裂隙弱度参数的波场特征

The wave field characteristics of the fracture weakness parameters

本文将Schoenberg线性滑移裂隙介质理论应用到HTI(LSD)介质的弹性波波场数值模拟之中.主要针对描述裂隙状态的2个裂隙参数——法向弱度E_N和切向弱度E_T对波场的影响进行了有限元模拟.模拟结果揭示了E_N主要影响快波而E_T主要影响慢波的波场特征,通过E_N和E_T变化对应的裂隙含水程度说明了E_N对裂隙中的流体敏感而E_T主要反映裂隙本身的弹性特征.裂隙参数的这个性质对于该理论在裂隙探测和裂隙含流体检测方面的进一步应用具有重要意义.通过数值模拟进一步说明,对于裂隙介质而言,E_N和E_T比Thomsen参数的物理意义更为明确和直观.

This paper applies the Schoenberg fracture media model theory to numerical simulation of elastic wave field in HTI （LSD） media. By means of the numerical simulation we revealed the wave field characteristics of the fracture parameter normal weakness EN and shear weakness ET （two dimensionless parameters）. The results of the wave field simulation indicate that the parameter EN has an effect on the fast wave and the parameter ET has an effect on the slow wave. E~ is very sensitive to fluid in fracture, and ET is sensitive to elastic characteristics of fracture＇s own. The conclusion has an important sense for the application of the Schoenberg fracture media model theory in the field of fracture prediction and fluid detection in fractures. The physics meaning of the normal weakness EN and the shear weakness ET are more definitude than the Thomsen parameters （∈,γ,δ）.