Rock-physics-based estimation of critical-clay-volume fraction and its effect on seismic velocity and petrophysical properties
Rock-physics-based estimation of critical-clay-volume fraction and its effect on seismic velocity and petrophysical properties
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DOI：
10.1190/geo2012-0510.1
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发表时间：
2014-05
期刊：
影响因子：
3.3
通讯作者：
H. Adesokan;Yuefeng Sun
中科院分区：
文献类型：
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作者：
H. Adesokan;Yuefeng Sun
摘要碎屑岩储层中粘土含量的研究对储层物性预测具有重要意义。我们使用了泥质砂和桑迪页岩的微观几何模型来定义临界粘土体积分数，并解释了体积模量对粘土含量的依赖性。我们发现，与临界粘土体积分数相关的孔隙纵横比的概念对于解释泥质砂岩的弹性行为是重要的。孔纵横比从约0.23到约0.04的突然下降，观察到粘土体积分数大于32%的临界值的研究数据集。在临界粘土体积分数为32%时，孔隙压缩系数也从约0.6 GPa-1增加到约11.25 GPa-1。结果表明，与其他模型相比，微几何模型可以更好地解释高度分散的纵波速度-孔隙度交会图的存在时，粘土含量接近临界量。我们发现，T…
ABSTRACTKnowledge of the clay content in clastic reservoirs is important for predicting reservoir quality and properties. We used a microgeometrical model for shaly sand and sandy shale to define the critical-clay-volume fraction and explain the dependence of the bulk modulus on clay content. We found that the concept of the pore-aspect ratio relating to the critical-clay-volume fraction was important to interpret the elastic behavior of shaly sandstone. An abrupt decrease in pore-aspect ratio from about 0.23 to about 0.04 was observed where the clay-volume fraction was greater than the critical value of 32% for the studied data set. At the critical-clay-volume fraction of 32%, an increase in pore compressibility also occurred from about 0.6 to about 11.25 GPa−1. Results revealed that the microgeometrical model compared to other models can better explain the existence of highly scattered compressional velocity-porosity crossplots when the clay content is close to the critical amount. We discovered that t...