叠前深度偏移技术在QMQ地区成像中的应用

Application of prestack depth migration in QMQ area

位于东部QMQ地区的地震资料,其地表地质条件较好,但因勘探目的层是奥陶系复杂的古潜山,因此,适合应用叠前深度偏移技术进行潜山顶及其内幕的成像。通过Kirchhoff叠前深度偏移技术中精细的数据准备、速度-深度模型的建立与优化、偏移孔径的试验与选择和偏移成像4个关键环节的应用研究,完成了QMQ地区地震资料的Kirchhoff叠前深度偏移。通过与叠前时间偏移剖面对比,叠前深度成像改善了QMQ地区地震数据的信噪比和分辨率,同时提高了奥陶系潜山及其内幕的成像精度,为后续的深度域地质解释和构造成图提供了可靠的偏移数据,研究成果对深层煤勘探所面临的底板奥灰水的研究具有借鉴意义。

QMQ area is located in an oil field in eastern China.Complex Ordovician buried hill is the main target in this area.The Pre-Stack Depth Migration（PSDM） technique is applied in this area to image the top of buried hill and its interior.This paper mainly introduces 4 key steps of PSDM,i.e.,data preparation,velocity-depth modeling and op-timization,migration aperture test and optimization,as well as final PSDM imaging.Compared with traditional PSTM,the PSDM improved the S/N ratio and resolution of seismic data in QMQ area,and promoted the imaging accuracy of the Ordovician buried hill and its interior.The application of this technique provided reliable migrated data for future seismic interpretation and mapping in depth domain.Moreover,it will be useful in deep coal mining by studying the underlying Ordovician carbonate water.