广义线性反演地震岩性模拟技术

地震岩性模拟可用于解决薄层反演问题。本文利用广义线性反演技术实现岩性模拟。由于反射波与模型的波阻抗界面有关,所以本文取波阻抗为模型参数。为了能反演出最小的薄层,初始模型取为一层,再进行等间隔细分层,细分层的间隔取我们所能分辨的薄层厚度。这样,模型参数仅为一系列波阻抗参数,减少了反演的多解性。反演中采用奇异值分解法(SVD)解正规方程,以便得到模型参数修改量。理论模型的试算表明,本方法收敛速度快,能得到非常精确的解。实际资料计算中,将反演得到的波阻抗曲线与测井得到的波阻抗曲线比较,具有很好的一致性。因而证实了该方法分辨薄层的能力较强。

Seismic lithologic modeling technique using generalized linear inversion.

Seismic lithologic modeling may be used to achieve thin layer inversion. It is realized by using generalized linear inversion. The article takes wave impedance as model parameter because reflections are related to the impedance interfaces of the model. In order to realize inversion of the thinnest layer, I use single layer model, which will be subdivided into equal small intervals we can distinquish. Model parameters are thus a series of wave impedance values, so that multisolution phenomenon is reduced. In the inversion, singular value decomposition is introduced to solve normal equation so as to obtain model parameter variables. Theoretical computation says this technique brings fast convergence and very accurate solution. Real data computation shows that the wave impedance curve obtained by the inversion is excellently consistent with the wave impedance curve derived from logging data. It is proved that this method results in better thin layer resolution.