到2050年实现零净温室气体排放的集体努力激发了人们对全球碳捕集和封存工程解决方案的兴趣。一种这样的方法涉及将CO2永久储存在地球丰富的Ca-中,Fe-,含镁硅酸盐岩石和矿物通过CO2矿化过程作为碳酸盐。这需要在地质相关条件下彻底了解碳酸盐转化。然而,通过自然破碎的主体岩石或诱导裂缝进行矿化的CO2注入研究,研究重点是地质工程CO2封存中的岩石力学和刺激储层体积(SRV),不断扩大。这项研究解决了与确定二氧化碳矿化有利地理位置相关的关键挑战。它特别关注镁的丰富可用性,Ca,和Fe阳离子用于放热CO2反应及其对原位矿化过程中裂缝导流能力的影响。对来自澳大利亚和新西兰不同地点的26个菱铁矿和蛇纹岩样品进行了全面分析,包括10个来自一个有核心的钻孔,进行了。二价阳离子的定量(Mg,Ca,使用XRF和XRD的Fe)含量和阳离子释放能力表明,与蛇纹岩样品(约26%)相比,在石膏矿样品中的阳离子百分比更高(约30%)。此外,该研究估算了受激岩体与CO2封存比[公式:见正文],dunite样品平均约为2.20[公式:见正文]值,蛇纹岩样品平均约为2.53。地质力学测试可以预测注入CO2水溶液以进行原位矿化的裂缝扩展压力,并可以估算裂缝的几何形状。强调岩石刚度在确定裂缝宽度(平均6.0毫米)中的作用。此外,该研究估计了注入过程中暴露于含CO2流体的岩石体积,特别关注GHQ-3样本,理论上相当于大约600公斤的岩石,对于10立方米的流体体积,CO2浓度为1摩尔千克-1,能够封存大约300公斤的CO2。该研究建立了注入体积与CO2吸收之间的关系,通过使用水平井和压裂额外的区域,提出了显著的二氧化碳封存可扩展性的潜力,从而沿单个目标区产生并相交多个横向裂缝。
The collective drive towards achieving net-zero greenhouse gas emissions by 2050 has spurred interest in engineering solutions for carbon capture and storage worldwide. One such approach involves the permanent storage of CO2 in earth-abundant Ca-, Fe-, and Mg-bearing silicate rocks and minerals as carbonates via the process of CO2
mineralisation. This necessitates a thorough understanding of carbonate conversion under geologically relevant conditions. Nevertheless, research on CO2 injection for
mineralisation via naturally fractured host rocks or induced fractures, with a research emphasis on rock mechanics and stimulated reservoir volumes (SRV) within geoengineering CO2 storage, is continuously expanding. This research addresses critical challenges related to identifying favourable geographic locations for CO2
mineralisation. It specifically focuses on the abundant availability of Mg, Ca, and Fe cations for exothermic CO2 reactions and their impact on fracture conductivity during in-situ
mineralisation. A comprehensive analysis of 26 dunite and serpentinite samples from diverse locations in Australia and New Zealand, including 10 from a cored drilled hole, was conducted. Quantification of divalent cation (Mg, Ca, Fe) content and cation release capacity using XRF and XRD revealed higher cation percentages in dunite samples (approximately 30 %) compared to serpentinite samples (approximately 26 %). Additionally, the study estimated the stimulated rock mass-to-CO2 sequestered ratio, [Formula: see text] , with dunite samples averaging approximately 2.20 [Formula: see text] values and serpentinite samples averaging approximately 2.53. Geomechanical testing enabled the prediction of fracture propagation pressures during aqueous CO2 injection for in-situ
mineralisation and the estimation of fracture geometries, emphasizing the role of rock stiffness in determining fracture width (averaging 6.0 mm). Furthermore, the research estimated the rock volume exposed to CO2-laden fluid during injection, particularly focusing on the GHQ-3 sample, which theoretically amounted to approximately 600 kg of rock capable of sequestering around 300 kg of CO2 for a 10 m3 fluid volume with a CO2 concentration of 1molkg-1. The study established a relationship between injected volume and CO2 uptake, suggesting the potential for significant CO2 sequestration scalability by employing horizontal wells and fracturing additional zones, thereby creating and intersecting multiple transverse fractures along a single target zone.