基于二维有限差分法的井径变化对补偿声波测井响应的影响  

Effect of borehole variations on borehole compensated sonic logging(BCSL) based on 2D finite-difference method(FDM)

作　　者：丛健生[1] 乔文孝[1] 

机构地区：[1]中国石油大学(北京)资源与信息学院

出　　处：《大庆石油学院学报》2008年第1期1-4,共4页Journal of Daqing Petroleum Institute

基　　金：国家自然科学基金项目(10534040);黑龙江省自然科学基金项目(A2004-03)

摘　　要：采用二维有限差分方法,模拟计算不同岩性和井径变化对补偿声波测井响应的影响,并采用二元线性回归方法给出了测井响应校正曲线.结果表明:地层岩性对补偿声波测井有一定影响.当井径变化时,补偿声波测井的补偿能力是不同的;当扩径井段半径不变时,随着扩径井段轴向长度增加,补偿能力开始逐渐变差;当补偿声波时差达到最大值时,补偿能力最差,然后补偿能力逐渐变好;当扩径或缩径井段轴向长度不变时,随着井半径增加或减小,补偿能力逐渐变差.实例证实,二元线性回归方法优于传统的算术平均法.The slowness time of BCSL was numerically calculated in different lithology of the formation and in borehole variations using 2D FDM.The correction curve of the slowness time was obtained using linear bivariateregression method.It was shown that the lithology of the formation can have certain effect on slowness time of BCSL.The compensated ability of BCSL is different when the borehole varies.When the diameter of the borehole is constant,the compensated ability is getting gradually worse with the increase of the borehole enlargement along the axis.The ability is the worst when the slowness time is the largest,then the compensated ability begins to improve gradually.When the length of the borehole enlargement or cave-in along borehole axis is constant,the compensated ability is getting worse with the increase of the diameter of the borehole enlargement or the decrease of the diameter of the borehole cave-in.The linear bivariateregression method in this paper is proved better than the method of traditional arithmetic average.

关 键 词：有限差分 补偿声波测井 井径变化 二元线性回归 补偿能力 

分 类 号：P313.3[天文地球—固体地球物理学]