本井气柱塞气举排水采气动态模型的求解及应用

The Solution and Application of Dynamic Modelof Plunger Gas Lift by Crude Gas

本文根据本井气柱塞气举排水采气工艺举升过程中的动力学分析,应用质量守恒和动量守恒定律,建立了多因素影响下的柱塞和液体段塞运动变系数二阶常微分方程,应用局部截断误差修正过的Miline-Hamming法和Runge-Kutta法相结合的方法对柱塞气举动态方程进行求解。可以预测举升过程中各关键参数的变化规律及系统动态特征,为本井气柱塞气举优化设计及故障诊断提供了理论依据。通过编制计算机应用程序,用算例对模型进行验证,预测柱塞气举下行过程任一时刻井筒内柱塞速度、位移、瞬时加速度等关键参数的变化规律,符合现场实际生产情况。

In this paper, according to the dynamic analysis of the lifting process of the gas drainage process in the gas column, Based on the conservation of mass and the law of conservation of momentum, the second-order ordinary differential equation of the variable coefficient of plunger and liquid slug under the influence of multiple factors is established. The dynamic equation of the plunger gas lift is solved by the combination of the Miline-Hamming method and the Runge-Kutta method, which is modified by local truncation error, which can predict the changing rules and the dynamic characteristics of each key parameter in the process of lifting and provides a theoretical basis for the optimal design and fault diagnosis of the gas column. Through the preparation of the computer application program, the calculating example is used to verify the model and the variation of the key parameters such as the speed, displacement and instantaneous acceleration in the wellbore at any time is predicted, which is in accordance with the actual production situation.