【摘要】 油气勘探逐渐向深层、深海、非常规、隐蔽岩性油气藏的勘探推进。高精度地震波成像提供的宽带反射波成像结果仍是目前进行油藏描述和含油气性评价的最核心的基础数据。但是随着油气勘探目标的复杂化，常规的地震波构造成像已经无法满足当前油藏描述和含油气性评价的要求，定量的弹性参数反演并结合岩石物理转化为物性参数估计逐渐成为地震波成像的目标。因此提出了特征波反演(CWI)+宽带波阻抗建模(WBIM)的技术路线。宽带波阻抗模型的背景部分决定了三维全空间上岩性变化的趋势；宽带反射系数决定了波阻抗在三维全空间上岩性的局部跃变。采用特征波反演(CWI)方法构建背景速度模型，然后利用基于空间散乱数据约束重构方法构建背景密度，从而得到背景阻抗。宽带反射系数的生成采用保真成像道集生成、最佳照明优选的保真叠加、弱旁瓣反射系数重构以及井震结合的反射系数定量标定的技术组合。利用背景阻抗和保真高分辨的宽带反射系数，求解约束优化反问题，得到宽带波阻抗模型，它反映了地下岩石性质在三维全空间上的变化。上述基于信息融合的宽带波阻抗重构方法规避了全波形反演宽带波阻抗的不收敛性，使其适用于陆上深层超深层、非常规和岩性油气藏的勘探。从宽带反射系数、宽带波阻抗及地震分辨率的基本物理含义的分析入手，对背景阻抗模型和宽带反射系数对宽带阻抗重构结果精度的影响进行分析，数值分析结果表明，定量、保真、高分辨(即弱旁瓣窄主瓣)的宽带反射系数是宽带波阻抗建模精度的核心影响因素，保真高分辨率地震波成像应将弱旁瓣窄主瓣反射系数作为成像目标，定量的弱旁瓣窄主瓣(角度)反射系数本身应是非常规、岩性、隐蔽油气藏描述与评价的重要基础数据。弱旁瓣反射系数的形成严重依赖低频激发、低频接收所包含的低中频数据，因此岩性油藏勘探时必须重视、保护低中频数据。更多还原

【Abstract】 Oil and gas exploration has gradually advanced towards deep layers, deep sea, unconventional and lithologic reservoirs.High-precision seismic wave imaging, providing broadband reflection coefficient imaging results, remains the fundamental data for reservoir characterization and hydrocarbon evaluation.As exploration targets have become more complex, elastic parameter inversion is combined with rock physics to obtain petrophysical parameters for quantitative evaluation.A feasible route for quantitative reservoir characterization is the combination of Characteristic Wave Inversion(CWI) and Wide Band Impedance Modeling(WBIM).The low-frequency information provided by the background wideband impedance determines the trend of the fused impedance, which in turn determines the lithologic variation in the three-dimensional space.Wide band reflection coefficients provide high-frequency variations in impedance within localized regions of the three-dimensional space.This paper starts with an analysis of the basic physical meanings of wide band reflection coefficients, wide band impedance, and seismic resolution, and analyzes the impact of background impedance and wide band reflection coefficients on the reconstruction of wide band impedance.Detailed numerical experiments demonstrate that reducing the sidelobes of the limited-bandwidth reflection coefficients is one of the key technical challenges for high-resolution seismic imaging.Based on this, it is crucial to focus on the mid-to-low wavenumber range.To further improve resolution, higher wavenumber components need to be incorporated, provided that the energy of the low-to-medium wavenumber components is dominant.The ultimate goal is to address the key technical issues and solutions in information fusion-based, lithology-oriented, and quantitative seismic wave image.更多还原