复杂区三维折射静校正技术与应用效果

3D refraction static corrections in complex regions and its applied effects

三维折射静校正技术是一项配套技术,它涉及地震记录的折射初至拾取、折射层段划分、折射速度分析、延迟时计算、建立近地表模型及计算基准面静校正量等一系列步骤。为了提高最终静校正效果,要求对上述各个环节实行严格的质量监控。在拾取折射初至时间时,必须确保大部分道的初至时间是正确的,才能保证后续处理符合要求。因地震记录折射初至具有连续性和高覆盖次数,增加了统计效应,所以由此建立的近地表模型更加真实,计算的静校正量更加准确。三维折射静校正技术适用于复杂地表条件,如山地、过渡带、黄土塬。

3D refraction static corrections technique is a complete set of techniques,which is concerned with such steps as pickup of first breaks of refractions on seismic records,strata partitioning of refractors,analyzing refraction velocity,computation of time delay,building up near-surface model and computing datum statics.In order to improving the final effects of static corrections,strict QC for above-mentioned links is needed.It should ensure that the times of first breaks of most traces are correct while picking up times of refracted first breaks,that can ensure the subsequent processing to meet the demand.Because the times of refracted first breaks on the seismic records are characteristics of continuity and high folds,increasing statistical effects,the near-surface models building up therefor are more practical and computed statics are more correct.3D refraction static corrections are suitable for such complex surface conditions as mountains,transient zones,loess plateaus,hills,which have more severe static corrections problem.