摘要 井内连续变化的地层温度会对智能完井系统液压控制管线内流体流动造成较大的影响,而现有的连续方程、运动方程对变温环境下液压管线内流体流动不能很好地求解,针对此问题,根据能量方程的定义,分析流体微元以及所采用的32号液压油特性,推导出一个特定形式的能量方程,再联立现有的连续方程、运动方程,得到一个新方程组,并利用特征线法(method of characteristics, MOC)结合MATLAB软件对新方程组进行计算求解.若干恒温条件与2种连续变温条件下的仿真结果显示新方程组均比旧方程组求解精度高,验证了所推导的能量方程的合理性与准确性,表示其能用于恒温与变温环境下液压管线内流体流动问题的计算求解,进而推广至智能完井系统液压控制管线等问题的计算求解,对智能完井井下流量控制阀开启状态进行判断.该研究可为智能完井系统液压控制等研究提供参考.
Abstract：The continuously changing formation temperature in the well will have a great influence on the fluid flow in the hydraulic control pipeline of the intelligent completion system, but the existing continuous equation and motion equations cannot solve the fluid flow in the hydraulic pipeline under the variable temperature environment. Aiming to resolve this problem, according to the definition of the energy equation, this paper analyzed the fluid infinitesimal and the characteristics of No.32 hydraulic oil used, deduced a specific form of the energy equation, and then established the existing continuous equation and motion equation. A new set of equations was obtained, and the new set of equations was solved by using the method of characteristics(MOC)combined with MATLAB software. The simulation results under some constant temperature conditions and two continuous variable temperature conditions show that the new set of equations is more accurate than the old set of equations, which verifies the rationality and accuracy of the energy equation deduced in this paper. It shows that it can be used to calculate and solve fluid flow problems in hydraulic pipelines under constant temperature and variable temperature environments. And it can be extended to calculate and solve the hydraulic control pipeline of intelligent completion system, and judge the open state of downhole flow control valve of intelligent completion. The research results in this paper can provide a reference for hydraulic control of intelligent completion systems.
