饱和黏弹性孔隙介质中压缩波的频散与衰减

Dispersion and attenuation of compression waves in saturated viscoelastic porous media

波的频散现象及其成因是岩石物理学与孔隙介质声学研究的一个热点。基于Biot理论与Darcy-Brinkman定律,提出了Maxwell-Brinkman与Kelvin-Brinkman黏弹性孔隙介质力学模型,建立了压缩波的频散关系,揭示了波的频散与衰减规律,分析了应力松弛与蠕变对波的传播速度与逆品质因子的影响。低频情况下,Kelvin-Brinkman模型与Darcy-Brinkman-Biot模型预测的压缩波的频散及其衰减一致。高频情况下,Maxwell-Brinkman模型与Darcy-Brinkman-Biot模型预测的压缩波的频散及其衰减一致。结合墨西哥湾的试验数据,验证了物理模型的可靠性。通过参数敏感性分析,探讨了基于实测数据优化介质参数的方法。

The phenomenon of wave dispersion and its causes are a hot topic in the study of rock physics and acoustics of porous media.Based on the Biot theory and Darcy-Brinkman law,Maxwell-Brinkman and Kelvin-Brinkman viscoelastic porous media mechanical models were proposed,and the dispersion relationship of compression waves was established.The dispersion and attenuation laws of waves were revealed,and the effects of stress relaxation and creep on wave propagation velocity and inverse quality factor were analyzed.At low frequencies,the dispersion and attenuation of compression waves predicted by the Kelvin-Brinkman model and the Darcy-Brinkman-Biot model are consistent.While,at high frequencies,the dispersion and attenuation of compression waves predicted by the Maxwell-Brinkman model agree well with those by the Darcy-Brinkman-Biot model.The reliability of the physical model was verified using experimental data from the Gulf of Mexico.Through parameter sensitivity analysis,the method for optimizing medium parameters based on measured data was discussed.