【摘要】 地震波在传播过程中的能量衰减特征表现为:一方面为球面扩散,另一方面是由于地层含流体而引起的衰减,它直接和地层的岩性、含流体性密切相关。由于含流体岩石存在的内摩擦性及粘滞性,使得地震波在传播过程中能量得到衰减,且高频能量衰减强,低频能量衰减弱,从而成为形成低频阴影现象的重要原因。作者在基于波动方程正演的基础上,从岩石的内摩擦性和粘滞性出发,模拟地震波穿过含流体地层时的频率能量变化特征,解释由于含流体地层的吸收衰减而导致的低频阴影现象,并在实际处理中得以应用。更多还原

【Abstract】 There are two sides of the energy attenuation for the seismic along with the propagation in the medium.One is the sphere spread,and the other is the attenuation caused by the liquid in the rock,and it has a close relation with the lithology character and the liquid.The diffusivity and viscosity in the rock saturated with the liquid make the seismic energy attenuate when the seismic wave propagates in the rock.Further more,the energy of high frequency attenuates faster and more,in reverse,the energy of the low frequency attenuates slower and less,so they become the important reason of the low frequency shadow.Based on the wave equation theory,and starting from the diffusivity and the viscosity,the paper mainly simulates the attenuation character of the signal frequency energy when the seismic wave promulgates in strata,then explains the theory of the low frequency shadow caused by the attenuation,and eventually uses it in the actual processing.更多还原