Integrated subsurface characterization of a basin-scale carbon reservoir target

碳捕获和储存对于减少化石燃料消费对气候的影响至关重要，也是英国在不违反二氧化碳配额的情况下保持能源安全的唯一途径。乌齐拉砂岩是北海盆地最大和分布最广的砂体之一，由于其孔隙体积大，在北海地下约800-1200 m处的地下分布理想，被确定为碳封存的主要目标2。然而，其储层特性的记录相对较少，并且其顶部密封能力在人类或地质时间尺度上保留气柱的能力在成功的Sleipner CO2注入现场附近之外是未知的3。直到2015年，在北海钻探的数千口威尔斯井在乌齐拉砂岩中没有发现任何碳氢化合物，这引起了对其顶部密封完整性的怀疑，最近（当地）对影响储层及其顶部密封的密封旁路系统4和注砂5的研究也提出了质疑。现有的乌齐拉砂岩模型从深海到浅海，其环境可能在整个盆地中有所不同。北海的油气勘探已有50多年，形成了一个庞大的遗留数据库，其中包括数千口威尔斯井和几乎完整的三维地震覆盖面，从而可以对储层结构、岩相、上覆岩层性质和管道系统进行前所未有的深入了解，为流体逃逸到较浅的含水层并最终到达海底提供了可能的途径。本研究将利用最先进的三维地震技术通过威尔斯井校准，提供乌齐拉砂岩及其覆盖层的第一个全流域特征，以提供可行的碳注入地点和顶部密封风险的全面清单，这将是成功实施英国和挪威碳源碳储存的关键。将提取关于更深结构、储层结构和上覆岩层泄漏路径之间联系的一般见解，以提供关于密封旁路系统形成的一般见解。将检查浅层气藏，以避免将成像伪影误解为泄漏路径。开发的方法和见解将普遍适用于盆地分析，石油勘探和碳储存，并将产生重要的见解，为未来的政策和碳储存战略的实施提供信息。在英国和挪威。

Carbon capture and storage is crucial for reduction of the climate impact of fossil fuel consumption and the only way for the UK to retain energy security without breaching CO2 quotas1. The Utsira sandstone is one of the largest and most widespread sand bodies in the North Sea basin and is identified as a prime target for carbon sequestration due to its large pore volume and ideal subsurface distribution some 800-1200 m beneath the North Sea2. However, its reservoir properties are relatively poorly documented and its top seal capacity to withhold a gas column over human or geological time scales is unknown beyond the immediate vicinity of the successful Sleipner CO2 injection site3. Until 2015, thousands of wells drilled in the North Sea had not encountered any hydrocarbons in the Utsira sandstone raising doubts over its top seal integrity, also questioned by recent (local) studies of seal bypass systems4 and sand injectites5 that affect both the reservoir and its topseal. Existing models for the Utsira sandstone range from deep- to shallow marine and its environment is likely to vary across the basin. The North Sea has been explored for hydrocarbons for over 50 years resulting in a vast legacy database comprising thousands of wells and almost complete 3D seismic coverage allowing unprecedented insights into both reservoir architecture and facies and overburden properties and plumbing systems providing possible pathways for fluid escape into shallower aquifers and eventually to the seabed.This study will leverage state of the art 3D seismic technology calibrated by wells to provide the first basinwide characterization of the Utsira sandstone and its overburden in order to provide a comprehensive inventory of viable carbon injection sites and top seal risk, which will be key to successful implementation of carbon storage for both UK and Norwegian carbon sources. Generic insights regarding the links between deeper structures, reservoir architecture and overburden leakage paths will be extracted to provide insights into the formation of seal bypass systems in general. Shallow gas reservoirs will be examined to avoid misinterpreting imaging artifacts as leakage paths. The methods and insights developed will have general applicability to basin analysis, petroleum exploration and carbon storage, and will yield crucial insights to inform future policy and implementation of carbon storage strategies. in the UK and Norway.