地震波衰减规律及其恢复方法  

Seismic wave attenuation and recovering method

作　　者：李子顺[1] 

机构地区：[1](1.大庆油田有限责任公司勘探开发研究院大庆

出　　处：《地球物理学进展》2007年第5期1545-1551,共7页Progress in Geophysics

摘　　要：针对地面地震分辨率低，不能有效识别薄层储层、薄层地层等问题，本文通过地震波衰减规律的分析，提出了一种恢复地震波高频衰减获得宽频带地震剖面的方法，从而大幅度地提高了地震分辨率．应用双井微地震测井资料对松辽盆地地震波动力学特征研究表明，地震波衰减规律是在近地表低速层和近地表低速层的近震源区地震波高频衰减巨大，而在高速层地震波高频衰减很小．药量大近震源区地震波高频衰减大，药量小近震源区地震波高频衰减小．那么，近震源区和近地表低速层对地震波的衰减是地面地震资料频带窄、分辨率低的主要原因．据此提出了如下确定性反褶积方法，用双井微地震测井资料求取近震源区、近地表低速层和虚反射等滤波因子，用其对地面地震资料作确定性反褶积处理，从而恢复近震源区、近地表低速层等几种因素的地震波衰减，将大药量激发地表接收的地面地震延拓成小药量激发高速层接收的宽频带地震．应用该方法对松辽盆地优势频带宽5～90Hz，视主频50Hz的地面地震资料处理后，地震剖面优势频带宽达5～360Hz，视主频达180Hz，使常规地震剖面分辨率提高2倍．具体的说松辽盆地中部含油组合的地面地震分辨能力由9～15m提高到3～5m．宽频带地震剖面与160Hz的人工合成地震记录对比符合的很好，表明其处理结果是正确．该成果在油气勘探开发中的油气储层预测、构造学研究、沉积学研究等方面有重要的意义．The bandwidth of conventional surface seismic data is narrow and its resolution is low, which could not fulfill the requirement of recognizing thin layers of hydrocarbon bearing reservoirs with the conventional seismic technique during oil exploration and development. After studying dual holes micro-seismogram-log data, it shows that the main reason of that is resulted from wave attenuation in near source area and near surface low velocity layers. A new deterministic de-convolution method, which improves the seismic resolution in a large scale, is proposed. Using MVSP from dual holes micro-seismogram survey deriving filter operator of near source area ,ghost reflection and near surface low velocity layers, using the filter operator to do de-convolution to the surface seismic data and recover the mentioned several seismic wave decays. This method was applied at several operation sites in Songliao basin and the good results were achieved. The bandwidth of new seismic section recorded at a 1-ms sample rate could reach 5-360 Hz,the dominant frequency is 180 Hz. The resolution of the new seismic section is 3 times of the conventional seismic section and the new seismic section coincides with the synthetic seismogram very good.

关 键 词：微地震测井 地震波动力学 地震波衰减高分辨率地震 确定性反褶积 

分 类 号：P631[天文地球—地质矿产勘探]