Migration of CO2 through North Sea Geological Carbon Storage Sites: Impact of Faults, Geological Heterogeneities and Dissolution

二氧化碳通过北海地质碳封存点的迁移：断层、地质异质性和溶解的影响

• 批准号: NE/N016173/1
• 负责人: Samuel Krevor
• 金额: $ 89.23万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FN016173%2F1
• 关键词: Migration; CO2; through; North; Sea

The storage of CO2 in deep geological formations is one of the chief technological means of reducing anthropogenic emissions of CO2 to the atmosphere. The process requires capturing CO2 at source (e.g. coal-fired power plants), transporting CO2 to the injection site, and pumping liquefied CO2 into kilometre deep, porous reservoirs that are typically initially saturated in saline water or previously contained oil or gas. Initially, buoyant CO2 tends to rise through the porous reservoir until it is trapped by an impermeable horizon, in the same way that oil or gas has been trapped over millennia. Subsequently, buoyant CO2 may be more securely trapped by dissolving CO2 into water (carbonated water is more dense than non-carbonated water and will sink), or by capillary forces acting to hold the CO2 in the small confines of the pore space. Any risk of buoyant CO2 migrating through the overburden is therefore reduced by these trapping processes. Constraining the rates of dissolution and capillary trapping in realistic geological overburden is a key component of strategies to quantify and reduce the risks of leakage. The UK is geologically well placed to implement offshore CO2 storage, with many potential reservoirs in the North Sea.This proposal will improve our understanding of the risks of leakage through the overburden by quantifying trapping rates in faults and heterogeneous strata typical of the overburden of North Sea reservoirs, and by quantifying our ability to seismically detect any CO2 in the overburden. CO2 is less viscous than water and will finger along more permeable layers. Sedimentary strata exhibit large variations in permeability on all scales that will substantially increase the rates at which CO2 dissolves in the formation waters.The analysis, while general in scope and resultant techniques, is applied to the Goldeneye field, a target for CO2 storage and a candidate for the Government's CCS commercialisation competition. Our approach is to geologically characterise the relevant geological heterogeneity within the overburden, and to map the structure and propensity for fluid flow within faults in that locality. Drill core provides samples of rock (5x20 cm) that can then be interrogated in the laboratory. We will directly image, at conditions typical of the overburden, the rates of fluid flow, dissolution, and capillary trapping both at the scale of individual pores within the rock (microns) and over the length of the core (centimetres). Geochemical analysis of the fluids will allow us to measure in situ dissolution and precipitation rates in our core flooding experiments. In order to determine how rates of flow and trapping may be applied at the scale of the reservoir and overburden the results must be interpreted in light of flow through 1-100 centimetre scale geological heterogeneities and along faults. To assess the impact of heterogeneities on the rates of trapping we will construct simplified models of flow along predominantly layered strata, or along cross-cutting faults, along with laboratory analogue experiments in which we can optically assess trapping rates and thereby provide a firm benchmark for our predictions. Finally, at larger scales, we will image flow up chimney structures in existing CO2 experiments (eg Sleipner in the North Sea) and thus provide quantitative estimates of our ability to seismically resolve leakage pathways in the storage overburden. Our proposal will develop tools needed to geologically characterise the North Sea overburden, provide quantitative estimates of trapping rates in geologically complex overburden and fault complexes, and demonstrate the ability to seismically resolve fluid flow pathways. To date geological CO2 storage has been demonstrated at relatively safe storage sites. This work would greatly expand the potential for geological CO2 storage by quantifying the potential risks associated with leakage in more geologically complex storage sites.

