摘要
介绍了根据VSP资料逐层递推反演地层速度的一种方法,其主要特点是将直达波射线的传播路径分为直线传播和折线传播,利用VSP资料从上到下反演出各个地层的层速度。通过matlab程序设计五层水平介质模型,然后运用射线追踪法分别对三种井源距(300、1500、3 000 m)合成VSP记录。将两种方法的反演结果与模型数据比较,发现直线法适用于小井源距,折线法适用于小、中、大各种井源距;同时折线法的运行时间相比直线法长,但折线法受初至拾取误差影响较小,抗干扰能力强。
This paper reports a method for inversing interval velocity layer by layer according to VSP data,whose main feature is that the path of spread rays will be divided into linear transmission and refraction transmission,and then the interval velocity is inversed from top to bottom with VSP data.5 layers level medium model is designed on the basis of matlab,and then the ray tracing method is used to synthesize VSP records for three kinds of well-source distance（300 m,1500 m,3000 m）.A comparison of the inversion results of the two methods with model data shows that the linear method is applicable to the small well-source distance,and refraction method is applicable to all kinds of well-source distance.In addition,the running time of the refraction method is longer than that of the linear method,but the refraction method could only be weakly influenced by the error of first arrive,and its capability against interference is strong.
出处
《物探与化探》
CAS
CSCD
2012年第2期242-245,共4页
Geophysical and Geochemical Exploration
关键词
VSP
层速度反演
射线追踪
VSP； interval velocity inversion； ray tracing
