基于非稳态匹配的角度域叠前道集去调谐方法

地层调谐效应改变了不同偏移距处反射波的干涉模式,使得远偏移距数据振幅和频率信息发生畸变,将会降低AVO/AVA分析及反演的置信度和分辨率.文中首先给出了调谐作用下反射波合成记录,通过正演模拟说明了调谐对叠前道集的影响.考虑到不同地层厚度下调谐效应的差异性,借助局域Lamoureux窗实现地震数据的自适应分解,利用角度数据之间的差异,构建了角度域地震数据的非平稳匹配目标函数,形成了非平稳匹配去调谐方法,实现了叠前道集的振幅和波形拉伸校正.本文方法在实际应用中取得了较好的效果,能够有效地改善大角度地震数据品质,为储层预测与流体识别奠定了数据基础.

A non-stationary match method for detuning pre-stack seismic gather in incident angle domain

Under the layer tuning effects,the interference patterns are changing with different offsets of seismic reflections and,as a result,the amplitude and frequency information is distorted,and this will worsen the confidence and resolution of the AVO/AVA analysis and inversion.Firstly,the authors gave the seismic reflection equations with tuning effects,with the modeling examples illustrating characteristics of the tuned seismic gather.Secondly,in consideration of the different detuning levels caused by the changing layer-thickness,the authors coastructed the self-adaptive non-stationary decomposition via local Lamoureux time window.Finally,the authors built the non-stationary cost function for matching seismic angle gather to correct the amplitude and waveform stretch.Field application demonstrates the feasibility of the proposed method in improving the quality of seismic data with larger angle,with the high-quality data causing the success of reservoir prediction and hydrocarbon identification.