FPSO卧式三相分离器内部改造

Internal Improvement of Horizontal Three-phase Separator on FPSO

浮式生产储油卸油轮(FPSO)上的主要产液分离设备一般都是卧式三相分离器,随着接入新的边际油田开发,有必要对分离器进行升级改造以提高三相分离效果。卧式三相分离器存在内部结构简单、原油脱水效果差、脱出污水含油量高且不稳定等问题。通过分析分离器的内部流场和三相分离微观机理,并与高效分离器对比,认为目前的气液比可以具有较好的气浮效果,含水达到96%可以有效利用水洗功能提高油水分离速度。有针对性地对井液入口元件、整流元件、操作液位等进行改造、优化,延长三相分离器入口管线长度、增加均匀布液设施、升高堰板高度。采用FLUENT软件进行的CFD模拟结果表明,分离器内流速分布均匀、分界面波动较小、停留时间增加、分离效果好。现场应用结果也表明,分离器出水含油量平均值从改造前的217mg/L降至改造后的165mg/L,分离效率提高24%。

The main liquid-produced separation equipment on the Floating Production Storage and Offloading （FPSO） is always the horizontal three-phase separator.Along with the development of new marginal oilfields,the separator should be improved for better three-phase separation effect.The horizontal three-phase separator has the issues of simple internal structure ,poor effect of oil dehydration and high and unstable oil content in the sewage.Inner flow field and microscopic mechanism of three-phase separation of the separator were analyzed, and it was compared with high-efficient separator.It shows that good air-floating effect will be gained at present gas-liquid ratio,and washing performance may be used for improving the velocity of oil-water sepa- ration when the water cut is up to 96%.Entrance element,rectification component,operating liquid level of the drilling fluid was optimized one by one,and length of inlet pipeline of the three-phase separator,equip- ment of uniform liquid distribution and height of cut-off wall were increased.The results of CFD simulation by FLUENT software show that the separation effect is good with uniform flow rate ,little fluctuation of the interface and more residence time.The field application tent of the produced water in the separator decreased formation.Separation efficiency enhanced by 24%. results present that the average value of the oil con- from 217mg/L before reformation to 165mg/L after reformation.Separation efficiency enhanced by 24%.