高温高压模拟井筒流固耦合传热建模与数值求解

Modeling and Numerical Solution for Fluid-solid Coupled Heat Transfer of High Temperature and Pressure Simulated Wellbore

模拟井筒加温系统是用于模拟井下高温高压环境,对射孔器材进行高温性能检测的一种实验装置。模拟井筒为耐高温高压的厚壁圆柱形封闭腔体,为研究加温过程中腔体内流体与厚壁腔体之间的动态耦合传热过程,根据模拟井筒加热物理模型,建立了模拟井筒耦合传热数学模型。应用有限差分法离散模拟井筒耦合传热数学模型,得出厚壁井筒和腔体内流体数学模型的离散格式。使用迭代法分别计算厚壁井筒与腔体内流体区域的传热过程,在厚壁井筒与流体的交界边界处应用热平衡法进行耦合传热计算,求解模拟井筒耦合传热温度场,腔体内流体区域采用投影法对数学模型进行求解。研究结果表明:模型和求解方法可用于高温高压模拟井筒流固耦合传热的求解,其实验误差低于18%;通过模拟计算得到了井筒及其腔体内流体的动态耦合传热过程温度场分布规律,为模拟井筒加温系统设计提供理论依据。

A simulated wellbore heating system is an experimental device,which can be used to simulate the high temperature and pressure environment in the underground and perform high temperature performance testing on the perforating equipment.The simulated wellbore is a thick-walled cylindrical closed cavity with high temperature and high pressure resistance.In order to study the dynamic heating process between the fluid in the cavity and the thick-walled cavity,a mathematical model of simulated wellbore coupling heat transfer mathematical model was established.The finite difference method was used to discrete the mathematical model of simulated shaft heat transfer,and the discrete format of mathematical model of the thick-walled cavity and the fluid in the cavity was obtained.The iterative method was used to calculate the heat transfer process between the thick wall of the wellbore and the fluid region in the cavity.Coupling heat transfer calculations at the boundary between the thick wall and the fluid by application of heat balance method were used to solve the simulated shaft coupled heat transfer temperature field.The results show that the mathematical model of the fluid region in the cavity was solved by projection method.The model and solution method can be used for the simulation of fluid-structure coupled heat transfer in high temperature and high pressure wells,and the experimental deviation is less than 18%.The temperature field distribution of the dynamic coupling heat transfer process of the fluid in the wellbore and its cavity was obtained through simulation calculation,which provides a theoretical basis for the design of the wellbore heating system.