Performance and Injectivity of CO2 in Hyper-Saline Aquifers

气候变化是人为温室气体向大气过度排放造成的全球性挑战。据估计，全球三分之二的挑战是由二氧化碳造成的。为了减缓这一全球挑战，已经制定了几项政府间协议和立法，通过各种技术、社会和工业行动的结合来减少大气二氧化碳影响(例如2015年巴黎协议，2019年英国净零排放)。碳捕获与封存(CCS)是减少二氧化碳大气排放的关键途径之一。在CCS中，二氧化碳是从人为来源捕获的，并被注入到深层咸水层、枯竭的油气藏或其他地质圈闭中。深层咸水含水层发挥着重要作用，因为它们安全储存二氧化碳的能力比枯竭的油气藏大两个数量级。保持向地下注入二氧化碳是决定任何CCS项目成功的关键部分，然而，这并不总是一帆风顺的。前人的研究表明，在含盐含水层和高含盐含水层中注入干的超临界CO2后，孔隙空间中会形成盐类，渗透率降低，导致注水能力丧失。鉴于这一挑战，有必要发展基础知识和预测模型，以建立在不同热力条件(压力和温度)、水动力条件(注水速度)和岩石非均质性条件下的吸水率损失的专门知识，以下简称THR。PINCH项目旨在建立基础科学，以开发一种新的预测模型，并将其应用于由行业支持的真实现场数据。Pinch汇集了来自曼彻斯特大学、达勒姆大学、普林斯顿大学、英国石油公司、Equinor、壳牌的科学家，在五个工作包(WP)中交付项目目标。WP1解决了孔隙尺度的基本问题，以描述THR条件对盐形成的影响及其在高压高温(HPHT)条件下的聚集状态。微观模型的高温高压光学可视化和基于高温高压同步加速器的微岩心驱的X射线成像将用于可视化不同条件下孔隙形态的实时变化。WP1将提供独特和有价值的四维数据集，以建立基本知识和支持WP3数据要求。WP2在更大的物理尺度(岩心)上解决了与WP1在真实岩石材料中类似的研究问题。BGS将为获取所需的岩石材料提供便利。此外，还将测量不同THR条件下的压力注入量和岩石力学性质。我们将解决这些因素对注入性损失的作用方面的知识差距。这将有助于WP3中设想的预测建模的发展。WP3是PINCH项目的核心，提出了一种新的多尺度建模方法。将开发孔隙尺度模型来捕捉多相流、相变、盐层形成。该模型将根据WP1中的观测结果进行验证。此外，还将开发一个连续尺度模型，该模型将包括用于参数化的孔隙尺度模型。该模型将根据WP2中的实验进行验证。WP4将提供一项高影响力的研究，WP1和WP2中建立的所有基础科学和WP3中开发的工程工具将被用来解决与超临界二氧化碳注入高盐度含水层和随后的注入性损失有关的实际实验室和实地规模的挑战。三个候选CCS字段是耐力、任务和Snohvit。BP、Equinor、壳牌将通过提供上述领域所需的数据和技术建议，为PIPCH提供非常强大的实物贡献。为保证PINCH项目的影响，设想了WP5，其中包括产生影响、学术界和工业界之间的知识交流以及对初级工作人员的培训。

Climate change is a global challenge imposed by excessive emission of anthropogenic greenhouse gases to the atmosphere. It is estimated that CO2 is responsible for two-thirds of global challenge. To decelerate this global challenge, several inter-governmental agreements and legislation have been established to reduce the atmospheric CO2 effects (e.g. 2015 Paris agreement, 2019 UK NetZero) through a combination of various technological, societal and industrial actions. One of the key pathways to reduce CO2 atmospheric emission is carbon capture and storage (CCS). In CCS, CO2 is captured from anthropogenic sources and is injected into deep saline aquifers, depleted oil and gas reservoirs or other geological traps. Deep saline aquifers play an important role as their capacity for safe storage of CO2 is two orders of magnitude greater than depleted oil and gas reservoirs. Maintaining injection of CO2 into subsurface is a critical part determining the success of any CCS project, however, this is not always straightforward. Former studies show that with injection of dry super-critical CO2 in saline and hypersaline aquifers, salt forms in porous space and permeability decreases, leading to injectivity loss. Given this challenge it is essential to develop fundamental knowledge and a predictive model to establish know-how of injectivity loss under different thermodynamic conditions (pressure and temperature), hydrodynamic conditions (injection rate), and rock heterogeneity conditions, referred to as THR hereafter. The PINCH project aims to establish fundamental science to develop a novel predictive model and apply it to real field data supported by industries. PINCH brings together scientists from University of Manchester, Durham University, Princeton University, BP, Equinor, Shell to deliver project aims in five work packages (WP). WP1 addresses fundamental questions at pore scale to delineate impacts of THR conditions on salt formation and its aggregation regime under high-pressure high-temperature (HPHT) conditions. HPHT optical visualisation of micromodels and HPHT synchrotron-based X-ray imaging of micro-core flooding will be used to visualise the real-time change of pore morphology under different conditions. WP1 will deliver unique and valuable four-dimensional data sets to establish fundamental knowledge and to support WP3 data requirements. WP2 addresses similar research questions as WP1 in real rock materials at a larger physical scale (core). BGS will facilitate access to the rock materials required. Additionally, pressure injectivity and rock mechanical properties will be measured under different THR conditions. We will address the knowledge gaps in the role of these factors on the injectivity loss. This will assist development of predictive modelling as envisaged in WP3. WP3 is the core of PINCH project as a novel multiscale modelling approach is proposed. Pore-scale modelling will be developed to capture multiphase flow, phase change, salt formation. The model will be validated against the observations in WP1. Also a continuum-scale model will be developed which will incorporate the pore-scale modelling for parameterisation. The model will be validated against the experiments in WP2. WP4 will deliver a high-impact research all fundamental science established in WP1 and WP2 and the engineering tools developed in WP3 will be employed to address real-life laboratorial and field-scale challenge related to the injection of supercritical CO2 in hypersaline aquifers and subsequent injectivity loss. Three candidate CCS fields are Endurance, Quest and Snohvit. BP, Equinor, Shell will provide very strong in-kind contribution to PINCH by providing required data from the aforementioned fields and technical advise. To guarantee the impact of PINCH project, WP5 has been envisaged which covers impact generation, knowledge exchange between academia and industry, and training of junior staff.