OVT域叠前时间偏移在煤田高密度三维地震勘探中的应用

AApplication of OVT prestack migration in high density 3D seismic of mine field

为了提高沁水煤田某矿煤层陷落柱、断层、挠曲等小构造的探测准确率,将OVT域叠前偏移技术引入了高密度宽方位三维地震资料处理中。通过面元划分、五维规则化、OVT域叠前时间偏移、方位各向异性校正时差校正等处理过程,实现宽方位OVT域叠前时间偏移。研究结果表明,OVT域叠前时间偏移保留了方位角信息,可以反映地层随方位角的变化;方位各向异性校正解决了道集的方位各向同相轴“抖动”问题,提高了剖面的分辨率,使小断层位置、陷落柱边界更清晰,“串珠状”现象更聚焦;OVT域叠前时间偏移剖面波形自然、浅层同相轴连续性低频成分更丰富,频带更宽。

In order to improve the detection accuracy of collapse column,fault,deflection and other small structures in Qinshui coalfield,OVT prestack migration technology is introduced into high-density and wide azimuth 3D seismic data processing.Through the processing of bin division,five dimensional regularization,OVT prestack time migration,azimuth anisotropy correction and moveout correction,the wide azimuth OVT prestack migration is realized.The results show that prestack time migration in OVT domain preserves azimuth information,which can reflect the changes of strata with azimuth;azimuth anisotropy correction solves the problem of"shake"of azimuthal anisotropy in gathers,improves the resolution of profile,makes the location of small faults and the boundary of collapse column clearer,and"beaded"phenomenon more focused.The section of prestack time migration in OVT domain is natural and the shallow phase axis is continuous.The low frequency components are more abundant and the frequency band is wider.