Novel multi-scale 3D/4D characterization of pore networks in tight rocks: Enhanced understanding of clean gas extraction and safe carbon sequestration

“提供负担得起的能源和清洁增长”是绿色文件“建设我们的工业战略”中的一个关键目标。清洁天然气开采和安全碳储存是实现这一目标的两个重要方面。孔隙网络的精确重建和地下条件下致密岩石中气体运移的理解是这些领域的核心问题。迫切需要了解致密岩石储层（即页岩和致密气砂）中甲烷气体运输和地下储层和含水层中二氧化碳储存的相关问题。这一研究成果将为传统能源产业向“低碳高效能源体系”的转型做出巨大贡献。该研究项目旨在建立新颖先进的数字化方法，全面了解致密岩石（页岩和致密砂岩）中复杂的多尺度孔隙网络。致密岩石的强非均质性和细粒度使得微观结构和孔隙网络的表征极具挑战性。高温高压的地下条件更增加了天然气运移研究的难度.孔隙网络和流动行为不清晰，影响了工业决策和可持续发展。这项研究将首先在比以前更宽的尺寸范围内表征致密岩石中的微观结构，利用先进的相关3D成像技术从厘米到纳米（缩小），并使用申请人先前提出的多阶段方法的发展将纳米级孔隙系统重建到厘米级（放大）。将使用新型4D成像（3D加时间）观察地下条件下通过这些复杂孔隙网络的气体运输，从而通过实验室将二氧化碳注入含甲烷（或类似物）的样品中，测试致密岩石中同时的甲烷气体提取和二氧化碳储存。从图像中提取的结果将通过实验室高温高压下的体物性测量进行验证。将在这项研究的基础上评估即时天然气回收的潜在效率和长期碳封存的安全性。研究金的结果将使用前所未有的多尺度3D和4D视图来交付。它将在世界上最大规模的致密岩石中建立3D孔隙网络，并首次展示4D天然气储存和运输。申请人在地质和成像方面的丰富经验，加上曼彻斯特大学世界一流的3D和4D成像设施，将确保该项目具有低风险和高效益。该研究金将为天然气开采和碳储存行业提供增强的孔隙网络模型，并测试清洁能源解决方案的技术可行性，该解决方案可以减少碳排放并生产随后可以商业化的甲烷气体。此外，它还将推进曼彻斯特大学世界领先的多尺度成像和数字岩石研究。这些成功的经验有可能引导天然气开采和碳储存公司的联合结构，并进一步引领该技术在世界范围内的发展。

'Delivering affordable energy and clean growth' is a crucial goal in the green paper "Building Our Industrial Strategy". Clean gas extraction and safe carbon storage, are two essential aspects in achieving this goal. The precise reconstruction of the pore networks and understanding gas transport in tight rocks under subsurface conditions is a core problem in these areas. Linked issues around methane gas transport in tight rock reservoirs (i.e. shale, and tight-gas sands) and carbon dioxide storage in underground reservoirs and aquifers need to be understood urgently. The enhanced understanding will contribute in the transmission of traditional energy industry to a 'low-carbon and resource-efficient energy system' greatly.The aim of this fellowship is to build novel and advanced digital approaches fully to understand the complicated pore networks in tight rocks (shales and tight sands) across multiple scales. Strong heterogeneity and fine grain sizes of tight rocks makes the characterization of microstructure and pores network highly challenging. The high- temperature and high- pressure subsurface conditions even increase difficulty for the gas transport studies. The unclear pore network and flow behaviors adversely affect industrial decision making and sustainable development. This research will first characterize the microstructure in tight rocks over a wider size range than previously, from centimeter to nanometer (downscaling) utilizing advanced correlative 3D imaging techniques, and reconstruct the nano-scale pore system to centimeter-scale (upscaling) using a development of the multi-stage method previously proposed by the applicant. Gas transport under subsurface conditions through these complex pore networks will be observed using novel 4D imaging (3D plus time), leading to the testing of simultaneous methane gas extraction and carbon dioxide storage in tight rocks through the laboratory injection of carbon dioxide into methane (or analogue) bearing samples. The results extracted from images will be verified by laboratorial bulk properties measurement under high temperature and high pressure. The potential efficiency of instant gas recovery and safety of long-term carbon sequestration will be evaluated based on this research.Results of the fellowship will be delivered using unprecedented multi-scale 3D and 4D views. It will build 3D pore networks in tight rocks over the largest range of scales in the world, and present 4D gas storage and transport for the first time. The extensive experience of the applicant in geology and imaging, plus the world class 3D and 4D imaging facilities at the University of Manchester will ensure the project is low risk with high benefit. This fellowship will provide enhanced pore network models for gas extraction and carbon storage industry and test the technical feasibility of a clean energy solution that could reduce carbon emissions and produce methane gas that could be subsequently commercialized. Furthermore, it will advance the world-leading multiscale imaging and the digital rock research at the University of Manchester. Potentially, the successful experience can be lead to the combination structure of the gas extraction and carbon storage companies, and further lead this technique in the world.