Interaction between solid, liquid and biological components of the natural porous media - an experimental approach

地下多孔介质通常由固体、液体和生物成分组成。通过这种媒介的资源的存储容量和可交付性主要取决于这些组件之间的相互作用以及复杂相互作用的副产品。例如，当砂粒被微米级的非常细的颗粒材料（如碎屑粘土）覆盖时，其他块状矿物不能沉淀在颗粒上。这个简单的过程保持孔隙网络开放，并允许流体流过孔隙。虽然这种关系是众所周知的，但粘土涂层的机制并不完全清楚。几十年来，静电力被认为是将微米级粘土颗粒附着到沙粒上的主要过程。然而，最近的观察表明，生物控制（主要是生物膜）有一个显着的输入过程中，应详细investigated.This博士研究的目标是多孔介质中经常被忽视的组成部分，并调查生物膜与其他组件的相互作用与实验方法。通过这样做，该研究旨在更好地了解多孔介质的演变，从而为资源管理，勘探和基础设施设计提供有价值的投入。这项研究将从分子到微观到区域/流域尺度的各种尺度对这一主题进行调查，概述如下。生物膜与多孔介质（砂粒和粘土颗粒）的两个选定的固体成分的相互作用和重要的生态因素（如pH值，盐度，TOC）的贡献将通过控制实验室实验，使用天然来源的微生物群落进行研究。将通过DNA测序（使用系统发育标记基因）分析与沙粒（生物膜）和液相（自由生活）相关的群落组成。* 将通过成像技术（例如，共聚焦激光扫描和扫描电子显微镜）评估砂-粘土-生物膜相互作用。实验室实验的结果将用于使用类似的分析技术表征各种自然环境中的砂-粘土-生物膜相互作用（包括最近的地表和古代地下实例）。将在沉积学和孔隙尺度储层质量演化的背景下研究储层中粘土涂层颗粒的空间分布（盆地尺度）以及对这种分布的控制。

The subsurface porous media is typically composed of solid, liquid and biological components. The storage capacity and deliverability of the resources through this media is mainly dictated by the interaction between these components and by the by-products of the complex interactions. For example, when a sand grain is coated by a micrometre-scale very fine grained material (such as detrital clay), other blocky minerals cannot precipitate on the grain. This simple process keeps the pore network open and allows fluids to flow through the pores. Although this relationship is well known, the clay coating mechanism is not fully understood. Over few decades, electrostatic forces are accepted to be the main process of attaching micrometre-scale clay particles to sand grains. Recent observations, however, show that biological control (mostly biofilms) has a significant input to the process and should be investigated in detail.This PhD study targets the commonly overlooked component of porous media and investigates the interaction of biofilms with other components with an experimental approach. By doing this, the study aims to develop a better understanding of the evolution of the porous media, which in turn provide a valuable input to resource management, exploration and infrastructure design. The study will investigate the topic in various scales ranging from molecular to microscopic to regional/basinal scale as outline below.* The interaction of biofilms with two selected solid components of the porous media (sand grain and clay particles) and the contribution of important ecological factors (e.g. pH, salinity, TOC) will be investigated by controlled laboratory experiments using naturally-derived microbial communities. The community composition associated with sand grains (biofilm) and liquid phase (free-living) will be analysed by DNA sequencing (using phylogenetic marker genes). * The sand-clay-biofilm interaction will be assessed by imaging techniques (e.g. confocal-laser scanning and scanning electron microscopy). The results from laboratory experiment, will be used to characterised sand-clay-biofilm interaction in various natural environments (including recent surface and ancient subsurface examples) using similar analytical techniques.* The spatial distribution of clay coated grains in reservoirs (basin scale) and the controls on this distribution will be studied in the context of sedimentology and pore-scale reservoir quality evolution.