输气管道天然气水合物段塞形成机理  

Formation mechanism of gas hydrate slug in gas pipelines

作　　者：刘陈伟[1] 李明忠[1] 王卫阳[1] 李娣[1] 高永海[1] 

机构地区：[1]中国石油大学石油工程学院,山东青岛266555

出　　处：《石油学报》2012年第1期150-156,共7页Acta Petrolei Sinica

基　　金：国家自然科学基金项目(No.51004113);中央高校基本科研业务费专项资金(09CX0416A)资助

摘　　要：针对现有的多数水合物预测模型无法描述输气管道水合物段塞形成过程这一问题,依据管道中气液分布特点,构建了描述输气管道中水合物生成状态的物理模型。以此为基础,借用传热学、多相流和相平衡理论建立了预测水合物段塞形成的数学模型。给出了定解条件,继而采用数值模拟方法对水合物段塞的形成过程进行了研究。结果表明,模型可以成功预测段塞的形成位置、形态及变化过程;气流量、绝热层的厚度和导热系数对初始状态下水合物生成区域会产生明显的影响,而且随着气流量的增加,气芯的携液能力增强,液膜厚度减小;水合物段塞形成过程中引起管线压降增大、温度降低、气芯携液能力增强、液膜厚度减小等一系列参数的变化,这些变化又可以作用于段塞使其进一步生成。Most of the existing hydrate prediction models can not describe the formation process of hydrate slug in gas pipelines.We proposed a physical model for the hydrate formation state in gas pipelines based on distributional characteristics of gas and liquid in pipelines,established a mathematical model to predict the formation of hydrate slug in gas pipelines by means of the heat-transfer,multiphase-flow and phase-equilibrium theories,deduced definite conditions to solve the related problems,and finally described the formation process of hydrate slug by numerical simulation.The results show that the model can forecast the formation position,configuration and changing process of hydrate slug successfully.The gas flow rate,and the thickness and the thermal conductivity of thermal-insulating materials can significantly affect the initial formation region of hydrate.With the increase of gas flow rates,the liquid-carrying capacity of gas cores will get better and the thickness of liquid film will reduce.Furthermore,a series of changes in parameters will take place during the formation of gas hydrate slug,such as the increase of pipeline pressure differences,the decrease of temperatures,the enhancement of liquid-carrying capacity of gas cores and the decrease of liquid film thickness,all of these may,in return,react on the further formation of hydrate slug.

关 键 词：输气管道 水合物段塞 物理模型 数学模型 数值模拟 气芯 

分 类 号：TE732[石油与天然气工程]