。
文摘Temperature drop is commonly observed in subsea vertical X-mas trees during shutdown.The presence of a huge temperature difference between internal crude oil and external seawater can cause severe equipment degradation of the oil flow channel(e.g.,hydrate precipitation),which can block the oil flow channel and interrupt the production process.The most vulnerable parts of a subsea vertical X-mas tree tend to be components with high convective heat transfer rates,such as production modules and short joints.We proposed an innovative approach for the insulation design of underwater equipment under a shutdown condition.First,we obtained a heat transfer analysis of the tree under working conditions through computational fluid dynamics to ascertain the initial temperature condition for an unsteadystate analysis.Second,we investigated the unsteady heat transfer characteristics of the tree with an insulation layer in the shutdown state and derived the relationships between insulation duration and thickness by data analysis.We used data analysis to identify the relationship between insulation duration and thickness.Finally,we derived the empirical formula of insulation thickness for underwater equipment given the effect of environmental factors on the heat preservation effect.We performed the experiment with an oil pipeline,and the results showed that the internal oil of the equipment did not hydrate within 8 h under the shutdown condition with insulation layers.
