Computation of linear elastic properties from microtomographic images: Methodology and agreement between theory and experiment
Computation of linear elastic properties from microtomographic images: Methodology and agreement between theory and experiment
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DOI：
10.1190/1.1512785
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发表时间：
2002-09-01
期刊：
影响因子：
3.3
通讯作者：
Garboczi, EJ
中科院分区：
文献类型：
--
作者：
Arns, CH;Knackstedt, MA;Garboczi, EJ
弹性特性-孔隙度关系直接来源于显微层析成像图像。这是由孔隙度从7.5%到22%不等的枫丹白露砂岩的四组样品所说明的。采用有限元法推导了数字化图像的弹性特性。通过估计和最小化数值误差的几个来源，可以得到非常准确的性质预测，并且在很大的孔隙度范围内与实验测量结果非常吻合。我们考虑了数字化图像在干燥、水饱和和油饱和条件下的弹性特性。观察到的由于流体替代而引起的弹性性质的变化与精确的高斯曼方程非常吻合。这表明，将显微层析成像与弹性计算相结合，准确预测单个岩石形态的岩石物理性质，既准确又可行。我们将数值预测与各种经验、有效介质和严格近似进行比较，这些近似用于将岩石的弹性特性与不同饱和度条件下的孔隙度联系起来。
Elastic property-porosity relationships are derived directly from microtomographic images. This is illustrated for a suite of four samples of Fontainebleau sandstone with porosities ranging from 7.5% to 22%. A finite-element method is used to derive the elastic properties of digitized images. By estimating and minimizing several sources of numerical error, very accurate predictions of properties are derived in excellent agreement with experimental measurements over a wide range of the porosity. We consider the elastic properties of the digitized images under dry, water-saturated, and oil-saturated conditions. The observed change in the elastic properties due to fluid substitution is in excellent agreement with the exact Gassmann's equations. This shows both the accuracy and the feasibility of combining microtomographic images with elastic calculations to accurately predict petrophysical properties of individual rock morphologies. We compare the numerical predictions to various empirical, effective medium and rigorous approximations used to relate the elastic properties of rocks to porosity under different saturation conditions.