任意广角波动方程深度偏移参数优化分析

Depth Migration Based on Arbitrarily Wide-Angle Wave Equation with Parameters Optimization

强横向变速和陡倾角介质的成像问题是地震偏移成像的难点。本文在频率-空间域利用有限差分高阶分裂法求解任意广角波动方程实现了地震偏移成像。试验表明,参考速度的选取是影响成像精度的关键因素。脉冲响应测试表明通过优化参数任意广角波动方程能够以较低阶的方程获得较大的偏移角度。Marmousi模型数据叠前深度偏移试验表明,该方法能够适应强横向变速和陡倾角地质结构的成像,参数优化后能够取得更好的成像效果。

It is difficult to image the geological structure with strong lateral variation and steep dip. On the basis of the Arbitrarily Wide-Angle Wave Equation（AWWE） ,we implemented migration with finite difference high-split scheme in frequency-space domain. Optimization of the velocity parameters is a key factor in the accuracy of imaging. The test of impulse response clears that the low order AWWE can be adapted to higher steep dips by optimization of the parameters. The pre-stack migration of Marmousi data shows that the method can handle strong lateral variation and steep dip.