深水立管油包水乳化液天然气水合物相变预测  

Phase Transition Prediction of Water-in-Oil Emulsion Natural Gas Hydrate in Deepwater Riser

作　　者：梁维兴 娄敏[1] Liang Weixing;Lou Min(School of Petroleum Engineering,China University of Petroleum(Huadong))

机构地区：[1]中国石油大学(华东)石油工程学院

出　　处：《石油机械》2020年第12期79-86,共8页China Petroleum Machinery

基　　金：国家自然科学基金项目“深水顺应式垂直通路立管总体响应特性及优化设计研究”(51579245);国家重点研发计划项目“超深水多用途柔性管结构设计分析技术研究”(2016YFC0303800)。

摘　　要：油包水乳化液是多相混输立管中常见的一种油水存在状态,其在低温高压的环境极易生成水合物。为了提高深水油气输送安全性,对深水立管内油包水乳化液水合物相变进行预测,基于计算流体力学理论,建立了含水合物相变的多相内流模型,采用有限差分法进行求解并进行了敏感性分析。分析结果表明:入口温度升高会减小水合物生成区域和体积分数,当入口温度高于12.8℃时,在泥线以上一定范围内不再有水合物生成;水深增大会降低立管内温度,增大水合物生成区域和体积分数;乳化液流量减小会使立管内温度更加接近于环境温度,增大水合物生成区域和体积分数;出口压力增大会使整个立管内压力升高,增大水合物生成区域和体积分数;管径减小会增大管内摩阻,使立管内压力升高,增大水合物生成区域和体积分数。研究结果对深水油气混输流动保障具有一定的指导作用。Water in oil emulsion is a common oil-water state in multiphase mixed transportation riser,which is easy to form hydrate under the environment of low-temperature and high-pressure.In order to improve the safety of oil and gas transportation in deep water,the phase transition of water in oil emulsion hydrate in deep-water riser is predicted.Based on the theory of computational fluid dynamics,a multiphase internal flow model of hydrate phase transition is established.The finite difference method is used to solve the problem and the sensitivity analysis is carried out.The results show that the increase of inlet temperature will reduce the area of hydrate formation and volume fraction,and there is no hydrate formation in a certain range above the mud line when the inlet temperature is greater than 12.8℃;the increase of water depth will reduce the temperature in the riser and increase the hydrate formation area and volume fraction.The decrease of emulsion flow will make the temperature in the riser closer to the ambient temperature and increase the hydrate generation area and volume fraction.The increase of outlet pressure will increase the pressure in the whole riser and increase the hydrate generation area.With the decrease of pipe diameter,the friction in the pipe increases,the pressure in the riser increases,and the hydrate formation area and volume fraction increase.The research results can provide a reference for the oil and gas transportation in deep water.

关 键 词：深水立管 油包水乳化液 天然气水合物 相变 多相流动 

分 类 号：TE355[石油与天然气工程—油气田开发工程]