泥岩蚀变对声波测井影响的试验研究
|
摘要
通过泥岩岩样浸泡程度与声波时差响应的试验研究,揭示了2000m深度以下泥岩蚀变对声波时差测量的影响规律。结果表明,泥岩含水时的纵、横波速度均大于干岩样的速度,随着浸泡时间的增加,纵、横波速度逐渐增大,当达到一定数值时,纵、横波速度会随着泥岩浸泡时间的增加出现小幅下降,之后就趋于稳定,横波尤为明显。试验结果颠覆了泥岩被水浸泡后声速变小时差变大的一般性认识。试验结果对声波测井资料地震反演以及声波测井资料地质解释具有指导意义。
The influential law of shale erosion on acoustic logging measurement under the depth of 2000mwas presented through experimental study on acoustic transit time response of shale core samples with different soaked degrees.The study results indicate that the P wave velocity and shear wave velocity of shale are more than those of core samples with raised with the increase of shale soaked time when shale is water injected,but when the soaked time reaches a value,the velocity of P or S wave would slightly decrease with the increase of soaked time,and them it tends to stable,especially for S wave.However,velocity of shale after soaking is greater than dry shale samples whether P or S wave velocity.The experimental research subverts the general understanding that velocity decreases when shale is soaked by water.The result provides guidance for seismic inversion and geological interpretation of acoustic logging data.
The influential law of shale erosion on acoustic logging measurement under the depth of 2000mwas presented through experimental study on acoustic transit time response of shale core samples with different soaked degrees.The study results indicate that the P wave velocity and shear wave velocity of shale are more than those of core samples with raised with the increase of shale soaked time when shale is water injected,but when the soaked time reaches a value,the velocity of P or S wave would slightly decrease with the increase of soaked time,and them it tends to stable,especially for S wave.However,velocity of shale after soaking is greater than dry shale samples whether P or S wave velocity.The experimental research subverts the general understanding that velocity decreases when shale is soaked by water.The result provides guidance for seismic inversion and geological interpretation of acoustic logging data.
引文
[1]Arns C H,Knackstedt M A,Pincewski W V,et al.Computation of linear elastic properties from microtomographic images:method-ology and agreement between theory and experiment[J].Geophysics,2002,67(5):1396～1405.
[2]Han D H,Nur A,Morgan D.Effects of porosity and clay content on wave velocities in sandstones[J].Geophysics,1986,51(11):2093～2107.
[2]Han D H,Nur A,Morgan D.Effects of porosity and clay content on wave velocities in sandstones[J].Geophysics,1986,51(11):2093～2107.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心