Low-frequency Stoneley wave reflection in irregular borehole has been discussed. The essential physics of the low-frequency Stoneley waves are captured with a 1 -D model. A mass-balance boundary condition and a propagator matrix are used to express Stoneley-wave interactions with the borehole irreeularities. The simula tion results suggest that the borehole irreeularities can cause more distinguishing Stoneley-wave reflections than the elastic properties of formation. There is an important significance to the actual logging interpretation that should pay attention to the borehole irreeularities (washout) ,when using stoneley wave interpretation fracture. Comparing syn thetic records with an actual field records,the fracture can be identifyed.%讨论了不规则井眼内低频斯通利波反射.利用简化的一维模型研究低频斯通利波的物理性质.用质量平衡边界和传播矩阵表示井眼不规则度与斯通利波的相互关系.模拟结果表明,井径变化比岩性变化产生更强的斯通利波反射.这对实际测井资料解释有重要意义,即斯通利波解释裂缝时,应注意井径变化的影响.将合成模拟的波形与实测波形比较,可以识别裂缝的存在.
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