摘要
传统的VSP波场处理多是假定波传播是在波形和振幅均一的条件下完成,这种假定条件对于现实的不规则空间采样、多变的子波和噪声因素是不存在的。针对以上因素的影响,提出允许接收到的波在振幅和初至时间上相互独立存在,处理并运用包含非线性最小二乘法和特征值的最优迭代方法,每次选取出具有某种特征的波,当具有较强特征的波被选取后,弱特征性的波就变强,重复以上步骤,完成对波场的选取过程。该方法对各种波场都适用,VSP数据量相对较小,对该方法不存在计算的局限性。实际数据处理证明,该方法应用于VSP波场分离优于常规分离方法,对提高VSP处理精度具有重要意义。
Traditional methods for wave field separation typically assumed that the waves propagated uniformly with an unvarying wavelet shape and amplitude,but this assumption broke down in the presence of irregular spatial sampling,event truncations,wavelet variations,and noise.To eliminate their effects,it presented a method for wave field separation: Each event was regarded to propagate independent amplitude and independent arrival time.An optimum iterative method was used which concluded the nonlinear least square method and two eigenvalues at each step.A event with some character is stripped from the data at one time.As stronger events are predicted and removed,weaker events then become visible and can be modeled in turn.As each new event is approximately modeled,the fitting for all previously removed events is then revisited and updated.Iterations continue until the wave selection is finished.The method is suitable for all wave fields.As VSP data sets are relatively low,there is no limitation for using the method.The real-data processing demonstrates that this iterative approach can have better result for VSP wave-field separation than conventional techniques.It is of significance to improve the processing accuracy of 3D VSP data.
出处
《石油天然气学报》
CAS
CSCD
北大核心
2011年第6期81-85,8,共5页
Journal of Oil and Gas Technology
基金
国家"863"计划项目(2007AA060503)
关键词
三维VSP
波场分离
最小二乘法
最优迭代
3D VSP
wave field separation
high fidelity
optimization approach
