气水界面上的法向反射系数研究

Study of normal reflection coefficients on the gas-water interface

探讨地震频带内气水界面上的法向反射系数随频率的变化特征。分别利用新场气田和Denneman et al.(2002)模型的岩石和流体属性参数,建立了弹性孔隙介质的气水界面模型,然后,讨论了Gurevich et al.(2004)法向反射系数和Silin and Goloshubin(2010)的法向反射系数的简化计算方程。利用简化方程和建立的气水界面模型进行了计算,并探索了地震频带内法向反射系数随频率变化的规律。结果表明,Silin and Goloshubin(2010)的渐进方程的方法能有效反映地震频带内气水界面上反射系数随频率的变化。渐进方程的反射系数方法可用于研究实际气水界面上反射系数随频率的变化现象。

This paper approaches the variation features of normal reflection coefficients with frequency on the gas/water interface in a seismic frequency band and establishes the gas/water models of elastic porous medium by using the porous rock and porous fluid parameters from the Xinchang gas field and Denneman et al.（2002） model,respectively.Then,it discusses the simplified equations of normal reflection coefficients from Gurevich et al.（2004） and Silin and Goloshubin（2010）,and calculates the normal reflection coefficients using the simplified equations and the built gas/water interface model and searches for the variation rule of normal reflection coefficients with frequency in a seismic frequency band.The results show that the method of asymptotic equation of Silin and Goloshubin（2010） can effectively indicate the variation of reflection coefficients with frequency on the gas/water interface in a seismic frequency band.So the asymptotic equation is an effective way to study the phenomenon of normal reflection coefficients with frequency on a real gas/water interface.