高频波动对多孔弹性介质中稠油黏温参数影响规律研究

Study on Influence of High Frequency Vibration on Viscosity and Temperature Parameters of Heavy Oil in Porous Elastic Medium

为了定量描述高频波动激励井热力学降黏解堵的机理,基于高频波在多孔弹性介质中能量传播、损耗和转化的动力学特征,建立了高频波动激励下稠油油藏近井带储层中稠油温度及黏度变化的稳态和非稳态耦合动力学模型。该模型由能量衰减和转化方程、非均匀热源圆筒壁导热微分方程和温黏状态方程组成,采用耦合迭代方法进行数值计算,揭示了高频波对多孔弹性介质中稠油温度和黏度影响的主控因素及规律。结果表明:频率为20 k Hz的高频波动在r<0.6 m范围内作用效果明显,频率越高作用效果越好,但处理范围越小;与波动频率相比,振幅对其作用效果更显著;波动作用由非稳态向稳态过渡所用时间约400 s。该模型的建立与求解,为稠油油藏近井地带高频波动解堵增产增注技术提供了重要的理论依据。

In order to quantitatively describe the thermodynamic viscosity-reducing and plug-removing mechanism of high-frequency vi- bration excitation near wellbore, the steady and unsteady coupling dynamic models of heavy oil temperature and viscosity variation near wellbore of heavy oil reservoir caused by high-frequency vibration excitation are established respectively based on the energy transmis- sion,loss and transformation kinetics of high-frequency vibration wave in poroelastic medium. The models consist of energy attenuation and transformation equation, the differential equation of inhomogeneous heat source conduction in cylindrical wall and the temperature- viscosity equation of heavy oil, and they are solved using coupling iterative method to reveal the main controlling factors and laws of high-frequency vibration influencing the temperature and viscosity variation of heavy oil in poroelastic medium. The results show that the vibration of 20 kHz has a better effect within 0.6m;the higher the frequency of vibration,the better the viscosity-reducing and plug-re- moving effect of vibration, but the smaller the effect range of vibration ; compared with vibration frequency, vibration amplitude has grea- ter effect;it takes about 400 s for the effect of vibration to transit from non-steady state to steady state.