油水两相渗流多孔介质弹性波传播动力学模型研究

弹性波在储层渗流场中的传播与衰减规律是研究波场强化采油动力学机理的重要基础.基于等效流体理论和饱和静态流体弹性波传播Biot理论，建立油水两非混相流体渗流条件下储层多孔介质中弹性波传播的动力学模型，通过算例求解与分析，发现含油水两相渗流储层多孔介质中同时存在着3种纵波P1、P2、P3和1种横波S；受频率和含水饱和度的影响，各波波速和品质因子呈现出不同变化规律，4种体波波速与频率、饱和度正相关，P1、P2波品质因子与饱和度正相关，P3和S波品质因子与饱和度负相关；最后，通过与传统静态弹性波模型结果对比，进一步分析了宏观渗流场对弹性波传播特征的影响规律，为揭示低频人工地震波辅助强化采油技术的动力学机理和工艺参数优化提供了重要理论依据.

A dynamic model of elastic waves propagation through porous media with water and oil seepage flow

The propagation and attenuation of elastic waves in the seepage field of reservoirs are the major foundation for understanding the kinetic mechanism of wave-field intensified oil production technique. On the basics of the equivalent fluid theory and Biot theory, a dynamic model of elastic waves propagating through porous media with water and oil seepage flow of immiscible phases is established. The case analysis suggests that three kinds of P-waves (P1, P2 and P3) and one S-wave exist simultaneously in the porous media. Influenced by frequency and water saturation, each wave velocity and quality factor exhibit different variations. The velocities of these four body waves are positively proportional to the wave frequency and the water saturation. The attenuations of the first and the second P-waves are in positive proportion to the water saturation, while the attenuations of S-wave and the third P-wave are just opposite. The influence of the initial seepage field on elastic wave propagation characteristics is further analyzed by comparing with the traditional static model of elastic waves in porous media. This study provides a theoretical basis to reveal dynamic mechanism of the intensified oil production technique assisted with low-frequency man-made seismic waves and practical parameter optimization.