散射波模拟方法及影响因素分析  

Scattered Wave Simulation Method and Analysis of Influencing Factors

作　　者：滕厚华[1] 韩站一[1] 赵硕 叶峻林 丁仁伟 TENG Houhua;HAN Zhanyi;ZHAO Shuo;YE Junlin;DING Renwei(Geophysical Exploration Research Institute of Shengli Oil field Company of Sinopec,Dongying 257022,China;College of Earth Science and Engineering,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]中国石油化工股份有限公司胜利油田分公司物探研究院,山东东营257022 [2]山东科技大学地球科学与工程学院,山东青岛266590

出　　处：《CT理论与应用研究（中英文）》2024年第6期761-771,共11页Computerized Tomography Theory and Applications

基　　金：中国石油化工股份有限公司项目(准噶尔盆地石炭系地震处理关键技术研究(P21077-3))。

摘　　要：在复杂地质条件下,特别是小断层和裂缝发育的情况下,通常无法利用反射波进行准确探测。将小构造引起的散射波用于地震勘探,有利于提高小尺度离散地质体勘查资料的信噪比和分辨率。本文从理论模拟方法出发,分别推导用于描述散射波传播的时距曲线方程和基于Born近似的波动方程;利用快速步进法对程函方法的求解,通过设计相应的模拟测试,对散射波描述的精度与影响因素进行分析。测试结果表明,传统的时距曲线方程可以给出准确的散射波满足的时距关系,但结合程函方程对其进行成像时并不准确;而基于Born近似的波动方程可以实现对散射波的准确模拟。此外,Born近似中引入的散射体和散射势的假设对最终的模拟结果影响并不大;在保证正演稳定的前提下,子波主频越高,对散射波的描述越准确。In complex geological conditions,especially in the case of small faults and fractures,it is often impossible to use reflected waves for accurate detection.An alternative method is the use of the scattered waves caused by these small structures for seismic exploration.However,with the conventional description and utilization of scattered waves based on time–distance curves,it is difficult to meet the current needs of high-precision exploration.Therefore,starting from the theoretical description method,this study deduces the time–distance curve equation and the wave equation based on Born approximation for describing the propagation of scattered waves.Then,combined with the respective numerical simulation methods,namely,the fast step method to solve the program function method and the finite difference method to simulate the wave equation,the accuracy and influencing factors of the scattered wave description are analyzed.Finally,the corresponding simulation test is designed,and the numerical model is used to further show that the traditional time–distance curve equation can give the accurate time–distance relationship satisfied by the scattered wave,but it is not accurate when combined with the function equation for imaging.The wave equation based on Born approximation can achieve accurate simulation of scattered waves.The resulting assumptions of scatterers and scattering potential have little effect on the final simulation results.Under the premise of ensuring the stability of forward modeling,the higher the dominant frequency of the wavelet,the more accurate is the description of the scattered wave.

关 键 词：散射波 波动方程 射线方程 数值模拟 

分 类 号：O242[理学—计算数学] P631.4[理学—数学]