【摘要】 在方位各向异性介质中地震波沿不同方位的传播速度存在差异,会引起宽方位地震资料CDP道集内的道间时差,处理技术无法消除这一时差,必须寻找有效而适用的解决办法,以提高地震成像精度和分辨率。为了满足长垣油田开发后期剩余油挖潜精细地质研究对地震资料的品质要求,基于长垣油田高密度三维三分量(3D3C)地震实验区数据,分析了引起方位各向异性的地质原因,研究了地震资料中方位各向异性的表现特征。通过实际地震资料分析可知,该区快波速度方位约在NE67°,与现代主应力场方向及沉积物源方向一致,在CDP道集内方位各向异性时差约为10 ms,且各向异性强度和方向随深度而变化。进一步研究并试验了模型道相关法时差校正技术,以层剥离方式消除不同沉积时期的方位各向异性时差。通过最终成像效果对比可见,方位各向异性时差校正可提高地震数据成像品质,有利于小断层识别与薄砂体描述。更多还原

【Abstract】 The velocity varies with different azimuths as seismic wave travels through anisotropy media,which leads azimuth time delays among seismic traces in wide azimuth seismic data survey.Conventional methods for seismic data processing can not remove this kind of time delay.For high image quality and higher resolution of seismic data,new approaches must be probed to satisfy residual oil developing research in high water-cut stage.Based on the 3D seismic data with high density collection in Changyuan oilfield,the causations were firstly analyzed in this paper,and the characteristics of anisotropy media in real seismic data have been presented.The seismic data reveals that the azimuth of fast wave is around NE67°,which is consistent with modern stress field azimuth and also consistent with deposit material origin orientation.In NMO-ed CDP gather,the amount of azimuth time delay is about 10 ms,and its amplitude and orientation are variable as the depth increasing.The cross-correlation approach based on seismic model trace to correct azimuth time delay has been proposed,and the strategy of layer stripping was implemented to remove azimuth time delay in different depth levels.The final imaging data presents higher quality that is helpful for fault identification and sandstone description.更多还原