Abstract: Ordinary differential equation group,based on mass,momentum and energy conservation,is derived to describe the flow pressure,temperature,gas velocity and density in gas wells and numerically solved with the four order Runge-Kuta method.The numerical model,which accords with the actual situation of the gas wells,allows for the oblique angle,structure of well and tubing string, the radial heat transfer of the wellbore,different heat transfer medium in annular and the change,with the depth,of the physical properties of the formation.The basic data of the Keshen Well No.1(high temperature and high pressure gas well),6460 meters of depth in Xinjiang,are used for case history calculation,and sensitivity analysis is made for the model.The curves of the gas pressure,temperature,velocity and density along the depth of the well are plotted with different production,and it intuitively reflects the gas flowing law and the characteristic of the heat transfer in formation.The result can provide the technical reliance for the process design of well test in high temperature-high pressure gas wells and dynamic analysis (hydrate formation prediction, tubing string design) of production well.

Key words: ultra-deep well, gas well, well-bore flow, temperature distribution, pressure distribution, numerical simulation

摘要： 基于质量、动量、能量守恒原理,导出了描述气井流动气柱的压力、温度、流速及密度分布的常微分方程组,采用四阶龙格-库塔法数值求解.该数值模型综合考虑了井斜角、井身结构、油管柱结构、气井井筒的径向传热、不同环空传热介质及地层的热物理性质沿井深的变化,符合气井的实际情况.应用6460m的新疆柯深1井(高温高压气井)基本数据进行实例计算,并对模型进行了敏感性分析.计算绘出了不同产量下气体压力、温度、流速及密度沿井深的分布曲线,直观地反映了气井的流动规律和地层的传热特征.可为高温高压气井试井工艺设计和生产动态分析(如水化物预测、油管柱设计等)提供技术依据.

关键词: 超井深, 气井, 井筒流动, 温度分布, 压力分布, 数值模拟