基于CFD的海上钻井平台井喷天然气扩散规律研究  

On the flammable gas diffusion behaviour from the well-blowout on the offshore drilling platform based on CFD

作　　者：魏超南[1] 陈国明[1] 杨冬平[2] 

机构地区：[1]中国石油大学(华东)海洋油气装备与安全技术研究中心,山东青岛266580 [2]中国石化胜利油田检测中心,山东东营257062

出　　处：《安全与环境学报》2013年第5期271-277,共7页Journal of Safety and Environment

基　　金：中央高校基本科研业务费专项资金项目(09CX05008A);2012年安全科技"四个一批"项目(2012-507)

摘　　要：针对海上钻井平台作业过程中井喷失控后的天然气泄漏扩散问题,基于计算流体动力学(CFD)理论,建立海上钻井平台井喷事故后果的预测与评估模型。选取静风、全年平均风速和季风风速3种典型风况,对船艏、船艉、左舷和右舷来风条件下井喷天然气的运动行为及危险区域的分布规律进行模拟和分析。结果表明:井喷失控40 s后钻台区域井喷气体体积分数达到动态稳定值,甲烷较乙烷危险区域大,且受风况影响明显;10 min后悬臂梁和主甲板上井喷气体体积分数也达到动态稳定值;悬臂梁内部甲烷气体形成了较大范围的危险区域,易导致剧烈爆炸事故;船艏、船艉来风和低风速条件易造成可燃气体在生活楼或钻台区域通风效果较差的位置聚集;左、右舷来风和高风速条件有利于平台可燃气体的稀释和消散;风速越大,可燃气体对平台危害程度越小。The paPer is aimed to introduce our numerical simulation research of the diffusion behaviour of the flammable gas-fire caused by the oil-well blowout on the offshore drilling platforms by using a CFD-based model developed by us, which proves to be useful in pre- dicting and evaluating the outcome of the well-blowout accidents on the platform. For the research purpose, we have＇ chosen three typical wind speeds, that is, the static wind speed, the annual average wind speed and the monsoon wind speed, as the basic environmental con- ditions, and, then, made our detailed analysis of the spatial distribu- tion of the hazardous area and diffusion behaviour of the gas fire under different wind directions. The simulation results show that it would take about 40 seconds to formulate a steady concentration field of the gas with dynamic stable value in the drilling floor area, with a haz- ardous area of methane being much bigger than ethane＇ s due to the strong infection of the wind conditions. And, 10 minutes later, the field of the gas under the cantilever beam and on the main deck would reach a dynamically steady state, at which the methane gas would form a relatively extensive hazardous area under the cantilever beam, for example, with the hazardous volume covered by flammable methane with the larboard wind up to 2 098.8 m3. In such a situa- tion, a violent explosion is likely to be triggered as soon as the igni- tion source shows up. Since the wind condition may have a significant effect on the spreading behaviour of the gas, which can be easily stuck in the accommodation area or the drilling floor somewhere in the well, its ventilation efficiency can be rather poor with the different wind conditions. On the contrary, if the high speed larboard wind and starboard wind are helpful for the dilution and dissipation of the gas, the damage degree of the gas would turn to be weakened. Based on the above results, we have proposed some efficient nichetargeting countermeasures, to be taken as the basis of risk estimation of

关 键 词：安全工程 海上钻井平台 井喷 天然气 扩散规律 计算流体动力学 

分 类 号：X937[环境科学与工程—安全科学]