Models of flow and mixing of CO2 and brines in heterogeneous porous media

地下碳储存，包括从发电站燃料或废气中分离二氧化碳，并将二氧化碳注入和储存在地下，为社会管理其向低碳经济过渡提供了一种更经济和实用的方法。地下碳储存的一个关键方面是需要确保储存是安全和有效的，这需要有能力模拟二氧化碳在~ 10000年的储存期内的命运。提高CO2储存安全性的关键机制是残余捕集，其中一些CO2通过表面张力保留在孔隙空间中，以及溶解性捕集，其中CO2溶解在地层盐水中。这两种机制的运行速度将在很大程度上受到储层渗透率的中小尺度（10厘米至100米）非均质性的控制。该项目将研究沉积单元的特征非均质性对残留和溶解度捕获速率的影响。该项目将采用多种方法。大粘度差混相流的实验室实验和理论分析可用于了解盐水和CO2在储层非均质介质中的流动特性。该项目可能将其与沉积地层渗透率非均质性的现场研究相结合，并利用这些信息预测潜在二氧化碳储层的重要结构非均质性。学生将熟悉地质碳储存的过程和要求。他们将加入一个由10多人（教师、博士后和学生）组成的小组，研究与二氧化碳储存有关的一系列问题。学生将被鼓励与这个小组进行互动，他们在碳储存的各种问题上进行相关研究，包括多相流建模，储层地震成像以及储层内流体-流体和流体-矿物反应的研究。虽然建模将基于现场实例，但所开发的理论和实验工具将是通用的，并适用于广泛的异质介质。

Sub-surface carbon storage, which involves separation of CO2 from power station fuels or waste gases and injection and storage of the CO2 underground, offers one of the more economical and practical methods for society to manage its transition to a low-carbon economy. A key aspect of sub-surface carbon storage is the need to ensure that the storage is safe and efficient and this requires the ability to model the fate of the CO2 over the ~ 10000 year storage period. Key mechanisms which will increase the security of CO2 storage are residual trapping, where some CO2 is retained in pore space by surface tension, and solubility trapping in which CO2 dissolves in formation brines. The rate at which both these mechanisms will operate will be strongly controlled by the small and medium scale (10 cm to 100's m) heterogeneities in permeability of the reservoirs.The project will examine the impact of the characteristic heterogeneities in sedimentary units on the rates of residual and solubility trapping. The project will use a combination of approaches. Laboratory experiments and theoretical analysis for miscible currents with large viscosity differences may be used to understand the flow of brines and CO2 through heterogeneous media characteristic of reservoirs. The project may combine this with field studies of the permeability heterogeneities of sedimentary formations and use this information to predict the important structural heterogeneities of potential CO2 reservoirs.The student will become familiar with the processes and requirements for geological carbon storage. They will join a group of more than 10 (faculty, post-docs and students) working on a whole range of problems related to CO2 storage. The student will be encouraged to interact with this group who are carrying out related research on a variety of issues in carbon storage including modelling of multi-phase flow, seismic imaging of reservoirs and studying the fluid-fluid and fluid-mineral reactions within reservoirs. While the modelling will be based on the field examples, the theoretical and experimental tools developed will be generic and applicable to a wide range of heterogeneous media.