均匀振幅加权和余弦振幅加权定向地震波方法的对比

Comparison of uniform amplitude weighted and cosine amplitude weighted directional seismic beamforming method

随着勘探工作向深部发展,地震数据的信噪比分辨率要求越来越高.均匀振幅加权定向地震波方法(即基于接收阵列的时域地震波束形成方法,简称TSBBRA),可以增强目标信号、降低噪声,改善地震数据的质量.然而增大TSBBRA的控制参数N,会导致地震有效波束变窄,主波束不能覆盖整个接收排列,有时达不到对数据质量的要求.余弦振幅加权定向地震波方法(SDBCAD)通过余弦振幅加权展宽波束,能改善上述问题.过去对SDBCAD方法改善程度的研究仅限于理论模型上的研究,为了进一步探讨SDBCAD方法与TSBBRA方法对实际数据质量的影响,在吉林省农安县哈拉海镇开展了对比实验研究.通过TSBBRA和SDBCAD的实验剖面对比可知,SDBCAD方法能够在满足勘探精度要求的情况下合理展宽定向地震波束,能够更有效覆盖接收排列,表明了SDBCAD方法在宽接收排列情况下,能够更显著地改善地震数据质量.

With the development of deep exploration work,the signal-to-noise ratio and resolution of seismic data is required higher and higher. Time-domain seismic beam-forming based on receiver arrays,（ namely,the time domain seismic beamforming method based on the array,TSBBRA）,can enhance the energy of target signal and reduce the noise,improving the quality of seismic data.However,when increasing the control parameter N of TSBBRA,the effective beam will be narrow and the main beam can not cover the entire receiving arrangement. Sometimes,the result can not meet the requirement for the quality of data. Seismic directional beamforming with cosine amplitude distribution can broaden beam by cosine amplitude weighting,which can improve the problem. But,the research level of SDBCAD method is limited to research on the theory model. In order to further explore SDBCAD method and TSBBRA method on the quality of the actual data, contrast experimental research is conducted in Halahai,Nong ＇an,Jilin Province. Though the contrast of experiment profile of TSBBRA and SDBCAD,it can be known that SDBCAD method can broaden the beam and cover more receiving arrangement under satisfying the requirement of exploration precision,Which shows that SDBCAD method can more significantly improve the quality of seismic data under the condition of wide receiving arrangement.