二氧化碳在深层地质地层中的储存是将二氧化碳的人为排放减少到大气中的主要技术手段之一。该过程需要在源（例如燃煤电厂）捕获CO2，将二氧化碳运输到注射地点，并将液化二氧化碳泵送到最初在盐水中饱和或以前含有的石油或天然气的液化二氧化碳深度多孔的储层。最初，浮力二氧化碳倾向于通过多孔储层升起，直到被不可渗透的地平线捕获，就像将石油或天然气捕获在千年中一样。随后，将浮力二氧化碳溶解在水中（碳酸水比非碳酸水更致密，会下沉），或者通过毛细管将二氧化碳固定在孔隙空间的小范围内，可以更牢固地捕获。因此，这些诱捕过程降低了浮力二氧化碳迁移的任何风险。限制现实地质覆盖量中的溶解和毛细管捕获的速率是量化和降低泄漏风险的策略的关键组成部分。在地质上，英国在北海具有许多潜在的水库，这在地质上是一个很好的位置。该提案将通过量化北海储藏剂的过失和异质地层的诱捕率来提高我们对通过过度泄漏的风险，并通过量化二氧化碳的能力来确定二氧化碳的能力。二氧化碳比水较少，并且将沿着更渗透的层指控。在所有尺度上，沉积地层在渗透率上表现出很大的差异，这将大大提高二氧化碳溶解在地层水中的速率。尽管在范围和结果技术方面的一般分析却应用于Goldeneye Field，这是CO2存储的目标，并且是政府CCS商业化竞争的候选者。我们的方法是在地质上表征覆盖层内相关的地质异质性，并绘制该地区断层内流体流动的结构和倾向。钻头提供岩石样品（5x20 cm），然后可以在实验室中审问。我们将在典型的覆盖量的条件下直接成像，流体流量，溶解和毛细管捕获的速率在岩石内（微米）内的单个孔的尺度和核心长度（厘米）上（厘米）。对流体的地球化学分析将使我们能够在核心洪水实验中测量原位溶解和降水率。为了确定如何在储层和覆盖层的尺度上应用流量和捕获速率，必须根据1-1-100厘米规模的地质异质性以及沿断层来解释结果。为了评估异质性对捕获速率的影响，我们将构建沿主要分层地层或跨切割故障的简化流动模型，以及实验室模拟实验，在这些实验实验中，我们可以通过光学评估捕获率，从而为我们的预测提供牢固的基准。最后，在较大的尺度上，我们将在现有的CO2实验（例如北海的Sleipner）中对流动烟囱结构进行图像，从而对我们的地震渗漏途径在存储过度中的泄漏途径进行定量估计。我们的建议将开发地质表征北海覆盖层所需的工具，提供对地质复杂的过度覆盖和断层复合物中捕获率的定量估计，并证明可以解决地震液流体流动途径的能力。迄今为止，在相对安全的存储地点已证明地质二氧化碳存储。这项工作将通过量化与更复杂的地质复杂存储地点相关的潜在风险，从而大大扩大地质二氧化碳存储的潜力。

项目成果

Representative Elementary Volumes, Hysteresis, and Heterogeneity in Multiphase Flow From the Pore to Continuum Scale

• DOI: 10.1029/2019wr026396
• 发表时间: 2020-06-01
• 期刊: WATER RESOURCES RESEARCH
• 影响因子: 5.4
• 作者: Jackson, S. J.;Lin, Q.;Krevor, S.
• 通讯作者: Krevor, S.

Sensitivity Analysis of the Dynamic CO2 Storage Capacity Estimate for the Bunter Sandstone of the UK Southern North Sea

英国南北海 Bunter 砂岩动态二氧化碳封存能力估算的敏感性分析

• DOI: 10.1016/j.egypro.2017.03.1575
• 发表时间: 2017
• 期刊: Energy Procedia
• 作者: Agada S

The Emergent Impacts of Small Scale Capillary Heterogeneity on Field Scale CO2 Flow and Trapping

小规模毛细管异质性对现场规模二氧化碳流动和捕集的新兴影响

• DOI: 10.1002/essoar.10500303.1
• 发表时间: 2019
• 作者: Jackson S

Carbon capture and storage (CCS): the way forward

• DOI: 10.1039/c7ee02342a
• 发表时间: 2018-05-01
• 期刊: ENERGY & ENVIRONMENTAL SCIENCE
• 影响因子: 32.5
• 作者: Bui, Mai;Adjiman, Claire S.;Mac Dowell, Niall
• 通讯作者: Mac Dowell, Niall

High Resolution Modelling And Steady-State Upscaling Of Large Scale Gravity Currents In Heterogeneous Sandstone Reservoirs

非均质砂岩储层大规模重力流的高分辨率建模和稳态放大

• DOI: 10.3997/2214-4609.201802949
• 发表时间: 2018
• 作者: Jackson S