应用模拟退火法反演横波速度

S-wave velocity inversion using simulated annealing method

为了能够直接从地震资料中获得横波速度，本文在一维层状介质假设条件下和已知纵波的速度和密度（纵波速度和密度可由文献2中方法获取，密度也可由该地区的经验公式求取），利用常规资料进行平面波分解（τ-p变换）后作为输入记录，再应用模拟退火法及演横波速度。通过理论计算和井数据试算结果表明，在纵波速度和密度没有误差时能够准确的反演出横波速度；在纵波速度有误差的情况下也能得到较好的反演结果。

In order to derive S--wave velocity from seismic data , we take the presumption of one-dimension layered medium, and use known p--wave velocity and medium density, which were got by using the methods in reference [2], (the density can also be obtained from empirical formula of the given area). The seismic data which underwent plane wave decomposition (τ-p transfrom) are taken as input data, from which the S--wave velocity can be derived with the aid of the simulated annealing method. Theoretical and borehole data trials show that we obtain very accurate Swave velocity when no error exists in p--wave velocity and density, and that we estimate rather accurate S--wave velocity when p--wave velocity has slight error.