Biot coefficient and elastic moduli are typically assumed to have a constant value for analyzing poroelastic effects of fluid injection. To investigate the stress–pore pressure dependency of Biot coefficient and elastic moduli, we conducted a series of laboratory experiments on a porous dolomite core sample from a reef in Michigan basin. We varied the confining stress as well as the pore pressure in the experiments. Then, modeling was performed using analytical poroelastic solutions and a coupled two‐phase flow‐geomechanical numerical simulation (for CO₂ injection). The modeling results show that the variability of Biot coefficient and elastic moduli should be included in the geomechanical modeling to accurately predict the poroelastic responses of injection (i.e., stress changes and surface uplift). Using a constant stress‐independent Biot coefficient elastic moduli, which is the assumption in poroelastic modeling, leads to underestimation of the stress change and surface uplift due to injection compared to a realistic stress–pore pressure dependent Biot coefficient, which is updated at each time step of injection modeling. Modeling results indicate that decreasing elastic modulus combined with Biot coefficient increase due to the fluid injection could lead to a larger surface uplift and stress changes in the reservoir. In addition, the stress changes and uplift due to injection are a function of initial in situ stress due to Biot coefficient and elastic modulus stress–pore pressure dependency. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.

中文翻译：

---

Biot系数和弹性模量应力-孔隙压力依赖性对流体对流体弹塑性响应的影响：实验室实验和地质力学模型

通常假定比奥特系数和弹性模量具有恒定值，用于分析流体注入的孔隙弹性效应。为了研究毕奥系数和弹性模量对应力-孔隙压力的依赖性，我们对密歇根州盆地礁石上的多孔白云岩岩心样品进行了一系列实验室实验。在实验中，我们改变了围压和孔隙压力。然后，使用分析性孔隙弹性解和耦合的两相流地力学数值模拟（对于CO ₂注射）。建模结果表明，Biot系数和弹性模量的变化应包括在地质力学模型中，以准确预测注入的孔隙弹性响应（即应力变化和表面隆起）。与恒定的应力-孔隙压力相关的毕氏系数相比，使用恒定的应力无关的毕氏系数弹性模量（这是孔隙弹性建模中的假设）会导致低估因注入而引起的应力变化和表面隆起。注射建模步骤。建模结果表明，由于流体注入而降低的弹性模量与Biot系数增加可能导致更大的表面隆起和储层中的应力变化。此外，由于Biot系数和弹性模量应力-孔隙压力的依赖性而产生的原位应力。©2020年化学工业协会和John Wiley＆Sons，Ltd.