As part of the Synergetic Utilisation of CO₂ storage Coupled with geothermal EnErgy Deployment project, investigating CO₂ reinjection with different seismic methods, both passive and active seismic surveys have been conducted at the geothermal power plant at Hellisheiði, Iceland. During the 2021 survey, two geophone lines recorded noise for a week. We process the passive-source data with seismic interferometry to image the subsurface structure around the CarbFix2 reinjection reservoir. To improve image quality, we perform an illumination analysis to select only noise panels dominated by body-wave energy. The results show that most noise panels are dominated by air-wave energy arriving from the direction of the power plant. We use panels with a near-vertical incidence to create a zero-offset image and a larger selection of body-wave-dominated panels to create virtual common-shot gathers. We process the gathers with a simple reflection seismology processing workflow to obtain stacked images. The zero-offset images show a relatively lower signal-to-noise ratio and only horizontal reflectors. The stacked images show slightly dipping reflectors and possibly lateral amplitude variations around the expected injection region. This could indicate a region of interest for future research into the reinjection reservoir.

中文翻译：

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使用体波地震干涉测量技术对 CarbFix2 回注储层（冰岛 Hellisheiði）的玄武岩中二氧化碳回注进行成像

作为CO ₂储存协同利用与地热能源部署项目的一部分，研究了不同地震方法的CO ₂回注，在冰岛Hellisheiði 的地热发电厂进行了被动和主动地震勘探。在 2021 年的调查中，两条地震检波线记录了一周的噪音。我们使用地震干涉测量法处理被动源数据，对 CarbFix2 回注储层周围的地下结构进行成像。为了提高图像质量，我们进行照明分析以仅选择以体波能量为主的噪声面板。结果表明，大多数噪声板主要由来自发电厂方向的空气波能量主导。我们使用接近垂直入射的面板来创建零偏移图像，并使用更多的体波主导面板来创建虚拟共射集合。我们使用简单的反射地震学处理工作流程处理道集以获得堆叠图像。零偏移图像显示出相对较低的信噪比并且仅显示水平反射体。叠加的图像显示反射体略有倾斜，并且预期注入区域周围可能存在横向幅度变化。这可能表明未来回注油藏研究的一个感兴趣的领域。