基于Biot-Rosenbaum理论及动态渗透率的井中声场计算  

Calculation of the borehole acoustic field based on biot-rosenbaum theory and dynamic permeability

作　　者：岳崇旺[1,2] 王祝文[2] 范英 刘伟 孟波 伍东 

机构地区：[1]长安大学地质工程与测绘学院,西安710054 [2]吉林大学地球探测科学与技术学院,长春130026 [3]中油长城钻探录井公司,盘锦124010 [4]中油长城钻探测井公司,盘锦124010

出　　处：《地球物理学进展》2011年第3期1057-1063,共7页Progress in Geophysics

基　　金：国家自然科学基金项目(40874059)资助

摘　　要：井孔声场的二维谱是井孔声场在频率波数域内与地层性质和井眼条件有关的地层滤波函数在频率和波数域内的分布,它可以直观的表现声波场在地层中的传播特征.利用二维谱可以直观的考察声波在地层井孔中的传播特征.为了研究孔隙介质中的井孔声场的传播,考察孔隙介质中的井孔声场传播特征,在Biot-Rosenbaum理论模型基础上引入了Johnson动态渗透率近似计算公式,在波数域和频率域内数值计算了不同地层条件下的声场二维谱和井轴上一点接收到的理论声压波形,考察了地层性质对的声波传播模式的影响.从不同地层渗透率的井孔声场二维谱可以看出斯通利波对渗透率的变化敏感,其频率范围和幅度衰减均受渗透率的影响.渗透率越大,斯通利波衰减越快,斯通利波的频率范围也越低。从不同粘滞系数地层计算出的井孔声场二维谱可以看出斯通利波随粘滞系数的变化,粘滞系数越大,斯通利波的衰减越少,其频率范围也越大.Acoustic logging is a general method in oil and gas exploration. Studying the problems on mode waves propagating in a cylindrical borehole embedded in fluid-saturated poroelastic formation is necessary. The two- dimensional spectrum is the borehole acoustic field value in the frequency and wavenumber domains. It can be used to describe the characters of acoustic wave propagation in boreholes embedded in different formations. In order to study the characteristics of acoustic wave propagation in the cylindrical borehole embedded in fluid-saturated poroelastic formation, this paper calculated numerically, the two-dimensional spectrum of different formations. In the procedure the concept of Johnson＇s dynamic permeability was introduced into the theory of Biot-Rosenbaum. Furthermore, the receiving acoustic pressure waveform was also calculated numerically. From the calculated two dimensional spectrum with different permeability it can be seen that Stoneley wave is sensitive to the permeability, and the ranges of the frequency and amplitude of the Stoneley wave are influenced by the permeability. The greater permeability is, are the more attenuation of Stoneley wave and the lower range of the frequency. From the calculated two dimensional spectrum with different viscosities it can be seen that Stoneley wave varies with the viscosity. The more viscosity is, are the less attenuation of Stoneley wave and the higher range of the frequency.

关 键 词：孔隙介质 井中声场 动态渗透率 二维谱 

分 类 号：P631[天文地球—地质矿产勘探]