VTI介质中基于降阶补偿处理的旅行时计算方法  

A method of traveltime calculation based on descending order compensation processing in VTI medium

作　　者：魏建[1] 孙祥娥[1] WEI Jian;SUN Xiang′e(College of Electronics and Information Engineering,Yangtze University, Jingzhou, Hubei 434020,China)

机构地区：[1]长江大学电子信息学院,湖北荆州434023

出　　处：《山东科技大学学报（自然科学版）》2022年第1期86-91,共6页Journal of Shandong University of Science and Technology(Natural Science)

摘　　要：基于泰勒级数的旅行时计算公式是一种最基本的旅行时估计方法,针对其在VTI介质中计算的旅行时存在一定误差、与正演旅行时差距较大的问题,提出一种基于降阶补偿(DOC)处理的旅行时计算方法。首先利用泰勒级数展开将常规旅行时近似方程的偏移距阶数提高到6阶,然后利用降阶近似对其偏移距的6次方项进行降阶处理来满足其在理论上的使用要求。为了改变降阶处理无法体现泰勒级数高阶中“高”的意义的现状,将近似补偿方法应用到旅行时计算中,构建了应用于VTI介质中的基于降阶补偿的旅行时计算方法。测试结果显示:与移位双曲线法、广义时差近似法和微扰理论法相比,DOC方法在提高旅行时计算准确性的基础上进一步缩短了与正演旅行时的差距。DOC计算方法的提出为旅行时计算提供了一种新思路,也为地震信号与数据处理的后续操作提供参考。The travel time calculation equation based on Taylor series is one of the most basic methods in estimating travel time.For the travel time calculated by this method,there are still some errors and a large gap from the forward time in VTI(transverse isotropy with vertical symmetry axis)medium.Given this situation,a new approximation method of travel time calculation based on descending order compensation(DOC)was proposed in this paper.By using the Taylor series expansion,the offset order of the conventional approximation equation was increased to the sixth-order.Then,the sixth-order term of the offsets in the sixth-order travel time equation was processed by the method of descending order to meet the theoretical requirements.For the processing method's inability to reflect the meaning of the higher-order approximation,the approximation compensation method was used in travel time calculation to obtain an accurate and effective calculation equation for the travel time applied in VTI medium.The results of the model experiments show that compared with the shifted hyperbolic equation approximation method,the generalized moveout approximation method and the perturbation theory method,the DOC approximation method further shortens the gap from the forward time while improving the accuracy of the calculated travel time in VTI medium.The proposed method provides a new idea for the research in this field and lays a foundation for the subsequent operations of seismic signal and data processing.

关 键 词：旅行时 降阶补偿处理 泰勒级数 VTI 时差 

分 类 号：TE19[石油与天然气工程—油气勘探]