页理对测井响应及岩石力学参数影响分析

Effect analysis of shale bedding on well logging response and rock mechanics parameters

页岩页理通常都非常发育,目前有关页理对测井响应特征及岩石力学参数有何影响的相关研究较少。本文从直井与水平井的测井响应特征对比发现,声波时差受井型的影响较大,直井声波时差远大于水平井测值,由此设计实验并辅以数值模拟,分析页理密度与角度对测井响应及岩石力学参数的影响。实验与数值模拟结果表明,声波速度与杨氏模量、泊松比均受页理密度、角度的影响。声波速度与杨氏模量随页理密度增大而减小,泊松比在页理角度小于45°时随页理密度增大而减小,当大于45°时,变化规律较复杂。页理角度为45°是杨氏模量随页理角度变化的分界线,小于45°时,杨氏模量随页理角度增大而减小;大于45°时,杨氏模量随页理角度增大而增大。

Shale bedding is usually wery developed.At present,little research has been done on the influence of shale bedding on log response characteristics and rock mechanics parameters.By comparing the logging response characteristics of vertical with horizontal wells,it is found that the acoustic slowness,much larger in vertical wells than in horizontal wells,is greatly affected by well type.So experiments are designed and numerical simulation is carried out to analyze the influence of shale bedding density and angle on logging response and rock mechanics parameters.The results of experiment and numerical simulation show that the velocity of acoustic wave,Young s modulus and Poisson s ratio are affected by its density and angle.Sound velocity and Young s modulus decrease with shale bedding density.Poisson s ratio decreases with the increase of shale bedding density when its angle is less than 45 degrees,but the variation law is more complex when its angle is greater than 45 degrees.45 degrees is the demarcation line of Young s modulus changing with angle.Young s modulus decreases with the increase of angle when it is less than 45 degrees,conversely will increases.