浅谈地震剖面的假象识别  

Detecting artifacts in seismic profiles

作　　者：周华伟 邹志辉[1] 李哲豪 Zhou Hua-Wei;Zou Zhihui;Li Zhehao(Key Lab of Submarine Geosciences and Prospecting Techniques.MOE,College of Marine Geosciences,Ocean University of China,Qingdao 266100,China;Department of Earth&Atmospheric Sciences,University of Houston,Houston,Texas,USA 77204-5007)

机构地区：[1]中国海洋大学地球科学学院海底科学与探测技术教育部重点实验室,青岛266100 [2]美国休斯顿大学地球与大气科学系,美国休斯顿,TX 77204-5007

出　　处：《地球与行星物理论评》2021年第1期45-53,共9页Reviews of Geophysics and Planetary Physics

基　　金：国家自然科学基金资助项目(41230318);中央高校基本业务费资助项目(201964017)。

摘　　要：假象识别是正确解释地震剖面的前提,也是描述地震成像保真度(精准度)的主要标准之一.本文通过分析反射地震剖面实例,对几种常见的、易被误解的地震成像假象的特征进行了分类阐述,提出基于成因识别地震成像假象的思路.从地震剖面成像过程来看,假象的成因包括信号误判、成像畸变和波速模型误差这三个主要因素.许多不易被识别的假象起源于地震数据处理成像过程中对信号的误判,犹如“张冠李戴”;成像畸变假象的根源包括成像照明度、资料频宽和方法假设等方面的缺陷,造成抹痕等成像结果畸变假象;当地震波速度模型误差较大时,地震成像结果不仅会出现成像位置错误,还可能在波阻抗不连续点出现散射拖尾假象.因此,衡量地震成像精准度的标准应包括成像结果的分辨率、位置准确度和假象识别三个要素.这些要素相互影响,因此应该根据研究目标和实际情况,综合评判地震成像中假象的影响.Detecting imaging artifacts is a precondition for interpreting seismic profiles,as well as one of the fidelity(accuracy)measures for all seismic images.Based on field seismic reflection profiles,this paper analyzes some common and often miss-interpreted seismic imaging artifacts,and proposes to detect the artifacts through analyzing their origins.From the perspective of seismic imaging process,the origins of seismic imaging artifacts include three main factors:mistaking the signals,imaging distortions and errors in the reference velocity model.Many deceiving artifacts are originated by mistaking the signals in the processing and imaging processes.The imaging distortions are due to insufficiencies in seismic illumination,data frequency bandwidth and assumptions of the imaging methods,leading to smearing and other imaging distortion artifacts;With an erroneous reference velocity model,seismic images may show not only position errors,but also diffraction artifacts at discontinuous positions of seismic impedance.Hence,the measurable elements of the fidelity of seismic images should include resolution,position accuracy and artifact detection.These elements are connected with each other,thus should be evaluated jointly in detecting artifacts,according to the given study objectives and resources available.

关 键 词：地震剖面 地震成像 假象识别 假象成因 精准度 

分 类 号：P315.3[天文地球—地震学]