应用GeoEast系统提高牛中斜坡地震成像精度

Seismic imaging improvement in Niuzhong slope with GeoEast

牛中斜坡前期地震道集数据品质不高,纯波数据信噪比偏低,偏移成像精度不够。为此,以GeoEast系统为依托,应用自适应面波衰减、高能干扰分频压制及叠前线性干扰压制等去噪技术,在相对振幅保持条件下压制噪声;建立较精确的均方根速度场,并优选合适的偏移孔径做好叠前时间偏移。获得的道集成果信噪比大幅提高,有利于提高叠前含气检测精度;纯波数据信噪比及分辨率明显提高,地震响应异常突出,相对振幅保持程度高,为储层反演及油气预测奠定了基础;偏移成像精度大幅提升,断裂展布规律合理,断点较清晰。文中的成果对柴达木盆地三湖地区及其他岩性油气藏勘探目标区的地震数据处理具有借鉴作用。

Low signal-to-noise ratio(SNR)of old seismic data in Niuzhong slope affects migration imaging.Using approaches provided by GeoEast,we reprocess this data.We adapt a few noise removal techniques such as adaptive surface wave reduction,frequency-dependant high-energy interference and prestack linear interference suppressions under amplitude preservation, mean-square-root velocity field building,and migration aperture optimization.The processing results show that both data SNR and migration imaging are greatly improved.This may lay a solid foundation for reservoir inversion and prediction.The results may also provide useful references for seismic data in the Sanhu area,Qaidam Basin.