This study aims to develop a methodology for calibrating subsurface stress changes through time-lapse vertical seismic profiling (VSP) integration. The selected study site is a region around the injector well located within Farnsworth field unit (FWU), where there is an ongoing CO₂-enhanced oil recovery (EOR) operation. In our study, a site-specific rock physics model was created from extensive geological, geophysical, and geomechanical characterization through 3D seismic data, well logs, and core assessed as part of the 1D MEM conducted on the characterization well within the study area. The Biot-Gassmann workflow was utilized to combine the rock physics and reservoir simulation outputs to determine the seismic velocity change due to fluid substitution. Modeled seismic velocities attributed to mean effective stress were determined from the geomechanical simulation outputs, and the stress-velocity relationship developed from ultrasonic seismic velocity measurements. A machine learning-assisted workflow comprised of an artificial neural network and a particle swarm optimizer (PSO) was utilized to minimize a penalty function created between the modeled seismic velocities and the observed time-lapse VSP dataset. The successful execution of this workflow has affirmed the suitability of acoustic time-lapse measurements for 4D-VSP geomechanical stress calibration pending measurable stress sensitivities within the anticipated effective stress changes and the availability of suitable and reliable datasets for petroelastic modeling. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.

中文翻译：

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利用机器学习方法对地下应力场进行延时 VSP 积分和校准：FWU morrow B 地层的案例研究

本研究旨在开发一种通过时移垂直地震剖面（VSP）积分校准地下应力变化的方法。选定的研究地点是范斯沃斯油田单元 (FWU) 内注入井周围的区域，该区域正在进行 CO ₂-提高石油采收率（EOR）操作。在我们的研究中，根据广泛的地质、地球物理和地质力学特征，通过 3D 地震数据、测井曲线和岩心评估，创建了特定地点的岩石物理模型，这些特征是在研究区域内的特征井上进行的 1D MEM 的一部分。Biot-Gassmann 工作流程用于结合岩石物理和油藏模拟输出，以确定由于流体替代而引起的地震速度变化。归因于平均有效应力的建模地震速度是根据地质力学模拟输出确定的，并且应力-速度关系是根据超声波地震速度测量得出的。利用由人工神经网络和粒子群优化器 (PSO) 组成的机器学习辅助工作流程来最小化建模地震速度和观测到的时移 VSP 数据集之间创建的罚函数。该工作流程的成功执行确认了声学延时测量对于 4D-VSP 地质力学应力校准的适用性，以及在预期有效应力变化范围内可测量的应力敏感性，以及用于石油弹性建模的合适且可靠的数据集的可用性。© 2023 化学工业协会和 John Wiley & Sons, Ltd. 该工作流程的成功执行确认了声学延时测量对于 4D-VSP 地质力学应力校准的适用性，以及在预期有效应力变化范围内可测量的应力敏感性，以及用于石油弹性建模的合适且可靠的数据集的可用性。© 2023 化学工业协会和 John Wiley & Sons, Ltd. 该工作流程的成功执行确认了声学延时测量对于 4D-VSP 地质力学应力校准的适用性，以及在预期有效应力变化范围内可测量的应力敏感性，以及用于石油弹性建模的合适且可靠的数据集的可用性。© 2023 化学工业协会和 John Wiley & Sons, Ltd.