海底半埋输油管道的停输温降与冷凝过程分析  

Analysis of Temperature Drop and Condensation Process during Shutdownof Semi-buried Oil Pipelines on the Seabed

作　　者：滕然 邓一鸣 陈红伟 李洋 TENG Ran;DENG Yi-ming;CHEN Hong-wei;LI Yang(Northeastern Petroleum Pipeline Company,Shenyang 110031,China;College of Petroleum Engineering,Liaoning Petrochemical University,Fushun 113001,China)

机构地区：[1]东北石油管道有限公司,沈阳110031 [2]辽宁石油化工大学石油天然气工程学院,抚顺113001

出　　处：《科学技术与工程》2024年第34期14658-14665,共8页Science Technology and Engineering

基　　金：国家自然科学基金(52006094);辽宁省自然科学基金(2021-BS-248,2022-BS-289);东北石油管道有限公司委托技术开发项目(DBGS-KJXX-ZC-2023-13)。

摘　　要：埋于海泥中的输油管道易受洋流、风暴潮等恶劣环境的影响而被冲刷直至裸露在海床上,从而失去海泥的蓄热保温作用。为研究海底半埋输油管道的停输温降与冷凝过程,建立含海泥、海水、原油、管道、保温层等多要素的三维非稳态传热模型,利用停输前管道附近的温度场作为初始条件,计算停输后原油的散热和冷凝过程,分析原油温度和冷凝量随位置和停输时间的变化规律。结果表明:海底半埋管道停输后原油降温先快后慢,80 h降温超25℃,此过程管道中心油温始终高于壁面处温度,两者之间的温差先增大后减小,最大温差出现在停输20 h时,为26.8℃。半埋管道停输20 h后,原油开始从壁面处凝固并逐渐向管道中心扩展,凝固量不断增加,停输80 h,原油凝固量达到30%。半埋管道原油温度下降比全埋管道更快,相同时刻下温度平均低1.8℃,凝固量平均高2个百分点。不同地区的原油冷凝时间和冷凝量存在较大差异,应加以区分。研究结果可为海底半埋输油管道的停输和再启动作业提供参考。Oil pipelines buried in sea mud are easily affected by adverse environments such as ocean currents and storm surges,and are washed away until exposed on the seabed,thereby losing the heat storage and insulation function of sea mud.To study the shutdown temperature drop and condensation process of semi-buried subsea oil pipelines,a three-dimensional unsteady heat transfer model containing multiple elements such as sea mud,seawater,crude oil,pipelines,insulation layer,etc.was established.The temperature field near the pipeline before shutdown was used as the initial condition to calculate the heat dissipation and condensation process of crude oil after shutdown.The variation patterns of crude oil temperature and condensation rate with position and shutdown time were analyzed.The results show that after the shutdown of the semi-buried pipeline,the crude oil temperature drops first quickly and then slowly.When the shutdown lasts for 80 hours,the crude oil temperature drops by more than 25℃.During this process,the central oil temperature of the pipeline is always higher than the temperature at the wall,and the temperature difference between the two first increases and then decreases.The maximum temperature difference is up to 26.8℃when the pipeline is shut down for 20 hours.After the semi-buried pipeline is shut down for 20 hours,the crude oil begins to solidify from the wall and gradually expanded towards the center of the pipeline,with the solidification amount continuously increasing.When the shutdown lasts for 80 hours,the crude oil solidification reaches 30%.The temperature drop of crude oil in semi-buried pipelines is faster than that in fully buried pipelines.At the same time,the average temperature is 1.8℃lower and the average solidification rate is 2 percentage points higher.There are significant differences in the condensation time and amount of crude oil in different regions,which should be distinguished.The findings can provide reference for the shutdown and restart operations of semi-buried subsea o

关 键 词：原油 半埋管道 停输 温降 冷凝 

分 类 号：TE832[石油与天然气工程—油气储运工程]