Velocity–porosity–mineralogy trends in chalk and consolidated carbonate rocks
Velocity–porosity–mineralogy trends in chalk and consolidated carbonate rocks
复制标题
白垩岩和固结碳酸盐岩的速度-孔隙度-矿物学趋势
DOI：
10.1093/gji/ggz304
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发表时间：
2019
影响因子：
2.8
通讯作者：
A. Alabbad
中科院分区：
文献类型：
--
作者：
J. Dvorkin;A. Alabbad
已发表的碳酸盐岩实验室弹性波速度与孔隙度的数据表现出显着的分散，即使在一个固定的矿物。这种分散通常归因于岩石骨架或孔隙空间几何形状的强烈变化，而这反过来又是由这些非常活跃的沉积物中成岩蚀变的丰富性和复杂性所驱动的。然而，通过检查电缆数据，从含油的高至中等孔隙度白垩沉积，我们发现令人惊讶的紧密速度孔隙度的趋势。此外，这些趋势继续进入低孔隙度域的数据从一个位置数千英里以外的白垩领域。这种一致性意味着成岩趋势的普遍性，至少在所研究的块状矿床中是这样。我们还发现，纯方解石端员的弹性体积和剪切模量是略小于文献中报道的值。利用端元弹性常数的相关数据，我们建立了一个理论岩石物理模型来匹配和概括这些数据。
Published laboratory elastic-wave velocity versus porosity data in carbonate rocks exhibit significant scatter even at a fixed mineralogy. This scatter is usually attributed to the strong variability in the rock-frame or pore-space geometry, which, in turn, is driven by the richness and complexity of diagenetic alteration in these very reactive sediments. Yet, by examining wireline data from oil-bearing high-to-medium porosity chalk deposits, we find surprisingly tight velocity–porosity trends. Moreover, these trends are continued into the low-porosity domain by data from a location thousands of miles away from the chalk field. This congruence implies a universality of diagenetic trends, at least in the massive deposits under examination. We also find that the elastic bulk and shear moduli of the pure-calcite end member are somewhat smaller than such values reported in the literature. Using the end-member elastic constants relevant to the data under examination, we establish a theoretical rock physics model to match and generalize these data.