共聚焦点层析速度建模方法

Tomographic velocity modeling based on CFP technology

1. 西安交通大学,陕西西安 710049;2. 长庆油田公司,陕西西安 710021;3. 同济大学,上海 200092

Xi'an Jiongtong University, Xi'an 710049, China

讨论了基于双聚焦成像理论的层析速度反演方法的基本原理,利用该反演方法实现成像速度模型的迭代更新,使最终模型速度更接近于实际地层速度。由双聚焦成像产生的共聚焦点(CFP)道集是一个部分偏移过的道集,借助于反射层析思想,利用逆时聚焦算子和共聚焦点响应两者之间的时移,通过算子的更新来反演地层速度的更新量。该方法用向量参数化来描述速度模型,用摄动法来更新模型参数,因此提高了计算的稳定性。利用大庆油田的模型数据和胜利油田的实际地震数据对该方法进行了验证。结果表明,用该方法得到的速度模型进行叠前深度偏移,成像效果得到了改善。

Based on the fundament of inversion tomography, the method calculates imaging velocity update by operator update, which got from time difference between CFP response and inverse operator. The method uses vector parameterization to characterize velocity model and perturbation to update the model parameters to improve the stability of the inversion. To applied the velocity modeling for synthetic data sets and the real data sets and obtain satisfied results. The tests proved that the imaging effect of prestack depth migration have improved with the method.