纵波和转换波联合AVO反演方法研究

Joint amplitude versus offset inversion of P-P and P-SV seismic data

目前纵、横波振幅随偏移距变化(AVO)的联合反演,包括弹性参数反演、梯度反演、阻抗反演和模量反演时都假设速度比值为常数2。实际速度比值偏离2越大,抽取同一反射点纵波和转换波数据的误差越大,反演误差也越大。为此提出了一种基于方向加速度最优化方法的对上、下层纵、横波平均速度比值和上层纵、横波速度比值同时扫描的AVO联合反演方法。实践证明,利用该方法不但可以获得比常速度比值更精确的反演结果,而且可以得到较准确的速度平均比值和上、下层的速度比值。

At present, joint amplitude versus offset （AVO） inverston ot P-P and P-SV seismic data,which includes elastic parameters inversion, grade inversion, impedance inversion and module inversion, considers average interval velocity ratio as constant two. The more real interval velocity ratio deviates from two, the more the data of compress wave and shear wave abstracted from the same reflector point different and result of inversion deviate. Based on directional acceleration optimization, AVO inversion can be made by scaning average interval velocity ratio and interval velocity ratio of upper layer at the same time. Not only more accurate inversion results compared with constant velocity scan, but also accurate average imerval velocity ratio and interval velocity ratio at the both sides of reflector were obtained.