高频地表校正和起伏地表叠前时间偏移技术的应用——以普光气田双复杂地区为例

Application of High-frequency Surface Correction and Prestack Time Migration on Relief Surface——By Taking Double Complex Area of Puguang Gasfield for Example

普光气田地表条件和地下构造均十分复杂,属于典型的地震双复杂地区,该区地震资料处理难点主要有2条:一是地形起伏较大,低降速带变化较大,速度横向变化较大,使得波场传播复杂,不符合地表一致性假设,常规静校正误差大;二是传统偏移成像技术不能满足双复杂地质条件下的高陡构造成像。因此,在多次试验的基础上,提出高频地表校正和起伏地表叠前时间偏移相结合的处理思路,在普光气田的地震资料处理中取得了较好的效果。

In Puguang Gasfield surface condition and underground structure were complex,it belonged to a typical dualcomplex seismic area,where there existed 2difficulties for seismic data process.One was rugged surface with serious low and lateral velocity variation zones,so the wave field propagation was complex,it was not agree with surface hypothesis,there existed high errors in conventional static correction.The other was traditional migration imaging technique could not satisfy the high and steep structural imaging under dual-complex geological conditions.Therefore based on the experiments,it is proposed that the idea of high frequency surface correction should be combined with relief topography prestack time migration,good results are achieved in seismic data process of Puguang Gasfield.