三维转换波关键成像技术研究与应用

3D converted wave imaging

西部L地区碳酸盐岩缝洞储层是重要的油气储集空间,具有埋深大(超过5000m)、非均质性强、形态复杂等特点,单一应用纵波信息进行储层和流体预测精度偏低。为此,针对西部L地区超大面积(满覆盖面积1096km2)的三维转换波资料,通过研究形成了以转换波组合静校正、四参数叠前时间偏移速度建模和横波分裂时差校正为关键成像技术的转换波处理流程。最终在深层碳酸盐岩储层获得了高质量的转换波成像结果,尤其在气藏发育带转换波成像质量明显好于纵波,充分展现了转换波技术在超深碳酸盐岩勘探的适用性。

Converted wave seismic exploration can obtain both P-wave and converted wave information,which is more conducive to gas cloud imaging,lithology prediction,fluid identification,and fracture detection.But compared with the conventional Pwave data processing,the converted wave data processing is much more difficult due to its vector wave field characteristics and its propagation path asymmetry.Based on multi-wave processing tools provided by GeoEast,we propose a workflow for 3D converted wave dataset of the Block L.Three key imaging tools of the workflow are converted wave static corrections,velocity modeling on fourparameter prestack time migration,and S-wave moveout corrections.The final seismic sections show much better imaging,which provide a good base for deep carbonate reservoir identification.