高丰度含气区转换波地震资料构造恢复方法探索

由于高丰度含气所造成的气烟囱现象的存在,导致在柴达木盆地东部地区的纵波地震剖面上出现同相轴下拉、频率降低、成像模糊等现象,而在转换波剖面上,成像质量虽有了很大提高,但仍存在同相轴下拉的现象。为进一步提高含气区的成像效果,尝试将时间域转换波地震剖面转换到深度域中,验证深度域转换波地震剖面对同相轴下拉假象的消除能力。以高精度速度建模为基础,对高丰度含气区转换波地震剖面时深转换方法及流程进行了探索,并用实例说明利用声波测井速度建立的速度场可以对转换波地震资料进行时深转换,转换后的深度域剖面上的同相轴下拉现象得到了校正,可以在一定程度上消除这种时间域里的构造塌陷假象,并在此基础上分析了造成含气区同相轴下拉现象的原因,提出了提高柴东地区多波地震勘探资料品质及应用效果的改进措施。

Structure reconstruction with PS wave seismic data from high abundance gas fields

Because of the gas chimneys caused by high abundance of gas,seismic reflection events on P wave seismic sections have some special phenomena,such as drop down,lower frequency,and image blurring.Though the imaging quality of PS wave seismic data has been improved significantly,the drop down phenomenon of PS wave seismic reflection events still exist.To further enhance the imaging quality of gas fields,we transformed the PS wave seismic data from time domain to depth domain to verify the ability of PS wave seismic data in eliminating the artifacts in depth domain.The time depth conversion of PS wave data is based on a high precision velocity model.We demonstrated the time depth conversion of the PS seismic data with a velocity model built from acoustic logs.The drop down phenomenon is removed to a certain extent on PS wave seismic sections in depth domain.