基于BFGS 算法的地层品质因子反演方法

目前，油气勘探已经从简单构造勘探转向岩性勘探，今后勘探的主要地质目标之一是地层--岩性油气藏，Q 值在地层--岩性油气勘探中有重要作用。为较好地估计地层的Q 值，本文提出了基于 BFGS 算法和广义S 变换的Q 值估计方法。通过广义S 变换得到不同旅行时刻的振幅谱，构造一个最优化问题，引入BFGS 算法估计出地震品质因子。该方法可以在整个频带范围内计算振幅谱的互相关系数，避免了频带范围选择的问题，而且收敛速度更快。模拟算例和实际资料处理结果均表明，该方法可以有效快速地估计品质因子，并具有较好的抗噪性。

Inversion of stratigrarhic quality factor based on BFGS algorithm

Oil and gas explorations have been shifting from simple structure exploration to lithological exploration， today． One of the major geological exploration targets is the stratigrarhic-lithological reservoirs in the future． The Q value is significant in stratigrarhic-lithological exploration． In order to estimate the Q value，we propose the Q value estimation method based on BFGS algorithm and generalized S-transform． We get amplitude spectrum of different travel times by generalized S-transform and constructing an optimization problem，and then use BFGS algorithm to estimate seismic quality factor． The method can calculate the cross correlation coefficients of amplitude spectrum in the whole band range and avoid the influence of the band range． The convergence speed of the BFGS method is faster． Simulated examples and actual data processed results show that the method estimated quality factor effectively with better anti-noise property．