原位土体中单孔横波测井的数值研究

原位土体中单孔横波测井的数值研究 English Version

Institute of Acoustics Nanjing University Institute of Acoustics Tongji University

摘要: 本文计算了在无限土体介质中的裸眼井中的偶极子源激发的弯曲模式声波的声场,计算了其相速度频散曲线和接收声波的波形图。计算结果表明用极低频率的信号能有效地激发出以井壁介质横波声速传播的弯曲波。设计了一种极低频率的偶极子换能器,利用该换能器在土体中作了现场测试,证明了该方法的可行性,这在单一井孔条件下测试土体中的原位横波声速有着极其重要的意义。
- 土体 /
- 横波测井 /
- 充液井孔 /
- 横波声速 /
- 原位 /
- 数值研究 /
- 弯曲波 /
- 单孔 /
- 接收波 /
- 速度频散
Abstract: Dispersion curves and synthetic waveforms which excited by dipole sources in a fluid-filled borehole surrounded by infinite soil are calculated. It shows the flexural modal waves which propagate at shear wave velocity may be excited at very low frequencies. At this require, a dipole transducer which works at very low frequencies has been designed. Measurements have been made in a soil well by this transducer, and it proves this method is correct and feasible. It has great importance to shear wave velocity logging in soil formation.