摘要
基于模型的波阻抗(速度)反演中,约束是不可缺少的,它可以有效地减少反演多解性和提高运算效率.国内外大量学者均详细论述了一些反演的约束手段,但对于地震道与地震道之间的约束,除了采用测井外推模式之外,就鲜有介绍,相同的约束条件直接应用于全部的地震道,不再变化,这样势必会增加运算时间和影响反演效果.针对这些问题,本文描述了一种地震相关性分段约束速度反演的方法,其目的在于增加内在的道与道之间的约束,主要采用了地震道的相关特征去优化约束条件与减少反演计算量.本文先分析了地震反演的不同内在约束方法,并利用地震的相关性去分段自动选择约束的强弱与范围大小,而不是在全部地震道反演中采用相同的约束参数,即可大大优化运算效率;其次设计两个数学模型进行反演验证,在反演效果比较符合实际的基础上,运算时间大大减少;最后引入中国东部某地区的实例对该方法进行检验,反演剖面上可以清楚观察出冲积扇的沉积特点,各期砂体清晰可见,便于追踪解释与储层预测,具有较高的分辨率与可信度.结果表明该方法是一种有利于提高反演效果和效率的方法.
Model-based impedance inversion method is usually used in practical work, but the model set can be infinite bandwidth. It is not limited by seismic records, so model-based inversion will bring multi-solution, In other words, forward theories record of different models coincide with the actual seismic records. In order to reduce this multi-solution, the inversion must be using a variety of constraints, so the constrained method determines the authenticity of the inversion solution, at the same time the accurate constraints can reduce the number of iterations, thereby enhancing the operational efficiency. Many scholars have discussed in detail some of the constraints method of seismic inversion, but rarely described in the constraint between seismic trace, most methods are used well logging extrapolation, this ignores the correlation characteristics of seismic trace, will increase the computing time inversion. For these issues, this paper describes a method about seismic correlation constrained velocity inversion, mainly uses relevant characteristics of seismic to optimize constraints and reduce the computation, when seismic correlation is strong that reduce constraints and the number of iterations, otherwise increase the constraints and the number of iterations, so this can reduce the inversion time and Improve the inversion effect. This paper first analyzes the different constraints of seismic inversion methods, and uses seismic correlation to select the strength of constraints and the range of constraints, but not in all seismic trace inversion uses the same constraint parameters, It can greatly optimize the efficiency of operations; Then we design two mathematical models to validate the inversion method, the conclusion indicates the results of inversion conform to actual results and this method can greatly reduce the computing time. Finally, we used the actual data in eastern China to test the method; the characteristic of alluvial fan deposition are very obvious in the Inversion profile, the period of sand is clearly visible, and has a certain resolution and reliability.
出处
《地球物理学进展》
CSCD
北大核心
2012年第1期326-334,共9页
Progress in Geophysics
基金
国家"973"计划项目(2009CB219505)资助
关键词
相关性
速度反演
约束
随机模型
seismic correlation, velocity inversion, constraint, stochastic model
