全波声测井理论研究中的声源模型及其影响  

THE SOURCE MODEL AND ITS EFFECT ON FULL WAVEFORM ACOUSTIC LOGS

作　　者：余仕成[1] 伍先运[1] 王克协[1] 董庆德 

机构地区：[1]武汉化工学院,吉林大学物理系

出　　处：《地球物理学报》1995年第A01期232-241,共10页Chinese Journal of Geophysics

摘　　要：首先推导了弹性柱源和流体环源模型下，井外地层为双相介质时的井内外声场，将它们与点源和刚性柱源模型下的井内外声场作了比较，并把这４种声源模型条件下的井内外声场的数学表达式写成统一形式．弹性柱源模型下的井内外声场可以分别过渡到刚性柱源、流体环源和点源模型下的井内外声场．理论分析和数值计算表明，不同声源模型对各分波的相对幅度、导波的频散和激发特性都会产生影响，对纵波首波和横波首波的速度没有影响；在弹性柱源模型下，存在一类纵模式波．The fields both inside and outside borehole excited by a elastic cylindrical source and a circle fluid source, are derived in two phase medium, and are compared with the fields excited by a point source and a rigital cylindrical source. The fields excited by the four types of sources are expressed in the uniform formation. The field excited by a elastic cylindrical source can be changed into the fields excited by a point source, a circle fluid source and a rigital cylindrical source, respectively. It shows from theoretical analysis and numerical computation that the relative amplitude of wave components, dispersion and excitation of guide waves are all affected by the source models, and the velocities of P-wave and S-wave are hardly affected by them. It exists a compressional model wave which is excited by a elastic cylindrical source.

关 键 词：声源模型 频散 激发 全波波形 声波测井 

分 类 号：P631.814[天文地球—地质矿产勘探]