导　　师： 孟凡顺

学科专业： 081802

授予学位： 硕士

作　　者： ;

机构地区： 中国海洋大学

摘　　要： 随着我国石油和天然气工业的迅速发展，油气勘探的精度和难度也在不断的加大。这就要求我们必须深入了解地震波在地下介质中的传播规律，以便我们能更加准确的进行地下油气的勘探。地震波数值模拟技术是目前地震勘探领域人们研究地震波传播规律的一个重要手段。传统地震波数值模拟技术，一般假设地层介质是均匀和完全弹性的，在这种假设情况下，理论上的研究结果与地震波在地层中传播时观测到的实际记录很大的差别。这是因为地震波在实际地层中传播时由于地层的粘滞性会损耗地震波能量，并且越往深层这种吸收衰减越严重。研究表明，在粘弹介质中能够很好的反映出吸收衰减现象，这表明利用粘弹介质更模拟实际地层更为合理。 本论文主要探讨和研究了粘弹性介质中地震波传播的数值模拟方法及其吸收衰减规律。主要研究内容及取得主要成果有以下几点： 1、以粘弹介质的基本性质为基础，构造出了麦克斯韦尔介质模型、开尔芬介质模型、标准线性粘弹性介质模型三种常见的粘弹性介质模型并给出了他们本构方程，并详细分析了地震波的吸收衰减参数及其相互之间的关系。 2、在地震波基本理论的基础上，推导出了常规网格和交错网格高阶有限差分的离散差分格式，并对地震波数值模拟中存在的几个问题进行了讨论，如震源激发方式、稳定性条件分析以及吸收边界条件的选取等。 3、从粘弹性介质的基本概念入手，推导了粘弹性介质的波动方程，从理论上分析了地震波在粘弹性介质中的吸收和衰减规律。对粘弹性介质的速度——应力方程进行了交错网格高阶有限差分求解，实现了地震波在粘弹性介质中传播的数值模拟。 4、从纵波为无旋场和横波为无散场的思路出发，推导了满足此条件的粘弹 With the rapid development of oil and gas industry in China, The precision anddifficulty of oil and gas exploration are increasing. This requires that we mustunderstand the propagation rules of seismic wave in the underground medium clearly.Seismic numerical simulation technology is an important means which is used tostudy seismic wave propagation rules in the field of seismic exploration. In traditionalseismic wave numerical simulation technology, we usually suppose that the earthmedia is homogeneous and completely elastic. Under the condition of this assumption,the theoretical research results are very different with real results. The reason is thatwhen the seismic wave propagates in real formation, the viscosity of formation causethe loss of seismic wave energy. And in the deeper formation the loss is more serious.This anelastic behavior of real earth media can be described well by a viscoelasticmodel． In this paper，the numerical simulation method of viscoelastic model and the lawof attenuation about seismic wave were mainly researched and studied．The researchcontents and results mainly includes the following aspects: 1. On the basic properties of viscoelastic medium, three common viscoelastic mediummodels are constructed and their constitutive equation is presented. In this paper,several absorption and attenuation parameters of seismic wave and their mutualrelationship are analyzed in detail. 2. Based on the theory of seismic wave, the regular grid and high order staggered gridfinite difference methods are deduced and several problems in the seismic wavenumerical simulation are discussed, such as seismic source, the stability conditionanalysis and the selection of absorption boundary conditions, etc. 3. In this paper，absorption and attenuation of seismic wave in viscoelastic media havebeen analyzed from the theory through viscoelastic wave equation which were derived from the basic concept of viscoelastic media．The elastic wave equation inviscoelastic media was solved by high order s

关 键 词： 粘弹介质 交错网格 波场分离 吸收衰减

领　　域： [天文地球] [天文地球]