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声波测井中,在第二临界角下获得的沿井壁滑行的滑行波不是横波,而是类瑞利波。横波属于畸变波,是畸变波的特例,由各向同性均匀固体介质中的畸变波所需满足的条件,可知沿该固体以真空为界的表面滑行传播的畸变波位移振幅,要依负指数函数关系随深度而减弱。依此滑行畸变波的位移表达式和该固体表面处的边界条件,可以分析出横波作为畸变波的特例,不能存在于该固体表面附近,不能沿该固体表面滑行。由于这个论断可以近似地适用于裸眼井中井壁附近的情况,从而能够得出横波未能沿井壁滑行的理论解释。横波声速与类瑞利波声速在数值上的差别是明显的,不容忽视,不宜混淆。
In sonic logging, the gliding wave that glides along the borehole wall obtained at the second critical angle is not a shear wave but a Rayleigh wave. Transverse waves are distorted waves and are special cases of distorted waves. According to the conditions that the distorted waves in isotropic homogeneous solid medium must satisfy, it can be seen that the displacement amplitude of distorted waves propagating along the surface of the vacuum-borne solid boundary depends on the negative exponent The relationship between functions decreases with depth. Based on the displacement expression of the glide wave and the boundary conditions at the solid surface, the shear wave can be analyzed as a special case of the distorted wave and can not exist near the solid surface and can not glide along the solid surface. Since this argument can be applied approximately to the condition near the borehole wall in an open-hole well, a theoretical explanation of the failure of the shear-wave to slide along the borehole wall can be derived. The difference between the velocity of transverse wave and the velocity of Rayleigh wave is obvious, so it should not be confused.