Advanced petrophysics for the characterisation of trapping mechanisms for CO2 storage in the subsurface

该项目将使用最新的岩石物理和数字岩心技术来提高我们对地下CO2毛细管和溶解度捕获的理解，为现场规模模拟中基于物理的残余和溶解捕获表示提供工作流程和本质定律。这对于建立可靠的模拟和评估潜在的地质二氧化碳储存地点至关重要。在两个尺度上进行x射线成像的实验岩心洪水——其中孔隙尺度特征可以通过微型XCT扫描仪在毫米尺度的样品中得到解决，而在厘米尺度的岩石岩心上通过医用XCT扫描仪观察到连续属性——将与数值模拟相结合，以满足以下目标：评估岩石非均质性对大规模残余圈闭的影响，包括开发表征工作流程2。观察二氧化碳和盐水之间的传质速率作为流体流速、流体饱和度、流体-流体界面面积、与流体系统化学平衡的距离和长度尺度的函数，包括在油藏模拟中表示这些速率的本构定律的发展。基于对非均质岩心中残余圈闭的观察，将构建岩心的连续体数值模型。将从这些小尺度开始进行初始升级，以开发参数空间的指示，其中必须表征小尺度非均质，以准确预测场尺度捕获。

This project will use the latest in petrophysical and digital rock core technology to improve our understanding of capillary and solubility trapping of CO2 in the subsurface, providing workflows and constitutive laws for a physics based representation of residual and dissolution trapping in field scale simulation. These are essential to enabling reliable modelling and assessment of potential geological CO2 storage sites.Experimental core floods with X-ray imaging at two scales - where pore scale features may be resolved in mm-scale samples in a micro XCT scanner, and where continuum properties are observed over cm-scale rock cores in a medical XCT scanner - will be combined with numerical modelling to meet the following objectives:1. Evaluate the impacts of rock heterogeneity on upscaled residual trapping, including the development of a characterisation workflow,2. Observe rates of mass transfer between CO2 and brine as a function of fluid flow rates, fluid saturations, fluid-fluid interfacial areas, distance from chemical equilibrium of the fluid system and length scale, including the development of a constitutive law to represent these rates in reservoir simulationContinuum numerical models of rock cores will be constructed, based on these observations of residual trapping in heterogeneous rock cores. Initial upscaling from these small size scales will be performed to develop an indication of the parameter space in which small scale heterogeneities must be characterised for accurate predictions of field scale trapping.