横向各向同性(VTI)介质井孔斯通利波声弹效应研究

Acoustoelastic Effects on Stoneley Waves in a Fluid-filled Pressurized Borehole in a Transverse Isotropic Formation

发展了建立在地层本征状态为各向同性介质假定下的现行井孔声弹性理论,就井外为横向各向同性(VTI)、具有9个独立三阶弹性模量的介质,水平面内受双轴应力作用下,给出了一个简洁的与井内压力与应力之和有关的井孔Stoneley波声弹方程,并数值考察了受井孔静水压力和井外水平双轴应力作用时灵敏系数随频率的变化及具有各向同性的三阶弹性模量对Stoneley波频散曲线的影响。

This paper investigates acoustoelastic effect on Stoneley wave in a fluid-filled pressurized borehole surrounded by a transversely isotropic elastic solid(VTI) in presence of biaxial stresses,which has nine independent third-order elastic constants,develops a simplified formation formula that explicitly expresses the dependence of velocity dispersions on the sum of biaxial stresses,and seven independent third-order elastic constants,and presents the numerical results for the frequency dependence of sensitivity coefficients and velocity dispersion due to the presence of stresses and isotropic third-order elastic constants.