地震波形分析技术在川西新场地区沉积微相研究中的应用

摘要

In the seismic sedimentology studies,there are still absence of effective technical means to depict the nature and anisotropy of geologic bodies.Based on the characteristics of fast changing sedimentary facies and strong heterogeneity of Upper Triassic Xujiahe Formation (T3x) in West Sichuan,taking the seismic sedimentology as the main idea,and using seismic forward modeling technology and well-seismic calibration,this paper establishes a seismic waveform recognition mode of different sedimentary microfacies in Tax4-9 sand layer.The comparison and analysis of different seismic attributes and the verification of drilling wells reflect that the high-order statistics analysis is more sensitive to seismic reflection waveform change and can depict the nature of sand bodies.The skewness attribute can effectively reflect the seismic waveform changes of the different sedimentary microfacies.Then,one can depict and predict the superimposed river course favorable for T3x4-9 sand conglomerate reservoir development.%地震沉积学研究中仍缺乏对地质体性质及非均质性刻画的有效技术手段.针对四川盆地西部新场地区上三叠统须家河组(T3x)沉积相交化快、非均质性强的特点,以地震沉积学为主体思路,利用地震正演模拟技术及井-震标定,建立了T3x4-9砂组不同沉积微相的地震波形识别模式.通过不同地震属性的对比分析及钻井验证,反映高阶统计量分析技术对地震反射波形变化更具有敏感性,能够对砂体性质进行刻画.其中扭度属性能够有效地反映出不同沉积微相的地震波形变化,进而可以对新场地区T3x4-9砂组有利于储层发育的砂砾岩叠置河道进行刻画和预测.