摘要
地层品质因子是描述地层吸收衰减特性的重要参数之一。文中结合非弹性介质地震波传播衰减理论,借鉴各种地层速度的定义模式,分别定义了层品质因子、射线平均品质因子、以及三种平均品质因子和三种均方根品质因子;探讨了不同品质因子的差异及相互关系;同时给出了基于叠前与叠后地震资料进行层品质因子估算的递推算法。研究结果表明,地层品质因子与地层速度一样在剖面上具有成层分布的特点。射线平均品质因子是描述地震波沿不同射线路径传播的吸收衰减特性的最精确的参数之一,可以作为评价其他品质因子精度的重要指标。射线平均品质因子随炮检距的变化揭示了品质因子随炮检距变化(QVO)的内在本质。在常规地震勘探排列范围内,基于波垂直层面传播和类似平均速度形式定义的两种平均品质因子分别构成了射线平均品质因子的下限和近似上限值;视均方根品质因子较基于耗散率平方的时间加权均方根倒数和品质因子平方的时间加权均方根定义的两种均方根品质因子更具有实际应用价值。
Quality factor is one of the important parameters of describing the attenuation characteristics of formation.Combining with the attenuation theory on seismic wave propagation in inelastic medium and referencing to various formation velocity definition,layer quality factor,ray average quality factor,three average quality factors and three RMS quality factors are defined respectively.And the differences and mutual relationship among different quality factors are discussed.Meanwhile, based on pre-stack and post-stack seismic data, some recursion algorithms used to estimate quality factor are given.Research results show that formation quality factor has the same layer distribution characteristics as formation velocity.Ray average quality factor is the most accurate parameter describing formation absorption properties when seismic wave propagates along different ray path, which can be used as an important precision evaluation standard for other quality factor.And it reveals the essence of QVO for ray average quality factor variation with offset.In usual seismic spread length range,two kinds of average quality factors, which are defined according to the assumption that wave propagates vertical level and similar average velocity definition,form the lower and approximate upper limits of the rays average quality factor.Apparent RMS quality factor has more practical application value than other two RMS quality factors given by the inverse of root mean square of the weighted-by-time average of dissipation rate square and by the root mean square of the weighted-by-time average of quality factor square.
出处
《石油地球物理勘探》
EI
CSCD
北大核心
2013年第5期816-823,675-676+854,共8页
Oil Geophysical Prospecting
基金
河南理工大学博士基金项目(B2009-85)资助
