【摘要】 川东北地区长兴组碳酸盐岩储层埋藏深度大,获取大角度地震信息困难,地震资料信噪比较低。为此,本文通过引入新的近似式,从中、小角度两个弹性阻抗数据体中提取岩石物性参数。文中首先以佐普里兹方程的Aki-Richards近似式为基础,详细推导了以纵横波阻抗表示的新的两项型弹性波阻抗公式,该式不仅考虑了密度与其他地球物理参数的联系,而且在舍弃密度项时,利用纵波速度与密度幂指数拟合关系式使密度近似为纵波阻抗更加合理;其次引入Tikhonov正则化方法以提高该方法反演的精度、稳定性和抗噪性。数值试算与实际应用结果都证明了该方法的可行性。更多还原

【Abstract】 Changxing formation carbonate reservoirs are deeply buried in the Northeastern Sichuan Basin.Seismic data with large angle is hardly acquired,and data signal-to-noise ratio is very low.In order to meet these challenges,by introducing a new approximate formula,a method to pick up petro-physical parameters from two elastic impedance data volumes with middle and small angles is proposed in the paper.Based on Aki-Richards approximation formula of Zoeppritz’s equation,the new two-term elastic wave impedance formula expressed by compressional wave impedance and shear wave impedance is derived.In the discarded density item,the density approaches to compressional wave impedance by using compressional wave velocity and density of exponential fitting.On the other hand,the accuracy,stability,noise immunity of the inversion is improved by the Tikhonov regularization method.Numerical experiments and seismic data applications prove the feasibility of this method.更多还原