变速成图速度场随机建模的不确定性分析

Analysis of stochastic velocity field modeling uncertainty for variable-velocity mapping

在速度建模和变速成图中用到的确定性方法不能对深度域构造图的不确定性进行明确表征,也不能直接评价这种确定性方法的可靠性。为此,以随机模拟的理论与方法为基础,主要研究了基于概率场模拟和序贯高斯模拟的速度场随机建模方法,并对随机模拟获得的多次实现之间的不确定性进行了统计分析。实际应用结果表明:在空间上条件数据点处速度没有差异,在非条件数据点处速度具有不确定性;序贯高斯模拟的速度场表征的不确定性比概率场模拟的速度场小。

Deterministic methods used in velocity modeling and variable-velocity mapping cannot be used to characterize uncertainty of depth structure maps, and the reliability of these methods cannot be directly evaluated. Therefore, a stochastic velocity modeling method based on the theory of stochastic simulation is put forward to analyze probability field simulation and sequential Gauss simulation. Statistical analysis on the uncertainty of multiple realizations obtained by stochastic simulation is carried out. Application tests show that there is no velocity difference at conditional data points in the space, and velocity at non-conditional data points is uncertain. Velocity field uncertainty obtained by sequential Gauss simulation is smaller than that obtained by probability field simulation. © 2016, Editorial Department OIL GEOPHYSICAL PROSPECTING. All right reserved.