海底凝析天然气管道水合物形成条件预测

Prediction of Condensate Natural Gas Hydrate Forming Conditions in the Submarine Pipeline

刘武 陈才林 阳朝晖 曹学博

LIU Wu CHEN Cai-lin YANG Zhao-hui CAO Xue-bo

西南石油学院 石工院, 四川 南充 637001; 吐哈油田 开发事业部, 新疆 鄯善 838202; 科宏设计院, 四川遂宁 629000; 辽河油田 沈阳采油厂, 辽宁 沈阳 110000

Petroleum Engineering School of Southwest Petroleum Institute, Nanchong 637001, China; Exploitation Company of Tuha Oil Field Branch, Shanshan 838202, China; Ke Hong Design Institute, Suining 629000, China; Liaohe Oil Field Branch, Shenyang 110000, China

海底天然气管线由于运行条件、环境温度、输送工艺的特殊性,极易形成水合物。凝析天然气在海底管线中的输送过程属于两相流动范畴,沿线运行参数、水汽含量的计算方法与一般的天然气管线不同,文章根据平湖-上海和锦州20-2两条凝析气海底管线的实际生产数据,优选出适合海底凝析气管线工艺计算的两相流水力学和热力学模型,结合水合物生成条件和饱和含水量的统计热力学理论计算方法,能有效地预测海底管线水合物可能形成区域,对防止水合物形成,确保管线安全运行具有重要指导意义。

Owing to particularity of operating conditions, submarine temperature and transporting technique, condensate gas hydrate is easy to form in the submarine pipeline. Pipeline transportation of wet gas belongs to the category of oil-gas two-phase flow, so the method for calculating operating parameters and amount of water along the offshore pipeline is not the same as usual natural gas pipeline. In this paper, hydrodynamic and thermodynamic models that used to submarine pipeline with a relatively high accuracy have been optimally selected comparing with field data of JZ 20-2 and Pinghu-Shanghai offshore pipelines carrying condensate gas. In combination with statistical thermodynamic calculation approaches,the models can predict hydrate forming conditions and determine the amount of water of condensate gas.The foregoing studies are of great importance in terms of judging hydrate forming zones,preventing the hydrates from being generated and ensuring pipeline operating safely.

国家教委教改项目——油气储运工程专业发展战略研究子课题资助项目