一种基于拟相位信息目标泛函的反射波波形反演方法（英文）

发布时间：2019-06-18 12:02

【摘要】：反射波波形反演(RFWI)通过交替更新模型的中低波数和高波数成分,为传统的全波形反演(FWI)提供较为准确的初始速度场。但是由于低频信息的缺失和振幅信息的复杂性,传统的反射波波形反演存在极强的非线性。将振幅与相位信息的分离能够有效提高RFWI的线性程度,然而传统的相位计算方法具有严重的相位跳变(wrapping)问题。基于此,本文首先给出一种拟相位信息的计算方法,利用地震数据的包络信息,以避免传统相位信息的跳变问题。然后利用拟相位信息构建反射波波形反演的目标泛函,并给出相应的伴随震源和梯度表达式。理论分析证明了拟相位信息的计算方法能够保证相位信息的稳定和准确性,并且基于拟相位信息的目标泛函具有更广的全局收敛域。将本文方法应用到部分Sigsbee2A模型并与传统的目标泛函对比结果表明:与传统的全波形反演方法相结合,新的RFWI能够在初始模型不准确情况下得到较为准确的反演结果。除此之外,本文方法对含噪音数据和低频数据缺失情况具有一定的适用性。
[Abstract]:The reflected wave waveform inversion (RFWI) provides a more accurate initial velocity field for the traditional full waveform inversion (FWI) by alternately updating the low wavenumber and high wavenumber components of the model. However, due to the lack of low frequency information and the complexity of amplitude information, the traditional reflected wave waveform inversion has a strong nonlinear. The separation of amplitude and phase information can effectively improve the linearity of RFWI. However, the traditional phase calculation method has a serious phase jump (wrapping) problem. Based on this, this paper first presents a calculation method of quasi-phase information, which makes use of the envelope information of seismic data to avoid the jump problem of traditional phase information. Then the target functional of reflected wave waveform inversion is constructed by using quasi-phase information, and the corresponding expressions of adjoint source and gradient are given. It is proved by theoretical analysis that the calculation method of quasi-phase information can ensure the stability and accuracy of phase information, and the target functional based on quasi-phase information has a wider global convergence domain. The proposed method is applied to some Sigsbee2A models and compared with the traditional target functional. The results show that the new RFWI can obtain more accurate inversion results when the initial model is inaccurate combined with the traditional full waveform inversion method. In addition, this method has certain applicability to the absence of noise data and low frequency data.
【作者单位】：中国石油大学(华东)地球科学与技术学院;海洋国家实验室海洋矿产资源评价与探测技术功能实验室;卡尔加里大学数学与统计学系;莱斯大学地球科学系;
【基金】：jointly supported by the NSF(Nos.41104069 and 41274124) the National 973 Project(No.2014CB239006) National Oil and Gas Project(Nos.2016ZX05014001and 2016ZX05002) the Tai Shan Science Foundation for The Excellent Youth Scholars
【分类号】：P631.4

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