基于气液分离的天然气双入口优化设计  

Design optimization of natural gas double inlets based on gas–liquid separation

作　　者：邢树宾 陈瑶瑶 杨乐乐 余福春[5] 许晶禹[1,2] 吴应湘 XING Shubin;CHEN Yaoyao;YANG Lele;YU Fuchun;XU Jingyu;WU Yingxiang(Institute of Mechanics,Chinese Academy of Sciences,Beijing 102206,China;School of Engineering Sciences,University of Chinese Academy of Sciences,Beijing 102206,China;Sinopec Research Institute of Petroleum Engineering Co.,Ltd.,Beijing 100101,China;School of Civil Engineering and Transportation,South China University of Technology,Guangzhou,Guangdong 510641,China;Tarim Branch,Sinopec Shengli Petroleum Engineering Co.,Ltd.,Korla,Xinjiang 841000,China)

机构地区：[1]中国科学院力学研究所,102206 [2]中国科学院大学工程科学学院 [3]中石化石油工程技术研究院有限公司 [4]华南理工大学土木与交通学院,510641 [5]中国石化胜利石油工程有限公司塔里木公司

出　　处：《天然气工业》2023年第2期114-120,共7页Natural Gas Industry

基　　金：广东省基础与应用基础研究基金项目“高温高压下深海旋流分离器油水分离过程及机理研究”(编号:2022A151501 0025)。

摘　　要：天然气井采出的天然气通常含一定量的液体,这些液体不仅会堵塞管线、阀门,影响流量计计量的精确度,而且还会腐蚀设备、管道、仪表,易引起振动,破坏管道结构,严重影响集输生产管道寿命与安全,因此需尽快对采出液进行气液分离。为此,根据油气田现场采出液工况,设计了双入口气液分离器,并采用欧拉多相流模型,耦合标准k-ε湍流模型,对分离器内部的流场分布和分离特性开展了数值模拟研究。研究结果表明:(1)由于双入口的存在,分离器入口处湍流强度较小,流动较为平稳,能够增加入口气液混合液的分层程度,减少分离器下部发生折返的气体流量,进而减少气体出口带液量;(2)当入口液滴粒径大于0.1 mm时,仅有极少量的气体从液体出口流走,能够取得较好的分离效果;(3)随着分流比的减小,液体出口液体体积分数迅速增加,气体出口液体体积分数缓慢增加;(4)入口液体体积分数的变化主要影响分离后气体的纯度,对分离后液体的纯度影响较小。结论认为,在实际应用过程中,对于液滴粒径较小的来液工况,无论入口液体体积分数如何变化,均应调节分流比小于入口液体体积分数,使其液位略高于液体出口,以提高气液分离的效果。Natural gas produced by a gas well usually contains a certain amount of liquid, which will not only block the pipelines and valves and affect the accuracy of the flowmeter, but also corrode the equipment, pipelines and instruments. Besides, it is easy to cause vibration to damage the pipeline structure, which ultimately impacts the life and safety of gathering and production pipelines. Therefore,it is necessary to perform gas–liquid separation on produced fluids as soon as possible. Based on the working conditions of produced fluids in actual oil and gas fields, this paper designs a double-inlet gas–liquid separator. In addition, the flow field distribution and separation characteristics in the separator are numerically simulated by using the Euler multiphase flow model, coupled with the standard k–ε turbulence model. And the following research results are obtained. First, due to the existence of double inlets, the turbulence intensity at the inlet of the separator is smaller and the flow is relatively stable, which can increase the stratification degree of the gas–liquid mixture at the inlet and reduce the returning gas flow in the lower part of the separator, so as to reduce the liquid carrying capacity at the gas outlet. Second, when the droplet size at the inlet is larger than 0.1 mm, only a tiny amount of gas flows away through the liquid outlet,so as to achieve good separation effect. Third, with the decrease of the split ratio, the liquid volume fraction at the liquid outlet increases rapidly, while that at the gas outlet increases slowly. Fourth, the change of the liquid volume fraction at the inlet mainly affects the gas purity after separation, and has little effect on the liquid purity after separation. It is concluded that in the process of actual application,for the incoming working condition with small droplet size, no matter how the liquid volume fraction at the inlet changes, it is necessary to adjust the split ratio to be less than the liquid volume fraction at the inlet, so that the liq

关 键 词：气液分离 双入口 液滴粒径 分流比 液体体积分数 多相流模型 湍流强度 

分 类 号：TE866[石油与天然气工程—油气储运工程]