The Effect of Effective Pressure on the Relationship Between Static and Dynamic Young's Moduli and Poisson's Ratio of Naparima Hill Formation Mudstones
The Effect of Effective Pressure on the Relationship Between Static and Dynamic Young's Moduli and Poisson's Ratio of Naparima Hill Formation Mudstones
复制标题
有效压力对纳帕里马山组泥岩静动态杨氏模量与泊松比关系的影响
DOI：
10.1007/s00603-020-02140-0
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发表时间：
2020
影响因子：
6.2
通讯作者：
Blake O
中科院分区：
文献类型：
--
作者：
Blake O
根据应力应变数据得出的静态弹性特性，以及根据纵波和横波速度得出的动态弹性特性，对于岩石来说存在显著差异。大多数岩石几乎是静态变形的（由于构造力和油藏生产过程中的压实作用），但静态测量不如动态测量容易获得。因此，需要静力和动弹性之间的经验关系来将动弹性转换为静态值。在本研究中，同时测量了干燥和流体饱和泥岩样品的静态和动态杨氏模量和泊松比。试样仅在弹性区域内进行轴向加载，以确定静弹性。这些样品来自西印度群岛特立尼达的纳帕里马山组的四种不同的岩相。实验在高达130 MPa的有效压力下进行，以确定这种关系是否受到有效压力的影响。结果表明，动态杨氏模量大于静态杨氏模量。样品的饱和导致杨氏模量的降低和泊松比的增加。饱和也增加了静态和动态杨氏模量和泊松比之间的差异。静态杨氏模量与动态杨氏模量之间呈高度相关的线性关系（r2 > 0.9）。随着有效压力和轴向载荷的增加，线性关系梯度增大，截距减小。静态泊松比和动态泊松比之间没有明显的变化趋势。
Static elastic properties, derived from stress–strain data, and dynamic elastic properties, derived from P- and S-wave velocities, are significantly different for rocks. Most rocks are deformed nearly statically (due to tectonic forces and reservoir compaction during production of the reservoir) but static measurements are not as readily available as dynamic measurements. Hence, empirical relationships between the static and dynamic elastic properties are needed to convert the dynamic elastic properties to static values. In this study, the static and dynamic Young’s moduli and Poisson’s ratio were measured simultaneously for dry and fluid-saturated mudstone samples. The samples were axially loaded only within the elastic region to determine the static elasticity. The samples were from four different lithofacies within the Naparima Hill Formation, Trinidad, West Indies. Experiments were carried out at effective pressures up to 130 MPa to determine if the relationship, if any, is influenced by effective pressure. The results show that the dynamic Young’s modulus is greater than the static Young’s moduli. Saturation of the samples causes a decrease in the Young’s modulus and an increase in Poisson’s ratio. Saturation also increases the difference between the static and dynamic Young’s moduli and Poisson’s ratio. A linear relationship with high correlation (R2greater than 0.9) was established between the static and dynamic Young’s moduli. The gradient of the linear relationship increases, while the intercept decreases, with increasing effective pressure and axial loading. No clear trend was observed between the static and dynamic Poisson’s ratio.