道集品质对叠前AVO/AVA同时反演的影响

The effects of seismic data conditioning on pre-stack AVO/AVA simultaneous inversion

用于叠前反演的地震道集必须具备高的质量。针对辽河西部凹陷兴隆台地区叠前地震资料特点,本文首先采用多次波去除、随机噪声压制和道集拉平等修饰性处理手段提高道集品质,使得地震道集的AVO特征与合成记录的AVO特征一致;与原始记录相比,从处理后的道集中提取的地震子波在0～42Hz有效频段内比较稳定,目标区域反演剩余量减小了20%以上,反演所得的纵横波阻抗数据交会结果比较集中,而且适合岩性识别,能比较准确地确定目标储层范围,进而说明地震资料品质对叠前反演效果的重要性。

Seismic data used for pre-stack inversion should have high quality.To improve the seismic data quality of Xinglongtai area,Liaohe western sag,and make the AVO anomaly characterizes of gathers same as synthetics,this paper employs three conditioning processes—multiple removal,random noise attenuation,and gather flattening.After data conditioning processing,a comparison of wavelets extracted separately from the raw and conditioned angle stacks found amplitude and phase spectra to be much more stabilized in 0~42Hz.The seismic/synthetic inversion residuals of target area shows at least 20% drop in amplitude.Finally,the AI/SI cross-plot shows a much more compact signature that is more available for lithology discrimination and precise reservoir prediction.All these improvements show the importance of data quality on pre-stack inversion.